Stable isotope tracking of endangered sea turtles: validation with satellite telemetry and δ15N analysis of amino acids.

Directory of Open Access Journals (Sweden)

Jeffrey A Seminoff

Full Text Available Effective conservation strategies for highly migratory species must incorporate information about long-distance movements and locations of high-use foraging areas. However, the inherent challenges of directly monitoring these factors call for creative research approaches and innovative application of existing tools. Highly migratory marine species, such as marine turtles, regularly travel hundreds or thousands of kilometers between breeding and feeding areas, but identification of migratory routes and habitat use patterns remains elusive. Here we use satellite telemetry in combination with compound-specific isotope analysis of amino acids to confirm that insights from bulk tissue stable isotope analysis can reveal divergent migratory strategies and within-population segregation of foraging groups of critically endangered leatherback sea turtles (Dermochelys coriacea across the Pacific Ocean. Among the 78 turtles studied, we found a distinct dichotomy in δ(15N values of bulk skin, with distinct "low δ(15N" and "high δ(15N" groups. δ(15N analysis of amino acids confirmed that this disparity resulted from isotopic differences at the base of the food chain and not from differences in trophic position between the two groups. Satellite tracking of 13 individuals indicated that their bulk skin δ(15N value was linked to the particular foraging region of each turtle. These findings confirm that prevailing marine isoscapes of foraging areas can be reflected in the isotopic compositions of marine turtle body tissues sampled at nesting beaches. We use a Bayesian mixture model to show that between 82 and 100% of the 78 skin-sampled turtles could be assigned with confidence to either the eastern Pacific or western Pacific, with 33 to 66% of all turtles foraging in the eastern Pacific. Our forensic approach validates the use of stable isotopes to depict leatherback turtle movements over broad spatial ranges and is timely for establishing wise conservation

Stable isotope tracking of endangered sea turtles: validation with satellite telemetry and δ15N analysis of amino acids.

Science.gov (United States)

Seminoff, Jeffrey A; Benson, Scott R; Arthur, Karen E; Eguchi, Tomoharu; Dutton, Peter H; Tapilatu, Ricardo F; Popp, Brian N

2012-01-01

Effective conservation strategies for highly migratory species must incorporate information about long-distance movements and locations of high-use foraging areas. However, the inherent challenges of directly monitoring these factors call for creative research approaches and innovative application of existing tools. Highly migratory marine species, such as marine turtles, regularly travel hundreds or thousands of kilometers between breeding and feeding areas, but identification of migratory routes and habitat use patterns remains elusive. Here we use satellite telemetry in combination with compound-specific isotope analysis of amino acids to confirm that insights from bulk tissue stable isotope analysis can reveal divergent migratory strategies and within-population segregation of foraging groups of critically endangered leatherback sea turtles (Dermochelys coriacea) across the Pacific Ocean. Among the 78 turtles studied, we found a distinct dichotomy in δ(15)N values of bulk skin, with distinct "low δ(15)N" and "high δ(15)N" groups. δ(15)N analysis of amino acids confirmed that this disparity resulted from isotopic differences at the base of the food chain and not from differences in trophic position between the two groups. Satellite tracking of 13 individuals indicated that their bulk skin δ(15)N value was linked to the particular foraging region of each turtle. These findings confirm that prevailing marine isoscapes of foraging areas can be reflected in the isotopic compositions of marine turtle body tissues sampled at nesting beaches. We use a Bayesian mixture model to show that between 82 and 100% of the 78 skin-sampled turtles could be assigned with confidence to either the eastern Pacific or western Pacific, with 33 to 66% of all turtles foraging in the eastern Pacific. Our forensic approach validates the use of stable isotopes to depict leatherback turtle movements over broad spatial ranges and is timely for establishing wise conservation efforts in

Tracking System : Suaineadh satellite experiment

OpenAIRE

Brengesjö, Carl; Selin, Martine

2011-01-01

The purpose of this bachelor thesis is to present a tracking system for the Suaineadh satellite experiment. The experiment is a part of the REXUS (Rocket EXperiments for University Students) program and the objective is to deploy a foldable web in space. The assignment of this thesis is to develop a tracking system to find the parts from the Suaineadh experiment that will land on Earth. It is important to find the parts and recover all the data that the experiment performed during the travel ...

Sea Turtle Satellite Telemetry Data in North Atlantic Ocean from 2007-10-16 to 2010-11-26 (NCEI Accession 0159216)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains satellite telemetry data for sea turtles. Movements, migratory pathways, and foraging behavior of sea turtles were tracked and surfacing...

Blossom Point Satellite Tracking and Command Station

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: The Blossom Point Satellite Command and Tracking Facility (BP) provides engineering and operational support to several complex space systems for the Navy...

Transcom's next move: Improvements to DOE's transportation satellite tracking systems

International Nuclear Information System (INIS)

Harmon, L.H.; Harris, A.D. III; Driscoll, K.L.; Ellis, L.G.

1990-01-01

In today's society, the use of satellites is becoming the state-of-the-art method of tracking shipments. The United States Department of Energy (US DOE) has advanced technology in this area with its transportation tracking and communications system, TRANSCOM, which has been in operation for over one year. TRANSCOM was developed by DOE to monitor selected, unclassified shipments of radioactive materials across the country. With the latest technology in satellite communications, Long Range Navigation (Loran), and computer networks, TRANSCOM tracks shipments in near-real time, disseminates information on each shipment to authorized users of the system, and offers two-way communications between vehicle operators and TRANSCOM users anywhere in the country. TRANSCOM's successful tracking record, during fiscal year 1989, includes shipments of spent fuel, cesium, uranium hexafluoride, and demonstration shipments for the Waste Isolation Pilot Plant (WIPP). Plans for fiscal year 1990 include tracking additional shipments, implementing system enhancements designed to meet the users' needs, and continuing to research the technology of tracking systems so that TRANSCOM can provide its users with the newest technology available in satellite communications. 3 refs., 1 fig

Disentangling migratory routes and wintering grounds of Iberian near-threatened European Rollers Coracias garrulus.

Directory of Open Access Journals (Sweden)

Juan Rodríguez-Ruiz

Full Text Available Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias garrulus in order to identify conservation key areas for the non-breeding stage of this species. To this end, we used tracking data from seven satellite transmitters fitted to birds breeding in different populations throughout the Iberian Peninsula and four geolocators fitted to individuals in a southeastern Iberian population. Precise satellite data were used to describe daily activity patterns and speed in relation to the main regions crossed during the migration. Individuals from the most southwestern Iberian populations made a detour towards the Atlantic African coast whereas those from northeastern populations followed a straight north-to-south route. We identified important stopover areas in the Sahel belt, mainly in the surroundings of the Lake Chad, and wintering grounds on southwestern Africa farther west than previously reported for the species. Concerning the migratory strategy, satellite data revealed: 1 a mainly nocturnal flying activity, 2 that migration speed depended on the type of crossed habitat, with higher average speed while crossing the desert; and 3 that the migration was slower and lasted longer in autumn than in spring. The studied populations showed weak migratory connectivity, suggesting the confluence of birds from a wide range of breeding grounds in a restricted wintering area. Therefore, we suggest to target on defining precisely key areas for this species and identifying specific threats in them in order to develop an appropriate global conservation programme for the European Roller.

Probing the earth's gravity field using Satellite-to-Satellite Tracking (SST)

Science.gov (United States)

Vonbun, F. O.

1976-01-01

Satellite-to-Satellite (SST) tests, namely: (a) the ATS-6/GEOS-3 and (b) the ATS-6/Apollo-Soyuz experiment and some of the results obtained are described. The main purpose of these two experiments was first to track via ATS-6 the GEOS-3 as well as the Apollo-Soyuz and to use these tracking data to determine (a) both orbits, that is, ATS-6, GEOS-3 and/or the Apollo-Soyuz orbits at the same time; (b) each of these orbits alone; and (c) test the ATS-6/GEOS-3 and/or Apollo-Soyuz SST link to study local gravity anomalies; and, second, to test communications, command, and data transmission from the ground via ATS-6 to these spacecraft and back again to the ground. The Apollo-Soyuz Geodynamics Experiment is discussed in some detail.

A spring stopover of a migratory osprey (Pandion haliaetus in northern Spain as revealed by satellite tracking: implications for conservation

Directory of Open Access Journals (Sweden)

Galarza, A.

2009-12-01

Full Text Available Improvements in the accuracy of satellite telemetry locations now allow detailed studies on territorial behaviour or use of habitat that can be used to enhance bird conservation. In this paper we describe the behaviour of a satellite-tracked adult female osprey (Pandion haliaetus in the Urdaibai Biosphere Reserve (N Spain to evaluate the suitability of this protected area for the species. The data set consisted of 10 complete days with a total of 145 exact fixes received. Night roosts were mainly surrounded by high or intermediate level protected land, separated from roads or buildings by more than 200 m and located less than one km away from the feeding area. During daylight hours, most fixes (76.5% were located in wooded areas. We found that the bird selected holm oak woods and we suggest that this is related to low disturbance from human activity. We also suggest that northern Spanish estuaries are important as stopovers by migrating ospreys for feeding during migration.

High Precision Control of Ship-Mounted Satellite Tracking Antenna

DEFF Research Database (Denmark)

Mohsen, Soltani; Izadi-Zamanabadi, Roozbeh; Wisniewski, Rafal

2007-01-01

The telecommunication on a modern merchandise ship is maintained by means of satellite communication. The task of the tracking system is to position the on-board antenna toward a chosen satellite. The control system is capable of rejecting the external disturbances which affect on the under...

Dynamic Modeling and Simulation of Marine Satellite Tracking Antenna Using Lagrange Method

DEFF Research Database (Denmark)

Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar

2016-01-01

Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased controll......Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased...

A MEMS-based Adaptive AHRS for Marine Satellite Tracking Antenna

DEFF Research Database (Denmark)

Wang, Yunlong; Hussain, Dil Muhammed Akbar; Soltani, Mohsen

2015-01-01

Satellite tracking is a challenging task for marine applications. An attitude determination system should estimate the wave disturbances on the ship body accurately. To achieve this, an Attitude Heading Reference System (AHRS) based on Micro-Electro-Mechanical Systems (MEMS) sensors, composed...... of three-axis gyroscope, accelerometer and magnetometer, is developed for Marine Satellite Tracking Antenna (MSTA). In this paper, the attitude determination algorithm is improved using an adaptive mechanism that tunes the attitude estimator parameters based on an estimation of ship motion frequency...

When and where does mortality occur in migratory birds? Direct evidence from long- term satellite tracking of raptors

NARCIS (Netherlands)

Klaassen, Raymond H. G.; Hake, Mikael; Strandberg, Roine; Koks, Ben J.; Trierweiler, Christiane; Exo, Klaus-Michael; Bairlein, Franz; Alerstam, Thomas

Information about when and where animals die is important to understand population regulation. In migratory animals, mortality might occur not only during the stationary periods (e.g. breeding and wintering) but also during the migration seasons. However, the relative importance of population

A satellite-tracking millimeter-wave reflector antenna system for mobile satellite-tracking

Science.gov (United States)

Densmore, Arthur C.; Jamnejad, Vahraz; Woo, Kenneth E.

1995-03-01

A miniature dual-band two-way mobile satellite tracking antenna system mounted on a movable ground vehicle includes a miniature parabolic reflector dish having an elliptical aperture with major and minor elliptical axes aligned horizontally and vertically, respectively, to maximize azimuthal directionality and minimize elevational directionality to an extent corresponding to expected pitch excursions of the movable ground vehicle. A feed-horn has a back end and an open front end facing the reflector dish and has vertical side walls opening out from the back end to the front end at a lesser horn angle and horizontal top and bottom walls opening out from the back end to the front end at a greater horn angle. An RF circuit couples two different signal bands between the feed-horn and the user. An antenna attitude controller maintains an antenna azimuth direction relative to the satellite by rotating it in azimuth in response to sensed yaw motions of the movable ground vehicle so as to compensate for the yaw motions to within a pointing error angle. The controller sinusoidally dithers the antenna through a small azimuth dither angle greater than the pointing error angle while sensing a signal from the satellite received at the reflector dish, and deduces the pointing angle error from dither-induced fluctuations in the received signal.

Continent-wide tracking to determine migratory connectivity and tropical habitat associations of a declining aerial insectivore.

Science.gov (United States)

Fraser, Kevin C; Stutchbury, Bridget J M; Silverio, Cassandra; Kramer, Patrick M; Barrow, John; Newstead, David; Mickle, Nanette; Cousens, Bruce F; Lee, J Charlene; Morrison, Danielle M; Shaheen, Tim; Mammenga, Paul; Applegate, Kelly; Tautin, John

2012-12-22

North American birds that feed on flying insects are experiencing steep population declines, particularly long-distance migratory populations in the northern breeding range. We determine, for the first time, the level of migratory connectivity across the range of a songbird using direct tracking of individuals, and test whether declining northern populations have higher exposure to agricultural landscapes at their non-breeding grounds in South America. We used light-level geolocators to track purple martins, Progne subis, originating from North American breeding populations, coast-to-coast (n = 95 individuals). We show that breeding populations of the eastern subspecies, P. s. subis, that are separated by ca. 2000 km, nevertheless have almost completely overlapping non-breeding ranges in Brazil. Most (76%) P. s. subis overwintered in northern Brazil near the Amazon River, not in the agricultural landscape of southern Brazil. Individual non-breeding sites had an average of 91 per cent forest and only 4 per cent agricultural ground cover within a 50 km radius, and birds originating from declining northern breeding populations were not more exposed to agricultural landscapes than stable southern breeding populations. Our results show that differences in wintering location and habitat do not explain recent trends in breeding population declines in this species, and instead northern populations may be constrained in their ability to respond to climate change.

Nonlinear Uncertainty Propagation of Satellite State Error for Tracking and Conjunction Risk Assessment

Science.gov (United States)

2017-12-18

AFRL-RV-PS- AFRL-RV-PS- TR-2017-0177 TR-2017-0177 NONLINEAR UNCERTAINTY PROPAGATION OF SATELLITE STATE ERROR FOR TRACKING AND CONJUNCTION RISK...Uncertainty Propagation of Satellite State Error for Tracking and Conjunction Risk Assessment 5a. CONTRACT NUMBER FA9453-16-1-0084 5b. GRANT NUMBER...prediction and satellite conjunction analysis. Statistical approach utilizes novel methods to build better uncertainty state characterization in the context

Laser technology for high precision satellite tracking

Science.gov (United States)

Plotkin, H. H.

1974-01-01

Fixed and mobile laser ranging stations have been developed to track satellites equipped with retro-reflector arrays. These have operated consistently at data rates of once per second with range precision better than 50 cm, using Q-switched ruby lasers with pulse durations of 20 to 40 nanoseconds. Improvements are being incorporated to improve the precision to 10 cm, and to permit ranging to more distant satellites. These include improved reflector array designs, processing and analysis of the received reflection pulses, and use of sub-nanosecond pulse duration lasers.

Gravity model improvement using the DORIS tracking system on the SPOT 2 satellite

Science.gov (United States)

Nerem, R. S.; Lerch, F. J.; Williamson, R. G.; Klosko, S. M.; Robbins, J. W.; Patel, G. B.

1994-01-01

A high-precision radiometric satellite tracking system, Doppler Orbitography and Radio-positioning Integrated by Satellite system (DORIS), has recently been developed by the French space agency, Centre National d'Etudes Spatiales (CNES). DORIS was designed to provide tracking support for missions such as the joint United States/French TOPEX/Poseidon. As part of the flight testing process, a DORIS package was flown on the French SPOT 2 satellite. A substantial quantity of geodetic quality tracking data was obtained on SPOT 2 from an extensive international DORIS tracking network. These data were analyzed to assess their accuracy and to evaluate the gravitational modeling enhancements provided by these data in combination with the Goddard Earth Model-T3 (GEM-T3) gravitational model. These observations have noise levels of 0.4 to 0.5 mm/s, with few residual systematic effects. Although the SPOT 2 satellite experiences high atmospheric drag forces, the precision and global coverage of the DORIS tracking data have enabled more extensive orbit parameterization to mitigate these effects. As a result, the SPOT 2 orbital errors have been reduced to an estimated radial accuracy in the 10-20 cm RMS range. The addition of these data, which encompass many regions heretofore lacking in precision satellite tracking, has significantly improved GEM-T3 and allowed greatly improved orbit accuracies for Sun-synchronous satellites like SPOT 2 (such as ERS 1 and EOS). Comparison of the ensuing gravity model with other contemporary fields (GRIM-4C2, TEG2B, and OSU91A) provides a means to assess the current state of knowledge of the Earth's gravity field. Thus, the DORIS experiment on SPOT 2 has provided a strong basis for evaluating this new orbit tracking technology and has demonstrated the important contribution of the DORIS network to the success of the TOPEX/Poseidon mission.

Tracking target objects orbiting earth using satellite-based telescopes

Science.gov (United States)

De Vries, Willem H; Olivier, Scot S; Pertica, Alexander J

2014-10-14

A system for tracking objects that are in earth orbit via a constellation or network of satellites having imaging devices is provided. An object tracking system includes a ground controller and, for each satellite in the constellation, an onboard controller. The ground controller receives ephemeris information for a target object and directs that ephemeris information be transmitted to the satellites. Each onboard controller receives ephemeris information for a target object, collects images of the target object based on the expected location of the target object at an expected time, identifies actual locations of the target object from the collected images, and identifies a next expected location at a next expected time based on the identified actual locations of the target object. The onboard controller processes the collected image to identify the actual location of the target object and transmits the actual location information to the ground controller.

Atlantic leatherback migratory paths and temporary residence areas.

Directory of Open Access Journals (Sweden)

Sabrina Fossette

Full Text Available BACKGROUND: Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. METHODOLOGY/PRINCIPAL FINDINGS: Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration. Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. CONCLUSIONS/SIGNIFICANCE: Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios

The integrated satellite-acoustic telemetry (iSAT) system for tracking marine megafauna

KAUST Repository

De la Torre, Pedro

2012-10-06

This document describes the integrated satellite-acoustic telemetry (iSAT) system: an autonomous modular system for tracking the movements of large pelagic fish using acoustic telemetry and satellite communications. The sensor platform is described along with the propulsion and navigation systems. An application for tracking the whale shark (Rhincodon typus) in the Red Sea is included along with a discussion of the technical difficulties that such a system faces.

The integrated satellite-acoustic telemetry (iSAT) system for tracking marine megafauna

KAUST Repository

De la Torre, Pedro; Berumen, Michael L.; Salama, Khaled N.; Smith, E. Lloyd

2012-01-01

This document describes the integrated satellite-acoustic telemetry (iSAT) system: an autonomous modular system for tracking the movements of large pelagic fish using acoustic telemetry and satellite communications. The sensor platform is described along with the propulsion and navigation systems. An application for tracking the whale shark (Rhincodon typus) in the Red Sea is included along with a discussion of the technical difficulties that such a system faces.

Orbit Determination from Tracking Data of Artificial Satellite Using the Method of Differential Correction

OpenAIRE

Byoung-Sun Lee; Jung-Hyun Jo; Sang-Young Park; Kyu-Hong Choi; Chun-Hwey Kim

1988-01-01

The differential correction process determining osculating orbital elements as correct as possible at a given instant of time from tracking data of artificial satellite was accomplished. Preliminary orbital elements were used as an initial value of the differential correction procedure and iterated until the residual of real observation(O) and computed observation(C) was minimized. Tracking satellite was NOAA-9 or TIROS-N series. Two types of tracking data were prediction data precomputed fro...

The limits of direct satellite tracking with the Global Positioning System (GPS)

Science.gov (United States)

Bertiger, W. I.; Yunck, T. P.

1988-01-01

Recent advances in high precision differential Global Positioning System-based satellite tracking can be applied to the more conventional direct tracking of low earth satellites. To properly evaluate the limiting accuracy of direct GPS-based tracking, it is necessary to account for the correlations between the a-priori errors in GPS states, Y-bias, and solar pressure parameters. These can be obtained by careful analysis of the GPS orbit determination process. The analysis indicates that sub-meter accuracy can be readily achieved for a user above 1000 km altitude, even when the user solution is obtained with data taken 12 hours after the data used in the GPS orbit solutions.

Ecological specialization to fluctuating resources prevents long-distance migratory raptors from becoming sedentary on islands.

Science.gov (United States)

Gangoso, Laura; López-López, Pascual; Grande, Juan Manuel; Mellone, Ugo; Limiñana, Rubén; Urios, Vicente; Ferrer, Miguel

2013-01-01

The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora's falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors. Here, we compiled data concerning demography, banding recoveries and satellite tracking of Eleonora's falcons to discuss likely explanations for the exceptional behavior of this insular long-distance migratory species. New data reveal that Eleonora's falcons do return to the natal colonies in their first year and young birds are able to breed. However, in contrast to previous hypothesis, the highly specialized strategy of this and other ecologically similar species, as well as the virtual lack of food during winter at breeding areas prevent them from becoming sedentary on islands. Although the ultimate mechanisms underlying the process of sedentarization remain poorly understood, the evidence provided reveal the existence of important trade-offs associated with ecological specialization that may become particularly relevant in the present context of global change.

Tracking Small Satellites using Translated GPS

OpenAIRE

Lefevre, Don; Mulally, Daniel

1991-01-01

This paper discusses using translated GPS for tracking small satellites, the technical trade-offs involved, and the position and timing accuracies which are achievable using translated GPS. The Global Positioning System (GPS) uses the relative times-of-arrival of multiple spread-spectrum signals at an antenna to determine the position of the antenna. The system can also determine the time the antenna was at that position. The direct sequence spread spectrum signals are transmitted from GPS sa...

Design of tracking mount and controller for mobile satellite laser ranging system

Science.gov (United States)

Park, Cheol Hoon; Son, Young Su; Kim, Byung In; Ham, Sang Young; Lee, Sung Whee; Lim, Hyung Chul

2012-01-01

In this study, we have proposed and implemented a design for the tracking mount and controller of the ARGO-M (Accurate Ranging system for Geodetic Observation - Mobile) which is a mobile satellite laser ranging (SLR) system developed by the Korea Astronomy and Space Science Institute (KASI) and Korea Institute of Machinery and Materials (KIMM). The tracking mount comprises a few core components such as bearings, driving motors and encoders. These components were selected as per the technical specifications for the tracking mount of the ARGO-M. A three-dimensional model of the tracking mount was designed. The frequency analysis of the model predicted that the first natural frequency of the designed tracking mount was high enough. The tracking controller is simulated using MATLAB/xPC Target to achieve the required pointing and tracking accuracy. In order to evaluate the system repeatability and tracking accuracy of the tracking mount, a prototype of the ARGO-M was fabricated, and repeatability tests were carried out using a laser interferometer. Tracking tests were conducted using the trajectories of low earth orbit (LEO) and high earth orbit (HEO) satellites. Based on the test results, it was confirmed that the prototype of the tracking mount and controller of the ARGO-M could achieve the required repeatability along with a tracking accuracy of less than 1 arcsec.

Tracking the Autumn Migration of the Bar-Headed Goose (Anser indicus with Satellite Telemetry and Relationship to Environmental Conditions

Directory of Open Access Journals (Sweden)

Yaonan Zhang

2011-01-01

Full Text Available The autumn migration routes of bar-headed geese captured before the 2008 breeding season at Qinghai Lake, China, were documented using satellite tracking data. To assess how the migration strategies of bar-headed geese are influenced by environmental conditions, the relationship between migratory routes, temperatures, and vegetation coverage at stopovers sites estimated with the Normalized Difference Vegetation Index (NDVI were analyzed. Our results showed that there were four typical migration routes in autumn with variation in timing among individuals in start and end times and in total migration and stopover duration. The observed variation may be related to habitat type and other environmental conditions along the routes. On average, these birds traveled about 1300 to 1500 km, refueled at three to six stopover sites and migrated for 73 to 83 days. The majority of the habitat types at stopover sites were lake, marsh, and shoal wetlands, with use of some mountainous regions, and farmland areas.

Robust FDI for A Ship-mounted Satellite Tracking Antenna: A Nonlinear Approach

DEFF Research Database (Denmark)

Soltani, Mohsen; Izadi-Zamanabadi, Roozbeh; Wisniewski, Rafal

2008-01-01

Overseas telecommunication is preserved by means of satellite communication. Tracking system postures the on-board antenna toward a chosen satellite while the external disturbances affect the antenna. Certain faults (beam sensor malfunction or signal blocking) cause interruption in the communicat...

Satellite tracking of manta rays highlights challenges to their conservation.

Directory of Open Access Journals (Sweden)

Rachel T Graham

Full Text Available We describe the real-time movements of the last of the marine mega-vertebrate taxa to be satellite tracked - the giant manta ray (or devil fish, Manta birostris, the world's largest ray at over 6 m disc width. Almost nothing is known about manta ray movements and their environmental preferences, making them one of the least understood of the marine mega-vertebrates. Red listed by the International Union for the Conservation of Nature as 'Vulnerable' to extinction, manta rays are known to be subject to direct and incidental capture and some populations are declining. Satellite-tracked manta rays associated with seasonal upwelling events and thermal fronts off the Yucatan peninsula, Mexico, and made short-range shuttling movements, foraging along and between them. The majority of locations were received from waters shallower than 50 m deep, representing thermally dynamic and productive waters. Manta rays remained in the Mexican Exclusive Economic Zone for the duration of tracking but only 12% of tracking locations were received from within Marine Protected Areas (MPAs. Our results on the spatio-temporal distribution of these enigmatic rays highlight opportunities and challenges to management efforts.

Satellite tracking of manta rays highlights challenges to their conservation.

Science.gov (United States)

Graham, Rachel T; Witt, Matthew J; Castellanos, Dan W; Remolina, Francisco; Maxwell, Sara; Godley, Brendan J; Hawkes, Lucy A

2012-01-01

We describe the real-time movements of the last of the marine mega-vertebrate taxa to be satellite tracked - the giant manta ray (or devil fish, Manta birostris), the world's largest ray at over 6 m disc width. Almost nothing is known about manta ray movements and their environmental preferences, making them one of the least understood of the marine mega-vertebrates. Red listed by the International Union for the Conservation of Nature as 'Vulnerable' to extinction, manta rays are known to be subject to direct and incidental capture and some populations are declining. Satellite-tracked manta rays associated with seasonal upwelling events and thermal fronts off the Yucatan peninsula, Mexico, and made short-range shuttling movements, foraging along and between them. The majority of locations were received from waters shallower than 50 m deep, representing thermally dynamic and productive waters. Manta rays remained in the Mexican Exclusive Economic Zone for the duration of tracking but only 12% of tracking locations were received from within Marine Protected Areas (MPAs). Our results on the spatio-temporal distribution of these enigmatic rays highlight opportunities and challenges to management efforts.

Analysis of orbit determination from Earth-based tracking for relay satellites in a perturbed areostationary orbit

Science.gov (United States)

Romero, P.; Pablos, B.; Barderas, G.

2017-07-01

Areostationary satellites are considered a high interest group of satellites to satisfy the telecommunications needs of the foreseen missions to Mars. An areostationary satellite, in an areoequatorial circular orbit with a period of 1 Martian sidereal day, would orbit Mars remaining at a fixed location over the Martian surface, analogous to a geostationary satellite around the Earth. This work addresses an analysis of the perturbed orbital motion of an areostationary satellite as well as a preliminary analysis of the aerostationary orbit estimation accuracy based on Earth tracking observations. First, the models for the perturbations due to the Mars gravitational field, the gravitational attraction of the Sun and the Martian moons, Phobos and Deimos, and solar radiation pressure are described. Then, the observability from Earth including possible occultations by Mars of an areostationary satellite in a perturbed areosynchronous motion is analyzed. The results show that continuous Earth-based tracking is achievable using observations from the three NASA Deep Space Network Complexes in Madrid, Goldstone and Canberra in an occultation-free scenario. Finally, an analysis of the orbit determination accuracy is addressed considering several scenarios including discontinuous tracking schedules for different epochs and different areoestationary satellites. Simulations also allow to quantify the aerostationary orbit estimation accuracy for various tracking series durations and observed orbit arc-lengths.

First satellite tracks of neonate sea turtles redefine the ‘lost years’ oceanic niche

Science.gov (United States)

Mansfield, Katherine L.; Wyneken, Jeanette; Porter, Warren P.; Luo, Jiangang

2014-01-01

Few at-sea behavioural data exist for oceanic-stage neonate sea turtles, a life-stage commonly referred to as the sea turtle ‘lost years’. Historically, the long-term tracking of small, fast-growing organisms in the open ocean was logistically or technologically impossible. Here, we provide the first long-term satellite tracks of neonate sea turtles. Loggerheads (Caretta caretta) were remotely tracked in the Atlantic Ocean using small solar-powered satellite transmitters. We show that oceanic-stage turtles (i) rarely travel in Continental Shelf waters, (ii) frequently depart the currents associated with the North Atlantic Subtropical Gyre, (iii) travel quickly when in Gyre currents, and (iv) select sea surface habitats that are likely to provide a thermal benefit or refuge to young sea turtles, supporting growth, foraging and survival. Our satellite tracks help define Atlantic loggerhead nursery grounds and early loggerhead habitat use, allowing us to re-examine sea turtle ‘lost years’ paradigms. PMID:24598420

Limitations and mechanisms influencing the migratory performance of soaring birds

Science.gov (United States)

Tricia A. Miller; Brooks Robert P.; Michael J. Lanzone; David Brandes; Jeff Cooper; Junior A. Tremblay; Jay Wilhelm; Adam Duerr; Todd E. Katzner

2016-01-01

Migration is costly in terms of time, energy and safety. Optimal migration theory suggests that individual migratory birds will choose between these three costs depending on their motivation and available resources. To test hypotheses about use of migratory strategies by large soaring birds, we used GPS telemetry to track 18 adult, 13 sub-adult and 15 juvenile Golden...

Dynamic sensor tasking and IMM EKF estimation for tracking impulsively maneuvering satellites

Science.gov (United States)

Lace, Arthur A.

In order to efficiently maintain space situational awareness, care must be taken to optimally allocate expensive observation resources. In most situations the available sensors capable of tracking spacecraft have their time split between many different monitoring responsibilities. Tracking maneuvering spacecraft can be especially difficult as the schedule of maneuvers may not be known and will often throw off previous orbital models. Effectively solving this tasking problem is an ongoing focus of research in the area of space situational awareness. Most methods of automated tasking do not make use of interacting multiple model extended Kalman filter techniques to better track satellites during maneuvers. This paper proposes a modification to a Fisher information gain and estimated state covariance based sensor tasking method to take maneuver probability and multiple model dynamics into account. By incorporating the probabilistic maneuvering model, sensor tasking can be improved during satellite maneuvers using constrained resources. The proposed methods are verified through the use of numerical simulations with multiple maneuvering satellites and both orbital and ground-based sensors.

Counterintuitive roles of experience and weather on migratory performance

Science.gov (United States)

Rus, Adrian I.; Duerr, Adam E.; Miller, Tricia A.; Belthoff, James R.; Katzner, Todd E.

2017-01-01

Migration allows animals to live in resource-rich but seasonally variable environments. Because of the costs of migration, there is selective pressure to capitalize on variation in weather to optimize migratory performance. To test the degree to which migratory performance (defined as speed of migration) of Golden Eagles (Aquila chrysaetos) was determined by age- and season-specific responses to variation in weather, we analyzed 1,863 daily tracks (n = 83 migrant eagles) and 8,047 hourly tracks (n = 83) based on 15 min GPS telemetry data from Golden Eagles and 277 hourly tracks based on 30 s data (n = 37). Spring migrant eagles traveled 139.75 ± 82.19 km day−1 (mean ± SE; n = 57) and 25.59 ± 11.75 km hr−1 (n = 55). Autumn migrant eagles traveled 99.14 ± 59.98 km day−1 (n = 26) and 22.18 ± 9.18 km hr−1 (n = 28). Weather during migration varied by season and by age class. During spring, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by downward solar radiation and that older birds benefited less from flow assistance (tailwinds). During autumn, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by south–north winds and by flow assistance, again less strongly for older birds. In contrast, models for hourly performance based on data collected at 30 s intervals were not well described by a single model, likely reflecting eagles' rapid responses to the many weather conditions they experienced. Although daily speed of travel was similar for all age classes, younger birds traveled at faster hourly speeds than did adults. Our analyses uncovered strong, sometimes counterintuitive, relationships among weather, experience, and migratory flight, and they illustrate the significance of factors other than age in determining migratory performance.

Ground Simulation of an Autonomous Satellite Rendezvous and Tracking System Using Dual Robotic Systems

Science.gov (United States)

Trube, Matthew J.; Hyslop, Andrew M.; Carignan, Craig R.; Easley, Joseph W.

2012-01-01

A hardware-in-the-loop ground system was developed for simulating a robotic servicer spacecraft tracking a target satellite at short range. A relative navigation sensor package "Argon" is mounted on the end-effector of a Fanuc 430 manipulator, which functions as the base platform of the robotic spacecraft servicer. Machine vision algorithms estimate the pose of the target spacecraft, mounted on a Rotopod R-2000 platform, relay the solution to a simulation of the servicer spacecraft running in "Freespace", which performs guidance, navigation and control functions, integrates dynamics, and issues motion commands to a Fanuc platform controller so that it tracks the simulated servicer spacecraft. Results will be reviewed for several satellite motion scenarios at different ranges. Key words: robotics, satellite, servicing, guidance, navigation, tracking, control, docking.

Ecological specialization to fluctuating resources prevents long-distance migratory raptors from becoming sedentary on islands.

Directory of Open Access Journals (Sweden)

Laura Gangoso

Full Text Available BACKGROUND: The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora's falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors. METHODOLOGY/PRINCIPAL FINDINGS: Here, we compiled data concerning demography, banding recoveries and satellite tracking of Eleonora's falcons to discuss likely explanations for the exceptional behavior of this insular long-distance migratory species. CONCLUSIONS/SIGNIFICANCE: New data reveal that Eleonora's falcons do return to the natal colonies in their first year and young birds are able to breed. However, in contrast to previous hypothesis, the highly specialized strategy of this and other ecologically similar species, as well as the virtual lack of food during winter at breeding areas prevent them from becoming sedentary on islands. Although the ultimate mechanisms underlying the process of sedentarization remain poorly understood, the evidence provided reveal the existence of important trade-offs associated with ecological specialization that may become particularly relevant in the present context of global change.

Migration of Tundra Swans (Cygnus columbianus) Wintering in Japan Using Satellite Tracking: Identification of the Eastern Palearctic Flyway.

Science.gov (United States)

Chen, Wenbo; Doko, Tomoko; Fujita, Go; Hijikata, Naoya; Tokita, Ken-Ichi; Uchida, Kiyoshi; Konishi, Kan; Hiraoka, Emiko; Higuchi, Hiroyoshi

2016-02-01

Migration through the Eastern Palearctic (EP) flyway by tundra swans (Cygnus columbianus) has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1) to show the migration pattern of the EP flyway of tundra swans; 2) to compare this pattern with the migration pattern of whooper swans; and 3) to identify stopover sites that are important for these swans' conservation. Tundra swans were captured at Kutcharo Lake, Hokkaido, in 2009-2012 and satellite-tracked. A new method called the "MATCHED (Migratory Analytical Time Change Easy Detection) method" was developed. Based on median, the spring migration began on 18 April and ended on 27 May. Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5.5 days and 6.8 days for the spring and autumn migrations, respectively. The number of stopover sites was 3.0 and 2.5 for the spring and autumn migrations, respectively. The mean travel distances for the spring and autumn migrations were 6471 and 6331 km, respectively. Seven migration routes passing Sakhalin, the Amur River, and/or Kamchatka were identified. There were 15, 32, and eight wintering, stopover, and breeding sites, respectively. The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. The migration patterns of these two swan species that winter in Japan confirm the importance of the Amur River, Udyl' Lake, Shchastya Bay, Aniva Bay, zaliv Chayvo Lake, zal Piltun Lake, zaliv Baykal Lake, Kolyma River, Buyunda River, Sen-kyuyel' Lake, and northern coastal areas of the Sea of Okhotsk.

Orbit Determination from Tracking Data of Artificial Satellite Using the Method of Differential Correction

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Byoung-Sun Lee

1988-06-01

Full Text Available The differential correction process determining osculating orbital elements as correct as possible at a given instant of time from tracking data of artificial satellite was accomplished. Preliminary orbital elements were used as an initial value of the differential correction procedure and iterated until the residual of real observation(O and computed observation(C was minimized. Tracking satellite was NOAA-9 or TIROS-N series. Two types of tracking data were prediction data precomputed from mean orbital elements of TBUS and real data obtained from tracking 1.707GHz HRPT signal of NOAA-9 using 5 meter auto-track antenna in Radio Research Laboratory. According to tracking data either Gauss method or Herrick-Gibbs method was applied to preliminary orbit determination. In the differential correction stage we used both of the Escobal(1975's analytical method and numerical ones are nearly consistent. And the differentially corrected orbit converged to the same value in spite of the differences between preliminary orbits of each time span.

A Study on the Tracking and Position Predictions of Artificial Satellite (II

Directory of Open Access Journals (Sweden)

Pil-Ho Park

1991-06-01

Full Text Available We developed a software system called IODS (ISSA Orbit Determination System, which can predict the orbit of arbitrary artificial satellite using the numerical method. For evaluating the orbit prediction accuracy of IODS, the orbital data predicted for the meteorological satellite NOAA-11 and the stationary satellite INTELSAT-V are intercompared with those tracked at the Central Bureau of Meteorology and the Kum-San Satellites Communication Station. And the Perturbation affecting the orbit of these artificial satellites are quantitatively analyzed. The orbital variation and the eclipse phenomina due to the earth shadow are analyzed for a hypothetical geostationary satellite called KORSAT-1 which is assumed to be located in longitude 110°E.

Setting conservation priorities for migratory networks under uncertainty.

Science.gov (United States)

Dhanjal-Adams, Kiran L; Klaassen, Marcel; Nicol, Sam; Possingham, Hugh P; Chadès, Iadine; Fuller, Richard A

2017-06-01

Conserving migratory species requires protecting connected habitat along the pathways they travel. Despite recent improvements in tracking animal movements, migratory connectivity remains poorly resolved at a population level for the vast majority of species, thus conservation prioritization is hampered. To address this data limitation, we developed a novel approach to spatial prioritization based on a model of potential connectivity derived from empirical data on species abundance and distance traveled between sites during migration. We applied the approach to migratory shorebirds of the East Asian-Australasian Flyway. Conservation strategies that prioritized sites based on connectivity and abundance metrics together maintained larger populations of birds than strategies that prioritized sites based only on abundance metrics. The conservation value of a site therefore depended on both its capacity to support migratory animals and its position within the migratory pathway; the loss of crucial sites led to partial or total population collapse. We suggest that conservation approaches that prioritize sites supporting large populations of migrants should, where possible, also include data on the spatial arrangement of sites. © 2016 Society for Conservation Biology.

Development of Stable Isotope Analysis Technology for Epidemiological Study of Migratory Birds in Connection with Avian Influenza

International Nuclear Information System (INIS)

Kim, Jongyun; Park, Jongho; Han, Sunho; Song, Kyuseok; Ko, Yongkwon; Bae, Inae; Cho, Mihyun; Jung, Gahee; Yeom, Ina

2012-03-01

In order to clarify correlations between the spread of avian influenza and migratory routes of birds, various conventional methods including a ring method, gene analysis, geolocator and a satellite tracking method are being used together. We first report on the estimation of origin of migratory bird in the Korea based on the statistical method of stable isotope ratio analysis of feathers. It is expected that migratory birds in Junam reservoir were from the two different regions according to the stable isotope ration analysis. However, it is not easy to conclude the breeding ground of northern pintails based on the current data because the degree of precision or accuracy can be influenced by many factors. For this reason, this statistical analysis accuracy can be influenced by many factors. For this reason, this statistical analysis can have a scientific significance if the reliability of the whole measurement system is improved. Furthermore, databases are not enough to prepare base map of regional isotope ratios because database of stable isotope ratio in oxygen and hydrogen of rainwater in Korea should be constructed. Though the research has focused on the hydrogen and oxygen until now, investigation of other elements, such as carbon, sulfur, nitrogen and others that can describe metabolic process or regional characteristics, is also worthwhile subject. And it is believed that this research will improve a resolution of detection for the migratory pathway and habitat of birds

Development of Stable Isotope Analysis Technology for Epidemiological Study of Migratory Birds in Connection with Avian Influenza

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongyun; Park, Jongho; Han, Sunho; Song, Kyuseok; Ko, Yongkwon; Bae, Inae; Cho, Mihyun; Jung, Gahee; Yeom, Ina

2012-03-15

In order to clarify correlations between the spread of avian influenza and migratory routes of birds, various conventional methods including a ring method, gene analysis, geolocator and a satellite tracking method are being used together. We first report on the estimation of origin of migratory bird in the Korea based on the statistical method of stable isotope ratio analysis of feathers. It is expected that migratory birds in Junam reservoir were from the two different regions according to the stable isotope ration analysis. However, it is not easy to conclude the breeding ground of northern pintails based on the current data because the degree of precision or accuracy can be influenced by many factors. For this reason, this statistical analysis accuracy can be influenced by many factors. For this reason, this statistical analysis can have a scientific significance if the reliability of the whole measurement system is improved. Furthermore, databases are not enough to prepare base map of regional isotope ratios because database of stable isotope ratio in oxygen and hydrogen of rainwater in Korea should be constructed. Though the research has focused on the hydrogen and oxygen until now, investigation of other elements, such as carbon, sulfur, nitrogen and others that can describe metabolic process or regional characteristics, is also worthwhile subject. And it is believed that this research will improve a resolution of detection for the migratory pathway and habitat of birds.

Virtual target tracking (VTT) as applied to mobile satellite communication networks

Science.gov (United States)

Amoozegar, Farid

1999-08-01

Traditionally, target tracking has been used for aerospace applications, such as, tracking highly maneuvering targets in a cluttered environment for missile-to-target intercept scenarios. Although the speed and maneuvering capability of current aerospace targets demand more efficient algorithms, many complex techniques have already been proposed in the literature, which primarily cover the defense applications of tracking methods. On the other hand, the rapid growth of Global Communication Systems, Global Information Systems (GIS), and Global Positioning Systems (GPS) is creating new and more diverse challenges for multi-target tracking applications. Mobile communication and computing can very well appreciate a huge market for Cellular Communication and Tracking Devices (CCTD), which will be tracking networked devices at the cellular level. The objective of this paper is to introduce a new concept, i.e., Virtual Target Tracking (VTT) for commercial applications of multi-target tracking algorithms and techniques as applied to mobile satellite communication networks. It would be discussed how Virtual Target Tracking would bring more diversity to target tracking research.

Comparison of different "along the track" high resolution satellite stereo-pair for DSM extraction

Science.gov (United States)

Nikolakopoulos, Konstantinos G.

2013-10-01

The possibility to create DEM from stereo pairs is based on the Pythagoras theorem and on the principles of photogrammetry that are applied to aerial photographs stereo pairs for the last seventy years. The application of these principles to digital satellite stereo data was inherent in the first satellite missions. During the last decades the satellite stereo-pairs were acquired across the track in different days (SPOT, ERS etc.). More recently the same-date along the track stereo-data acquisition seems to prevail (Terra ASTER, SPOT5 HRS, Cartosat, ALOS Prism) as it reduces the radiometric image variations (refractive effects, sun illumination, temporal changes) and thus increases the correlation success rate in any image matching.Two of the newest satellite sensors with stereo collection capability is Cartosat and ALOS Prism. Both of them acquire stereopairs along the track with a 2,5m spatial resolution covering areas of 30X30km. In this study we compare two different satellite stereo-pair collected along the track for DSM creation. The first one is created from a Cartosat stereopair and the second one from an ALOS PRISM triplet. The area of study is situated in Chalkidiki Peninsula, Greece. Both DEMs were created using the same ground control points collected with a Differential GPS. After a first control for random or systematic errors a statistical analysis was done. Points of certified elevation have been used to estimate the accuracy of these two DSMs. The elevation difference between the different DEMs was calculated. 2D RMSE, correlation and the percentile value were also computed and the results are presented.

Landscape Characteristics of Oriental Honey Buzzards Wintering in Western Part of Flores Island Based on Satellite-Tracking Data

Science.gov (United States)

Syartinilia; Farisi, G. H. Al; Higuchi, H.

2017-10-01

Oriental Honey Buzzards (OHBs, Pernis ptilorhynchus) are migratory raptor that has been satellite-tracked since 2003. Some islands in Indonesia which are used for wintering habitat are Flores and Borneo. However, both islands have different characteristics of climate and land cover. The objectives of this research were to analyze the landscape characteristic of the OHBs wintering habitat in western Flores, and to subsequently compare landscape characteristic of the OHBs wintering habitat in Borneo. Landscape habitat characteristics were analyzed using Principal Component Analysis (PCA) combined with GIS and then compared to the previous study in Borneo Island. The result showed that the first of six principal components explained 79.14% and 77.59% of the observed variation in landscape characteristics of both core and edge habitats, subsequently. Habitat selection by OHBs at wintering site was influenced by the availability of thermal wind and food. Savannah was identified as the main landscape characteristic that was different between wintering habitat in Flores and Borneo. Savannah is well-known as a habitat for many species of amphibians, reptiles, and small mammals so that it can be a hunting area that provide alternative feed for OHBs.

GSFC network operations with Tracking and Data Relay Satellites

Science.gov (United States)

Spearing, R.; Perreten, D. E.

The Tracking and Data Relay Satellite System (TDRSS) Network (TN) has been developed to provide services to all NASA User spacecraft in near-earth orbits. Three inter-relating entities will provide these services. The TN has been transformed from a network continuously changing to meet User specific requirements to a network which is flexible to meet future needs without significant changes in operational concepts. Attention is given to the evolution of the TN network, the TN capabilities-space segment, forward link services, tracking services, return link services, the three basic capabilities, single access services, multiple access services, simulation services, the White Sands Ground Terminal, the NASA communications network, and the network control center.

GPS-based system for satellite tracking and geodesy

Science.gov (United States)

Bertiger, Willy I.; Thornton, Catherine L.

1989-01-01

High-performance receivers and data processing systems developed for GPS are reviewed. The GPS Inferred Positioning System (GIPSY) and the Orbiter Analysis and Simulation Software (OASIS) are described. The OASIS software is used to assess GPS system performance using GIPSY for data processing. Consideration is given to parameter estimation for multiday arcs, orbit repeatability, orbit prediction, daily baseline repeatability, agreement with VLBI, and ambiguity resolution. Also, the dual-frequency Rogue receiver, which can track up to eight GPS satellites simultaneously, is discussed.

A GPS measurement system for precise satellite tracking and geodesy

Science.gov (United States)

Yunck, T. P.; Wu, S.-C.; Lichten, S. M.

1985-01-01

NASA is pursuing two key applications of differential positioning with the Global Positioning System (GPS): sub-decimeter tracking of earth satellites and few-centimeter determination of ground-fixed baselines. Key requirements of the two applications include the use of dual-frequency carrier phase data, multiple ground receivers to serve as reference points, simultaneous solution for use position and GPS orbits, and calibration of atmospheric delays using water vapor radiometers. Sub-decimeter tracking will be first demonstrated on the TOPEX oceanographic satellite to be launched in 1991. A GPS flight receiver together with at least six ground receivers will acquire delta range data from the GPS carriers for non-real-time analysis. Altitude accuracies of 5 to 10 cm are expected. For baseline measurements, efforts will be made to obtain precise differential pseudorange by resolving the cycle ambiguity in differential carrier phase. This could lead to accuracies of 2 or 3 cm over a few thousand kilometers. To achieve this, a high-performance receiver is being developed, along with improved calibration and data processing techniques. Demonstrations may begin in 1986.

Sand dune tracking from satellite laser altimetry

Science.gov (United States)

Dabboor, Mohammed

Substantial problems arise from sand movement in arid and semi-arid countries. Sand poses a threat to infrastructure, agricultural and urban areas. These issues are caused by the encroachment of sand on roads and railway tracks, farmland, towns and villages, and airports, to name a few. Sand movement highly depends on geomorphology including vegetation cover, shape and height of the terrain, and grain size of the sand. However, wind direction and speed are the most important factors that affect efficient sand movement. The direction of the movement depends on the main direction of the wind, but it has been shown that a minimum wind speed is required, e.g. wind gusts, to initiate sand transport. This fact prevents a simple calculation of sand transport from conventional wind data as wind records rarely contain sub-minute intervals masking out any wind gusts. An alternative of predicting sand transport is the direct observation of sand advance by in situ measurements or via satellite. Until recently, satellite imagery was the only means to compare dune shape and position for predicting dune migration over several years. In 2003, the NASA laser altimetry mission ICESat became operational and monitors elevations over all surface types including sand dunes with an accuracy of about 10-20 cm. In this study, ICESat observations from repeat tracks (tracks overlapping eachother within 50 m) are used to derive sand dune advance and direction. The method employs a correlation of the elevation profiles over several dunes and was sucessfully validated with synthetic data. The accuracy of this method is 5 meters of dune advance. One of the most active areas exhibiting sand and dune movement is the area of the Arabian Peninsula. Approximately one-third of the Arabian Peninsula is covered by sand dunes. Different wind regimes (Shamal, Kaus) cause sand dune movement in the selected study area in the eastern part of the Arabian Peninsula between 20-25 degrees North and 45-55 degrees

Using Satellite Imagery to Identify Tornado Damage Tracks and Recovery from the April 27, 2011 Severe Weather Outbreak

Science.gov (United States)

Cole, Tony A.; Molthan, Andrew L.; Bell, Jordan R.

2014-01-01

Emergency response to natural disasters requires coordination between multiple local, state, and federal agencies. Single, relatively weak tornado events may require comparatively simple response efforts; but larger "outbreak" events with multiple strong, long-track tornadoes can benefit from additional tools to help expedite these efforts. Meteorologists from NOAA's National Weather Service conduct field surveys to map tornado tracks, assess damage, and determine the tornado intensity following each event. Moderate and high resolution satellite imagery can support these surveys by providing a high-level view of the affected areas. Satellite imagery could then be used to target areas for immediate survey or to corroborate the results of the survey after it is completed. In this study, the feasibility of using satellite imagery to identify tornado damage tracks was determined by comparing the characteristics of tracks observed from low-earth orbit to tracks assessed during the official NWS storm survey process. Of the 68 NWS confirmed centerlines, 24 tracks (35.3%) could be distinguished from other surface features using satellite imagery. Within each EF category, 0% of EF-0, 3% of EF-1, 50% of EF-2, 77.7% of EF-3, 87.5% of EF-4 and 100% of EF-5 tornadoes were detected. It was shown that satellite data can be used to identify tornado damage tracks in MODIS and ASTER NDVI imagery, where damage to vegetation creates a sharp drop in values though the minimum EF-category which can be detected is dependent upon the type of sensor used and underlying vegetation. Near-real time data from moderate resolution sensors compare favorably to field surveys after the event and suggest that the data can provide some value in the assessment process.

Bats adjust foraging behavior in response to migratory prey

Science.gov (United States)

Insect migrations represent large movements of resources across a landscape, and are likely to attract predators capable of detecting and catching them. Brazilian free-tailed bats (Tadarida brasiliensis) track resources in time and space and consume large numbers of migratory noctuid moths. During...

A preliminary study of level 1A data processing of a low–low satellite to satellite tracking mission

Directory of Open Access Journals (Sweden)

Peng Xu

2015-09-01

Full Text Available With the Gravity Recovery and Climate Experiment (GRACE mission as the prime example, an overview is given on the management and processing of Level 1A data of a low–low satellite to satellite tracking mission. To illustrate the underlying principle and algorithm, a detailed study is made on the K-band ranging (KBR assembly, which includes the measurement principles, modeling of noises, the generation of Level 1A data from that of Level 0 as well as Level 1A to Level 1B data processing.

The Accuracy Assessment of Determining the Axis of Railway Track Basing on the Satellite Surveying

Science.gov (United States)

Koc, Władysław; Specht, Cezary; Chrostowski, Piotr; Palikowska, Katarzyna

2012-09-01

In 2009, at the Gdansk University of Technology there have been carried out, for the first time, continuous satellite surveying of railway track by the use of the relative phase method based on geodesic active network ASG-EUPOS and NAVGEO service. Still continuing research works focused on the GNSS multi-receivers platform evaluation for projecting and stock-taking. In order to assess the accuracy of the railway track axis position, the values of deviations of transverse position XTE (Cross Track Error) were evaluated. In order to eliminate the influence of random measurement errors and to obtain the coordinates representing the actual shape of the track, the XTE variable was analyzed by signal analysis methods (Chebyshev low-pass filtering and fast Fourier transform). At the end the paper presents the module of the computer software SATTRACK which currently has been developing at the Gdansk University of Technology. The program serves visualization, assessment and design process of railway track, adapted to the technique of continuous satellite surveying. The module called TRACK STRAIGHT is designed to assess the straight sections. A description of its operation as well as examples of its functions has been presented.

Satellite tracking of a young Steppe Eagle from the United Arab ...

African Journals Online (AJOL)

Following recovery and successful rehabilitation, a young Steppe Eagle Aquila nipalensis was tagged with a 45 g GPS satellite transmitter to track its migration and identify potential wintering and summering areas of the species passing through the United Arab Emirates (UAE). The study is part of a larger study on ...

Orbit and clock determination of BDS regional navigation satellite system based on IGS M-GEX and WHU BETS tracking network

Science.gov (United States)

GENG, T.; Zhao, Q.; Shi, C.; Shum, C.; Guo, J.; Su, X.

2013-12-01

BeiDou Navigation Satellite System (BDS) began to provide the regional open service on December 27th 2012 and will provide the global open service by the end of 2020. Compared to GPS, the space segment of BDS Regional System consists of 5 Geostationary Earth Orbit satellites (GEO), 5 Inclined Geosynchronous Orbit satellites (IGSO) and 4 Medium Earth orbit (MEO) satellites. Since 2011, IGS Multiple-GNSS Experiment (M-GEX) focuses on tracking the newly available GNSS signals. This includes all signals from the modernized satellites of the GPS and GLONASS systems, as well as signals of the BDS, Galileo and QZSS systems. Up to now, BDS satellites are tracked by around 25 stations with a variety of different antennas and receivers from different GNSS manufacture communities in M-GEX network. Meanwhile, there are 17 stations with Unicore Communications Incorporation's GPS/BDS receivers in BeiDou Experimental Tracking Stations (BETS) network by Wuhan University. In addition, 5 BDS satellites have been tracking by the International Laser Ranging Service (ILRS). BDS performance is expected to be further studied by the GNSS communities. Following an introduction of the BDS system and above different tracking network, this paper discusses the achieved BDS characterization and performance assessment. Firstly, the BDS signal and measurement quality are analyzed with different antennas and receivers in detail compared to GPS. This includes depth of coverage for satellite observation, carrier-to-noise-density ratios, code noise and multipath, carrier phase errors. Secondly, BDS Precise Orbit Determination (POD) is processed. Different arc lengths and sets of orbit parameters are tested using Position And Navigation Data Analysis software (PANDA) which is developed at the Wuhan University. GEO, IGSO and MEO satellites orbit quality will be assessed using overlap comparison, 2-day orbit fit and external validations with Satellite Laser Range (SLR). Then BDS satellites are equipped

SeaTrack: Ground station orbit prediction and planning software for sea-viewing satellites

Science.gov (United States)

Lambert, Kenneth S.; Gregg, Watson W.; Hoisington, Charles M.; Patt, Frederick S.

1993-01-01

An orbit prediction software package (Sea Track) was designed to assist High Resolution Picture Transmission (HRPT) stations in the acquisition of direct broadcast data from sea-viewing spacecraft. Such spacecraft will be common in the near future, with the launch of the Sea viewing Wide Field-of-view Sensor (SeaWiFS) in 1994, along with the continued Advanced Very High Resolution Radiometer (AVHRR) series on NOAA platforms. The Brouwer-Lyddane model was chosen for orbit prediction because it meets the needs of HRPT tracking accuracies, provided orbital elements can be obtained frequently (up to within 1 week). Sea Track requires elements from the U.S. Space Command (NORAD Two-Line Elements) for the satellite's initial position. Updated Two-Line Elements are routinely available from many electronic sources (some are listed in the Appendix). Sea Track is a menu-driven program that allows users to alter input and output formats. The propagation period is entered by a start date and end date with times in either Greenwich Mean Time (GMT) or local time. Antenna pointing information is provided in tabular form and includes azimuth/elevation pointing angles, sub-satellite longitude/latitude, acquisition of signal (AOS), loss of signal (LOS), pass orbit number, and other pertinent pointing information. One version of Sea Track (non-graphical) allows operation under DOS (for IBM-compatible personal computers) and UNIX (for Sun and Silicon Graphics workstations). A second, graphical, version displays orbit tracks, and azimuth-elevation for IBM-compatible PC's, but requires a VGA card and Microsoft FORTRAN.

Wintering area DDE source to migratory white-faced ibis revealed by satellite telemetry and prey sampling

Science.gov (United States)

Yates, M.A.; Fuller, M.R.; Henny, C.J.; Seegar, W.S.; Garcia, Jorge H.

2010-01-01

Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyldichloro-ethylene (DDE) with no change, which is unusual, observed in egg concentrations between 1985 and 2000. About 45-63% of the earliest nesting segment shows reduced reproductive success correlated with elevated egg concentrations of >4 ??g/g wet weight (ww). Local prey (primarily earthworms) near nests contained little DDE so we tracked the migration and wintering movements of 20 adult males during 2000-2004 to determine the possible source. At various wintering sites, we found a correlation (r 2 = 0.518, P = 0.0125, N = 11) between DDE in earthworm composites and DDE in blood plasma of white-faced ibis wintering there, although the plasma was collected on their breeding grounds soon after arrival. The main source of DDE was wintering areas in the Mexicali Valley of Baja California Norte, Mexico, and probably the adjacent Imperial Valley, California, USA. This unusual continuing DDE problem for white-faced ibis is associated with: the long-term persistence in soil of DDE; the earthworms' ability to bioconcentrate DDE from soil; the proclivity of white-faced ibis to feed on earthworms in agricultural fields; the species's extreme sensitivity to DDE in their eggs; and perhaps its life history strategy of being a "capital breeder". We suggest surveying and sampling white-faced ibis eggs at nesting colonies, especially at Carson Lake, to monitor the continuing influence of DDE. ?? 2009 Springer Science+Business Media, LLC.

Wintering area DDE source to migratory white-faced ibis revealed by satellite telemetry and prey sampling.

Science.gov (United States)

Yates, Michael A; Fuller, Mark R; Henny, Charles J; Seegar, William S; Garcia, Jaqueline

2010-01-01

Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyldichloro-ethylene (DDE) with no change, which is unusual, observed in egg concentrations between 1985 and 2000. About 45-63% of the earliest nesting segment shows reduced reproductive success correlated with elevated egg concentrations of >4 microg/g wet weight (ww). Local prey (primarily earthworms) near nests contained little DDE so we tracked the migration and wintering movements of 20 adult males during 2000-2004 to determine the possible source. At various wintering sites, we found a correlation (r (2) = 0.518, P = 0.0125, N = 11) between DDE in earthworm composites and DDE in blood plasma of white-faced ibis wintering there, although the plasma was collected on their breeding grounds soon after arrival. The main source of DDE was wintering areas in the Mexicali Valley of Baja California Norte, Mexico, and probably the adjacent Imperial Valley, California, USA. This unusual continuing DDE problem for white-faced ibis is associated with: the long-term persistence in soil of DDE; the earthworms' ability to bioconcentrate DDE from soil; the proclivity of white-faced ibis to feed on earthworms in agricultural fields; the species's extreme sensitivity to DDE in their eggs; and perhaps its life history strategy of being a "capital breeder". We suggest surveying and sampling white-faced ibis eggs at nesting colonies, especially at Carson Lake, to monitor the continuing influence of DDE.

Serengeti wildebeest migratory patterns modeled from rainfall and new vegetation growth

NARCIS (Netherlands)

Boone, Randall B.; Thirgood, Simon J.; Hopcraft, J. Grant C.

We used evolutionary programming to model innate migratory pathways of wildebeest in the Serengeti Mara Ecosystem, Tanzania and Kenya. Wildebeest annually move from the southern short-grass plains of the Serengeti to the northern woodlands of the Mara. We used satellite images to create 12 average

Overseas seed dispersal by migratory birds.

Science.gov (United States)

Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi

2016-01-13

Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution. © 2016 The Author(s).

Highlights of satellite-based forest change recognition and tracking using the ForWarn System

Science.gov (United States)

Steven P. Norman; William W. Hargrove; Joseph P. Spruce; William M. Christie; Sean W. Schroeder

2013-01-01

For a higher resolution version of this file, please use the following link: www.geobabble.orgSatellite-based remote sensing can assist forest managers with their need to recognize disturbances and track recovery. Despite the long...

Sea Turtle Satellite Telemetry Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Sea turtles captured in various fishing gear (pound nets, long haul seines, gill nets) were outfitted with satellite transmitters so that their movements, migratory...

Tracking and Data Relay Satellite System user impact and network compatibility study. [antenna design and telecommunication links

Science.gov (United States)

1973-01-01

The report contains data on antenna configurations for the low data rate users of the Tracking and Data Relay Satellite System (TDRSS). It treats the coverage and mutual visibility considerations between the user satellites and the relay satellites and relates these considerations to requirements of antenna beamwidth and fractional user orbital coverage. A final section includes user/TDRS telecommunication link budgets and forward and return link data rate tradeoffs.

An adaptive Multiplicative Extened Kalman Filter for Attitude Estimation of Marine Satellite Tracking Antenna

DEFF Research Database (Denmark)

Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar

2016-01-01

, an adaptive Multiplicative Extended Kalman Filter (MEKF) for attitude estimation of Marine Satellite Tracking Antenna (MSTA) is presented with the measurement noise covariance matrix adjusted according to the norm of accelerometer measurements, which can significantly reduce the slamming influence from waves...

A Small Ku-Band Polarization Tracking Active Phased Array for Mobile Satellite Communications

Directory of Open Access Journals (Sweden)

Wei Shi

2013-01-01

Full Text Available A compact polarization tracking active phased array for Ku-band mobile satellite signal reception is presented. In contrast with conventional mechanically tracking antennas, the approach presented here meets the requirements of beam tracking and polarization tracking simultaneously without any servo components. The two-layer stacked square patch fed by two probes is used as antenna element. The impedance bandwidth of 16% for the element covers the operating frequency range from 12.25 GHz to 12.75 GHz. In the presence of mutual coupling, the dimensional parameters for each element of the small 7 × 7 array are optimized during beam scanning and polarization tracking. The compact polarization tracking modules based on the low-temperature cofired ceramic (LTCC system-in-package (SiP technology are proposed. A small active phased array prototype with the size of 120 mm (length × 120 mm (width × 55 mm (height is developed. The measured polarization tracking patterns of the prototype are given. The polarization tracking beam can be steered in the elevation up to 50°. The gain of no less than 16.0 dBi and the aperture efficiency of more than 50% are obtained. The measured and simulated polarization tracking patterns agreed well.

Tracking big and small agriculture with new satellite sensors

Science.gov (United States)

Lobell, D. B.; Azzari, G.; Jin, Z.

2017-12-01

New sensors from both the public and private sector are opening up exciting possibilities for monitoring agriculture and its use of water. This talk will present selected examples from recent work using data from Planet's Planetscope and Skysat sensors as well as Sentinel-1 and Sentinel-2 missions that are part of Europe's Copernicus program. Among other things, these satellites are now helping to track crop types and productivity for fields in rainfed cropping systems of East Africa and irrigated systems in South Asia. This information should contribute to understanding land and water use decisions throughout the world.

Tracking climate impacts on the migratory monarch butterfly

Science.gov (United States)

Zipkin, Elise F.; Ries, Leslie; Reeves, Rick; Regetz, James; Oberhauser, Karen S.

2012-01-01

Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad-scale climate metric can explain summer breeding phenology or the substantial year-to-year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state-wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to

S-band multiple-access interference study for advanced tracking and data relay satellite systems

Science.gov (United States)

Peng, Wei-Chung; Yang, Chau-Chin

1990-01-01

The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

Science.gov (United States)

2011-06-03

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by... Forces to incidentally take migratory birds during approved military readiness activities without violating the Migratory Bird Treaty Act (MBTA). The Authorization Act provided this interim authority to...

Software Design of Mobile Antenna for Auto Satellite Tracking Using Modem Correction and Elevation Azimuth Method

Directory of Open Access Journals (Sweden)

Djamhari Sirat

2010-10-01

Full Text Available Pointing accuracy is an important thing in satellite communication. Because the satellite’s distance to the surface of the earth's satellite is so huge, thus 1 degree of pointing error will make the antenna can not send data to satellites. To overcome this, the auto-tracking satellite controller is made. This system uses a microcontroller as the controller, with the GPS as the indicator location of the antenna, digital compass as the beginning of antenna pointing direction, rotary encoder as sensor azimuth and elevation, and modem to see Eb/No signal. The microcontroller use serial communication to read the input. Thus the programming should be focused on in the UART and serial communication software UART. This controller use 2 phase in the process of tracking satellites. Early stages is the method Elevation-Azimuth, where at this stage with input from GPS, Digital Compass, and the position of satellites (both coordinates, and height that are stored in microcontroller. Controller will calculate the elevation and azimuth angle, then move the antenna according to the antenna azimuth and elevation angle. Next stages is correction modem, where in this stage controller only use modem as the input, and antenna movement is set up to obtain the largest value of Eb/No signal. From the results of the controller operation, there is a change in the value of the original input level from -81.7 dB to -30.2 dB with end of Eb/No value, reaching 5.7 dB.

Satellite tracking of radioactive shipments - High technology solution to tough institutional problems

International Nuclear Information System (INIS)

Harmon, L.H.; Grimm, P.D.

1987-01-01

Three troublesome institutional issues face every large-quantity radioactive materials shipment. They are routing, pre-notification, and emergency response. The Transportation Communications System (TRANSCOM), under development by DOE, is based on a rapidly developing technology to determine geographical location using geo-positioning satellite systems. This technology will be used to track unclassified radioactive materials shipments in real-time. It puts those charged with monitoring transportation status on top of very shipment. Besides its practical benefits in the areas of logistics planning and execution, it demonstrates emergency preparedness has indeed been considered and close monitoring is possible. This paper describes TRANSCOM in its technical detail and DOE plans and policy for its implementation. The state of satellite positioning technology and its business future is also discussed

Postmortem evaluation of reintroduced migratory whooping cranes in eastern North America.

Science.gov (United States)

Cole, Gretchen A; Thomas, Nancy J; Spalding, Marilyn; Stroud, Richard; Urbanek, Richard P; Hartup, Barry K

2009-01-01

Reintroduction of endangered Whooping Cranes (Grus americana) in eastern North America has successfully established a migratory population between Wisconsin and Florida. Eighty birds (47 males, 33 females) were released between 2001 and 2006, and all birds were tracked following release with satellite and/or VHF monitoring devices. By the end of 2006, 17 deaths (12 males, five females) were recorded from this population. Postmortem findings and field data were evaluated for each bird to determine the cause of death. Causes included predation (n=8, 47%), trauma (n=2, 12%), and degenerative disease (n=1, 6%); the cause of death was undetermined for 35% (n=6) of the birds. Based on physical evidence, the primary predator of the birds was the bobcat (Lynx rufus). Limited roosting habitat availability or bird behavior were likely prime factors in the occurrence of predation. Traumatic injuries and mortality were caused by gunshot, electrical utility lines, and an unknown source. The lone case of degenerative disease was due to chronic exertional myopathy associated with translocation. Available postmortem testing did not indicate the presence of infectious disease in this limited sample.

The along track scanning radiometer - an analysis of coincident ship and satellite measurements

Science.gov (United States)

Barton, I. J.; Prata, A. J.; Llewellyn-Jones, D. T.

1993-05-01

Following the successful launch of the ERS-1 satellite in July 1991 we have undertaken several geophysical validation cruises in the Coral Sea. The prime aim of these cruises was to compare the sea surface temperature (SST) derived from the Along Track Scanning Radiometer (ATSR) with that measured using precision radiometers mounted on the ships. On most occasions when simultaneous satellite and ship measurements were taken we also launched a radiosonde from one of the research vessels. The results suggest that the ATSR is able to measure the ``skin'' temperature of the sea surface with an accuracy suitable for climate research applications. A case study comparison between the AVHRR and ATSR SST products will also be presented.

Integration of Satellite Tracking Data and Satellite Images for Detailed Characteristics of Wildlife Habitats

Science.gov (United States)

Dobrynin, D. V.; Rozhnov, V. V.; Saveliev, A. A.; Sukhova, O. V.; Yachmennikova, A. A.

2017-12-01

Methods of analysis of the results got from satellite tracking of large terrestrial mammals differ in the level of their integration with additional geographic data. The reliable fine-scale cartographic basis for assessing specific wildlife habitats can be developed through the interpretation of multispectral remote sensing data and extrapolation of the results to the entire estimated species range. Topographic maps were ordinated according to classified features using self-organizing maps (Kohonen's SOM). The satellite image of the Ussuriiskyi Nature Reserve area was interpreted for the analysis of movement conditions for seven wild Amur tigers ( Panthera tigris altaica) equipped with GPS collars. 225 SOM classes for cartographic visualization are sufficient for the detailed mapping of all natural complexes that were identified as a result of interpretation. During snow-free periods, tigers preferred deciduous and shrub associations at lower elevations, as well as mixed forests in the valleys of streams that are adjacent to sparse forests and shrub watershed in the mountain ranges; during heavy snow periods, the animals preferred the entire range of plant communities in different relief types, except for open sites in meadows and abandoned fields at foothills. The border zones of different biotopes were typically used by the tigers during all seasons. Amur tigers preferred coniferous forests for long-term movements.

An Attitude Heading and Reference System For Marine Satellite Tracking Antenna

DEFF Research Database (Denmark)

Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar

2017-01-01

One of the most challenging problems for marine satellite tracking antennas (MSTAs) is to estimate the antenna attitude, which is affected by the ship motion, especially the ship vibration and rotational motions caused by ocean waves. To overcome this problem, an attitude heading and reference...... conditions, an attitude estimator based on virtual horizontal reference is introduced for situations of accelerometer malfunction, where the ship is suffering from wave shocks in high sea states. The performance of the designed AHRS for MSTA is assessed through hardware experiments using a Stewart platform...

Optimal conservation of migratory species.

Directory of Open Access Journals (Sweden)

Tara G Martin

Full Text Available BACKGROUND: Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea-regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity bringing into question the utility and efficiency of current conservation efforts. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, whereas including information on migratory connectivity results in the protection of the species across its entire range. CONCLUSIONS/SIGNIFICANCE: We demonstrate that conservation strategies for migratory animals depend critically upon two factors: knowledge of

Code Tracking Algorithms for Mitigating Multipath Effects in Fading Channels for Satellite-Based Positioning

Directory of Open Access Journals (Sweden)

Markku Renfors

2007-12-01

Full Text Available The ever-increasing public interest in location and positioning services has originated a demand for higher performance global navigation satellite systems (GNSSs. In order to achieve this incremental performance, the estimation of line-of-sight (LOS delay with high accuracy is a prerequisite for all GNSSs. The delay lock loops (DLLs and their enhanced variants (i.e., feedback code tracking loops are the structures of choice for the commercial GNSS receivers, but their performance in severe multipath scenarios is still rather limited. In addition, the new satellite positioning system proposals specify the use of a new modulation, the binary offset carrier (BOC modulation, which triggers a new challenge in the code tracking stage. Therefore, in order to meet this emerging challenge and to improve the accuracy of the delay estimation in severe multipath scenarios, this paper analyzes feedback as well as feedforward code tracking algorithms and proposes the peak tracking (PT methods, which are combinations of both feedback and feedforward structures and utilize the inherent advantages of both structures. We propose and analyze here two variants of PT algorithm: PT with second-order differentiation (Diff2, and PT with Teager Kaiser (TK operator, which will be denoted herein as PT(Diff2 and PT(TK, respectively. In addition to the proposal of the PT methods, the authors propose also an improved early-late-slope (IELS multipath elimination technique which is shown to provide very good mean-time-to-lose-lock (MTLL performance. An implementation of a noncoherent multipath estimating delay locked loop (MEDLL structure is also presented. We also incorporate here an extensive review of the existing feedback and feedforward delay estimation algorithms for direct sequence code division multiple access (DS-CDMA signals in satellite fading channels, by taking into account the impact of binary phase shift keying (BPSK as well as the newly proposed BOC modulation

76 FR 19875 - Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary...

Science.gov (United States)

2011-04-08

..., carriage, or export of any * * * bird, or any part, nest, or egg'' of migratory game birds can take place... 50 CFR Part 20 Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian Tribal Proposals and Requests for 2013 Spring and Summer Migratory Bird...

78 FR 53217 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

Science.gov (United States)

2013-08-28

..., and by what means such birds or any part, nest, or egg thereof may be taken, hunted, captured, killed... Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal...-FXMB1231099BPP0] RIN 1018-AY87 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal...

Satellite tracking and stable isotope analysis link wintering and feeding grounds of North Atlantic baleen whales

NARCIS (Netherlands)

e Silva, Monica Almeida; Prieto, Rui; Gauffier, Pauline; Palsboll, Per; Bérubé, Martine; Colaco, Ana

2017-01-01

Knowledge of the distribution of baleen whales throughout their annual cycle is critical for understanding their ecology, life history and behavior, and for their effective conservation. We combined analysis of stable isotopes (δ15N and δ13C) and satellite tracking data of blue (Balaenoptera

Automatic tracking of dynamical evolutions of oceanic mesoscale eddies with satellite observation data

Science.gov (United States)

Sun, Liang; Li, Qiu-Yang

2017-04-01

The oceanic mesoscale eddies play a major role in ocean climate system. To analyse spatiotemporal dynamics of oceanic mesoscale eddies, the Genealogical Evolution Model (GEM) based on satellite data is developed, which is an efficient logical model used to track dynamic evolution of mesoscale eddies in the ocean. It can distinguish different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, a mononuclear eddy detection method was firstly developed with simple segmentation strategies, e.g. watershed algorithm. The algorithm is very fast by searching the steepest descent path. Second, the GEM uses a two-dimensional similarity vector (i.e. a pair of ratios of overlap area between two eddies to the area of each eddy) rather than a scalar to measure the similarity between eddies, which effectively solves the ''missing eddy" problem (temporarily lost eddy in tracking). Third, for tracking when an eddy splits, GEM uses both "parent" (the original eddy) and "child" (eddy split from parent) and the dynamic processes are described as birth and death of different generations. Additionally, a new look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the number N of look-ahead time steps, and the total number of time steps T, the total computer time is O (LM(N+1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another. Although eddy splitting or merging is ubiquitous in the ocean, they have different geographic distribution in the Northern Pacific Ocean. Both the merging and splitting rates of the eddies are high, especially at the western boundary, in currents and in "eddy deserts". GEM is useful not only for

Satellite tracking reveals habitat use by juvenile green sea turtles Chelonia mydas in the Everglades, Florida, USA

Science.gov (United States)

Hart, Kristen M.; Fujisaki, Ikuko

2010-01-01

We tracked the movements of 6 juvenile green sea turtles captured in coastal areas of southwest Florida within Everglades National Park (ENP) using satellite transmitters for periods of 27 to 62 d in 2007 and 2008 (mean ± SD: 47.7 ± 12.9 d). Turtles ranged in size from 33.4 to 67.5 cm straight carapace length (45.7 ± 12.9 cm) and 4.4 to 40.8 kg in mass (16.0 ± 13.8 kg). These data represent the first satellite tracking data gathered on juveniles of this endangered species at this remote study site, which may represent an important developmental habitat and foraging ground. Satellite tracking results suggested that these immature turtles were resident for several months very close to capture and release sites, in waters from 0 to 10 m in depth. Mean home range for this springtime tracking period as represented by minimum convex polygon (MCP) was 1004.9 ± 618.8 km2 (range 374.1 to 2060.1 km2), with 4 of 6 individuals spending a significant proportion of time within the ENP boundaries in 2008 in areas with dense patches of marine algae. Core use areas determined by 50% kernel density estimates (KDE) ranged from 5.0 to 54.4 km2, with a mean of 22.5 ± 22.1 km2. Overlap of 50% KDE plots for 6 turtles confirmed use of shallow-water nearshore habitats =0.6 m deep within the park boundary. Delineating specific habitats used by juvenile green turtles in this and other remote coastal areas with protected status will help conservation managers to prioritize their efforts and increase efficacy in protecting endangered species.

Mathematical pointing model establishment of the visual tracking theodolite for satellites in two kinds of observation methods.

Science.gov (United States)

Zhang, Yuncheng

The mathematical pointing model is establishment of the visual tracking theodolite for satellites in two kinds of observation methods at Yunnan Observatory, which is related to the digitalisation reform and the optical-electronic technique reform, is introduced respectively in this paper.

From Chilean Patagonia to Galapagos, Ecuador: novel insights on blue whale migratory pathways along the Eastern South Pacific

Directory of Open Access Journals (Sweden)

Rodrigo Hucke-Gaete

2018-04-01

Full Text Available Background The most traditional scheme for migration among baleen whales comprises yearly migrations between productive waters at high latitude summer feeding grounds and warmer waters at lower latitudes where whales calve and mate, but rarely feed. Evidence indicates, however, that large departures from this scheme exist among populations and individuals. Furthermore, for some populations there is virtually no information on migratory pathways and destinations. Such is the case of Chilean blue whales throughout the Eastern South Pacific; hence, the goal of this study was to assess its migratory behavior. Methods Dedicated marine surveys and satellite tagging efforts were undertaken during the austral summer and early autumn on blue whale feeding grounds off Chilean Northern Patagonia (CNP during 2013, 2015 and 2016. Positional data derived from satellite tags regarding movement patterns and behavior were analyzed using Bayesian switching first-difference correlated random walk models. Results We instrumented 10 CNP blue whales with satellite transmitters and documented individual variation in departure time, northbound migratory routes and potential wintering grounds. The onset of migration occurred from mid/late austral autumn to well into the austral winter. Blue whales moved in various directions, but ultimately converged toward a general NW movement direction along a wide corridor exceeding 2,000 km. Area-Restricted Search behavior was exhibited within fjords and channels of CNP and also South of Galapagos Archipelago (GA and northern Peru, but never during migration. Interestingly, dive profiles for one whale that reached GA showed a sharp and consistent increase in depth north of 5°S and extreme deep dives of up to 330 m. Discussion Information derived from satellite tagged blue whales in this study is the first of its kind off the Eastern Southern Pacific. Our results provide valuable information on their migratory timing, routes and

Landscape movements of migratory birds and bats reveal an expanded scale of stopover.

Directory of Open Access Journals (Sweden)

Philip D Taylor

Full Text Available Many species of birds and bats undertake seasonal migrations between breeding and over-wintering sites. En-route, migrants alternate periods of flight with time spent at stopover--the time and space where individuals rest and refuel for subsequent flights. We assessed the spatial scale of movements made by migrants during stopover by using an array of automated telemetry receivers with multiple antennae to track the daily location of individuals over a geographic area ~20 × 40 km. We tracked the movements of 322 individuals of seven migratory vertebrate species (5 passerines, 1 owl and 1 bat during spring and fall migratory stopover on and adjacent to a large lake peninsula. Our results show that many individuals leaving their capture site relocate within the same landscape at some point during stopover, moving as much as 30 km distant from their site of initial capture. We show that many apparent nocturnal departures from stopover sites are not a resumption of migration in the strictest sense, but are instead relocations that represent continued stopover at a broader spatial scale.

Resource tracking within and across continents in long-distance bird migrants

KAUST Repository

Thorup, Kasper

2017-01-05

Migratory birds track seasonal resources across and between continents. We propose a general strategy of tracking the broad seasonal abundance of resources throughout the annual cycle in the longest-distance migrating land birds as an alternative to tracking a certain climatic niche or shorter-term resource surplus occurring, for example, during spring foliation. Whether and how this is possible for complex annual spatiotemporal schedules is not known. New tracking technology enables unprecedented spatial and temporal mapping of long-distance movement of birds. We show that three Palearctic-African species track vegetation greenness throughout their annual cycle, adjusting the timing and direction of migratory movements with seasonal changes in resource availability over Europe and Africa. Common cuckoos maximize the vegetation greenness, whereas red-backed shrikes and thrush nightingales track seasonal surplus in greenness. Our results demonstrate that the longest-distance migrants move between consecutive staging areas even within the wintering region in Africa to match seasonal variation in regional climate. End-of-century climate projections indicate that optimizing greenness would be possible but that vegetation surplus might be more difficult to track in the future.

Resource tracking within and across continents in long-distance bird migrants.

Science.gov (United States)

Thorup, Kasper; Tøttrup, Anders P; Willemoes, Mikkel; Klaassen, Raymond H G; Strandberg, Roine; Vega, Marta Lomas; Dasari, Hari P; Araújo, Miguel B; Wikelski, Martin; Rahbek, Carsten

2017-01-01

Migratory birds track seasonal resources across and between continents. We propose a general strategy of tracking the broad seasonal abundance of resources throughout the annual cycle in the longest-distance migrating land birds as an alternative to tracking a certain climatic niche or shorter-term resource surplus occurring, for example, during spring foliation. Whether and how this is possible for complex annual spatiotemporal schedules is not known. New tracking technology enables unprecedented spatial and temporal mapping of long-distance movement of birds. We show that three Palearctic-African species track vegetation greenness throughout their annual cycle, adjusting the timing and direction of migratory movements with seasonal changes in resource availability over Europe and Africa. Common cuckoos maximize the vegetation greenness, whereas red-backed shrikes and thrush nightingales track seasonal surplus in greenness. Our results demonstrate that the longest-distance migrants move between consecutive staging areas even within the wintering region in Africa to match seasonal variation in regional climate. End-of-century climate projections indicate that optimizing greenness would be possible but that vegetation surplus might be more difficult to track in the future.

Predictive ethoinformatics reveals the complex migratory behaviour of a pelagic seabird, the Manx Shearwater

Science.gov (United States)

Freeman, Robin; Dean, Ben; Kirk, Holly; Leonard, Kerry; Phillips, Richard A.; Perrins, Chris M.; Guilford, Tim

2013-01-01

Understanding the behaviour of animals in the wild is fundamental to conservation efforts. Advances in bio-logging technologies have offered insights into the behaviour of animals during foraging, migration and social interaction. However, broader application of these systems has been limited by device mass, cost and longevity. Here, we use information from multiple logger types to predict individual behaviour in a highly pelagic, migratory seabird, the Manx Shearwater (Puffinus puffinus). Using behavioural states resolved from GPS tracking of foraging during the breeding season, we demonstrate that individual behaviours can be accurately predicted during multi-year migrations from low cost, lightweight, salt-water immersion devices. This reveals a complex pattern of migratory stopovers: some involving high proportions of foraging, and others of rest behaviour. We use this technique to examine three consecutive years of global migrations, revealing the prominence of foraging behaviour during migration and the importance of highly productive waters during migratory stopover. PMID:23635496

75 FR 27143 - Migratory Bird Hunting; Proposed 2010-11 Migratory Game Bird Hunting Regulations (Preliminary...

Science.gov (United States)

2010-05-13

... Convention and the subsequent 1936 Mexico Convention for the Protection of Migratory Birds and Game Mammals... Part III Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed 2010-11 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian...

Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size

Science.gov (United States)

Namgail, Tsewang; Takekawa, John Y.; Balachandran, Sivananinthaperumal; Sathiyaselvam, Ponnusamy; Mundkur, Taej; Newman, Scott H.

2014-01-01

Relationship between species' home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.

Precise orbit determination for BDS3 experimental satellites using iGMAS and MGEX tracking networks

Science.gov (United States)

Li, Xingxing; Yuan, Yongqiang; Zhu, Yiting; Huang, Jiande; Wu, Jiaqi; Xiong, Yun; Zhang, Xiaohong; Li, Xin

2018-04-01

In this contribution, we focus on the precise orbit determination (POD) for BDS3 experimental satellites with the international GNSS Monitoring and Assessment System (iGMAS) and Multi-GNSS Experiment (MGEX) tracking networks. The datasets of DOY (day of year) 001-230 in 2017 are analyzed with different processing strategies. By comparing receiver clock biases and receiver B1I-B3I DCBs, it is confirmed that there is no obvious systematic bias between experimental BDS3 and BDS2 in the common B1I and B3I signals, which indicates that experimental BDS3 and BDS2 can be treated as one system when performing combined POD. With iGMAS-only BDS3 stations, the 24-h overlap RMS of BDS3 + BDS2 + GPS combined POD is 24.3, 16.1 and 8.4 cm in along-track, cross-track and radial components, which is better than BDS3-only POD by 80-90% and better than BDS3+BDS2 combined POD by about 10%. With more stations (totally 20 stations from both iGMAS and MGEX) and the proper ambiguity resolution strategy (GEO ambiguities are float and BDS3 ambiguities are fixed), the performance of BDS3 POD can be further improved to 14.6, 7.9 and 3.7 cm, respectively, in along-track, cross-track and radial components, which is comparable to the performance of BDS2 POD. The 230-day SLR validations of C32, C33 and C34 show that the mean differences of - 3.48 , 7.81 and 8.19 cm can be achieved, while the STD is 13.35, 13.46 and 13.11 cm, respectively. Furthermore, the 230-day overlap comparisons reveal that C31 most likely still uses an orbit-normal mode and exhibits similar orbit modeling problems in orbit-normal periods as found in most of the BDS2 satellites.

77 FR 6949 - Tracking and Data Relay Satellite System (TDRSS) Rates for Non-U.S. Government Customers

Science.gov (United States)

2012-02-10

... Tracking and Data Relay Satellite System (TDRSS) Rates for Non- U.S. Government Customers AGENCY: National... customer flexibility, allowing more efficient use of the system. This notion was never implemented in the... commercial customers, as well as Arctic and Antarctic science programs. In this direct final rule, NASA is...

76 FR 59298 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

Science.gov (United States)

2011-09-26

... such birds or any part, nest, or egg thereof may be taken, hunted, captured, killed, possessed, sold...-0014; 91200-1231-9BPP-L2] RIN 1018-AX34 Migratory Bird Hunting; Migratory Bird Hunting Regulations on... Service, Interior. ACTION: Final rule. SUMMARY: This rule prescribes special late-season migratory bird...

Tracking males and females: investigating protandry throughout the annual cycle in a small migratory songbird

DEFF Research Database (Denmark)

Pedersen, Lykke; Tøttrup, Anders P.; Thorup, Kasper

Protandry, the phenomenon of males arriving earlier at the breeding grounds than females, has been demonstrated in several migratory bird species. The pattern is linked to reproductive success and often ascribed to selection for securing the highest quality territories or mates. Protandry can...

Changes in hydrogen isotope ratios in sequential plumage stages: an implication for the creation of isotope-base maps for tracking migratory birds.

Science.gov (United States)

Duxbury, J M; Holroyd, G L; Muehlenbachs, K

2003-09-01

Accurate reference maps are important in the use of stable-isotopes to track the movements of migratory birds. Reference maps created by the analysis of samples collected from young at the nest site are more accurate than simply referring to naturally occurring patterns of hydrogen isotope ratios created by precipitation cycles. Ratios of hydrogen isotopes in the nutrients incorporated early in the development of young birds can be derived from endogenous, maternal sources. Base-maps should be created with the analysis of tissue samples from hatchlings after local the isotopic signature of exogenous nutrients is dominant. Migratory species such as Peregrine Falcons are known to use endogenous sources in the creation of their eggs, therefore knowledge of what plumage stage best represents the local hydrogen ratios would assist in the planning of nest visits. We conducted diet manipulation experiments involving Japanese Quail and Peregrine Falcons to determine the plumage stage when hydrogen isotope ratios were indicative of a switch in their food source. The natal down of both the quail and falcons reflected the diet of breeding adult females. The hydrogen isotope ratios of a new food source were dominant in the juvenile down of the young falcons, although a further shift was detected in the final juvenile plumage. The juvenile plumage is grown during weeks 3-4 after hatch on Peregrine Falcons. Nest visits for the purpose of collecting feathers for isotope-base-map creation should be made around 4 weeks after the presumed hatch of the young falcons.

Satellite and acoustic tracking device

KAUST Repository

Berumen, Michael L.

2014-02-20

The present invention relates a method and device for tracking movements of marine animals or objects in large bodies of water and across significant distances. The method and device can track an acoustic transmitter attached to an animal or object beneath the ocean surface by employing an unmanned surface vessel equipped with a hydrophone array and GPS receiver.

Satellite and acoustic tracking device

KAUST Repository

Berumen, Michael L.; De la Torre, Pedro

2014-01-01

The present invention relates a method and device for tracking movements of marine animals or objects in large bodies of water and across significant distances. The method and device can track an acoustic transmitter attached to an animal or object beneath the ocean surface by employing an unmanned surface vessel equipped with a hydrophone array and GPS receiver.

Escaping peril: perceived predation risk affects migratory propensity

DEFF Research Database (Denmark)

Hulthén, Kaj; Chapman, Ben B.; Nilsson, P. Anders

2015-01-01

Although migratory plasticity is increasingly documented, the ecological drivers of plasticity are not well understood. Predation risk can influence migratory dynamics, but whether seasonal migrants can adjust their migratory behaviour according to perceived risk is unknown. We used electronic ta......) affected timing but not propensity showing that elevated risk carried over to alter migratory behaviour in the wild. Our key finding demonstrates predator-driven migratory plasticity, highlighting the powerful role of predation risk for migratory decision-making and dynamics.......Although migratory plasticity is increasingly documented, the ecological drivers of plasticity are not well understood. Predation risk can influence migratory dynamics, but whether seasonal migrants can adjust their migratory behaviour according to perceived risk is unknown. We used electronic tags...... in their lake summer habitat and monitored individual migration to connected streams over an entire season. Individuals exposed to increased perceived direct predation risk (i.e. a live predator) showed a higher migratory propensity but no change in migratory timing, while indirect risk (i.e. roach density...

75 FR 18764 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

Science.gov (United States)

2010-04-13

... rulemaking, accomplishments since the Migratory Bird Treaties with Canada and Mexico were amended, and a... the spring and summer months. The Canada and Mexico migratory bird treaties were recently amended for... rural Alaska. The amendments to the Migratory Bird Treaties with Canada and Mexico recognize the...

Orbit Determination of the SELENE Satellites Using Multi-Satellite Data Types and Evaluation of SELENE Gravity Field Models

Science.gov (United States)

Goossens, S.; Matsumoto, K.; Noda, H.; Araki, H.; Rowlands, D. D.; Lemoine, F. G.

2011-01-01

The SELENE mission, consisting of three separate satellites that use different terrestrial-based tracking systems, presents a unique opportunity to evaluate the contribution of these tracking systems to orbit determination precision. The tracking data consist of four-way Doppler between the main orbiter and one of the two sub-satellites while the former is over the far side, and of same-beam differential VLBI tracking between the two sub-satellites. Laser altimeter data are also used for orbit determination. The contribution to orbit precision of these different data types is investigated through orbit overlap analysis. It is shown that using four-way and VLBI data improves orbit consistency for all satellites involved by reducing peak values in orbit overlap differences that exist when only standard two-way Doppler and range data are used. Including laser altimeter data improves the orbit precision of the SELENE main satellite further, resulting in very smooth total orbit errors at an average level of 18m. The multi-satellite data have also resulted in improved lunar gravity field models, which are assessed through orbit overlap analysis using Lunar Prospector tracking data. Improvements over a pre-SELENE model are shown to be mostly in the along-track and cross-track directions. Orbit overlap differences are at a level between 13 and 21 m with the SELENE models, depending on whether l-day data overlaps or I-day predictions are used.

75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

Science.gov (United States)

2010-01-25

...-0082; 91200-1231-9BPP-L2] RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife Service, Interior... Service, are reopening the public comment period on our proposed rule to establish migratory bird...

Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population.

Science.gov (United States)

Pulido, Francisco; Berthold, Peter

2010-04-20

Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic adjustments are largely unknown. This knowledge is still crucial to predict whether populations of migratory birds will adapt to a rapid increase in temperature. We monitored migratory behavior in a population of blackcaps (Sylvia atricapilla) to test for evolutionary responses to recent climate change. Using a common garden experiment in time and captive breeding we demonstrated a genetic reduction in migratory activity and evolutionary change in phenotypic plasticity of migration onset. An artificial selection experiment further revealed that residency will rapidly evolve in completely migratory bird populations if selection for shorter migration distance persists. Our findings suggest that current alterations of the environment are favoring birds wintering closer to the breeding grounds and that populations of migratory birds have strongly responded to these changes in selection. The reduction of migratory activity is probably an important evolutionary process in the adaptation of migratory birds to climate change, because it reduces migration costs and facilitates the rapid adjustment to the shifts in the timing of food availability during reproduction.

Defining management units for cetaceans by combining genetics, morphology, acoustics and satellite tracking

Directory of Open Access Journals (Sweden)

Signe Sveegaard

2015-01-01

Full Text Available Managing animal units is essential in biological conservation and requires spatial and temporal identification of such units. Since even neighbouring populations often have different conservation status and face different levels of anthropogenic pressure, detailed knowledge of population structure, seasonal range and overlap with animals from neighbouring populations is required to manage each unit separately. Previous studies on genetic structure and morphologic separation suggests three distinct populations of harbour porpoises with limited geographic overlap in the North Sea (NS, the Belt Sea (BS and the Baltic Proper (BP region. In this study, we aim to identify a management unit for the BS population of harbour porpoises. We use Argos satellite data and genetics from biopsies of tagged harbour porpoises as well as acoustic data from 40 passive acoustic data loggers to determine management areas with the least overlap between populations and thus the least error when abundance and population status is estimated. Discriminant analysis of the satellite tracking data from the BS and NS populations showed that the best fit of the management unit border during the summer months was an east–west line from Denmark to Sweden at latitude 56.95°N. For the border between BS and BP, satellite tracking data indicate a sharp decline in population density at 13.5°E, with 90% of the locations being west of this line. This was supported by the acoustic data with the average daily detection rate being 27.5 times higher west of 13.5°E as compared to east of 13.5°E. By using this novel multidisciplinary approach, we defined a management unit for the BS harbour porpoise population. We recommend that these boundaries are used for future monitoring efforts of this population under the EU directives. The boundaries may also be used for conservation efforts during the summer months, while seasonal movements of harbour porpoises should be considered during

78 FR 11988 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

Science.gov (United States)

2013-02-21

..., accomplishments since the Migratory Bird Treaties with Canada and Mexico were amended, and a history, was... purposes during the spring and summer months. The Canada and Mexico migratory bird treaties were amended...-0066; FF09M21200-123-FXMB1231099BPP0L2] RIN 1018-AY70 Migratory Bird Subsistence Harvest in Alaska...

Investigating Factors that Generate and Maintain Variation in Migratory Orientation: A Primer for Recent and Future Work.

Science.gov (United States)

Delmore, Kira E; Liedvogel, Miriam

2016-01-01

The amazing accuracy of migratory orientation performance across the animal kingdom is facilitated by the use of magnetic and celestial compass systems that provide individuals with both directional and positional information. Quantitative genetics analyses in several animal systems suggests that migratory orientation has a strong genetic component. Nevertheless, the exact identity of genes controlling orientation remains largely unknown, making it difficult to obtain an accurate understanding of this fascinating behavior on the molecular level. Here, we provide an overview of molecular genetic techniques employed thus far, highlight the pros and cons of various approaches, generalize results from species-specific studies whenever possible, and evaluate how far the field has come since early quantitative genetics studies. We emphasize the importance of examining different levels of molecular control, and outline how future studies can take advantage of high-resolution tracking and sequencing techniques to characterize the genomic architecture of migratory orientation.

Early life events carry over to influence pre-migratory condition in a free-living songbird.

Directory of Open Access Journals (Sweden)

Greg W Mitchell

Full Text Available Conditions experienced during development can have long-term consequences for individual success. In migratory songbirds, the proximate mechanisms linking early life events and survival are not well understood because tracking individuals across stages of the annual cycle can be extremely challenging. In this paper, we first use a 13 year dataset to demonstrate a positive relationship between 1(st year survival and nestling mass in migratory Savannah sparrows (Passerculus sandwichensis. We also use a brood manipulation experiment to show that nestlings from smaller broods have higher mass in the nest relative to individuals from larger broods. Having established these relationships, we then use three years of field data involving multiple captures of individuals throughout the pre-migratory period and a multi-level path model to examine the hypothesis that conditions during development limit survival during migration by affecting an individual's ability to accumulate sufficient lean tissue and fat mass prior to migration. We found a positive relationship between fat mass during the pre-migratory period (Sept-Oct and nestling mass and a negative indirect relationship between pre-migratory fat mass and fledging date. Our results provide the first evidence that conditions during development limit survival during migration through their effect on fat stores. These results are particularly important given recent evidence showing that body condition of songbirds at fledging is affected by climate change and anthropogenic changes to landscape structure.

76 FR 54657 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

Science.gov (United States)

2011-09-01

... Migratory Game Birds in the Contiguous United States, Alaska, Hawaii, Puerto Rico, and the Virgin Islands... Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous United States, Alaska...; migratory game birds in Alaska, Hawaii, Puerto Rico, and the Virgin Islands; and some extended falconry...

Variability and trends of migratory anticyclones affecting the Mediterranean

Science.gov (United States)

Hatzaki, Maria; Flocas, Helena A.; Simmonds, Ian; Kouroutzoglou, John; keay, Kevin; Rudeva, Irina

2014-05-01

A comprehensive climatology of migratory anticyclones affecting the Mediterranean was generated with the aid of the University of Melbourne finding and tracking algorithm, applied to 34 years (1979-2012) of ERA-Interim mean sea level pressures. The algorithm is employed for the first time to study anticyclones in this region, thus, its robustness and reliability in efficiently capturing the individual characteristics of the anticyclonic tracks in the Mediterranean were checked and verified. The tracks and the statistical properties of the migratory systems revealed two major anticyclonic routes: over the northern (i.e. from the Iberian towards the Balkan Peninsula) and over the southern (i.e. the North Africa coast) Mediterranean barriers. A transition of the system density and anticyclogenesis maxima is evident throughout the year from solely continental environments in winter and autumn to also maritime in spring and summer. These variations can be attributed to the seasonal variability of the major anticyclonic systems that are involved in this region. The interannual variability of synoptic systems can be attributed to natural low frequency variability. The interannual variations of the system density and strength were linked to the Northern Hemisphere modes of atmospheric variability; e.g. more (less) antiyclonic tracks are observed around the Mediterranean basin during periods of positive (negative) NAO, with a consequent enhancement (decline) of the pressure field. Moreover, possible trends in the frequency and intensity of the anticyclonic systems were explored in an attempt to examine any impacts of recent global warming conditions. Positive trends of system density, genesis and intensity prevail during the cold period over the greater area around the Mediterranean basin. During summer, the general increase in system density is not followed by a corresponding tendency in the number of the generating systems and the intensity. Regarding the depth of the

78 FR 53199 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

Science.gov (United States)

2013-08-28

... Migratory Game Birds in the Contiguous United States, Alaska, Hawaii, Puerto Rico, and the Virgin Islands... Seasons and Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous United States... seasons; migratory game birds in Alaska, Hawaii, Puerto Rico, and the Virgin Islands; youth waterfowl day...

77 FR 53751 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

Science.gov (United States)

2012-08-31

... Migratory Game Birds in the Contiguous United States, Alaska, Hawaii, Puerto Rico, and the Virgin Islands... Seasons and Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous United States... seasons; migratory game birds in Alaska, Hawaii, Puerto Rico, and the Virgin Islands; youth waterfowl day...

75 FR 53226 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

Science.gov (United States)

2010-08-31

... Limits for Certain Migratory Game Birds in the Contiguous United States, Alaska, Hawaii, Puerto Rico, and...; sandhill cranes; sea ducks; early (September) waterfowl seasons; migratory game birds in Alaska, Hawaii... regulations for hunting migratory game birds under Sec. Sec. 20.101 through 20.107, 20.109, and 20.110 of...

Understanding the migratory orientation program of birds

DEFF Research Database (Denmark)

Thorup, Kasper; Holland, Richard A.; Tøttrup, Anders P.

2010-01-01

in migrating raptors (satellite telemetry) and thrushes (conventional telemetry), highlighting that findings in the natural setting may not always be as expected on the basis of cage-experiments. Furthermore, field tracking methods combined with experimental approaches have finally allowed for an extension...

A Palaearctic migratory raptor species tracks shifting prey availability within its wintering range in the Sahel

NARCIS (Netherlands)

Trierweiler, Christiane; Mullie, Wim C.; Drent, Rudi H.; Exo, Klaus-Michael; Komdeur, Jan; Bairlein, Franz; Harouna, Abdoulaye; de Bakker, Marinus; Koks, Ben J.

Mid-winter movements of up to several hundreds of kilometres are typical for many migratory bird species wintering in Africa. Unpredictable temporary food concentrations are thought to result in random movements of such birds, whereas resightings and recoveries of marked birds suggest some degree of

78 FR 65578 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

Science.gov (United States)

2013-11-01

...-0037; FF09M21200-134-FXMB1231099BPP0] RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We revise the regulations that allow control of depredating birds in California. We specify the counties in...

An overview of migratory birds in Brazil

Directory of Open Access Journals (Sweden)

Marina Somenzari

2018-03-01

Full Text Available Abstract We reviewed the occurrences and distributional patterns of migratory species of birds in Brazil. A species was classified as migratory when at least part of its population performs cyclical, seasonal movements with high fidelity to its breeding grounds. Of the 1,919 species of birds recorded in Brazil, 198 (10.3% are migratory. Of these, 127 (64% were classified as Migratory and 71 (36% as Partially Migratory. A few species (83; 4.3% were classified as Vagrant and eight (0,4% species could not be defined due to limited information available, or due to conflicting data.

77 FR 19164 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

Science.gov (United States)

2012-03-30

... RIN 0648-XB121 Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery..., United States Virgin Islands (USVI) St. Thomas, USVI, San Juan, Puerto Rico (PR), Ponce, PR, and Mayaguez... INFORMATION CONTACT: Greg Fairclough or Randy Blankinship at 727-824-5399. SUPPLEMENTARY INFORMATION: Atlantic...

76 FR 59271 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

Science.gov (United States)

2011-09-26

...-0014; 91200-1231-9BPP-L2] RIN 1018-AX34 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule... of migratory birds is prohibited unless specifically provided for by annual regulations. This rule...

Automated cell tracking and analysis in phase-contrast videos (iTrack4U): development of Java software based on combined mean-shift processes.

Science.gov (United States)

Cordelières, Fabrice P; Petit, Valérie; Kumasaka, Mayuko; Debeir, Olivier; Letort, Véronique; Gallagher, Stuart J; Larue, Lionel

2013-01-01

Cell migration is a key biological process with a role in both physiological and pathological conditions. Locomotion of cells during embryonic development is essential for their correct positioning in the organism; immune cells have to migrate and circulate in response to injury. Failure of cells to migrate or an inappropriate acquisition of migratory capacities can result in severe defects such as altered pigmentation, skull and limb abnormalities during development, and defective wound repair, immunosuppression or tumor dissemination. The ability to accurately analyze and quantify cell migration is important for our understanding of development, homeostasis and disease. In vitro cell tracking experiments, using primary or established cell cultures, are often used to study migration as cells can quickly and easily be genetically or chemically manipulated. Images of the cells are acquired at regular time intervals over several hours using microscopes equipped with CCD camera. The locations (x,y,t) of each cell on the recorded sequence of frames then need to be tracked. Manual computer-assisted tracking is the traditional method for analyzing the migratory behavior of cells. However, this processing is extremely tedious and time-consuming. Most existing tracking algorithms require experience in programming languages that are unfamiliar to most biologists. We therefore developed an automated cell tracking program, written in Java, which uses a mean-shift algorithm and ImageJ as a library. iTrack4U is a user-friendly software. Compared to manual tracking, it saves considerable amount of time to generate and analyze the variables characterizing cell migration, since they are automatically computed with iTrack4U. Another major interest of iTrack4U is the standardization and the lack of inter-experimenter differences. Finally, iTrack4U is adapted for phase contrast and fluorescent cells.

Automated cell tracking and analysis in phase-contrast videos (iTrack4U: development of Java software based on combined mean-shift processes.

Directory of Open Access Journals (Sweden)

Fabrice P Cordelières

Full Text Available Cell migration is a key biological process with a role in both physiological and pathological conditions. Locomotion of cells during embryonic development is essential for their correct positioning in the organism; immune cells have to migrate and circulate in response to injury. Failure of cells to migrate or an inappropriate acquisition of migratory capacities can result in severe defects such as altered pigmentation, skull and limb abnormalities during development, and defective wound repair, immunosuppression or tumor dissemination. The ability to accurately analyze and quantify cell migration is important for our understanding of development, homeostasis and disease. In vitro cell tracking experiments, using primary or established cell cultures, are often used to study migration as cells can quickly and easily be genetically or chemically manipulated. Images of the cells are acquired at regular time intervals over several hours using microscopes equipped with CCD camera. The locations (x,y,t of each cell on the recorded sequence of frames then need to be tracked. Manual computer-assisted tracking is the traditional method for analyzing the migratory behavior of cells. However, this processing is extremely tedious and time-consuming. Most existing tracking algorithms require experience in programming languages that are unfamiliar to most biologists. We therefore developed an automated cell tracking program, written in Java, which uses a mean-shift algorithm and ImageJ as a library. iTrack4U is a user-friendly software. Compared to manual tracking, it saves considerable amount of time to generate and analyze the variables characterizing cell migration, since they are automatically computed with iTrack4U. Another major interest of iTrack4U is the standardization and the lack of inter-experimenter differences. Finally, iTrack4U is adapted for phase contrast and fluorescent cells.

Polar bears from space: Assessing satellite imagery as a tool to track Arctic wildlife

Science.gov (United States)

Stapleton, Seth P.; LaRue, Michelle A.; Lecomte, Nicolas; Atkinson, Stephen N.; Garshelis, David L.; Porter, Claire; Atwood, Todd C.

2014-01-01

Development of efficient techniques for monitoring wildlife is a priority in the Arctic, where the impacts of climate change are acute and remoteness and logistical constraints hinder access. We evaluated high resolution satellite imagery as a tool to track the distribution and abundance of polar bears. We examined satellite images of a small island in Foxe Basin, Canada, occupied by a high density of bears during the summer ice-free season. Bears were distinguished from other light-colored spots by comparing images collected on different dates. A sample of ground-truthed points demonstrated that we accurately classified bears. Independent observers reviewed images and a population estimate was obtained using mark- recapture models. This estimate (N: 94; 95% Confidence Interval: 92-105) was remarkably similar to an abundance estimate derived from a line transect aerial survey conducted a few days earlier (N: 102; 95% CI: 69-152). Our findings suggest that satellite imagery is a promising tool for monitoring polar bears on land, with implications for use with other Arctic wildlife. Large scale applications may require development of automated detection processes to expedite review and analysis. Future research should assess the utility of multi-spectral imagery and examine sites with different environmental characteristics.

Polar bears from space: assessing satellite imagery as a tool to track Arctic wildlife.

Directory of Open Access Journals (Sweden)

Seth Stapleton

Full Text Available Development of efficient techniques for monitoring wildlife is a priority in the Arctic, where the impacts of climate change are acute and remoteness and logistical constraints hinder access. We evaluated high resolution satellite imagery as a tool to track the distribution and abundance of polar bears. We examined satellite images of a small island in Foxe Basin, Canada, occupied by a high density of bears during the summer ice-free season. Bears were distinguished from other light-colored spots by comparing images collected on different dates. A sample of ground-truthed points demonstrated that we accurately classified bears. Independent observers reviewed images and a population estimate was obtained using mark-recapture models. This estimate (N: 94; 95% Confidence Interval: 92-105 was remarkably similar to an abundance estimate derived from a line transect aerial survey conducted a few days earlier (N: 102; 95% CI: 69-152. Our findings suggest that satellite imagery is a promising tool for monitoring polar bears on land, with implications for use with other Arctic wildlife. Large scale applications may require development of automated detection processes to expedite review and analysis. Future research should assess the utility of multi-spectral imagery and examine sites with different environmental characteristics.

Polar bears from space: assessing satellite imagery as a tool to track Arctic wildlife.

Science.gov (United States)

Stapleton, Seth; LaRue, Michelle; Lecomte, Nicolas; Atkinson, Stephen; Garshelis, David; Porter, Claire; Atwood, Todd

2014-01-01

Development of efficient techniques for monitoring wildlife is a priority in the Arctic, where the impacts of climate change are acute and remoteness and logistical constraints hinder access. We evaluated high resolution satellite imagery as a tool to track the distribution and abundance of polar bears. We examined satellite images of a small island in Foxe Basin, Canada, occupied by a high density of bears during the summer ice-free season. Bears were distinguished from other light-colored spots by comparing images collected on different dates. A sample of ground-truthed points demonstrated that we accurately classified bears. Independent observers reviewed images and a population estimate was obtained using mark-recapture models. This estimate (N: 94; 95% Confidence Interval: 92-105) was remarkably similar to an abundance estimate derived from a line transect aerial survey conducted a few days earlier (N: 102; 95% CI: 69-152). Our findings suggest that satellite imagery is a promising tool for monitoring polar bears on land, with implications for use with other Arctic wildlife. Large scale applications may require development of automated detection processes to expedite review and analysis. Future research should assess the utility of multi-spectral imagery and examine sites with different environmental characteristics.

Resource tracking within and across continents in long-distance bird migrants

KAUST Repository

Thorup, Kasper; Tø ttrup, Anders P.; Willemoes, Mikkel; Klaassen, Raymond H. G.; Strandberg, Roine; Vega, Marta Lomas; Dasari, Hari Prasad; Araú jo, Miguel B.; Wikelski, Martin; Rahbek, Carsten

2017-01-01

spatial and temporal mapping of long-distance movement of birds. We show that three Palearctic-African species track vegetation greenness throughout their annual cycle, adjusting the timing and direction of migratory movements with seasonal changes

77 FR 59842 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

Science.gov (United States)

2012-10-01

... vessels permitted in the Atlantic tunas General category in Puerto Rico and 10 in the U.S. Virgin Islands... [Docket No. 080603729-2454-02] RIN 0648-AW83 Atlantic Highly Migratory Species; 2006 Consolidated Highly... management plan (FMP) amendment addresses Atlantic highly migratory species (HMS) fishery management measures...

76 FR 65700 - Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast...

Science.gov (United States)

2011-10-24

.... Virgin Islands and Puerto Rico, and each of the constituent interstate commissions: the Atlantic States... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA776 Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast Data, Assessment...

Tracking- and Scintillation-Aware Channel Model for GEO Satellite to Land Mobile Terminals at Ku-Band

Directory of Open Access Journals (Sweden)

Ali M. Al-Saegh

2015-01-01

Full Text Available Recent advances in satellite to land mobile terminal services and technologies, which utilize high frequencies with directional antennas, have made the design of an appropriate model for land mobile satellite (LMS channels a necessity. This paper presents LMS channel model at Ku-band with features that enhance accuracy, comprehensiveness, and reliability. The effect of satellite tracking loss at different mobile terminal speeds is considered for directional mobile antenna systems, a reliable tropospheric scintillation model for an LMS scenario at tropical and temperate regions is presented, and finally a new quality indicator module for different modulation and coding schemes is included. The proposed extended LMS channel (ELMSC model is designed based on actual experimental measurements and can be applied to narrow- and wide-band signals at different regions and at different speeds and multichannel states. The proposed model exhibits lower root mean square error (RMSE and significant performance observation compared with the conventional model in terms of the signal fluctuations, fade depth, signal-to-noise ratio (SNR, and quality indicators accompanied for several transmission schemes.

75 FR 58993 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

Science.gov (United States)

2010-09-24

... Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds; Final Rule #0;#0;Federal...-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for...

Mates but not sexes differ in migratory niche in a monogamous penguin species.

Science.gov (United States)

Thiebot, Jean-Baptiste; Bost, Charles-André; Dehnhard, Nina; Demongin, Laurent; Eens, Marcel; Lepoint, Gilles; Cherel, Yves; Poisbleau, Maud

2015-09-01

Strong pair bonds generally increase fitness in monogamous organisms, but may also underlie the risk of hampering it when re-pairing fails after the winter season. We investigated whether partners would either maintain contact or offset this risk by exploiting sex-specific favourable niches during winter in a migratory monogamous seabird, the southern rockhopper penguin Eudyptes chrysocome. Using light-based geolocation, we show that although the spatial distribution of both sexes largely overlapped, pair-wise mates were located on average 595 ± 260 km (and up to 2500 km) apart during winter. Stable isotope data also indicated a marked overlap between sex-specific isotopic niches (δ¹³C and δ¹⁵N values) but a segregation of the feeding habitats (δ¹³C values) within pairs. Importantly, the tracked females remained longer (12 days) at sea than males, but all re-mated with their previous partners after winter. Our study provides multiple evidence that migratory species may well demonstrate pair-wise segregation even in the absence of sex-specific winter niches (spatial and isotopic). We suggest that dispersive migration patterns with sex-biased timings may be a sufficient proximal cause for generating such a situation in migratory animals.

78 FR 65974 - Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast...

Science.gov (United States)

2013-11-04

... Management Councils, the 18 states in the Atlantic and Gulf of Mexico, both the U.S. Virgin Islands and... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC935 Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast Data, Assessment...

77 FR 58627 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

Science.gov (United States)

2012-09-21

... Service 50 CFR Part 20 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds; Final Rule #0;#0;Federal Register / Vol. 77 , No. 184 / Friday, September 21, 2012... Part 20 [Docket No. FWS-R9-MB-2012-0005; FF09M21200-123-FXMB1231099BPP0L2] RIN 1018-AX97 Migratory Bird...

Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population

OpenAIRE

Pulido, Francisco; Berthold, Peter

2010-01-01

Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic adjustments are largely unknown. This knowledge is still crucial to predict whether populations of migratory birds will adapt to a rapid increase in temperature. We monitored migratory behavior in...

African vultures don't follow migratory herds: scavenger habitat use is not mediated by prey abundance.

Directory of Open Access Journals (Sweden)

Corinne J Kendall

Full Text Available The ongoing global decline in vulture populations raises major conservation concerns, but little is known about the factors that mediate scavenger habitat use, in particular the importance of abundance of live prey versus prey mortality. We test this using data from the Serengeti-Mara ecosystem in East Africa. The two hypotheses that prey abundance or prey mortality are the main drivers of vulture habitat use provide alternative predictions. If vultures select areas based only on prey abundance, we expect tracked vultures to remain close to herds of migratory wildebeest regardless of season. However, if vultures select areas where mortality rates are greatest then we expect vultures to select the driest regions, where animals are more likely to die of starvation, and to be attracted to migratory wildebeest only during the dry season when wildebeest mortality is greatest. We used data from GSM-GPS transmitters to assess the relationship between three vulture species and migratory wildebeest in the Mara-Serengeti ecosystem. Results indicate that vultures preferentially cluster around migratory herds only during the dry season, when herds experience their highest mortality. Additionally during the wet season, Ruppell's and Lappet-faced vultures select relatively dry areas, based on Normalized Difference Vegetation Index, whereas White-backed vultures preferred wetter areas during the wet season. Differences in habitat use among species may mediate coexistence in this scavenger guild. In general, our results suggest that prey abundance is not the primary driver of avian scavenger habitat use. The apparent reliance of vultures on non-migratory ungulates during the wet season has important conservation implications for vultures in light of on-going declines in non-migratory ungulate species and use of poisons in unprotected areas.

Optical Tracking Data Validation and Orbit Estimation for Sparse Observations of Satellites by the OWL-Net.

Science.gov (United States)

Choi, Jin; Jo, Jung Hyun; Yim, Hong-Suh; Choi, Eun-Jung; Cho, Sungki; Park, Jang-Hyun

2018-06-07

An Optical Wide-field patroL-Network (OWL-Net) has been developed for maintaining Korean low Earth orbit (LEO) satellites' orbital ephemeris. The OWL-Net consists of five optical tracking stations. Brightness signals of reflected sunlight of the targets were detected by a charged coupled device (CCD). A chopper system was adopted for fast astrometric data sampling, maximum 50 Hz, within a short observation time. The astrometric accuracy of the optical observation data was validated with precise orbital ephemeris such as Consolidated Prediction File (CPF) data and precise orbit determination result with onboard Global Positioning System (GPS) data from the target satellite. In the optical observation simulation of the OWL-Net for 2017, an average observation span for a single arc of 11 LEO observation targets was about 5 min, while an average optical observation separation time was 5 h. We estimated the position and velocity with an atmospheric drag coefficient of LEO observation targets using a sequential-batch orbit estimation technique after multi-arc batch orbit estimation. Post-fit residuals for the multi-arc batch orbit estimation and sequential-batch orbit estimation were analyzed for the optical measurements and reference orbit (CPF and GPS data). The post-fit residuals with reference show few tens-of-meters errors for in-track direction for multi-arc batch and sequential-batch orbit estimation results.

Mapping global diversity patterns for migratory birds.

Directory of Open Access Journals (Sweden)

Marius Somveille

Full Text Available Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions

Science.gov (United States)

Macmynowski, Dena P.; Root, Terry L.

2007-05-01

The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979 2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species’ arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species’ responses to changing climate as well as evaluate the underlying biological mechanisms.

77 FR 58443 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

Science.gov (United States)

2012-09-20

... to move toward a more holistic and uniform approach to Canada goose harvest management across the... selections to: Chief, Division of Migratory Bird Management, U.S. Fish and Wildlife Service, ms MBSP-4107... address above, or from the Division of Migratory Bird Management's Web site at http://www.fws.gov...

Signature of biased range in the non-dynamical Chern-Simons modified gravity and its measurements with satellite-satellite tracking missions: theoretical studies

Science.gov (United States)

Qiang, Li-E.; Xu, Peng

2015-08-01

Having great accuracy in the range and range rate measurements, the GRACE mission and the planed GRACE follow on mission can in principle be employed to place strong constraints on certain relativistic gravitational theories. In this paper, we work out the range observable of the non-dynamical Chern-Simons modified gravity for the satellite-to-satellite tracking (SST) measurements. We find out that a characteristic time accumulating range signal appears in non-dynamical Chern-Simons gravity, which has no analogue found in the standard parity-preserving metric theories of gravity. The magnitude of this Chern-Simons range signal will reach a few times of cm for each free flight of these SST missions, here is the dimensionless post-Newtonian parameter of the non-dynamical Chern-Simons theory. Therefore, with the 12 years data of the GRACE mission, one expects that the mass scale of the non-dynamical Chern-Simons gravity could be constrained to be larger than eV. For the GRACE FO mission that scheduled to be launched in 2017, the much stronger bound that eV is expected.

Working out Migratory Attitudes Scale of Personality

Directory of Open Access Journals (Sweden)

S A Kuznetsova

2014-12-01

Full Text Available In the article the first cycle of working out the migratory attitude scale is presented. The results of the research of the migratory attitudes in Magadan young people show the adequacy of theoretical hypotheses and the validity of the estimation procedure. The scale application has rendered possible to obtain the data about the age features of migratory attitudes.

Migrating swans profit from favourable changes in wind conditions at low altitude

NARCIS (Netherlands)

Klaassen, M; Beekman, JH; Kontiokorpi, J; Mulder, RJW; Nolet, BA

Because energy reserves limit flight range, wind assistance may be of crucial importance for migratory birds. We tracked eight Bewick's swans Cygnus columbianus bewickii, using 95-g satellite transmitters with altimeters and activity sensors, during their spring migration from Denmark to northern

Migrating swans profit from favourable changes in wind conditions at low altitude

NARCIS (Netherlands)

Klaassen, M.R.J.; Beekman, J.H.; Kontiokorpi, J.; Mulder, R.J.W.; Nolet, B.A.

2004-01-01

Because energy reserves limit flight range, wind assistance may be of crucial importance for migratory birds. We tracked eight Bewicks swans Cygnus columbianus bewickii, using 95-g satellite transmitters with altimeters and activity sensors, during their spring migration from Denmark to northern

Astrometry and Geostationary Satellites in Venezuela

Science.gov (United States)

Lacruz, E.; Abad, C.

2015-10-01

We present the current status and the first results of the astrometric project CIDA - ABAE for tracking geo-stationary satellites. This project aims to determine a preliminary orbit for the Venezuelan satellite VENESAT-1, using astrometric positions obtained from an optical telescope. The results presented here are based on observations from the Luepa space tracking ground station in Venezuela, which were processed using astrometric procedures.

78 FR 75321 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

Science.gov (United States)

2013-12-11

... the taking of migratory birds and the collection of their eggs, by the indigenous inhabitants of the... particular land ownership, but applies to the harvesting of migratory bird resources throughout Alaska. A... ensure an effective and meaningful role for Alaska's indigenous inhabitants in the conservation of...

Satellite telemetry reveals higher fishing mortality rates than previously estimated, suggesting overfishing of an apex marine predator.

Science.gov (United States)

Byrne, Michael E; Cortés, Enric; Vaudo, Jeremy J; Harvey, Guy C McN; Sampson, Mark; Wetherbee, Bradley M; Shivji, Mahmood

2017-08-16

Overfishing is a primary cause of population declines for many shark species of conservation concern. However, means of obtaining information on fishery interactions and mortality, necessary for the development of successful conservation strategies, are often fisheries-dependent and of questionable quality for many species of commercially exploited pelagic sharks. We used satellite telemetry as a fisheries-independent tool to document fisheries interactions, and quantify fishing mortality of the highly migratory shortfin mako shark ( Isurus oxyrinchus ) in the western North Atlantic Ocean. Forty satellite-tagged shortfin mako sharks tracked over 3 years entered the Exclusive Economic Zones of 19 countries and were harvested in fisheries of five countries, with 30% of tagged sharks harvested. Our tagging-derived estimates of instantaneous fishing mortality rates ( F = 0.19-0.56) were 10-fold higher than previous estimates from fisheries-dependent data (approx. 0.015-0.024), suggesting data used in stock assessments may considerably underestimate fishing mortality. Additionally, our estimates of F were greater than those associated with maximum sustainable yield, suggesting a state of overfishing. This information has direct application to evaluations of stock status and for effective management of populations, and thus satellite tagging studies have potential to provide more accurate estimates of fishing mortality and survival than traditional fisheries-dependent methodology. © 2017 The Author(s).

[Migratory circuits in western Mexico].

Science.gov (United States)

Durand, J

1986-11-01

The author examines patterns of internal and international migration in western Mexico. "Drawing on data from different sources and statistics, the essay demonstrates the importance of both types of migration, the changes in endogenous and exogenous factors which have affected the life and the migratory patterns of the population of this region. The migratory circuit being a flow not only of persons, but of goods and capital as well, the cities, specifically that of Guadalajara, have a strategic importance. They fulfill various functions and have become the backbone of the migratory process: they serve as centers for attracting and 'hosting' internal migrants as well as places of origin for other migrants; jumping-off points for international migrants; and the milieu in which many returning migrants of rural origin settle." (SUMMARY IN ENG AND FRE) excerpt

Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots.

Science.gov (United States)

Queiroz, Nuno; Humphries, Nicolas E; Mucientes, Gonzalo; Hammerschlag, Neil; Lima, Fernando P; Scales, Kylie L; Miller, Peter I; Sousa, Lara L; Seabra, Rui; Sims, David W

2016-02-09

Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.

50 CFR 20.25 - Wanton waste of migratory game birds.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Wanton waste of migratory game birds. 20... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.25 Wanton waste of migratory game birds. No person shall kill or cripple any migratory game bird pursuant to this part without...

Defining management units for cetaceans by combining genetics, morphlogy, acoustics and satellite tracking

DEFF Research Database (Denmark)

Sveegaard, Signe; Galatius, Anders; Dietz, Rune

2015-01-01

Managing animal units is essential in biological conservation and requires spatial and temporal identification of such units. Since even neighbouring populations often have different conservation status and face different levels of anthropogenic pressure, detailed knowledge of population structure......, seasonal range and overlap with animals from neighbouring populations is required to manage each unit separately. Previous studies on genetic structure and morphologic separation suggests three distinct populations of harbour porpoises with limited geographic overlap in the North Sea (NS), the Belt Sea (BS...... with the least overlap between populations and thus the least error when abundance and population status is estimated. Discriminant analysis of the satellite tracking data from the BS and NS populations showed that the best fit of the management unit border during the summer months was an east-west line from...

Kinematic Orbit Determination Method Optimization and Test Analysis for BDS Satellites with Short-arc Tracking Data

Directory of Open Access Journals (Sweden)

GUO Rui

2017-04-01

Full Text Available Rapid orbit recovery is a puzzle for the BDS satellites after orbit maneuvers. Two kinematic orbit determination methods are studied, with two orbit determination models being established. The receiver system error and serious multipath error exist in the BDS system. The co-location method is proposed to estimate and calibrate the receiver system errors. A CNMC (code noise and multipath correction method is introduced to weaken the multipath error. Therefore the data quality is controlled efficiently for the receivers in the short tracking arc. The GEO/IGSO/MEO real data is emploied to carry out tests and validation. Using 10 min short tracking arc, the kinematic precise orbit determination accuracy is about 3.27 m for the GEOs, and 8.19 m for the IGSOs, and 5.9 m for the MEOs. Rapid orbit determination is achieved, which satisfying the orbit requirements from the BDS RDSS services. The kinematic precise orbit determination method also supports the RDSS service walking up to the global world.

Multi-GNSS orbit determination using satellite laser ranging

Science.gov (United States)

Bury, Grzegorz; Sośnica, Krzysztof; Zajdel, Radosław

2018-04-01

Galileo, BeiDou, QZSS, and NavIC are emerging global navigation satellite systems (GNSSs) and regional navigation satellite systems all of which are equipped with laser retroreflector arrays for range measurements. This paper summarizes the GNSS-intensive tracking campaigns conducted by the International Laser Ranging Service and provides results from multi-GNSS orbit determination using solely SLR observations. We consider the whole constellation of GLONASS, all active Galileo, four BeiDou satellites: 1 MEO, 3 IGSO, and one QZSS. We analyze the influence of the number of SLR observations on the quality of the 3-day multi-GNSS orbit solution. About 60 SLR observations are needed for obtaining MEO orbits of sufficient quality with the root mean square (RMS) of 3 cm for the radial component when compared to microwave-based orbits. From the analysis of a minimum number of tracking stations, when considering the 3-day arcs, 5 SLR stations do not provide a sufficient geometry of observations. The solution obtained using ten stations is characterized with RMS of 4, 9, and 18 cm in the radial, along-track, and cross-track direction, respectively, for MEO satellites. We also investigate the impact of the length of orbital arc on the quality of SLR-derived orbits. Hence, 5- and 7-day arcs constitute the best solution, whereas 3-day arcs are of inferior quality due to an insufficient number of SLR observations and 9-day arcs deteriorate the along-track component. The median RMS from the comparison between 7-day orbital arcs determined using SLR data with microwave-based orbits assumes values in the range of 3-4, 11-16, and 15-27 cm in radial, along-track, and cross-track, respectively, for MEO satellites. BeiDou IGSO and QZSS are characterized by RMS values higher by a factor of 8 and 24, respectively, than MEO orbits.

Migratory decisions in birds: Extent of genetic versus environmental control

Science.gov (United States)

Ogonowski, M.S.; Conway, C.J.

2009-01-01

Migration is one of the most spectacular of animal behaviors and is prevalent across a broad array of taxa. In birds, we know much about the physiological basis of how birds migrate, but less about the relative contribution of genetic versus environmental factors in controlling migratory tendency. To evaluate the extent to which migratory decisions are genetically determined, we examined whether individual western burrowing owls (Athene cunicularia hypugaea) change their migratory tendency from one year to the next at two sites in southern Arizona. We also evaluated the heritability of migratory decisions by using logistic regression to examine the association between the migratory tendency of burrowing owl parents and their offspring. The probability of migrating decreased with age in both sexes and adult males were less migratory than females. Individual owls sometimes changed their migratory tendency from one year to the next, but changes were one-directional: adults that were residents during winter 2004-2005 remained residents the following winter, but 47% of adults that were migrants in winter 2004-2005 became residents the following winter. We found no evidence for an association between the migratory tendency of hatch-year owls and their male or female parents. Migratory tendency of hatch-year owls did not differ between years, study sites or sexes or vary by hatching date. Experimental provision of supplemental food did not affect these relationships. All of our results suggest that heritability of migratory tendency in burrowing owls is low, and that intraspecific variation in migratory tendency is likely due to: (1) environmental factors, or (2) a combination of environmental factors and non-additive genetic variation. The fact that an individual's migratory tendency can change across years implies that widespread anthropogenic changes (i.e., climate change or changes in land use) could potentially cause widespread changes in the migratory tendency of

A Continent-Wide Migratory Divide in North American Breeding Barn Swallows (Hirundo rustica.

Directory of Open Access Journals (Sweden)

Keith A Hobson

Full Text Available Populations of most North American aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. We used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (Hirdundo rustica; n = 27 from populations across North America to determine their migratory connectivity. We identified an east-west continental migratory divide for barn swallows with birds from western regions (Washington State, USA (n = 8 and Saskatchewan, Canada (n = 5 traveling shorter distances to wintering areas ranging from Oregon to northern Colombia than eastern populations (Ontario (n = 3 and New Brunswick (n = 10, Canada which wintered in South America south of the Amazon basin. A single swallow from a stable population in Alabama shared a similar migration route to eastern barn swallows but wintered farther north in northeast Brazil indicating a potential leap frog pattern migratory among eastern birds. Six of 9 (67% birds from the two eastern populations and Alabama underwent a loop migration west of fall migration routes including around the Gulf of Mexico travelling a mean of 2,224 km and 722 km longer on spring migration, respectively. Longer migration distances, including the requirement to cross the Caribbean Sea and Gulf of Mexico and subsequent shorter sedentary wintering periods, may exacerbate declines for populations breeding in northeastern North America.

50 CFR 20.40 - Gift of migratory game birds.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Gift of migratory game birds. 20.40... (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No...

Mobility management in satellite networks

Science.gov (United States)

Johanson, Gary A.

1995-01-01

This paper addresses the methods used or proposed for use in multi-beam and/or multi-satellite networks designed to provide Mobile Satellite Services (MSS). Specific topics include beam crossover in the North American Mobile Satellite (MSAT) system as well as registration and live call hand-off for a multi-regional geosynchronous (GEO) satellite based system and a global coverage Low Earth Orbiting (LEO) system. In the MSAT system, the individual satellite beams cover very large geographic areas so the need for live call hand-off was not anticipated. This paper discusses the methods used to keep track of the beam location of the users so that incoming call announcements or other messages may be directed to them. Proposed new GEO systems with large numbers of beams will provide much smaller geographic coverage in individual beams and thus the need arises to keep track of the user's location as well as to provide live call hand-off as the user traverses from beam to beam. This situation also occurs in proposed LEO systems where the problems are worsened by the need for satellite to satellite hand-off as well as beam to beam hand-off within a single satellite. The paper discusses methods to accomplish these handoffs and proposes system architectures to address the various hand-off scenarios.

Improving BeiDou precise orbit determination using observations of onboard MEO satellite receivers

Science.gov (United States)

Ge, Haibo; Li, Bofeng; Ge, Maorong; Shen, Yunzhong; Schuh, Harald

2017-12-01

In recent years, the precise orbit determination (POD) of the regional Chinese BeiDou Navigation Satellite System (BDS) has been a hot spot because of its special constellation consisting of five geostationary earth orbit (GEO) satellites and five inclined geosynchronous satellite orbit (IGSO) satellites besides four medium earth orbit (MEO) satellites since the end of 2012. GEO and IGSO satellites play an important role in regional BDS applications. However, this brings a great challenge to the POD, especially for the GEO satellites due to their geostationary orbiting. Though a number of studies have been carried out to improve the POD performance of GEO satellites, the result is still much worse than that of IGSO and MEO, particularly in the along-track direction. The major reason is that the geostationary characteristic of a GEO satellite results in a bad geometry with respect to the ground tracking network. In order to improve the tracking geometry of the GEO satellites, a possible strategy is to mount global navigation satellite system (GNSS) receivers on MEO satellites to collect the signals from GEO/IGSO GNSS satellites so as that these observations can be used to improve GEO/IGSO POD. We extended our POD software package to simulate all the related observations and to assimilate the MEO-onboard GNSS observations in orbit determination. Based on GPS and BDS constellations, simulated studies are undertaken for various tracking scenarios. The impact of the onboard GNSS observations is investigated carefully and presented in detail. The results show that MEO-onboard observations can significantly improve the orbit precision of GEO satellites from metres to decimetres, especially in the along-track direction. The POD results of IGSO satellites also benefit from the MEO-onboard data and the precision can be improved by more than 50% in 3D direction.

Use of along-track magnetic field differences in lithospheric field modelling

DEFF Research Database (Denmark)

Kotsiaros, Stavros; Finlay, Chris; Olsen, Nils

2015-01-01

. Experiments in modelling the Earth's lithospheric magnetic field with along-track differences are presented here as a proof of concept. We anticipate that use of such along-track differences in combination with east–west field differences, as are now provided by the Swarm satellite constellation......We demonstrate that first differences of polar orbiting satellite magnetic data in the along-track direction can be used to obtain high resolution models of the lithospheric field. Along-track differences approximate the north–south magnetic field gradients for non-polar latitudes. In a test case......, using 2 yr of low altitude data from the CHAMP satellite, we show that use of along-track differences of vector field data results in an enhanced recovery of the small scale lithospheric field, compared to the use of the vector field data themselves. We show that the along-track technique performs...

Moving across the border: Modeling migratory bat populations

Science.gov (United States)

Ruscena, Wiederholt; López-Hoffman, Laura; Cline, Jon; Medellin, Rodrigo; Cryan, Paul M.; Russell, Amy; McCracken, Gary; Diffendorfer, Jay; Semmens, Darius J.

2013-01-01

The migration of animals across long distances and between multiple habitats presents a major challenge for conservation. For the migratory Mexican free-tailed bat (Tadarida brasiliensis mexicana), these challenges include identifying and protecting migratory routes and critical roosts in two countries, the United States and Mexico. Knowledge and conservation of bat migratory routes is critical in the face of increasing threats from climate change and wind turbines that might decrease migratory survival. We employ a new modeling approach for bat migration, network modeling, to simulate migratory routes between winter habitat in southern Mexico and summer breeding habitat in northern Mexico and the southwestern United States. We use the model to identify key migratory routes and the roosts of greatest conservation value to the overall population. We measure roost importance by the degree to which the overall bat population declined when the roost was removed from the model. The major migratory routes—those with the greatest number of migrants—were between winter habitat in southern Mexico and summer breeding roosts in Texas and the northern Mexican states of Sonora and Nuevo Leon. The summer breeding roosts in Texas, Sonora, and Nuevo Leon were the most important for maintaining population numbers and network structure – these are also the largest roosts. This modeling approach contributes to conservation efforts by identifying the most influential areas for bat populations, and can be used as a tool to improve our understanding of bat migration for other species. We anticipate this approach will help direct coordination of habitat protection across borders.

A Physics-Inspired Mechanistic Model of Migratory Movement Patterns in Birds.

Science.gov (United States)

Revell, Christopher; Somveille, Marius

2017-08-29

In this paper, we introduce a mechanistic model of migratory movement patterns in birds, inspired by ideas and methods from physics. Previous studies have shed light on the factors influencing bird migration but have mainly relied on statistical correlative analysis of tracking data. Our novel method offers a bottom up explanation of population-level migratory movement patterns. It differs from previous mechanistic models of animal migration and enables predictions of pathways and destinations from a given starting location. We define an environmental potential landscape from environmental data and simulate bird movement within this landscape based on simple decision rules drawn from statistical mechanics. We explore the capacity of the model by qualitatively comparing simulation results to the non-breeding migration patterns of a seabird species, the Black-browed Albatross (Thalassarche melanophris). This minimal, two-parameter model was able to capture remarkably well the previously documented migration patterns of the Black-browed Albatross, with the best combination of parameter values conserved across multiple geographically separate populations. Our physics-inspired mechanistic model could be applied to other bird and highly-mobile species, improving our understanding of the relative importance of various factors driving migration and making predictions that could be useful for conservation.

Formation Flying/Satellite Swarm Concept Project

Science.gov (United States)

Youngquist, Robert C.

2014-01-01

NASA needs a method of not only propelling and rotating small satellites, but also to track their position and orientation. We propose a concept that will, for the first time, demonstrate both tracking and propulsion simultaneously in the same system.

Communication satellite applications

Science.gov (United States)

Pelton, Joseph N.

The status and future of the technologies, numbers and services provided by communications satellites worldwide are explored. The evolution of Intelsat satellites and the associated earth terminals toward high-rate all-digital telephony, data, facsimile, videophone, videoconferencing and DBS capabilities are described. The capabilities, services and usage of the Intersputnik, Eutelsat, Arabsat and Palapa systems are also outlined. Domestic satellite communications by means of the Molniya, ANIK, Olympus, Intelsat and Palapa spacecraft are outlined, noting the fast growth of the market and the growing number of different satellite manufacturers. The technical, economic and service definition issues surrounding DBS systems are discussed, along with presently operating and planned maritime and aeronautical communications and positioning systems. Features of search and rescue and tracking, data, and relay satellite systems are summarized, and services offered or which will be offered by every existing or planned communication satellite worldwide are tabulated.

Unraveling navigational strategies in migratory insects.

Science.gov (United States)

Merlin, Christine; Heinze, Stanley; Reppert, Steven M

2012-04-01

Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied directional strategy relies on a time-compensated sun compass, used by diurnal insects, for which neural circuits have begun to be delineated. Yet, a growing body of evidence suggests that migratory insects may also rely on other compasses that use night sky cues or the Earth's magnetic field. Those mechanisms are ripe for exploration. Copyright © 2011 Elsevier Ltd. All rights reserved.

OBIS - ARGOS Satellite Tracking of Animals

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Various species have been tracked using ARGOS PTT trackers since the early 1990's. These include Emperor, King and Adelie pengiuns, Light-mantled Sooty, Grey-headed...

76 FR 9529 - Migratory Birds; Draft Eagle Conservation Plan Guidance

Science.gov (United States)

2011-02-18

...-1231-9BPP] RIN 1018-AX53 Migratory Birds; Draft Eagle Conservation Plan Guidance AGENCY: Fish and... mail to: Attention: Eagle Conservation Plan Guidance; Division of Migratory Bird Management; U.S. Fish... implementing statutes including the Bald and Golden Eagle Protection Act (BGEPA), the Migratory Bird Treaty Act...

Unraveling navigational strategies in migratory insects

OpenAIRE

Merlin, Christine; Heinze, Stanley; Reppert, Steven M.

2011-01-01

Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied d...

GPS-based tracking system for TOPEX orbit determination

Science.gov (United States)

Melbourne, W. G.

1984-01-01

A tracking system concept is discussed that is based on the utilization of the constellation of Navstar satellites in the Global Positioning System (GPS). The concept involves simultaneous and continuous metric tracking of the signals from all visible Navstar satellites by approximately six globally distributed ground terminals and by the TOPEX spacecraft at 1300-km altitude. Error studies indicate that this system could be capable of obtaining decimeter position accuracies and, most importantly, around 5 cm in the radial component which is key to exploiting the full accuracy potential of the altimetric measurements for ocean topography. Topics covered include: background of the GPS, the precision mode for utilization of the system, past JPL research for using the GPS in precision applications, the present tracking system concept for high accuracy satellite positioning, and results from a proof-of-concept demonstration.

50 CFR 92.6 - Use and possession of migratory birds.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or offer...

Measurement-based perturbation theory and differential equation parameter estimation with applications to satellite gravimetry

Science.gov (United States)

Xu, Peiliang

2018-06-01

The numerical integration method has been routinely used by major institutions worldwide, for example, NASA Goddard Space Flight Center and German Research Center for Geosciences (GFZ), to produce global gravitational models from satellite tracking measurements of CHAMP and/or GRACE types. Such Earth's gravitational products have found widest possible multidisciplinary applications in Earth Sciences. The method is essentially implemented by solving the differential equations of the partial derivatives of the orbit of a satellite with respect to the unknown harmonic coefficients under the conditions of zero initial values. From the mathematical and statistical point of view, satellite gravimetry from satellite tracking is essentially the problem of estimating unknown parameters in the Newton's nonlinear differential equations from satellite tracking measurements. We prove that zero initial values for the partial derivatives are incorrect mathematically and not permitted physically. The numerical integration method, as currently implemented and used in mathematics and statistics, chemistry and physics, and satellite gravimetry, is groundless, mathematically and physically. Given the Newton's nonlinear governing differential equations of satellite motion with unknown equation parameters and unknown initial conditions, we develop three methods to derive new local solutions around a nominal reference orbit, which are linked to measurements to estimate the unknown corrections to approximate values of the unknown parameters and the unknown initial conditions. Bearing in mind that satellite orbits can now be tracked almost continuously at unprecedented accuracy, we propose the measurement-based perturbation theory and derive global uniformly convergent solutions to the Newton's nonlinear governing differential equations of satellite motion for the next generation of global gravitational models. Since the solutions are global uniformly convergent, theoretically speaking

Automated Tracking of Cell Migration with Rapid Data Analysis.

Science.gov (United States)

DuChez, Brian J

2017-09-01

Cell migration is essential for many biological processes including development, wound healing, and metastasis. However, studying cell migration often requires the time-consuming and labor-intensive task of manually tracking cells. To accelerate the task of obtaining coordinate positions of migrating cells, we have developed a graphical user interface (GUI) capable of automating the tracking of fluorescently labeled nuclei. This GUI provides an intuitive user interface that makes automated tracking accessible to researchers with no image-processing experience or familiarity with particle-tracking approaches. Using this GUI, users can interactively determine a minimum of four parameters to identify fluorescently labeled cells and automate acquisition of cell trajectories. Additional features allow for batch processing of numerous time-lapse images, curation of unwanted tracks, and subsequent statistical analysis of tracked cells. Statistical outputs allow users to evaluate migratory phenotypes, including cell speed, distance, displacement, and persistence, as well as measures of directional movement, such as forward migration index (FMI) and angular displacement. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

A Microstrip Patch-Fed Short Backfire Antenna for the Tracking and Data Relay Satellite System-Continuation (TDRSS-C) Multiple Access (MA) Array

Science.gov (United States)

Nessel, James A.; Kory, Carol L.; Lambert, Kevin M.; Acosta, Roberto J.

2006-01-01

Short Backfire Antennas (SBAs) are widely utilized for mobile satellite communications, tracking, telemetry, and wireless local area network (WLAN) applications due to their compact structure and excellent radiation characteristics [1-3]. Typically, these SBA s consist of an excitation element (i.e., a half-wavelength dipole), a reflective bottom plane, a planar sub-reflector located above the "exciter", and an outer circular rim. This configuration is capable of achieving gains on the order of 13-15 dBi, but with relatively narrow bandwidths (approx.3%-5%), making it incompatible with the requirements of the next generation enhanced Tracking and Data Relay Satellite System-Continuation (TDRSS-C) Multiple Access (MA) array [1]. Several attempts have been made to enhance the bandwidth performance of the common dipole-fed SBA by employing various other feeding mechanisms (e.g., waveguide, slot) with moderate success [4-5]. In this paper, a novel method of using a microstrip patch is employed for the first time to excite an SBA. The patch element is fed via two H-shaped slots electromagnetically coupled to a broadband hybrid coupler to maintain a wide bandwidth, as well as provide for dual circular polarization capabilities.

Simulation of an advanced small aperture track system

Science.gov (United States)

Williams, Tommy J.; Crockett, Gregg A.; Brunson, Richard L.; Beatty, Brad; Zahirniak, Daniel R.; Deuto, Bernard G.

2001-08-01

Simulation development for EO Systems has progressed to new levels with the advent of COTS software tools such as Matlab/Simulink. These tools allow rapid reuse of simulation library routines. We have applied these tools to newly emerging Acquisition Tracking and Pointing (ATP) systems using many routines developed through a legacy to High Energy Laser programs such as AirBorne Laser, Space Based Laser, Tactical High Energy Laser, and The Air Force Research Laboratory projects associated with the Starfire Optical Range. The simulation architecture allows ease in testing various track algorithms under simulated scenes with the ability to rapidly vary system hardware parameters such as track sensor and track loop control systems. The atmospheric turbulence environment and associated optical distortion is simulated to high fidelity levels through the application of an atmospheric phase screen model to produce scintillation of the laser illuminator uplink. The particular ATP system simulated is a small transportable system for tracking satellites in a daytime environment and projects a low power laser and receives laser return from retro-reflector equipped satellites. The primary application of the ATP system (and therefore the simulation) is the determination of the illuminator beam profile, jitter, and scintillation of the low power laser at the satellite. The ATP system will serve as a test bed for satellite tracking in a high background during daytime. Of particular interest in this simulation is the ability to emulate the hardware modelogic within the simulation to test and refine system states and mode change decisions. Additionally, the simulation allows data from the hardware system tests to be imported into Matlab and to thereby drive the simulation or to be easily compared to simulation results.

Migratory Fishes of South America : Biology, Fisheries, and ...

International Development Research Centre (IDRC) Digital Library (Canada)

Migratory Fishes of South America : Biology, Fisheries, and Conservation Status. Couverture du livre Migratory Fishes of South America : Biology, Fisheries, and Conservation Status. Directeur(s) : Joachim Carolsfield, Brian Harvey, Carmen Ross et Anton Baer. Maison(s) d'édition : World Fisheries Trust, Banque mondiale, ...

Role of TDRSS in tracking and data acquisition

Science.gov (United States)

Spearing, R. E.

1980-01-01

The integration and operation of the Tracking Data Relay Satellite System (TDRSS) into the NASA Communications Network (NASCOM) equipment and services is described. The system concept employs spacecraft in geosynchronous orbit, operating as communications front-ends, and a single ground terminal, which provides primary tracking and data acquisition services for earth-orbiting user satellites and for the Space Shuttle. The TDRSS system is further characterized by real-time throughput of user data and a high degree of automation.

Migratory divides and their consequences for dispersal, population size and parasite-host interactions.

Science.gov (United States)

Møller, A P; Garamszegi, L Z; Peralta-Sánchez, J M; Soler, J J

2011-08-01

Populations of migratory birds differ in their direction of migration with neighbouring populations often migrating in divergent directions separated by migratory divides. A total of 26% of 103 passerine bird species in Europe had migratory divides that were located disproportionately often along a longitudinal gradient in Central Europe, consistent with the assumption of a Quaternary glacial origin of such divides in the Iberian and Balkan peninsulas followed by recolonization. Given that studies have shown significant genetic differentiation and reduced gene flow across migratory divides, we hypothesized that an absence of migratory divides would result in elevated rates of gene flow and hence a reduced level of local adaptation. In a comparative study, species with migratory divides had larger population sizes and population densities and longer dispersal distances than species without migratory divides. Species with migratory divides tended to be habitat generalists. Bird species with migratory divides had higher richness of blood parasites and higher growth rates of Staphylococcus on their eggs during the incubation period. There was weaker cell-mediated immunity in adults and stronger cell lysis in species with migratory divides. These findings may suggest that migratory divides constitute barriers to dispersal with consequences for ecology and evolution of distributions, population sizes, habitats and parasite-host interactions. They also suggest that migratory divides may play a role in local adaptation in host-parasite interactions. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

The function of migratory bird calls

DEFF Research Database (Denmark)

Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye

The function of migratory bird calls: do they influence orientation and navigation?   Thomas Reichl1, Bent Bach Andersen2, Ole Naesbye Larsen2, Henrik Mouritsen1   1Institute of Biology, University of Oldenburg, Oldenburg, D-26111 Oldenburg, Germany 2Institute of Biology, University of Southern...... migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...... the experimental bird could be activated successively to simulate a migrating Robin cruising E-W, W-E, S-N or N-S at a chosen height (mostly about 40 m), at 10 m/s and emitting Robin flight calls of 80 dB(A) at 1 m. The simulated flight of a "ding" sound served as a control. During an experiment the bird was first...

Tracking on non-active collaborative objects from San Fernando Laser station

Science.gov (United States)

Catalán, Manuel; Quijano, Manuel; Cortina, Luis M.; Pazos, Antonio A.; Martín-Davila, José

2016-04-01

The Royal Observatory of the Spanish Navy (ROA) works on satellite geodesy from the early days of the space age, when the first artificial satellite tracking telescope was installed in 1958: the Baker-Nunn camera. In 1975 a French satellite Laser ranging (SLR) station was installed and operated at ROA . Since 1980, ROA has been operating this instrument which was upgraded to a third generation and it is still keep into a continuous update to reach the highest level of operability. Since then ROA has participated in different space geodesy campaigns through the International Laser Service Stations (ILRS) or its European regional organization (EUROLAS), tracking a number of artificial satellites types : ERS, ENVISAT, LAGEOS, TOPEX- POSEIDON to name but a few. Recently we opened a new field of research: space debris tracking, which is receiving increasing importance and attention from international space agencies. The main problem is the relatively low accuracy of common used methods. It is clear that improving the predicted orbit accuracy is necessary to fulfill our aims (avoiding unnecessary anti-collision maneuvers,..). Following results obtained by other colleagues (Austria, China, USA,...) we proposed to share our time-schedule using our satellite ranging station to obtain data which will make orbital elements predictions far more accurate (sub-meter accuracy), while we still keep our tracking routines over active satellites. In this communication we report the actions fulfill until nowadays.

Pamela tracking system status report

CERN Document Server

Taccetti, F; Bonechi, L; Bongi, M; Boscherini, M; Castellini, G; D'Alessandro, R; Gabbanini, A; Grandi, M; Papini, P; Piccardi, S; Ricciarini, S; Spillantini, P; Straulino, S; Tesi, M; Vannuccini, E

2002-01-01

The Pamela apparatus will be launched at the end of 2002 on board of the Resurs DK Russian satellite. The tracking system, composed of six planes of silicon sensors inserted inside a permanent magnetic field was intensively tested during these last years. Results of tests have shown a good signal-to-noise ratio and an excellent spatial resolution, which should allow to measure the antiproton flux in an energy range from 80 MeV up to 190 GeV. The production of the final detector modules is about to start and mechanical and thermal tests on the tracking tower are being performed according to the specifications of the Russian launcher and satellite.

A method for optical ground station reduce alignment error in satellite-ground quantum experiments

Science.gov (United States)

He, Dong; Wang, Qiang; Zhou, Jian-Wei; Song, Zhi-Jun; Zhong, Dai-Jun; Jiang, Yu; Liu, Wan-Sheng; Huang, Yong-Mei

2018-03-01

A satellite dedicated for quantum science experiments, has been developed and successfully launched from Jiuquan, China, on August 16, 2016. Two new optical ground stations (OGSs) were built to cooperate with the satellite to complete satellite-ground quantum experiments. OGS corrected its pointing direction by satellite trajectory error to coarse tracking system and uplink beacon sight, therefore fine tracking CCD and uplink beacon optical axis alignment accuracy was to ensure that beacon could cover the quantum satellite in all time when it passed the OGSs. Unfortunately, when we tested specifications of the OGSs, due to the coarse tracking optical system was commercial telescopes, the change of position of the target in the coarse CCD was up to 600μrad along with the change of elevation angle. In this paper, a method of reduce alignment error between beacon beam and fine tracking CCD is proposed. Firstly, OGS fitted the curve of target positions in coarse CCD along with the change of elevation angle. Secondly, OGS fitted the curve of hexapod secondary mirror positions along with the change of elevation angle. Thirdly, when tracking satellite, the fine tracking error unloaded on the real-time zero point position of coarse CCD which computed by the firstly calibration data. Simultaneously the positions of the hexapod secondary mirror were adjusted by the secondly calibration data. Finally the experiment result is proposed. Results show that the alignment error is less than 50μrad.

Satellite tagging, remote sensing, and autonomous vehicles reveal interactions between physiology and environment in a North Pacific top marine predator species

Science.gov (United States)

Pelland, N.; Sterling, J.; Springer, A.; Iverson, S.; Johnson, D.; Lea, M. A.; Bond, N. A.; Ream, R.; Lee, C.; Eriksen, C.

2016-02-01

Behavioral responses by top marine predators to oceanographic features such as eddies, river plumes, storms, and coastal topography suggest that biophysical interactions in these zones affect predators' prey, foraging behaviors, and potentially fitness. However, examining these pathways is challenged by the obstacles inherent in obtaining simultaneous observations of surface and subsurface environmental fields and predator behavior. This work describes recent publications and ongoing studies of northern fur seal (NFS) foraging ecology during their 8-month migration. Satellite-tracked movement and dive behavior in the North Pacific ocean was compared to remotely sensed data, atmospheric reanalysis, autonomous in situ ocean sampling, and animal borne temperature and salinity data. Integration of these data demonstrates how reproductive fitness, physiology, and environment shape NFS migratory patterns. Seal mass correlates with dive ability and thus larger males exploit prey aggregating at the base of the winter mixed-layer depth in the Bering Sea and interior northern North Pacific Ocean. Smaller adult females migrate to the Gulf of Alaska and California Current ecosystems - where surface wind speeds decline, mixed-layer depths shoal, and coastal production is fueled by upwelling, coastal capes, and eddies - and less commonly to the Transitional Zone Chlorophyll Front, where fronts and eddies may concentrate prey. Surface wind speed and direction influence movement behavior of all age and size classes, though to a greater degree in the smaller pups and adult females than adult males. For naïve and physiologically less-capable pups, the timing and strength of autumn winds during migratory dispersal may play a role in shaping migratory routes and the environmental conditions faced by pups along these routes. In combination with other factors such as pup condition, this may play a role in interannual variations in overwinter survivorship.

Optical neural network system for pose determination of spinning satellites

Science.gov (United States)

Lee, Andrew; Casasent, David

1990-01-01

An optical neural network architecture and algorithm based on a Hopfield optimization network are presented for multitarget tracking. This tracker utilizes a neuron for every possible target track, and a quadratic energy function of neural activities which is minimized using gradient descent neural evolution. The neural net tracker is demonstrated as part of a system for determining position and orientation (pose) of spinning satellites with respect to a robotic spacecraft. The input to the system is time sequence video from a single camera. Novelty detection and filtering are utilized to locate and segment novel regions from the input images. The neural net multitarget tracker determines the correspondences (or tracks) of the novel regions as a function of time, and hence the paths of object (satellite) parts. The path traced out by a given part or region is approximately elliptical in image space, and the position, shape and orientation of the ellipse are functions of the satellite geometry and its pose. Having a geometric model of the satellite, and the elliptical path of a part in image space, the three-dimensional pose of the satellite is determined. Digital simulation results using this algorithm are presented for various satellite poses and lighting conditions.

Loss of migratory behaviour increases infection risk for a butterfly host

Science.gov (United States)

Satterfield, Dara A.; Maerz, John C.; Altizer, Sonia

2015-01-01

Long-distance animal migrations have important consequences for infectious disease dynamics. In some cases, migration lowers pathogen transmission by removing infected individuals during strenuous journeys and allowing animals to periodically escape contaminated habitats. Human activities are now causing some migratory animals to travel shorter distances or form sedentary (non-migratory) populations. We focused on North American monarch butterflies and a specialist protozoan parasite to investigate how the loss of migratory behaviours affects pathogen spread and evolution. Each autumn, monarchs migrate from breeding grounds in the eastern US and Canada to wintering sites in central Mexico. However, some monarchs have become non-migratory and breed year-round on exotic milkweed in the southern US. We used field sampling, citizen science data and experimental inoculations to quantify infection prevalence and parasite virulence among migratory and sedentary populations. Infection prevalence was markedly higher among sedentary monarchs compared with migratory monarchs, indicating that diminished migration increases infection risk. Virulence differed among parasite strains but was similar between migratory and sedentary populations, potentially owing to high gene flow or insufficient time for evolutionary divergence. More broadly, our findings suggest that human activities that alter animal migrations can influence pathogen dynamics, with implications for wildlife conservation and future disease risks. PMID:25589600

Combining direct and indirect tracking techniques to assess the impact of sub-Saharan conditions on cross-continental songbird migration

DEFF Research Database (Denmark)

Pedersen, Lykke; Fraser, Kevin C.; Kyser, T. Kurt

2016-01-01

Understanding how events throughout the annual cycle interact to influence individual fitness and hence population dynamics is crucial to optimize conservation strategies for migratory birds. Despite major advancements in technology, direct tracking devices for passerine songbirds are still limited...

Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

Science.gov (United States)

Bergsrud, Corey Alexis Marvin

Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

Experimental study on the precise orbit determination of the BeiDou navigation satellite system.

Science.gov (United States)

He, Lina; Ge, Maorong; Wang, Jiexian; Wickert, Jens; Schuh, Harald

2013-03-01

The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO), five Inclined Geosynchronous Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS) network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better.

Migration and wintering sites of Pelagic Cormorants determined by satellite telemetry

Science.gov (United States)

Hatch, Shyla A.; Gill, V.A.; Mulcahy, D.M.

2011-01-01

Factors affecting winter survival may be key determinants of status and population trends of seabirds, but connections between breeding sites and wintering areas of most populations are poorly known. Pelagic Cormorants (Phalacrocorax pelagicus; N= 6) surgically implanted with satellite transmitters migrated from a breeding colony on Middleton Island, northern Gulf of Alaska, to wintering sites in southeast Alaska and northern British Columbia. Winter locations averaged 920 km (range = 600-1190 km) from the breeding site. Migration flights in fall and spring lasted ???5 d in four instances. After reaching wintering areas, cormorants settled in narrowly circumscribed inshore locations (~10-km radius) and remained there throughout the nonbreeding period (September- March). Two juveniles tagged at the breeding colony as fledglings remained at their wintering sites for the duration of the tracking interval (14 and 22 mo, respectively). Most cormorants used multiple sites within their winter ranges for roosting and foraging. Band recoveries show that Pelagic Cormorants in southern British Columbia and Washington disperse locally in winter, rather than migrating like the cormorants in our study. Radio-tagging and monitoring cormorants and other seabirds from known breeding sites are vital for understanding migratory connectivity and improving conservation strategies for local populations. ?? 2011 The Authors. Journal of Field Ornithology ?? 2011 Association of Field Ornithologists.

Comparison of Navigation-Related Brain Regions in Migratory versus Non-Migratory Noctuid Moths

Directory of Open Access Journals (Sweden)

Liv de Vries

2017-09-01

Full Text Available Brain structure and function are tightly correlated across all animals. While these relations are ultimately manifestations of differently wired neurons, many changes in neural circuit architecture lead to larger-scale alterations visible already at the level of brain regions. Locating such differences has served as a beacon for identifying brain areas that are strongly associated with the ecological needs of a species—thus guiding the way towards more detailed investigations of how brains underlie species-specific behaviors. Particularly in relation to sensory requirements, volume-differences in neural tissue between closely related species reflect evolutionary investments that correspond to sensory abilities. Likewise, memory-demands imposed by lifestyle have revealed similar adaptations in regions associated with learning. Whether this is also the case for species that differ in their navigational strategy is currently unknown. While the brain regions associated with navigational control in insects have been identified (central complex (CX, lateral complex (LX and anterior optic tubercles (AOTU, it remains unknown in what way evolutionary investments have been made to accommodate particularly demanding navigational strategies. We have thus generated average-shape atlases of navigation-related brain regions of a migratory and a non-migratory noctuid moth and used volumetric analysis to identify differences. We further compared the results to identical data from Monarch butterflies. Whereas we found differences in the size of the nodular unit of the AOTU, the LX and the protocerebral bridge (PB between the two moths, these did not unambiguously reflect migratory behavior across all three species. We conclude that navigational strategy, at least in the case of long-distance migration in lepidopteran insects, is not easily deductible from overall neuropil anatomy. This suggests that the adaptations needed to ensure successful migratory behavior

Migratory culture, population structure and stock identity in North Pacific beluga whales (Delphinapterus leucas)

Science.gov (United States)

Suydam, Robert; Quakenbush, Lori; Potgieter, Brooke; Harwood, Lois; Litovka, Dennis; Ferrer, Tatiana; Citta, John; Burkanov, Vladimir; Frost, Kathy; Mahoney, Barbara

2018-01-01

The annual return of beluga whales, Delphinapterus leucas, to traditional seasonal locations across the Arctic may involve migratory culture, while the convergence of discrete summering aggregations on common wintering grounds may facilitate outbreeding. Natal philopatry and cultural inheritance, however, has been difficult to assess as earlier studies were of too short a duration, while genetic analyses of breeding patterns, especially across the beluga’s Pacific range, have been hampered by inadequate sampling and sparse information on wintering areas. Using a much expanded sample and genetic marker set comprising 1,647 whales, spanning more than two decades and encompassing all major coastal summering aggregations in the Pacific Ocean, we found evolutionary-level divergence among three geographic regions: the Gulf of Alaska, the Bering-Chukchi-Beaufort Seas, and the Sea of Okhotsk (Φst = 0.11–0.32, Rst = 0.09–0.13), and likely demographic independence of (Fst-mtDNA = 0.02–0.66), and in many cases limited gene flow (Fst-nDNA = 0.0–0.02; K = 5–6) among, summering groups within regions. Assignment tests identified few immigrants within summering aggregations, linked migrating groups to specific summering areas, and found that some migratory corridors comprise whales from multiple subpopulations (PBAYES = 0.31:0.69). Further, dispersal is male-biased and substantial numbers of closely related whales congregate together at coastal summering areas. Stable patterns of heterogeneity between areas and consistently high proportions (~20%) of close kin (including parent-offspring) sampled up to 20 years apart within areas (G = 0.2–2.9, p>0.5) is the first direct evidence of natal philopatry to migration destinations in belugas. Using recent satellite telemetry findings on belugas we found that the spatial proximity of winter ranges has a greater influence on the degree of both individual and genetic exchange than summer ranges (rwinter-Fst-mtDNA = 0

Moderating Argos location errors in animal tracking data

Science.gov (United States)

Douglas, David C.; Weinziert, Rolf; Davidson, Sarah C.; Kays, Roland; Wikelski, Martin; Bohrer, Gil

2012-01-01

1. The Argos System is used worldwide to satellite-track free-ranging animals, but location errors can range from tens of metres to hundreds of kilometres. Low-quality locations (Argos classes A, 0, B and Z) dominate animal tracking data. Standard-quality animal tracking locations (Argos classes 3, 2 and 1) have larger errors than those reported in Argos manuals.

Dual Fine Tracking Control of a Satellite Laser Communication Uplink

National Research Council Canada - National Science Library

Noble, Louis A

2006-01-01

A dual fine tracking control system (FTCS) is developed for a single aperture optical communication receiver to compensate for high frequency disturbances affecting tracking of two incident laser communication beams...

Implementation and development of vehicle tracking and immobilization technologies.

Science.gov (United States)

2010-01-01

Since the mid-1980s, limited use has been made of vehicle tracking using satellite communications to mitigate the security and safety risks created by the highway transportation of certain types of hazardous materials. However, vehicle-tracking techn...

Estimating migratory connectivity of birds when re-encounter probabilities are heterogeneous

Science.gov (United States)

Cohen, Emily B.; Hostelter, Jeffrey A.; Royle, J. Andrew; Marra, Peter P.

2014-01-01

Understanding the biology and conducting effective conservation of migratory species requires an understanding of migratory connectivity – the geographic linkages of populations between stages of the annual cycle. Unfortunately, for most species, we are lacking such information. The North American Bird Banding Laboratory (BBL) houses an extensive database of marking, recaptures and recoveries, and such data could provide migratory connectivity information for many species. To date, however, few species have been analyzed for migratory connectivity largely because heterogeneous re-encounter probabilities make interpretation problematic. We accounted for regional variation in re-encounter probabilities by borrowing information across species and by using effort covariates on recapture and recovery probabilities in a multistate capture–recapture and recovery model. The effort covariates were derived from recaptures and recoveries of species within the same regions. We estimated the migratory connectivity for three tern species breeding in North America and over-wintering in the tropics, common (Sterna hirundo), roseate (Sterna dougallii), and Caspian terns (Hydroprogne caspia). For western breeding terns, model-derived estimates of migratory connectivity differed considerably from those derived directly from the proportions of re-encounters. Conversely, for eastern breeding terns, estimates were merely refined by the inclusion of re-encounter probabilities. In general, eastern breeding terns were strongly connected to eastern South America, and western breeding terns were strongly linked to the more western parts of the nonbreeding range under both models. Through simulation, we found this approach is likely useful for many species in the BBL database, although precision improved with higher re-encounter probabilities and stronger migratory connectivity. We describe an approach to deal with the inherent biases in BBL banding and re-encounter data to demonstrate

Precise Object Tracking under Deformation

International Nuclear Information System (INIS)

Saad, M.H.

2010-01-01

The precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This framework focuses on the precise object tracking under deformation such as scaling, rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high precession results. xiiiThe precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This framework focuses on the precise object tracking under deformation such as scaling, rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high

Wildfire Detection and Tracking over Greece Using MSG‑SEVIRI Satellite Data

Directory of Open Access Journals (Sweden)

Nicolaos I. Sifakis

2011-03-01

Full Text Available Greece is a high risk Mediterranean country with respect to wildfires. This risk has been increasing under the impact of climate change, and in summer 2007 approximately 200,000 ha of vegetated land were burnt. The SEVIRI sensor, on board the Meteosat Second Generation (MSG geostationary satellite, is the only spaceborne sensor providing five and 15-minute observations of Europe in 12 spectral channels, including a short-wave infrared band sensitive to fire radiative temperature. In August 2007, when the bulk of the destructive wildfires started in Greece, the receiving station, operated by the Institute for Space Applications and Remote Sensing, provided us with a time series of MSG-SEVIRI images. These images were processed in order to test the reliability of a real‑time detection and tracking system and its complementarity to conventional means provided by the Fire Brigade. EUMETSAT’s Active Fire Monitoring (FIR image processing algorithm for fire detection and monitoring was applied to SEVIRI data, then fine-tuned according to Greek conditions, and evaluated. Alarm announcements from the Fire Brigade’s archives were used as ground truthing data in order to assess detection reliability and system performance. During the examined period, MSG-SEVIRI data successfully detected 82% of the fire events in Greek territory with less than 1% false alarms.

Telecoupling framework for research on migratory species in the Anthropocene

Directory of Open Access Journals (Sweden)

Jacqueline Hulina

2017-03-01

Full Text Available Migratory species are an important component of biodiversity and provide essential ecosystem services for humans, but many are threatened and endangered. Numerous studies have been conducted on the biology of migratory species, and there is an increased recognition of the major role of human dimensions in conserving migratory species. However, there is a lack of systematic integration of socioeconomic and environmental factors. Because human activities affect migratory species in multiple places, integrating socioeconomic and environmental factors across space is essential, but challenging. The holistic framework of telecoupling (socioeconomic and environmental interactions over distances has the potential to help meet this challenge because it enables researchers to integrate human and natural interactions across multiple distant places. The use of the telecoupling framework may also lead to new conservation strategies and actions. To demonstrate its potential, we apply the framework to Kirtland’s warblers ('Setophaga kirtlandii' , a conservation-reliant migratory songbird. Results show accomplishments from long-term research and recovery efforts on the warbler in the context of the telecoupling framework. The results also show 24 research gaps even though the species has been relatively well-studied compared to many other species. An important gap is a lack of systematic studies on feedbacks among breeding, wintering, and stopover sites, as well as other “spillover” systems that may affect and be affected by migration (e.g., via tourism, land use, or climate change. The framework integrated scattered information and provided useful insights about new research topics and flow-centered management approaches that encapsulate the full annual cycle of migration. We also illustrate the similarities and differences between Kirtland’s warblers and several other migratory species, indicating the applicability of the telecoupling framework to

Water level affects availability of optimal feeding habitats for threatened migratory waterbirds

DEFF Research Database (Denmark)

Aharon-Rotman, Yaara; McEvoy, John; Zheng Zhaoju

2017-01-01

within the lake. Changing the natural hydrological system will affect waterbirds dependent on water level changes for food availability and accessibility. We tracked two goose species with different feeding behaviors (greater white-fronted geese Anser albifrons [grazing species] and swan geese Anser......Extensive ephemeral wetlands at Poyang Lake, created by dramatic seasonal changes in water level, constitute the main wintering site for migratory Anatidae in China. Reductions in wetland area during the last 15years have led to proposals to build a Poyang Dam to retain high winter water levels...... cygnoides [tuber-feeding species]) during two winters with contrasting water levels (continuous recession in 2015; sustained high water in 2016, similar to those predicted post-Poyang Dam), investigating the effects of water level change on their habitat selection based on vegetation and elevation. In 2015...

Revolutionary non-migratory migrants

NARCIS (Netherlands)

Jonker, M.R.

2011-01-01

In the migratory behaviour of the Barnacle Goose Branta leucopsis several changes have

occurred over the past few decades. Barnacle geese breeding in Russia have delayed the

commencement of spring migration with approximately one month since the 1980s,

new

Using radar to advance migratory bird management: An interagency collaboration

Science.gov (United States)

Sojda, R.; Ruth, J.M.; Barrow, W.C.; Dawson, D.K.; Diehl, R.H.; Manville, A.; Green, M.T.; Krueper, D.J.; Johnston, S.

2005-01-01

Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

Wind Turbines as Landscape Impediments to the Migratory Connectivity of Bats

Science.gov (United States)

Cryan, Paul M.

2011-01-01

Unprecedented numbers of migratory bats are found dead beneath industrial-scale wind turbines during late summer and autumn in both North America and Europe. Prior to the wide-scale deployment of wind turbines, fatal collisions of migratory bats with anthropogenic structures were rarely reported and likely occurred very infrequently. There are no other well-documented threats to populations of migratory tree bats that cause mortality of similar magnitude to that observed at wind turbines. Just three migratory species comprise the vast majority of bat kills at turbines in North America and there are indications that turbines may actually attract migrating individuals toward their blades. Although fatality of certain migratory species is consistent in occurrence across large geographic regions, fatality rates differ across sites for reasons mostly unknown. Cumulative fatality for turbines in North America might already range into the hundreds of thousands of bats per year. Research into the causes of bat fatalities at wind turbines can ascertain the scale of the problem and help identify solutions. None of the migratory bats known to be most affected by wind turbines are protected by conservation laws, nor is there a legal mandate driving research into the problem or implementation of potential solutions.

Home Range and Habitat Use of the New Zealand Falcon (Falco novaeseelandiae within a Plantation Forest: A Satellite Tracking Study

Directory of Open Access Journals (Sweden)

Bindi Thomas

2010-01-01

Full Text Available We tracked two adult and three juvenile New Zealand falcons (Falco novaeseelandiae in Kaingaroa Forest pine plantation from 2002 to 2008 using Argos satellite technology. The home ranges for both adults and juveniles varied, ranging between 44 and 587 km2. The falcons occasionally utilised areas outside the forest and used stands of all ages within the forest, generally in proportion to their availability. For the most part, the juveniles remained within ca. 8 km of their nests and dispersed at 58, 69, and 68 days after fledging. Falcon movement information was obtained from an average of four location points per tracking day per falcon at a putative accuracy of 350 m. The transmitters, including their solar charge capability, performed well in the forest environment. The use of all stand ages highlights the importance of forestry practises that maintain a mosaic of different aged pine stands.

Prevalence and heritability of psoriasis and benign migratory glossitis in one Brazilian population*

Science.gov (United States)

Jorge, Maria Augusta; Gonzaga, Heron Fernando de Sousa; Tomimori, Jane; Picciani, Bruna Lavinas Sayed; Barbosa, Calógeras Antônio

2017-01-01

Background An oral condition associated to psoriasis is benign migratory glossitis. The review of the literature does not show any publication about heritability in both soriasis and benign migratory glossitis and prevalence of psoriasis in the Brazilian population. Objective This research was carried out in order to determine the prevalence of psoriasis and benign migratory glossitis in the Brazilian population from a Brazilian sample, as well as the heritability in these conditions. Methods Six thousand patients were studied from the records of the outpatient dermatology department. The sample had 129 patients with cutaneous psoriasis, 399 with benign migratory glossitis without psoriasis and a control group with 5,472 patients. After data collection, the statistical analysis was made using Woolf, Chi-square and Falconer tests. Results The prevalence of psoriasis was 2.15% and the benign migratory glossitis was 7.0%. The prevalence of benign migratory glossitis in the psoriasis group was high (16.3%), and that was statistically significant. Family history in the psoriasis group was 38% for the condition itself and 2,75% for benign migratory glossitis and in the benign migratory glossitis group was 17.54% for the condition itself and 1.5% for psoriasis. The study of heritability was 38.8% for psoriasis and 36.6% for benign migratory glossitis, both with medium heritability. Study limitations This study was only in the state of São Paulo. Conclusion This is the first publication that quantifies how much of these conditions have a genetic background and how important the environmental factors are in triggering them. PMID:29364438

Mapping migratory flyways in Asia using dynamic Brownian bridge movement models.

Science.gov (United States)

Palm, Eric C; Newman, Scott H; Prosser, Diann J; Xiao, Xiangming; Ze, Luo; Batbayar, Nyambayar; Balachandran, Sivananinthaperumal; Takekawa, John Y

2015-01-01

Identifying movement routes and stopover sites is necessary for developing effective management and conservation strategies for migratory animals. In the case of migratory birds, a collection of migration routes, known as a flyway, is often hundreds to thousands of kilometers long and can extend across political boundaries. Flyways encompass the entire geographic range between the breeding and non-breeding areas of a population, species, or a group of species, and they provide spatial frameworks for management and conservation across international borders. Existing flyway maps are largely qualitative accounts based on band returns and survey data rather than observed movement routes. In this study, we use satellite and GPS telemetry data and dynamic Brownian bridge movement models to build upon existing maps and describe waterfowl space use probabilistically in the Central Asian and East Asian-Australasian Flyways. Our approach provided new information on migratory routes that was not easily attainable with existing methods to describe flyways. Utilization distributions from dynamic Brownian bridge movement models identified key staging and stopover sites, migration corridors and general flyway outlines in the Central Asian and East Asian-Australasian Flyways. A map of space use from ruddy shelducks depicted two separate movement corridors within the Central Asian Flyway, likely representing two distinct populations that show relatively strong connectivity between breeding and wintering areas. Bar-headed geese marked at seven locations in the Central Asian Flyway showed heaviest use at several stopover sites in the same general region of high-elevation lakes along the eastern Qinghai-Tibetan Plateau. Our analysis of data from multiple Anatidae species marked at sites throughout Asia highlighted major movement corridors across species and confirmed that the Central Asian and East Asian-Australasian Flyways were spatially distinct. The dynamic Brownian bridge

Satellite Tracking and Site Fidelity of Short Ocean Sunfish, Mola ramsayi, in the Galapagos Islands

Directory of Open Access Journals (Sweden)

Tierney M. Thys

2017-01-01

Full Text Available Ocean sunfishes, with their peculiar morphology, large size, and surface habits, are valuable assets in ecotourism destinations worldwide. This study investigates site fidelity and long-range movements of short ocean sunfish, Mola ramsayi (Giglioli 1883, at Punta Vicente Roca (PVR off Isabela Island in the Galapagos Islands. Five individuals were tracked between 32 and 733 days using ultrasonic receivers and transmitters. Two of the 5 were also tracked with towed pop-off satellite tags. One travelled to the equatorial front covering 2700 km in 53 days, with dive depths in the upper 360 m at temperatures between 9.2°C and 22°C. During its westward travel, dives extended to 1112 m (the deepest depth yet recorded for Molidae into temperatures ranging between 4.5°C and 23.2°C. The remaining four individuals demonstrated site fidelity to PVR and were detected at the site between 128–1361 times for a total of 3557 reports. Forty-eight percent of the reports occurred during daytime hours and 52% after dark. Presumed cleaning session durations had a median of 15 minutes and a maximum of nearly 100 minutes. No other ultrasonic arrays around Galapagos or in the Eastern Pacific regional network recorded the presence of tagged individuals. These data are combined with tourist vessel sightings and submersible observations to confirm Punta Vicente Roca as an important sunfish hotspot.

78 FR 12273 - Highly Migratory Species; 2006 Consolidated Atlantic Highly Migratory Species Fishery Management...

Science.gov (United States)

2013-02-22

... Migratory Species Fishery Management Plan; Amendment 8 AGENCY: National Marine Fisheries Service (NMFS... and an overall reduction in catch since 1987 have supported the recovery of the North Atlantic... long-term for seafood dealers, marinas, bait, tackle, and ice suppliers, restaurants, and similar...

77 FR 15701 - Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management Plan...

Science.gov (United States)

2012-03-16

... Species Fishery Management Plan; Amendment 4 AGENCY: National Marine Fisheries Service (NMFS), National.... SUMMARY: This fishery management plan (FMP) amendment addresses Atlantic highly migratory species (HMS... to create an HMS Caribbean Small Boat Commercial Permit (CSBP) allowing fishing for and sales of...

Identification of the rostral migratory stream in the canine and feline brain.

Directory of Open Access Journals (Sweden)

Saafan Z Malik

Full Text Available In the adult rodent brain, neural progenitor cells migrate from the subventricular zone of the lateral ventricle towards the olfactory bulb in a track known as the rostral migratory stream (RMS. To facilitate the study of neural progenitor cells and stem cell therapy in large animal models of CNS disease, we now report the location and characteristics of the normal canine and feline RMS. The RMS was found in Nissl-stained sagittal sections of adult canine and feline brains as a prominent, dense, continuous cellular track beginning at the base of the anterior horn of the lateral ventricle, curving around the head of the caudate nucleus and continuing laterally and ventrally to the olfactory peduncle before entering the olfactory tract and bulb. To determine if cells in the RMS were proliferating, the thymidine analog 5-bromo-2-deoxyuridine (BrdU was administered and detected by immunostaining. BrdU-immunoreactive cells were present throughout this track. The RMS was also immunoreactive for markers of proliferating cells, progenitor cells and immature neurons (Ki-67 and doublecortin, but not for NeuN, a marker of mature neurons. Luxol fast blue and CNPase staining indicated that myelin is closely apposed to the RMS along much of its length and may provide guidance cues for the migrating cells. Identification and characterization of the RMS in canine and feline brain will facilitate studies of neural progenitor cell biology and migration in large animal models of neurologic disease.

The glucagonoma syndrome and necrolytic migratory erythema : A clinical review

NARCIS (Netherlands)

van Beek, André P.; de Haas, Ellen R.M.; van Vloten, Willem A.; Lips, Cees J.M.; Roijers, Janine F.M.; Canninga-van Dijk, Marijke R.

2004-01-01

The glucagonoma syndrome is a rare disease in which a typical skin disorder, necrolytic migratory erythema, is often one of the first presenting symptoms. Weight loss and diabetes mellitus are two other prevalent characteristics of this syndrome. Necrolytic migratory erythema belongs to the recently

Future Satellite Gravimetry and Earth Dynamics

CERN Document Server

Flury, Jakob

2005-01-01

Currently, a first generation of dedicated satellite missions for the precise mapping of the Earth’s gravity field is in orbit (CHAMP, GRACE, and soon GOCE). The gravity data from these satellite missions provide us with very new information on the dynamics of planet Earth. In particular, on the mass distribution in the Earth’s interior, the entire water cycle (ocean circulation, ice mass balance, continental water masses, and atmosphere), and on changes in the mass distribution. The results are fascinating, but still rough with respect to spatial and temporal resolution. Technical progress in satellite-to-satellite tracking and in gravity gradiometry will allow more detailed results in the future. In this special issue, Earth scientists develop visions of future applications based on follow-on high-precision satellite gravimetry missions.

Optical Tracking Data Validation and Orbit Estimation for Sparse Observations of Satellites by the OWL-Net

Directory of Open Access Journals (Sweden)

Jin Choi

2018-06-01

Full Text Available An Optical Wide-field patroL-Network (OWL-Net has been developed for maintaining Korean low Earth orbit (LEO satellites’ orbital ephemeris. The OWL-Net consists of five optical tracking stations. Brightness signals of reflected sunlight of the targets were detected by a charged coupled device (CCD. A chopper system was adopted for fast astrometric data sampling, maximum 50 Hz, within a short observation time. The astrometric accuracy of the optical observation data was validated with precise orbital ephemeris such as Consolidated Prediction File (CPF data and precise orbit determination result with onboard Global Positioning System (GPS data from the target satellite. In the optical observation simulation of the OWL-Net for 2017, an average observation span for a single arc of 11 LEO observation targets was about 5 min, while an average optical observation separation time was 5 h. We estimated the position and velocity with an atmospheric drag coefficient of LEO observation targets using a sequential-batch orbit estimation technique after multi-arc batch orbit estimation. Post-fit residuals for the multi-arc batch orbit estimation and sequential-batch orbit estimation were analyzed for the optical measurements and reference orbit (CPF and GPS data. The post-fit residuals with reference show few tens-of-meters errors for in-track direction for multi-arc batch and sequential-batch orbit estimation results.

The use of satellite tags to redefine movement patterns of spiny dogfish (Squalus acanthias along the U.S. east coast: implications for fisheries management.

Directory of Open Access Journals (Sweden)

Amy E Carlson

Full Text Available Spiny dogfish (Squalus acanthias are assumed to be a highly migratory species, making habitual north-south migrations throughout their northwestern Atlantic United States (U.S. range. Also assumed to be a benthic species, spiny dogfish stock structure is estimated through Northeast Fisheries Science Center (NEFSC bottom-trawl surveys. Recent anomalies in population trends, including a recent four-fold increase in estimated spawning stock biomass, suggest alternative movement patterns could exist for this shark species. To obtain a better understanding of the horizontal and vertical movement dynamics of this species, Microwave Telemetry pop-up satellite archival X-Tags were attached to forty adult spiny dogfish at the northern (Gulf of Maine and southern (North Carolina extents of their core U.S. geographic range. Reconstructed geolocation tracks ranging in lengths from two to 12 months suggest that the seasonal migration patterns appear to be local in nature to each respective northern and southern deployment site, differing from previously published migration paradigms. Differences in distance and direction traveled between seasonal geolocations possibly indicate separate migratory patterns between groups. Kernel utilization distribution models also suggest strong separate core home ranges. Significant differences in seasonal temperature and depths between the two regions further substantiate the possibility of separate regional movement patterns between the two groups. Vertical utilization also suggests distinct diel patterns and that this species may not utilize the benthos as previously thought, potentially decreasing availability to benthic gear.

The use of satellite tags to redefine movement patterns of spiny dogfish (Squalus acanthias) along the U.S. east coast: implications for fisheries management.

Science.gov (United States)

Carlson, Amy E; Hoffmayer, Eric R; Tribuzio, Cindy A; Sulikowski, James A

2014-01-01

Spiny dogfish (Squalus acanthias) are assumed to be a highly migratory species, making habitual north-south migrations throughout their northwestern Atlantic United States (U.S.) range. Also assumed to be a benthic species, spiny dogfish stock structure is estimated through Northeast Fisheries Science Center (NEFSC) bottom-trawl surveys. Recent anomalies in population trends, including a recent four-fold increase in estimated spawning stock biomass, suggest alternative movement patterns could exist for this shark species. To obtain a better understanding of the horizontal and vertical movement dynamics of this species, Microwave Telemetry pop-up satellite archival X-Tags were attached to forty adult spiny dogfish at the northern (Gulf of Maine) and southern (North Carolina) extents of their core U.S. geographic range. Reconstructed geolocation tracks ranging in lengths from two to 12 months suggest that the seasonal migration patterns appear to be local in nature to each respective northern and southern deployment site, differing from previously published migration paradigms. Differences in distance and direction traveled between seasonal geolocations possibly indicate separate migratory patterns between groups. Kernel utilization distribution models also suggest strong separate core home ranges. Significant differences in seasonal temperature and depths between the two regions further substantiate the possibility of separate regional movement patterns between the two groups. Vertical utilization also suggests distinct diel patterns and that this species may not utilize the benthos as previously thought, potentially decreasing availability to benthic gear.

The Impacts of Satellite Remotely Sensed Winds and Total Precipitable Vapour in WRF Tropical Cyclone Track Forecasts

Directory of Open Access Journals (Sweden)

Diandong Ren

2016-01-01

Full Text Available This study assesses the impact assimilating the scatterometer near-surface wind observations and total precipitable water from the SSMI, into WRF on genesis and track forecasting of four tropical cyclones (TCs. These TCs are selected to be representative of different intensity categories and basins. Impact is via a series of data denial experiments that systematically exclude the remote sensed information. Compared with the control case, in which only the final analysis atmospheric variables are used to initialize and provide the lateral boundary conditions, the data assimilation runs performed consistently better, but with very different skill levels for the different TCs. Eliassen-Palm flux analyses are employed. It is confirmed that if a polar orbital satellite footprint passes over the TC’s critical genesis region, the forecast will profit most from assimilating the remotely sensed information. If the critical genesis region lies within an interorbital gap then, regardless of how strong the TC later becomes (e.g., Katrina 2005, the improvement from assimilating near-surface winds and total precipitable water in the model prediction is severely limited. This underpins the need for a synergy of data from different scatterometers/radiometers. Other approaches are suggested to improve the accuracy in the prediction of TC genesis and tracks.

Seasonal mortality and sequential density dependence in a migratory bird

NARCIS (Netherlands)

Rakhimberdiev, Eldar; van den Hout, Piet J.; Brugge, Maarten; Spaans, Bernard; Piersma, Theunis

2015-01-01

Migratory bird populations may be limited during one or more seasons, and thus at one or more places, but there is a dearth of empirical examples of this possibility. We analyse seasonal survival in a migratory shellfish-eating shorebird (red knot Calidris canutus islandica) during a series of years

75 FR 29917 - Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation

Science.gov (United States)

2010-05-28

... governing migratory bird rehabilitation in the United States. Before creation of those regulations... language in the final paragraph of the 2003 regulations dealt with the transition of special purpose permit... regulations is to remove all of the language under paragraph (i). This change is simply a ministerial...

Upper ocean currents and sea surface temperatures (SST) from Satellite-tracked drifting buoys (drifters) as part of the Global Drifter Program for Hawaii region 1980/02/01 - 2009/03/31 (NODC Accession 0063296)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Satellite-tracked drifting buoys ("drifters") collect measurements of upper ocean currents and sea surface temperatures (SST) around the world as part of the Global...

An exception to the rule: carry-over effects do not accumulate in a long-distance migratory bird.

Directory of Open Access Journals (Sweden)

Nathan R Senner

Full Text Available Recent years have seen a growing consensus that events during one part of an animal's annual cycle can detrimentally affect its future fitness. Notably, migratory species have been shown to commonly display such carry-over effects, facing severe time constraints and physiological stresses that can influence events across seasons. However, to date, no study has examined a full annual cycle to determine when these carry-over effects arise and how long they persist within and across years. Understanding when carry-over effects are created and how they persist is critical to identifying those periods and geographic locations that constrain the annual cycle of a population and determining how selection is acting upon individuals throughout the entire year. Using three consecutive years of migration tracks and four consecutive years of breeding success data, we tested whether carry-over effects in the form of timing deviations during one migratory segment of the annual cycle represent fitness costs that persist or accumulate across the annual cycle for a long-distance migratory bird, the Hudsonian godwit, Limosa haemastica. We found that individual godwits could migrate progressively later than population mean over the course of an entire migration period, especially southbound migration, but that these deviations did not accumulate across the entire year and were not consistently detected among individuals across years. Furthermore, neither the accumulation of lateness during previous portions of the annual cycle nor arrival date at the breeding grounds resulted in individuals suffering reductions in their breeding success or survival. Given their extreme life history, such a lack of carry-over effects suggests that strong selection exists on godwits at each stage of the annual cycle and that carry-over effects may not be able to persist in such a system, but also emphasizes that high-quality stopover and wintering sites are critical to the

NOAA-L satellite arrives at Vandenberg AFB

Science.gov (United States)

2000-01-01

Outside the B16-10 spacecraft processing hangar at Vandenberg Air Force Base, Calif., a crated National Oceanic and Atmospheric Administration (NOAA-L) satellite is lowered to the ground before being moved inside. NOAA-L is part of the Polar-Orbiting Operational Environmental Satellite (POES) program that provides atmospheric measurements of temperature, humidity, ozone and cloud images, tracking weather patterns that affect the global weather and climate. The launch of the NOAA-L satellite is scheduled no earlier than Sept. 12 aboard a Lockheed Martin Titan II rocket. 75 FR 9314 - Migratory Bird Permits; Control of Purple Swamphens

Science.gov (United States)

2010-03-01

...) purple swamphens are not migratory and (2) are invasive and should be removed. Though the species is a migratory bird species under the MBTA, it is invasive in the continental U.S. and other locations outside... allow removal of an introduced species that competes with native species of wildlife. Purple swamphens...

The eastern migratory caribou: the role of genetic introgression in ecotype evolution.

Science.gov (United States)

Klütsch, Cornelya F C; Manseau, Micheline; Trim, Vicki; Polfus, Jean; Wilson, Paul J

2016-02-01

Understanding the evolutionary history of contemporary animal groups is essential for conservation and management of endangered species like caribou (Rangifer tarandus). In central Canada, the ranges of two caribou subspecies (barren-ground/woodland caribou) and two woodland caribou ecotypes (boreal/eastern migratory) overlap. Our objectives were to reconstruct the evolutionary history of the eastern migratory ecotype and to assess the potential role of introgression in ecotype evolution. STRUCTURE analyses identified five higher order groups (i.e. three boreal caribou populations, eastern migratory ecotype and barren-ground). The evolutionary history of the eastern migratory ecotype was best explained by an early genetic introgression from barren-ground into a woodland caribou lineage during the Late Pleistocene and subsequent divergence of the eastern migratory ecotype during the Holocene. These results are consistent with the retreat of the Laurentide ice sheet and the colonization of the Hudson Bay coastal areas subsequent to the establishment of forest tundra vegetation approximately 7000 years ago. This historical reconstruction of the eastern migratory ecotype further supports its current classification as a conservation unit, specifically a Designatable Unit, under Canada's Species at Risk Act. These findings have implications for other sub-specific contact zones for caribou and other North American species in conservation unit delineation.

Reliable Control of Ship-mounted Satellite Tracking Antenna

DEFF Research Database (Denmark)

Soltani, Mohsen; Izadi-Zamanabadi, Roozbeh; Wisniewski, Rafal

2010-01-01

Motorized antenna is a key element in overseas satellite telecommunication. The control system directs the on-board antenna toward a chosen satellitewhile the high sea waves disturb the antenna. Certain faults (communication system malfunction or signal blocking) cause interruption in the communi...

MIGRATORY THREATS TO NATIONAL SECURITY OF UKRAINE: CURRENT CHALLENGES AND WAYS OF REGULATION

Directory of Open Access Journals (Sweden)

Mychailo Romaniuk

2016-11-01

Full Text Available The purpose of the article is to disclose the migratory threats which are connected with external and mass internal inter-regional migrations, which are caused by the annexation of the Crimea and military aggression in Donbas by Russia. Methodological and practical aspects of improving the management of intensive interstate and inter-regional migratory processes, negative consequences of which threaten national security of the country because of hybrid war in Donbas, illegal migration, worsening of the demographic situation, departure of scientists and specialists abroad are described in the article too. The main strategic objective, which consists of maintenance of state sovereignty, territorial integrity of Ukraine, and also integration in European and migratory space, ensuring close to the world standards of quality and length of life, realization of rights and freedoms of citizens, is formulated. Actions and tasks of the state migratory policy, ways and methods of regulation of external migrations of the population are considered. Principal reasons of external migrations of population are identified and analysed. The inwardly-regional, interregional and intergovernmental migrations of population of Ukraine in the years of its state independence (1991- 2014 are analyzed in details. The results of analysis showed that migratory activity goes down on inwardly-regional and interregional levels. Also intensity of exchange of population went down between the regions of country. At the same time Ukraine for years state independence through depopulation processes lost 6,5 million persons, and in the external migratory moving of population of loss made over 1 million persons. The problem of illegal external labour migration is considered. It is noted that illegal migration from Ukraine to the threats to national security in the Law of Ukraine "On the National Security of Ukraine" is not included, and a threat to national security posed by illegal

GPS Navigation and Tracking Device

Directory of Open Access Journals (Sweden)

Yahya Salameh Khraisat

2011-10-01

Full Text Available Since the introduction of GPS Navigation systems in the marketplace, consumers and businesses have been coming up with innovative ways to use the technology in their everyday life. GPS Navigation and Tracking systems keep us from getting lost when we are in strange locations, they monitor children when they are away from home, keep track of business vehicles and can even let us know where a philandering partner is at all times. Because of this we attend to build a GPS tracking device to solve the mentioned problems. Our work consists of the GPS module that collects data from satellites and calculates the position information before transmitting them to the user’s PC (of Navigation system or observers (of Tracking System using wireless technology (GSM.

Launching the First Indian Satellite

Indian Academy of Sciences (India)

long run, this is not bad since it generates self-confidence and self-reliance - which in the final analysis are .... hopes to find some new X-ray sources. The second ... from the state of health of the satellite can be judged. A tracking network gives ...

Shape up or ship out: migratory behaviour predicts morphology across spatial scale in a freshwater fish.

Science.gov (United States)

Chapman, Ben B; Hulthén, Kaj; Brönmark, Christer; Nilsson, P Anders; Skov, Christian; Hansson, Lars-Anders; Brodersen, Jakob

2015-09-01

1. Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body morphology can be explained by variation in migratory strategy within a species. 2. We address this question in roach Rutilus rutilus, a partially migratory freshwater fish that migrates from lakes into streams during winter. We both compare body shape between populations that differ in migratory opportunity (open vs. closed lakes), and between individuals from a single population that vary in migratory propensity (migrants and residents from a partially migratory population). Following hydrodynamic theory, we posit that migrants should have a more shallow body depth, to reduce the costs associated with migrating into streams with higher flow conditions than the lakes the residents occupy all year round. 3. We find evidence both across and within populations to support our prediction, with individuals from open lakes and migrants from the partially migratory population having a more slender, shallow-bodied morphology than fish from closed lakes and all-year residents. 4. Our data suggest that a shallow body morphology is beneficial to migratory individuals and our study is one of the first to link migratory strategy and intraspecific variation in body shape. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Scientific analysis of satellite ranging data

Science.gov (United States)

Smith, David E.

1994-01-01

A network of satellite laser ranging (SLR) tracking systems with continuously improving accuracies is challenging the modelling capabilities of analysts worldwide. Various data analysis techniques have yielded many advances in the development of orbit, instrument and Earth models. The direct measurement of the distance to the satellite provided by the laser ranges has given us a simple metric which links the results obtained by diverse approaches. Different groups have used SLR data, often in combination with observations from other space geodetic techniques, to improve models of the static geopotential, the solid Earth, ocean tides, and atmospheric drag models for low Earth satellites. Radiation pressure models and other non-conservative forces for satellite orbits above the atmosphere have been developed to exploit the full accuracy of the latest SLR instruments. SLR is the baseline tracking system for the altimeter missions TOPEX/Poseidon, and ERS-1 and will play an important role in providing the reference frame for locating the geocentric position of the ocean surface, in providing an unchanging range standard for altimeter calibration, and for improving the geoid models to separate gravitational from ocean circulation signals seen in the sea surface. However, even with the many improvements in the models used to support the orbital analysis of laser observations, there remain systematic effects which limit the full exploitation of SLR accuracy today.

Managing conflicts between economic activities and threatened migratory marine species toward creating a multiobjective blue economy.

Science.gov (United States)

Harris, Linda R; Nel, Ronel; Oosthuizen, Herman; Meÿer, Mike; Kotze, Deon; Anders, Darrell; McCue, Steven; Bachoo, Santosh

2018-04-01

Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement-based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species' 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of 50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives. © 2017 Society for Conservation Biology.

Carry-over effects on the annual cycle of a migratory seabird: an experimental study.

Science.gov (United States)

Fayet, Annette L; Freeman, Robin; Shoji, Akiko; Kirk, Holly L; Padget, Oliver; Perrins, Chris M; Guilford, Tim

2016-11-01

Long-lived migratory animals must balance the cost of current reproduction with their own condition ahead of a challenging migration and future reproduction. In these species, carry-over effects, which occur when events in one season affect the outcome of the subsequent season, may be particularly exacerbated. However, how carry-over effects influence future breeding outcomes and whether (and how) they also affect behaviour during migration and wintering is unclear. Here we investigate carry-over effects induced by a controlled, bidirectional manipulation of the duration of reproductive effort on the migratory, wintering and subsequent breeding behaviour of a long-lived migratory seabird, the Manx shearwater Puffinus puffinus. By cross-fostering chicks of different age between nests, we successfully prolonged or shortened by ∼25% the chick-rearing period of 42 breeding pairs. We tracked the adults with geolocators over the subsequent year and combined migration route data with at-sea activity budgets obtained from high-resolution saltwater-immersion data. Migratory behaviour was also recorded during non-experimental years (the year before and/or two years after manipulation) for a subset of birds, allowing comparison between experimental and non-experimental years within treatment groups. All birds cared for chicks until normal fledging age, resulting in birds with a longer breeding period delaying their departure on migration; however, birds that finished breeding earlier did not start migrating earlier. Increased reproductive effort resulted in less time spent at the wintering grounds, a reduction in time spent resting daily and a delayed start of breeding with lighter eggs and chicks and lower breeding success the following breeding season. Conversely, reduced reproductive effort resulted in more time resting and less time foraging during the winter, but a similar breeding phenology and success compared with control birds the following year, suggesting that

Orbit determination for ISRO satellite missions

Science.gov (United States)

Rao, Ch. Sreehari; Sinha, S. K.

Indian Space Research Organisation (ISRO) has been successful in using the in-house developed orbit determination and prediction software for satellite missions of Bhaskara, Rohini and APPLE. Considering the requirements of satellite missions, software packages are developed, tested and their accuracies are assessed. Orbit determination packages developed are SOIP, for low earth orbits of Bhaskara and Rohini missions, ORIGIN and ODPM, for orbits related to all phases of geo-stationary missions and SEGNIP, for drift and geo-stationary orbits. Software is tested and qualified using tracking data of SIGNE-3, D5-B, OTS, SYMPHONIE satellites with the help of software available with CNES, ESA and DFVLR. The results match well with those available from these agencies. These packages have supported orbit determination successfully throughout the mission life for all ISRO satellite missions. Member-Secretary

Deep space optical communication via relay satellite

Science.gov (United States)

Dolinar, S.; Vilnrotter, V.; Gagliardi, R.

1981-01-01

The application of optical communications for a deep space link via an earth-orbiting relay satellite is discussed. The system uses optical frequencies for the free-space channel and RF links for atmospheric transmission. The relay satellite is in geostationary orbit and contains the optics necessary for data processing and formatting. It returns the data to earth through the RF terrestrial link and also transmits an optical beacon to the satellite for spacecraft return pointing and for the alignment of the transmitting optics. Future work will turn to modulation and coding, pointing and tracking, and optical-RF interfacing.

Satellite tracking of the migration of Whooper Swans Cygnus cygnus wintering in Japan

Science.gov (United States)

Shimada, Tetsuo; Yamaguchi, Noriyuki M.; Hijikata, N.; Hiraoka, Emiko N.; Hupp, Jerry; Flint, Paul L.; Tokita, Ken-ichi; Fujita, Go; Uchida, Kiyoshi; Sato, F.; Kurechi, Masayuki; Pearce, John M.; Ramey, Andy M.; Higuchi, Hiroyoshi

2014-01-01

We satellite-tracked Whooper Swans Cygnus cygnus wintering in northern Japan to document their migration routes and timing, and to identify breeding areas. From 47 swans that we marked at Lake Izunuma-Uchinuma, Miyagi Prefecture, northeast Honshu, and at Lake Kussharo, east Hokkaido, we observed 57 spring and 33 autumn migrations from 2009-2012. In spring, swans migrated north along Sakhalin Island from eastern Hokkaido using stopovers in Sakhalin, at the mouth of the Amur River and in northern coastal areas of the Sea of Okhotsk. They ultimately reached molting/breedmg areas along the Indigirka River and the lower Kolyma River in northern Russia. In autumn, the swans basically reversed the spring migration routes. We identified northern Honshu, eastern Hokkaido, coastal areas in Sakhalin, the lower Amur River and northern coastal areas of the Sea of Okhotsk as the most frequent stopover sites, and the middle reaches of the Indigirka and the lower Kolyma River as presumed breeding sites. Our results are helpful in understanding the distribution of the breeding and stopover sites of Whooper Swans wintering in Japan and in identifying their major migration habitats. Our findings contribute to understanding the potential transmission process of avian influenza viruses potentially carried by swans, and provide information necessary to conserve Whooper Swans in East Asia.

Activities of Canadian Satellite Communications, Inc.

Science.gov (United States)

1992-12-01

Canadian Satellite Communications (Cancom) has as its core business the provision of television and radio signals to cable systems in Canada, with the objective of making affordable broadcast signals available to remote and/or small communities. Cancom also provides direct-to-home services to backyard receiving dishes, as well as satellite digital data business communications services, satellite business television, and satellite network services. Its business communication services range from satellite links for big-city businesses with small branch operations located far from major centers, to a mobile messaging and tracking system for the trucking industry. Revenues in 1992 totalled $48,212,000 and net income was just over $7 million. Cancom bought 10 percent interest in Leosat Corp. of Washington, DC, who are seeking approval to operate a position locator network from low-orbit satellites. Cancom has also become a partner in SovCan Star Satellite Communications Inc., which will build an international satellite system in partnership with Russia. The first satellite in this east-west business network will be placed in a Russian orbital slot over the Atlantic by 1996, and a second satellite will follow for the Pacific region. This annual report of Cancom's activities for 1992 includes financial statements and a six year financial review.

Data Mining Approaches for Habitats and Stopovers Discovery of Migratory Birds

Directory of Open Access Journals (Sweden)

Qiang Xu

2013-03-01

Full Text Available This paper focuses on using data mining technology to efficiently and accurately discover habitats and stopovers of migratory birds. The three methods we used are as follows: 1. a density-based clustering method, detecting stopovers of birds during their migration through density-based clustering of location points; 2. A location histories parser method, detecting areas that have been overstayed by migratory birds during a set time period by setting time and distance thresholds; and 3. A time-parameterized line segment clustering method, clustering directed line segments to analyze shared segments of migratory pathways of different migratory birds and discover the habitats and stopovers of these birds. Finally, we analyzed the migration data of the bar-headed goose in the Qinghai Lake Area through the three above methods and verified the effectiveness of the three methods and, by comparison, identified the scope and context of the use of these three methods respectively.

H5N1 surveillance in migratory birds in Java, Indonesia.

Science.gov (United States)

Stoops, Arthur C; Barbara, Katie A; Indrawan, Mochamad; Ibrahim, Ima N; Petrus, Wicaksana B; Wijaya, Susan; Farzeli, Arik; Antonjaya, Ungke; Sin, Lim W; Hidayatullah, N; Kristanto, Ige; Tampubolon, A M; Purnama, S; Supriatna, Adam; Burgess, Timothy H; Williams, Maya; Putnam, Shannon D; Tobias, Steve; Blair, Patrick J

2009-12-01

We sought to elucidate the role of migratory birds in transmission of H5N1 in an enzoonotic area. Resident, captive, and migratory birds were sampled at five sites in Java, Indonesia. Mist nets were used to trap birds. Birds were identified to species. RNA was extracted from swabs and reverse transcriptase polymerase chain reaction (RT-PCR) conducted for the HA and M genes of H5N1. Antibodies were detected by enzyme-linked immunosorbent assay and hemagglutination inhibition test. Between October 2006 and September 2007, a total of 4,067 captive, resident, and migratory birds comprising 98 species in 23 genera were sampled. The most commonly collected birds were the common sandpiper (6% of total), striated heron (3%), and the domestic chicken (14%). The overall prevalence of H5N1 antibodies was 5.3%. A significantly higher percentage of captive birds (16.1%) showed antibody evidence of H5N1 exposure when compared to migratory or resident birds. The greatest number of seropositive birds in each category were Muschovy duck (captive), striated heron (resident), and the Pacific golden plover (migratory). Seven apparently well captive birds yielded molecular evidence of H5N1 infection. Following amplification, the HA, NA, and M genes were analyzed. Phylogenetic analysis of the HA gene showed that the isolates were 97% similar to EU124153.1 A/chicken/West Java/Garut May 2006, an isolate obtained in a similar region of West Java. While no known markers of neuraminidase inhibitor resistance were found within the NA gene, M segment analysis revealed the V27A mutation known to confer resistance to adamantanes. Our results demonstrate moderate serologic evidence of H5N1 infection in captive birds, sampled in five sites in Java, Indonesia, but only occasional infection in resident and migratory birds. These data imply that in an enzoonotic region of Indonesia the role of migratory birds in transmission of H5N1 is limited.

76 FR 44729 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

Science.gov (United States)

2011-07-26

...- 2010 average (3.4 0.03 million). As expected, residual water from summer 2010 precipitation remained in... preliminary 2010 Migratory Bird Harvest Information Program (HIP) estimate of harvest was 84,900 birds. In... trend in the population indices between 1966 and 2010. According to HIP surveys, the preliminary harvest...

Fat, weather, and date affect migratory songbirds' departure decisions, routes, and time it takes to cross the Gulf of Mexico.

Science.gov (United States)

Deppe, Jill L; Ward, Michael P; Bolus, Rachel T; Diehl, Robert H; Celis-Murillo, Antonio; Zenzal, Theodore J; Moore, Frank R; Benson, Thomas J; Smolinsky, Jaclyn A; Schofield, Lynn N; Enstrom, David A; Paxton, Eben H; Bohrer, Gil; Beveroth, Tara A; Raim, Arlo; Obringer, Renee L; Delaney, David; Cochran, William W

2015-11-17

Approximately two thirds of migratory songbirds in eastern North America negotiate the Gulf of Mexico (GOM), where inclement weather coupled with no refueling or resting opportunities can be lethal. However, decisions made when navigating such features and their consequences remain largely unknown due to technological limitations of tracking small animals over large areas. We used automated radio telemetry to track three songbird species (Red-eyed Vireo, Swainson's Thrush, Wood Thrush) from coastal Alabama to the northern Yucatan Peninsula (YP) during fall migration. Detecting songbirds after crossing ∼1,000 km of open water allowed us to examine intrinsic (age, wing length, fat) and extrinsic (weather, date) variables shaping departure decisions, arrival at the YP, and crossing times. Large fat reserves and low humidity, indicative of beneficial synoptic weather patterns, favored southward departure across the Gulf. Individuals detected in the YP departed with large fat reserves and later in the fall with profitable winds, and flight durations (mean = 22.4 h) were positively related to wind profit. Age was not related to departure behavior, arrival, or travel time. However, vireos negotiated the GOM differently than thrushes, including different departure decisions, lower probability of detection in the YP, and longer crossing times. Defense of winter territories by thrushes but not vireos and species-specific foraging habits may explain the divergent migratory behaviors. Fat reserves appear extremely important to departure decisions and arrival in the YP. As habitat along the GOM is degraded, birds may be limited in their ability to acquire fat to cross the Gulf.

Fat, weather, and date affect migratory songbirds’ departure decisions, routes, and time it takes to cross the Gulf of Mexico

Science.gov (United States)

Deppe, Jill L.; Ward, Michael P.; Bolus, Rachel T.; Diehl, Robert H.; Celis-Murillo, A.; Zenzal, Theodore J.; Moore, Frank R.; Benson, Thomas J.; Smolinsky, Jaclyn A.; Schofield, Lynn N.; Enstrom, David A.; Paxton, Eben H.; Bohrer, Gil; Beveroth, Tara A.; Raim, Arlo; Obringer, Renee L.; Delaney, David; Cochran, William W.

2015-01-01

Approximately two thirds of migratory songbirds in eastern North America negotiate the Gulf of Mexico (GOM), where inclement weather coupled with no refueling or resting opportunities can be lethal. However, decisions made when navigating such features and their consequences remain largely unknown due to technological limitations of tracking small animals over large areas. We used automated radio telemetry to track three songbird species (Red-eyed Vireo, Swainson’s Thrush, Wood Thrush) from coastal Alabama to the northern Yucatan Peninsula (YP) during fall migration. Detecting songbirds after crossing ∼1,000 km of open water allowed us to examine intrinsic (age, wing length, fat) and extrinsic (weather, date) variables shaping departure decisions, arrival at the YP, and crossing times. Large fat reserves and low humidity, indicative of beneficial synoptic weather patterns, favored southward departure across the Gulf. Individuals detected in the YP departed with large fat reserves and later in the fall with profitable winds, and flight durations (mean = 22.4 h) were positively related to wind profit. Age was not related to departure behavior, arrival, or travel time. However, vireos negotiated the GOM differently than thrushes, including different departure decisions, lower probability of detection in the YP, and longer crossing times. Defense of winter territories by thrushes but not vireos and species-specific foraging habits may explain the divergent migratory behaviors. Fat reserves appear extremely important to departure decisions and arrival in the YP. As habitat along the GOM is degraded, birds may be limited in their ability to acquire fat to cross the Gulf.

The 2017 Hurricane Season: A Revolution in Geostationary Weather Satellite Imaging and Data Processing

Science.gov (United States)

Weiner, A. M.; Gundy, J.; Brown-Bertold, B.; Yates, H.; Dobler, J. T.

2017-12-01

Since their introduction, geostationary weather satellites have enabled us to track hurricane life-cycle movement from development to dissipation. During the 2017 hurricane season, the new GOES-16 geostationary satellite demonstrated just how far we have progressed technologically in geostationary satellite imaging, with hurricane imagery showing never-before-seen detail of the hurricane eye and eyewall structure and life cycle. In addition, new ground system technology, leveraging high-performance computing, delivered imagery and data to forecasters with unprecedented speed—and with updates as often as every 30 seconds. As additional satellites and new products become operational, forecasters will be able to track hurricanes with even greater accuracy and assist in aftermath evaluations. This presentation will present glimpses into the past, a look at the present, and a prediction for the future utilization of geostationary satellites with respect to all facets of hurricane support.

iSAT: The Integrated Satellite and Acoustic Telemetry system for tracking marine megafauna

KAUST Repository

De La Torre, Pedro R.

2014-05-01

In this dissertation an innovative technology to study whale sharks, Rhincodon typus is presented. The Integrated Satellite and Acoustic Telemetry project (iSAT) combines underwater acoustic telemetry, autonomous navigation and radio frequency communications into a standalone system. The whale shark, a resident of the Saudi Arabian Red Sea, is the target of the study. The technology presented is designed to help close current gaps in the knowledge of whale shark biology; these are gaps that prohibit the design of optimal conservation strategies. Unfortunately, the various existing tracking technologies each have limitations and are unable to solve all the unanswered questions. Whale shark populations are increasingly threatened by anthropogenic activities such as targeted and indirect fishing pressure, creating an urgent need for better management practices. This dissertation addresses the current state-of-the-art of relevant technologies, including autonomous surface vehicles (ASVs), sensors for research in the ocean and remote monitoring of wild fauna (biotelemetry). iSAT contains components of all of these technologies, but the primary achievement of this dissertation is the development of iSAT’s Acoustic Tracking System (ATS). Underwater, the most efficient way of transmitting energy through long distances is sound. An electronic tag is attached to an animal and works as its acoustic identifier. iSAT’s hydrophone array detects the presence and direction of the acoustic signal generated by the tag. The expected performance, range, and capacity to tell the direction to the tag are explained and compared to the actual measured values. The first operational iSAT ATS is demonstrated. This work represents significant advancement towards a fully autonomous iSAT system. Developments on the power electronics, navigation, renewable energy harvesting, and other modules are included in this research. With the recent integration of digital acquisition systems, i

Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

Science.gov (United States)

Smith, William E.; Kwak, Thomas J.

2014-01-01

Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

Accumulation features of persistent organochlorines in resident and migratory birds from Asia

International Nuclear Information System (INIS)

Kunisue, Tatsuya; Watanabe, Mafumi; Subramanian, Annamalai; Sethuraman, Alagappan; Titenko, Alexei M.; Qui, Vo; Prudente, Maricar; Tanabe, Shinsuke

2003-01-01

Accumulation features of persistent organochlorines in migratory birds from Asia did not necessarily reflect only the pollution in the sampling area. - Concentrations of organochlorine contaminants including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) were determined in the resident and migratory birds, which were collected from India, Japan, Philippines, Russia (Lake Baikal) and Vietnam. Accumulation patterns of organochlorine concentrations in resident birds suggested that the predominant contaminants of each country were as follows: Japan-PCBs Philippines-PCBs and CHLs, India-HCHs and DDTs, Vietnam-DDTs, and Lake Baikal-PCBs and DDTs. The migratory birds from Philippines and Vietnam retained mostly the highest concentrations of DDTs among the organochlorines analyzed, indicating the presence of stopover and breeding grounds of those birds in China and Russia. On the other hand, migratory birds from India and Lake Baikal showed different patterns of organochlorine residues, reflecting that each species has inherent migratory routes and thus has exposure to different contaminants. Species which have breeding grounds around the Red Sea and Persian Gulf showed high levels of PCBs, indicating the presence of areas heavily polluted by PCBs in the Middle East

USDA Forest Service goals and programs for monitoring neotropical migratory birds

Science.gov (United States)

Patricia Manley

1993-01-01

The USDA Forest Service (USFS) developed goals, objectives, and guidelines for monitoring neotropical migratory birds (NTMB) on National Forest System lands in response to the Neotropical Migratory Bird Conservation Program Partners in Flight. A USFS task group developed a hierarchical monitoring framework designed to define priorities for type of monitoring data....

Clock gene polymorphism, migratory behaviour and geographic distribution: a comparative study of trans-Saharan migratory birds.

Science.gov (United States)

Bazzi, Gaia; Cecere, Jacopo G; Caprioli, Manuela; Gatti, Emanuele; Gianfranceschi, Luca; Podofillini, Stefano; Possenti, Cristina D; Ambrosini, Roberto; Saino, Nicola; Spina, Fernando; Rubolini, Diego

2016-12-01

Migratory behaviour is controlled by endogenous circannual rhythms that are synchronized by external cues, such as photoperiod. Investigations on the genetic basis of circannual rhythmicity in vertebrates have highlighted that variation at candidate 'circadian clock' genes may play a major role in regulating photoperiodic responses and timing of life cycle events, such as reproduction and migration. In this comparative study of 23 trans-Saharan migratory bird species, we investigated the relationships between species-level genetic variation at two candidate genes, Clock and Adcyap1, and species' traits related to migration and geographic distribution, including timing of spring migration across the Mediterranean Sea, migration distance and breeding latitude. Consistently with previous evidence showing latitudinal clines in 'circadian clock' genotype frequencies, Clock allele size increased with breeding latitude across species. However, early- and late-migrating species had similar Clock allele size. Species migrating over longer distances, showing delayed spring migration and smaller phenotypic variance in spring migration timing, had significantly reduced Clock (but not Adcyap1) gene diversity. Phylogenetic confirmatory path analysis suggested that migration date and distance were the most important variables directly affecting Clock gene diversity. Hence, our study supports the hypothesis that Clock allele size increases poleward as a consequence of adaptation to the photoperiodic regime of the breeding areas. Moreover, we show that long-distance migration is associated with lower Clock diversity, coherently with strong stabilizing selection acting on timing of life cycle events in long-distance migratory species, likely resulting from the time constraints imposed by late spring migration. © 2016 John Wiley & Sons Ltd.

78 FR 58233 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

Science.gov (United States)

2013-09-23

... a primary emphasis on such species as mourning and white-winged dove. Late seasons begin about... migratory bird surveys and assigned the following OMB control numbers: 1018-0010--Mourning Dove Call Count... bag limit is 10 mourning or white-winged doves, singly, or in the aggregate. For the late season, the...

75 FR 47681 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

Science.gov (United States)

2010-08-06

... million). Residual water remains in the Parklands and these were classified as fair to good. Most of the... stabilized at around 100,000 birds; the preliminary 2009 Migratory Bird Harvest Information Program (HIP... and 2009. According to HIP surveys, the preliminary harvest estimate for 2009 was 66,100 white-winged...

Advancing migratory bird conservation and management by using radar: An interagency collaboration

Science.gov (United States)

Ruth, Janet M.; Barrow, Wylie C.; Sojda, Richard S.; Dawson, Deanna K.; Diehl, Robert H.; Manville, Albert; Green, Michael T.; Krueper, David J.; Johnston, Scott

2005-01-01

Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected or proposed across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

Attitude Control and Orbital Dynamics Challenges of Removing the First 3-Axis Stabilized Tracking and Data Relay Satellite from the Geosynchronous ARC

Science.gov (United States)

Benet, Charles A.; Hofman, Henry; Williams, Thomas E.; Olney, Dave; Zaleski, Ronald

2011-01-01

Launched on April 4, 1983 onboard STS 6 (Space Shuttle Challenger), the First Tracking and Data Relay Satellite (TDRS 1) was retired above the Geosynchronous Orbit (GEO) on June 27, 2010 after having provided real-time communications with a variety of low-orbiting spacecraft over a 26-year period. To meet NASA requirements limiting orbital debris 1, a team of experts was assembled to conduct an End-Of-Mission (EOM) procedure to raise the satellite 350 km above the GEO orbit. Following the orbit raising via conventional station change maneuvers, the team was confronted with having to deplete the remaining propellant and passivate all energy storage or generation sources. To accomplish these tasks within the time window, communications (telemetry and control links), electrical power, propulsion, and thermal constraints, a spacecraft originally designed as a three-axis stabilized satellite was turned into a spinner. This paper (a companion paper to Innovative Approach Enabled the Retirement of TDRS 1, paper # 1699, IEEE 2011 Aerospace Conference, March 5-12, 2011 sup 2) focuses on the challenges of maintaining an acceptable spinning dynamics, while repetitively firing thrusters. Also addressed are the effects of thruster firings on the orbit characteristics and how they were mitigated by a careful scheduling of the fuel depletion operations. Periodic thruster firings for spin rate adjustment, nutation damping, and precession of the momentum vector were also required in order to maintain effective communications with the satellite. All operations were thoroughly rehearsed and supported by simulations thus lending a high level of confidence in meeting the NASA EOM goals.

Visibility Analysis of Domestic Satellites on Proposed Ground Sites for Optical Surveillance

Directory of Open Access Journals (Sweden)

Jung Hyun Jo1

2011-12-01

Full Text Available The objectives of this study are to analyze the satellite visibility at the randomly established ground sites, to determine the five optimal ground sites to perform the optical surveillance and tracking of domestic satellites, and to verify the acquisition of the optical observation time sufficient to maintain the precise ephemeris at optimal ground sites that have been already determined. In order to accomplish these objectives, we analyzed the visibility for sun-synchronous orbit satellites, low earth orbit satellites, middle earth orbit satellites and domestic satellites as well as the continuous visibility along with the fictitious satellite ground track, and calculate the effective visibility. For the analysis, we carried out a series of repetitive process using the satellite tool kit simulation software developed by Analytical Graphics Incorporated. The lighting states of the penumbra and direct sun were set as the key constraints of the optical observation. The minimum of the observation satellite elevation angle was set to be 20 degree, whereas the maximum of the sun elevation angle was set to be -10 degree which is within the range of the nautical twilight. To select the candidates for the optimal optical observation, the entire globe was divided into 84 sectors in a constant interval, the visibility characteristics of the individual sectors were analyzed, and 17 ground sites were arbitrarily selected and analyzed further. Finally, five optimal ground sites (Khurel Togoot Observatory, Assy-Turgen Observatory, Tubitak National Observatory, Bisdee Tier Optical Astronomy Observatory, and South Africa Astronomical Observatory were determined. The total observation period was decided as one year. To examine the seasonal variation, the simulation was performed for the period of three days or less with respect to spring, summer, fall and winter. In conclusion, we decided the optimal ground sites to perform the optical surveillance and tracking

Analysis of Errors in a Special Perturbations Satellite Orbit Propagator

Energy Technology Data Exchange (ETDEWEB)

Beckerman, M.; Jones, J.P.

1999-02-01

We performed an analysis of error densities for the Special Perturbations orbit propagator using data for 29 satellites in orbits of interest to Space Shuttle and International Space Station collision avoidance. We find that the along-track errors predominate. These errors increase monotonically over each 36-hour prediction interval. The predicted positions in the along-track direction progressively either leap ahead of or lag behind the actual positions. Unlike the along-track errors the radial and cross-track errors oscillate about their nearly zero mean values. As the number of observations per fit interval decline the along-track prediction errors, and amplitudes of the radial and cross-track errors, increase.

Long-term GPS tracking of ocean sunfish Mola mola offers a new direction in fish monitoring.

Science.gov (United States)

Sims, David W; Queiroz, Nuno; Humphries, Nicolas E; Lima, Fernando P; Hays, Graeme C

2009-10-09

Satellite tracking of large pelagic fish provides insights on free-ranging behaviour, distributions and population structuring. Up to now, such fish have been tracked remotely using two principal methods: direct positioning of transmitters by Argos polar-orbiting satellites, and satellite relay of tag-derived light-level data for post hoc track reconstruction. Error fields associated with positions determined by these methods range from hundreds of metres to hundreds of kilometres. However, low spatial accuracy of tracks masks important details, such as foraging patterns. Here we use a fast-acquisition global positioning system (Fastloc GPS) tag with remote data retrieval to track long-term movements, in near real time and position accuracy of GPS tagging to provide tracks of unparalleled accuracy for monitoring movements of large pelagic fish, and with nearly four times as many locations obtained by the GPS tag than by a conventional Argos transmitter. The results signal the potential of GPS-tagged pelagic fish that surface regularly to be detectors of resource 'hotspots' in the blue ocean and provides a new capability for understanding large pelagic fish behaviour and habitat use that is relevant to ocean management and species conservation.

Methods of quantitative and qualitative analysis of bird migration with a tracking radar

Science.gov (United States)

Bruderer, B.; Steidinger, P.

1972-01-01

Methods of analyzing bird migration by using tracking radar are discussed. The procedure for assessing the rate of bird passage is described. Three topics are presented concerning the grouping of nocturnal migrants, the velocity of migratory flight, and identification of species by radar echoes. The height and volume of migration under different weather conditions are examined. The methods for studying the directions of migration and the correlation between winds and the height and direction of migrating birds are presented.

Migratory herds of wildebeests and zebras indirectly affect calf survival of giraffes.

Science.gov (United States)

Lee, Derek E; Kissui, Bernard M; Kiwango, Yustina A; Bond, Monica L

2016-12-01

In long-distance migratory systems, local fluctuations in the predator-prey ratio can exhibit extreme variability within a single year depending upon the seasonal location of migratory species. Such systems offer an opportunity to empirically investigate cyclic population density effects on short-term food web interactions by taking advantage of the large seasonal shifts in migratory prey biomass.We utilized a large-mammal predator-prey savanna food web to evaluate support for hypotheses relating to the indirect effects of "apparent competition" and "apparent mutualism" from migratory ungulate herds on survival of resident megaherbivore calves, mediated by their shared predator. African lions ( Panthera leo ) are generalist predators whose primary, preferred prey are wildebeests ( Connochaetes taurinus ) and zebras ( Equus quagga ), while lion predation on secondary prey such as giraffes ( Giraffa camelopardalis ) may change according to the relative abundance of the primary prey species.We used demographic data from five subpopulations of giraffes in the Tarangire Ecosystem of Tanzania, East Africa, to test hypotheses relating to direct predation and indirect effects of large migratory herds on calf survival of a resident megaherbivore. We examined neonatal survival via apparent reproduction of 860 adult females, and calf survival of 449 giraffe calves, during three precipitation seasons over 3 years, seeking evidence of some effect on neonate and calf survival as a consequence of the movements of large herds of migratory ungulates.We found that local lion predation pressure (lion density divided by primary prey density) was significantly negatively correlated with giraffe neonatal and calf survival probabilities. This supports the apparent mutualism hypothesis that the presence of migratory ungulates reduces lion predation on giraffe calves.Natural predation had a significant effect on giraffe calf and neonate survival, and could significantly affect giraffe

Spotted fever group rickettsiae in ticks of migratory birds in Romania.

Science.gov (United States)

Mărcuţan, Ioan-Daniel; Kalmár, Zsuzsa; Ionică, Angela Monica; D'Amico, Gianluca; Mihalca, Andrei Daniel; Vasile, Cozma; Sándor, Attila D

2016-05-20

Birds are important hosts and dispersers of parasitic arthropods and vector-borne zoonotic pathogens. Particularly migratory species may carry these parasites over long distances in short time periods. Migratory hotspots present ideal conditions to get a snapshot of parasite and pathogen diversity of birds migrating between continents. The aim of this study was to investigate the presence and diversity of Rickettsia spp. in ticks collected from birds at a migratory hot-spot in the Danube Delta, Romania, eastern Europe. DNA was extracted from ticks that were collected from migratory birds in the Danube Delta during migratory seasons in 2011-2012. Two 360 bp  fragments of the 16S ribosomal RNA gene and a 381 bp  fragment Gene gltA were PCR amplified and analyzed by sequence analysis (performed at Macrogen Europe, Amsterdam, The Netherlands). Nucleotide sequences were compared to reference sequences available in the GenBank database, using Basic Local Alignment Search Tool. Four hundred ticks of four different species were found on 11 bird species. The prevalence of Rickettsia spp. infection was 14 % (56/400, CI: 11.7-29.1), with significantly more nymphs hosting rickettsial infection compared to larvae (48 vs 7; P birds migrating through eastern Europe may carry ticks infected with a high diversity of rickettsial pathogens, with four Rickettsia spp. recorded. Migratory direction was important for pathogen burden, with seasonal differences in the occurrence of individual Rickettsia species. Here we report the first individual records of different Rickettsia spp. in H. concinna (R. monacensis), I. arboricola (R. helvetica, R. massiliae) and I. redikorzevi (R. helvetica) and also the first geographical record of occurrence of R. massiliae in Romania, representing the easternmost observation on the continent.

Habitat use of migratory bats killed during autumn at wind turbines.

Science.gov (United States)

Voigt, Christian C; Lindecke, Oliver; Schönborn, Sophia; Kramer-Schadt, Stephanie; Lehmann, David

2016-04-01

The killing of large numbers of migratory bats at wind turbines is a pressing conservation problem. Even though avoidance and mitigation measures could benefit from a better knowledge of the species' migratory habits, we lack basic information about what habitats and corridors bats use during migration. We studied the isotopic niche dimensions of three bat species that are frequently killed at wind turbines in Germany: non-migratory Pipistrellus pipistrellus, mid-distance migratory Nyctalus noctula, and long- distance migratory Pipistrellus nathusii. We measured stable carbon and nitrogen isotope ratios (δ¹³C, δ¹⁵N) in five tissues that differed in isotopic retention time (fur, wing membrane tissue, muscle, liver, blood) to shed light on the species-specific habitat use during the autumn migration period using standard ellipse areas (SEAc). Further, we used stable isotope ratios of non-exchangeable hydrogen (δ²H(K)) in fur keratin to assess the breeding origin of bats. We inferred from isotopic composition (δ¹³C, δ¹⁵N) of fur keratin that isotopic niche dimensions of P. nathusii was distinct from that of N. noctula and P. pipistrellus, probably because P. nathusii was using more aquatic habitats than the other two species. Isoscape origin models supported that traveled distances before dying at wind turbines was largest for P. nathusii, intermediate for N. noctula, and shortest for P. pipistrellus. Isotopic niche dimensions calculated for each sample type separately reflected the species' migratory behavior. Pipistrellus pipistrellus and N. noctula showed similar isotopic niche breadth across all tissue types, whereas SEAc values of P. nathusii increased in tissues with slow turnaround time. Isotopic data suggested that P. nathusii consistently used aquatic habitats throughout the autumn period, whereas N. noctula showed a stronger association with terrestrial habitats during autumn compared to the pre-migration period.

Interferometric Imaging of Geostationary Satellites: Signal-to-Noise Considerations

Science.gov (United States)

Jorgensen, A.; Schmitt, H.; Mozurkewich, D.; Armstrong, J.; Restaino, S.; Hindsley, R.

2011-09-01

Geostationary satellites are generally too small to image at high resolution with conventional single-dish telescopes. Obtaining many resolution elements across a typical geostationary satellite body requires a single-dish telescope with a diameter of 10’s of m or more, with a good adaptive optics system. An alternative is to use an optical/infrared interferometer consisting of multiple smaller telescopes in an array configuration. In this paper and companion papers1, 2 we discuss the performance of a common-mount 30-element interferometer. The instrument design is presented by Mozurkewich et al.,1 and imaging performance is presented by Schmitt et al.2 In this paper we discuss signal-to-noise ratio for both fringe-tracking and imaging. We conclude that the common-mount interferometer is sufficiently sensitive to track fringes on the majority of geostationary satellites. We also find that high-fidelity images can be obtained after a short integration time of a few minutes to a few tens of minutes.

Seasonal and circadian biases in bird tracking with solar GPS-tags

OpenAIRE

Silva, Rafa; Afán, Isabel; Gil, Juan A.; Bustamante, Javier

2017-01-01

Global Positioning System (GPS) tags are nowadays widely used in wildlife tracking. This geolocation technique can suffer from fix loss biases due to poor satellite GPS geometry, that result in tracking data gaps leading to wrong research conclusions. In addition, new solar-powered GPS tags deployed on birds can suffer from a new "battery drain bias" currently ignored in movement ecology analyses. We use a GPS tracking dataset of bearded vultures (Gypaetus barbatus), tracked for several years...

Precise object tracking under deformation

International Nuclear Information System (INIS)

Saad, M.H

2010-01-01

The precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This frame-work focuses on the precise object tracking under deformation such as scaling , rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high precession results.

Migratory Fishes of South America

International Development Research Centre (IDRC) Digital Library (Canada)

FAO Fisheries Technical Paper 262. ..... The abundance of most migratory fish was greater in the wet year. .... intensities in years of different flood intensities in the Upper Paraná (1985–1987 were dry years, whereas 1992–1993 were wet years). ...... Costa, M. R. C., G. Hermann, C. S. Martins, L. V. Lins, and I. R. Lamas.

Tracking wildlife by satellite: Current systems and performance

Science.gov (United States)

Harris, Richard B.; Fancy, Steven G.; Douglas, David C.; Garner, Gerald W.; Amstrup, Steven C.; McCabe, Thomas R.; Pank, Larry F.

1990-01-01

Since 1984, the U.S. Fish and Wildlife Service has used the Argos Data Collection and Location System (DCLS) and Tiros-N series satellites to monitor movements and activities of 10 species of large mammals in Alaska and the Rocky Mountain region. Reliability of the entire system was generally high. Data were received from instrumented caribou (Rangifer tarandus) during 91% of 318 possible transmitter-months. Transmitters failed prematurely on 5 of 45 caribou, 2 of 6 muskoxen (Ovibos moschatus), and 1 of 2 gray wolves (Canis lupus). Failure rates were considerably higher for polar (Ursus maritimus) and brown (U. arctos) bears than for caribou (Rangifer tarandus). Efficiency of gathering both locational and sensor data was related to both latitude and topography.Mean error of locations was estimated to be 954 m (median = 543 m) for transmitters on captive animals; 90% of locations were indices of animal activity were developed and evaluated. For several species, the long-term index was correlated with movement patterns and the short-term index was calibrated to specific activity categories (e.g., lying, feeding, walking).Data processing and sampling considerations were evaluated. Algorithms for choosing the most reliable among a series of reported locations were investigated. Applications of satellite telemetry data and problems with lack of independence among locations are discussed.

An overview of reference user services during the ATDRSS (Advanced Tracking and Data Relay Satellite System) era

Science.gov (United States)

Weinberg, Aaron

1989-01-01

The Tracking and Data Relay Satellite System (TDRSS) is an integral part of the overall NASA Space Network (SN) that will continue to evolve into the 1990's. Projections for the first decade of the 21st century indicate the need for an SN evolution that must accommodate growth int he LEO user population and must further support the introduction of new/improved user services. A central ingredient of this evolution is an Advanced TDRSS (ATDRSS) follow-on to the current TDRSS that must initiate operations by the late 1990's in a manner that permits an orderly transition from the TDRSS to the ATDRSS era. An SN/ATDRSS architectural and operational concept that will satisfy the above goals is being developed. To this date, an SN/ATDRSS baseline concept was established that provides users with an end-to-end data transport (ENDAT) service. An expanded description of the baseline ENDAT concept, from the user perspective, is provided with special emphasis on the TDRSS/ATDRSS evolution. A high-level description of the end-to-end system that identifies the role of ATDRSS is presented; also included is a description of the baseline ATDRSS architecture and its relationship with the TDRSS 1996 baseline. Other key features of the ENDAT service are then expanded upon, including the multiple grades of service, and the RF telecommunications/tracking services to be available. The ATDRSS service options are described.

Sea surface temperature measurements by the along-track scanning radiometer on the ERS 1 satellite: Early results

Science.gov (United States)

Mutlow, C. T.; ZáVody, A. M.; Barton, I. J.; Llewellyn-Jones, D. T.

1994-11-01

The along-track scanning radiometer (ATSR) was launched in July 1991 on the European Space Agency's first remote sensing satellite, ERS 1. An initial analysis of ATSR data demonstrates that the sea surface temperature (SST) can be measured from space with very high accuracy. Comparison of simultaneous measurements of SST made from ATSR and from a ship-borne radiometer show that they agree to within 0.3°C. To assess data consistency, a complementary analysis of SST data from ATSR was also carried out. The ATSR global SST field was compared on a daily basis with daily SST analysis of the United Kingdom Meteorological Office (UKMO). The ATSR global field is consistently within 1.0°C of the UKMO analysis. Also, to demonstrate the benefits of along-track scanning SST determination, the ATSR SST data were compared with high-quality bulk temperature observations from drifting buoys. The likely causes of the differences between ATSR and the bulk temperature data are briefly discussed. These results provide early confidence in the quantitative benefit of ATSR's two-angle view of the Earth and its high radiometric performance and show a significant advance on the data obtained from other spaceborne sensors. It should be noted that these measurements were made at a time when the atmosphere was severely contaminated with volcanic aerosol particles, which degrade infrared measurements of the Earth's surface made from space.

Consequences of resource supplementation for disease risk in a partially migratory population.

Science.gov (United States)

Brown, Leone M; Hall, Richard J

2018-05-05

Anthropogenic landscape features such as urban parks and gardens, landfills and farmlands can provide novel, seasonally reliable food sources that impact wildlife ecology and distributions. In historically migratory species, food subsidies can cause individuals to forgo migration and form partially migratory or entirely sedentary populations, eroding a crucial benefit of migration: pathogen avoidance through seasonal abandonment of transmission sites and mortality of infected individuals during migration. Since many migratory taxa are declining, and wildlife populations in urban areas can harbour zoonotic pathogens, understanding the mechanisms by which anthropogenic resource subsidies influence infection dynamics and the persistence of migration is important for wildlife conservation and public health. We developed a mathematical model for a partially migratory population and a vector-borne pathogen transmitted at a shared breeding ground, where food subsidies increase the nonbreeding survival of residents. We found that higher resident nonbreeding survival increased infection prevalence in residents and migrants, and lowered the fraction of the population that migrated. The persistence of migration may be especially threatened if residency permits emergence of more virulent pathogens, if resource subsidies reduce costs of infection for residents, and if infection reduces individual migratory propensity.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'. © 2018 The Author(s).

Sex and migratory strategy influence corticosterone levels in winter-grown feathers, with positive breeding effects in a migratory pelagic seabird.

Science.gov (United States)

Pérez, Cristóbal; Granadeiro, José Pedro; Dias, Maria P; Catry, Paulo

2016-08-01

To overcome unpredictable stressful transitory events, animals trigger an allostatic response involving the hypothalamic-pituitary-adrenal cortex. This hormonal response, which involves the release of glucocorticoids which in turn mediate between the main physiological mechanisms that regulate the energetic demands and resource allocation trade-off with behavioural responses to environmental perturbations and may ultimately lead to variation in fitness. We have used the Cory's shearwater Calonectris borealis, a sexually dimorphic pelagic seabird with a partial migratory strategy, as a model bird species to analyse a number of traits related to the stress response. We investigated whether the activation of a stressful response, mediated by corticosterone, during the wintering period (1) correlated with the previous breeding success, (2) was affected by the migratory behaviour of male birds and (3) had consequences in the fitness of the birds. Corticosterone levels in feathers grown overwinter were analysed in 61 adult birds during three consecutive migratory periods (2009-2012) and in 14 immature birds in the wintering period 2010-2011. Moreover, the levels of corticosterone were analysed in experimental birds which were freed from their reproductive duties and compared with control birds which raised fledglings to the end of the breeding period. The results show that the levels of corticosterone were sex dependent, differed between years and were affected by the migratory strategy performed by the birds. The activation of the stressful response over the wintering period generated residual carry-over effects that positively affected the reproductive output in the subsequent breeding stage, a phenomenon previously undescribed in a long-lived pelagic seabird. Our study provides evidence that the analysis of corticosterone from feathers is a useful tool to evaluate carry-over effects in birds far away from breeding sites, opening new possibilities for future studies in

Experimental temperature manipulations alter songbird autumnal nocturnal migratory restlessness

Directory of Open Access Journals (Sweden)

Berchtold Adrienne

2017-02-01

Full Text Available Migrating birds may respond to a variety of environmental cues in order to time migration. During the migration season nocturnally migrating songbirds may migrate or stop-over at their current location, and when migrating they may vary the rate or distance of migration on any given night. It has long been known that a variety of weather-related factors including wind speed and direction, and temperature, are correlated with migration in free-living birds, however these variables are often correlated with each other. In this study we experimentally manipulated temperature to determine if it would directly modulate nocturnal migratory restlessness in songbirds. We experimentally manipulated temperature between 4, 14, and 24°C and monitored nocturnal migratory restlessness during autumn in white-throated sparrows (Zonotrichia albicollis. White-throated sparrows are relatively shortdistance migrants with a prolonged autumnal migration, and we thus predicted they might be sensitive to weatherrelated cues when deciding whether to migrate or stopover. At warm temperatures (24°C none of the birds exhibited migratory restlessness. The probability of exhibiting migratory restlessness, and the intensity of this restlessness (number of infra-red beam breaks increased at cooler (14°C, 4°C temperatures. These data support the hypothesis that one of the many factors that birds use when making behavioural decisions during migration is temperature, and that birds can respond to temperature directly independently of other weather-related cues.

A Two-Dimensional Solar Tracking Stationary Guidance Method Based on Feature-Based Time Series

Directory of Open Access Journals (Sweden)

Keke Zhang

2018-01-01

Full Text Available The amount of satellite energy acquired has a direct impact on operational capacities of the satellite. As for practical high functional density microsatellites, solar tracking guidance design of solar panels plays an extremely important role. Targeted at stationary tracking problems incurred in a new system that utilizes panels mounted in the two-dimensional turntable to acquire energies to the greatest extent, a two-dimensional solar tracking stationary guidance method based on feature-based time series was proposed under the constraint of limited satellite attitude coupling control capability. By analyzing solar vector variation characteristics within an orbit period and solar vector changes within the whole life cycle, such a method could be adopted to establish a two-dimensional solar tracking guidance model based on the feature-based time series to realize automatic switching of feature-based time series and stationary guidance under the circumstance of different β angles and the maximum angular velocity control, which was applicable to near-earth orbits of all orbital inclination. It was employed to design a two-dimensional solar tracking stationary guidance system, and a mathematical simulation for guidance performance was carried out in diverse conditions under the background of in-orbit application. The simulation results show that the solar tracking accuracy of two-dimensional stationary guidance reaches 10∘ and below under the integrated constraints, which meet engineering application requirements.

The greenscape shapes surfing of resource waves in a large migratory herbivore.

Science.gov (United States)

Aikens, Ellen O; Kauffman, Matthew J; Merkle, Jerod A; Dwinnell, Samantha P H; Fralick, Gary L; Monteith, Kevin L

2017-06-01

The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e. green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that migratory routes are more than a link between seasonal ranges, and they provide an important, but often overlooked, foraging habitat. In addition, the spatiotemporal configuration of forage resources that propagate along migratory routes shape animal movement and presumably, energy gains during migration. © 2017 John Wiley & Sons Ltd/CNRS.

Estimating the per-capita contribution of habitats and pathways in a migratory network: A modelling approach

Science.gov (United States)

Wiederholt, Ruscena; Mattsson, Brady J.; Thogmartin, Wayne E.; Runge, Michael C.; Diffendorfer, Jay E.; Erickson, Richard A.; Federico, Paula; Lopez-Hoffman, Laura; Fryxell, John; Norris, D. Ryan; Sample, Christine

2018-01-01

Every year, migratory species undertake seasonal movements along different pathways between discrete regions and habitats. The ability to assess the relative demographic contributions of these different habitats and pathways to the species’ overall population dynamics is critical for understanding the ecology of migratory species, and also has practical applications for management and conservation. Metrics for assessing habitat contributions have been well-developed for metapopulations, but an equivalent metric is not currently available for migratory populations. Here, we develop a framework for estimating the demographic contributions of the discrete habitats and pathways used by migratory species throughout the annual cycle by estimating the per capita contribution of cohorts using these locations. Our framework accounts for seasonal movements between multiple breeding and non-breeding habitats and for both resident and migratory cohorts. We illustrate our framework using a hypothetical migratory network of four habitats, which allows us to better understand how variations in habitat quality affect per capita contributions. Results indicate that per capita contributions for any habitat or pathway are dependent on habitat-specific survival probabilities in all other areas used as part of the migratory circuit, and that contribution metrics are spatially linked (e.g. reduced survival in one habitat also decreases the contribution metric for other habitats). Our framework expands existing theory on the dynamics of spatiotemporally structured populations by developing a generalized approach to estimate the habitat- and pathway-specific contributions of species migrating between multiple breeding and multiple non-breeding habitats for a range of life histories or migratory strategies. Most importantly, it provides a means of prioritizing conservation efforts towards those migratory pathways and habitats that are most critical for the population viability of

ISAT: The mega-fauna acoustic tracking system

KAUST Repository

De la Torre, Pedro; Smith, Egan Lloyd; Sancheti, Ajay; Salama, Khaled N.; Berumen, Michael L.

2013-01-01

The acoustic tracking module of the Integrated Satellite and Acoustic Telemetry (iSAT) system is discussed in detail. iSAT is capable of detecting the relative direction of an acoustic source by measuring the order of arrival (OOA) of the acoustic

50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

Science.gov (United States)

2010-10-01

... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING... taking migratory game birds by falconry. This section provides annual regulations by which falconers may...

Fatalities at wind turbines may threaten population viability of a migratory bat

Science.gov (United States)

W.F. Frick; E.F. Baerwald; J.F. Pollock; R.M.R. Barclay; J.A. Szymanski; Ted Weller; A.L. Russell; Susan Loeb; R.A. Medellin; L.P. McGuire

2017-01-01

Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus),...

Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population

NARCIS (Netherlands)

Pulido, F.; Berthold, P.

2010-01-01

Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic

Accounting for the ecosystem services of migratory species: Quantifying migration support and spatial subsidies

Science.gov (United States)

Semmens, Darius J.; Diffendorfer, James E.; López-Hoffman, Laura; Shapiro, Carl D.

2011-01-01

Migratory species support ecosystem process and function in multiple areas, establishing ecological linkages between their different habitats. As they travel, migratory species also provide ecosystem services to people in many different locations. Previous research suggests there may be spatial mismatches between locations where humans use services and the ecosystems that produce them. This occurs with migratory species, between the areas that most support the species' population viability – and hence their long-term ability to provide services – and the locations where species provide the most ecosystem services. This paper presents a conceptual framework for estimating how much a particular location supports the provision of ecosystem services in other locations, and for estimating the extent to which local benefits are dependent upon other locations. We also describe a method for estimating the net payment, or subsidy, owed by or to a location that balances benefits received and support provided by locations throughout the migratory range of multiple species. The ability to quantify these spatial subsidies could provide a foundation for the establishment of markets that incentivize cross-jurisdictional cooperative management of migratory species. It could also provide a mechanism for resolving conflicts over the sustainable and equitable allocation of exploited migratory species.

Evolution of NASA's Near-Earth Tracking and Data Relay Satellite System (TDRSS)

Science.gov (United States)

Flaherty, Roger; Stocklin, Frank; Weinberg, Aaron

2006-01-01

NASA's Tracking and Data Relay Satellite System (TDRSS) is now in its 23rd year of operations and its spacecraft fleet includes three second-generation spacecraft launched since the year 2000; a figure illustrates the first generation TDRSS spacecraft. During this time frame the TDRSS has provided communications relay support to a broad range of missions, with emphasis on low-earth-orbiting (LEO) spacecraft that include unmanned science spacecraft (e.g., Hubble Space Telescope), and human spaceflight (Space Shuttle and Space Station). Furthermore, the TDRSS has consistently demonstrated its uniqueness and adaptability in several ways. First, its S- and K-band services, combined with its multi-band/steerable single-access (SA) antennas and ground-based configuration flexibility, have permitted the mission set to expand to unique users such as scientific balloons and launch vehicles. Second, the bent-pipe nature of the system has enabled the introduction of new/improved services via technology insertion and upgrades at each of the ground terminals; a specific example here is the Demand Access Service (DAS), which, for example, is currently providing science-alert support to NASA science missions Third, the bent-pipe nature of the system, combined with the flexible ground-terminal signal processing architecture has permitted the demonstration/vaIidation of new techniques/services/technologies via a real satellite channel; over the past 10+ years these have, for example, included demonstrations/evaluations of emerging modulation/coding techniques. Given NASA's emerging Exploration plans, with missions beginning later this decade and expanding for decades to come, NASA is currently planning the development of a seamless, NASA-wide architecture that must accommodate missions from near-earth to deep space. Near-earth elements include Ground-Network (GN) and Near-Earth Relay (NER) components and both must efficiently and seamlessly support missions that encompass: earth

Residency and movement patterns of an apex predatory shark (Galeocerdo cuvier at the Galapagos Marine Reserve.

Directory of Open Access Journals (Sweden)

David Acuña-Marrero

Full Text Available The potential effectiveness of marine protected areas (MPAs as a conservation tool for large sharks has been questioned due to the limited spatial extent of most MPAs in contrast to the complex life history and high mobility of many sharks. Here we evaluated the movement dynamics of a highly migratory apex predatory shark (tiger shark Galeocerdo cuvier at the Galapagos Marine Reserve (GMR. Using data from satellite tracking passive acoustic telemetry, and stereo baited remote underwater video, we estimated residency, activity spaces, site fidelity, distributional abundances and migration patterns from the GMR and in relation to nesting beaches of green sea turtles (Chelonia mydas, a seasonally abundant and predictable prey source for large tiger sharks. Tiger sharks exhibited a high degree of philopatry, with 93% of the total satellite-tracked time across all individuals occurring within the GMR. Large sharks (> 200 cm TL concentrated their movements in front of the two most important green sea turtle-nesting beaches in the GMR, visiting them on a daily basis during nocturnal hours. In contrast, small sharks (< 200 cm TL rarely visited turtle-nesting areas and displayed diurnal presence at a third location where only immature sharks were found. Small and some large individuals remained in the three study areas even outside of the turtle-nesting season. Only two sharks were satellite-tracked outside of the GMR, and following long-distance migrations, both individuals returned to turtle-nesting beaches at the subsequent turtle-nesting season. The spatial patterns of residency and site fidelity of tiger sharks suggest that the presence of a predictable source of prey and suitable habitats might reduce the spatial extent of this large shark that is highly migratory in other parts of its range. This highly philopatric behaviour enhances the potential effectiveness of the GMR for their protection.

Shape up or ship out: Migratory behaviour predicts morphology across spatial scale in a freshwater fish

DEFF Research Database (Denmark)

Chapman, B.B.; Hulthén, K.; Brönmark, C.

2015-01-01

Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body...... (open vs. closed lakes), and between individuals from a single population that vary in migratory propensity (migrants and residents from a partially migratory population). Following hydrodynamic theory, we posit that migrants should have a more shallow body depth, to reduce the costs associated...... with migrating into streams with higher flow conditions than the lakes the residents occupy all year round. We find evidence both across and within populations to support our prediction, with individuals from open lakes and migrants from the partially migratory population having a more slender, shallow...

Tracking radioactive shipments using radio-navigation and satellite telecommunication systems

International Nuclear Information System (INIS)

Harmon, L.H.; Habib, E.J.; Hurley, J.D.; Carlson, R.D.

1988-01-01

The United States Department of Enegy (USDOE) Waste Transportation Management Division (WMTD) has commissioned the development of a transportation tracking management and communication system to monitor movement of radioactive material shipments throughout the United States. The system, TRANSCOM, is being developed to enhance DOE's management oversight and operational control over the transport of sensitive materials (e.g., spent fuel, highlevel waste, transuranic waste etc.) and to address state and local government concerns regarding public safety. These goals are accomplished through providing a near real time tracking and communication system complete with information database management to support emergency response capabilities

IceBridge GPS L0 Raw Satellite Navigation Data

Data.gov (United States)

National Aeronautics and Space Administration — The NASA IceBridge GPS L0 Raw Satellite Navigation Data (IPUTG0) data set contains GPS readings, including latitude, longitude, track, ground speed, off distance,...

WIPP Transparency Project - container tracking and monitoring demonstration using the Authenticated Tracking and Monitoring System (ATMS)

International Nuclear Information System (INIS)

SCHOENEMAN, J. LEE; SMARTT, HEIDI ANNE; HOFER, DENNIS

2000-01-01

The Authenticated Tracking and Monitoring System (ATMS) is designed to answer the need for global monitoring of the status and location of proliferation-sensitive items on a worldwide basis, 24 hours a day. ATMS uses wireless sensor packs to monitor the status of the items within the shipment and surrounding environmental conditions. Receiver and processing units collect a variety of sensor event data that is integrated with GPS tracking data. The collected data are transmitted to the International Maritime Satellite (INMARSAT) communication system, which then sends the data to mobile ground stations. Authentication and encryption algorithms secure the data during communication activities. A typical ATMS application would be to track and monitor the stiety and security of a number of items in transit along a scheduled shipping route. The resulting tracking, timing, and status information could then be processed to ensure compliance with various agreements

Ecosystem services from transborder migratory species: Implications for conservation governance

Science.gov (United States)

Lopez-Hoffman, Laura; Chester, Charles C.; Semmens, Darius J.; Thogmartin, Wayne E.; Rodriguez-McGoffin, M. Sofia; Merideth, Robert; Diffendorfer, Jay E.

2017-01-01

This article discusses the conservation challenges of volant migratory transborder species and conservation governance primarily in North America. Many migratory species provide ecosystem service benefits to society. For example, insectivorous bats prey on crop pests and reduce the need for pesticides; birds and insects pollinate food plants; and birds afford recreational opportunities to hunters and birdwatchers. Migration is driven by the seasonal availability of resources; as resources in one area become seasonally scarce, individuals move to locations where resources have become seasonally abundant. The separation of the annual lifecycle means that species management and governance is often fractured across international borders. Because migratory species depend on habitat in different locations, their ability to provide ecosystem services in one area depends on the spatial subsidies, or support, provided by habitat and ecological processes in other areas. This creates telecouplings, or interconnections across geographic space, of areas such that impacts to the habitat of a migratory species in one location will affect the benefits enjoyed by people in other locations. Information about telecoupling and spatial subsidies can be used to craft new governance arrangements such as Payment for Ecosystem Services programs that target specific stakeholder groups and locations. We illustrate these challenges and opportunities with three North American case studies: the Duck Stamp Program, Mexican free-tailed bats (Tadarida brasiliensis mexicana), and monarch butterflies (Danaus plexippus).

Leonardo-BRDF: A New Generation Satellite Constellation

Science.gov (United States)

Esper, Jaime; Neeck, Steven; Wiscombe, Warren; Ryschkewitsch, Michael; Andary, J. (Technical Monitor)

2000-01-01

alongtrack or cross-track mode, or anything in between, at ground command. This provides inherent system redundancy and cross-calibration capability. Several "wing-man" satellites in non-static orbits fly in formation up to 1000 km out from the keystone satellites to provide additional along- and cross-track angular sampling. They view the target(s) observed by the keystone satellites from different zenith and azimuth angles and are maneuverable within a limited range of zenith angle using thrusters, and within a large range of azimuth angle using clever orbit design. The wing-man satellites carry single miniature imaging radiometers with just a few wavelength bands in order to be lighter and more agile.

Advanced domestic digital satellite communications systems experiments

Science.gov (United States)

Iso, A.; Izumisawa, T.; Ishida, N.

1984-02-01

The characteristics of advanced digital transmission systems were measured, using newly developed small earth stations and a K-band and C-band communication satellite. Satellite link performance for data, facsimile, video and packet switching information transmission at bit rates ranging from 6.4 kbit/s to 6.3 Mbit/s have been confirmed, using a small K-band earth station and a demand-assignment time division multiple access system. A low-capacity omni-use C-band terminal experiment has verified a telephone channel transmission performance by spread-spectrum multiple access. Single point to multipoint transmission characteristics of the 64 kbit/s data signals from the computer center were tested, using a receive-only 4 GHz earth terminal. Basic satellite link performance was confirmed under clear-sky conditions. Precise satellite orbit and attitude keeping experiments were carried out to obtain precise satellite antenna pointing accuracy for development of K-band earth stations that do not require satellite tracking equipment. Precise station keeping accuracy of 0.02 degrees was obtained.

77 FR 50470 - Proposed Information Collection; Comment Request; Atlantic Highly Migratory Species Recreational...

Science.gov (United States)

2012-08-21

..., West Atlantic sailfish, or North Atlantic swordfish in states (and the United States Virgin Islands and... Collection; Comment Request; Atlantic Highly Migratory Species Recreational Landings Reports AGENCY: National... provides important data used to monitor catches of Atlantic highly migratory species (HMS) and supplements...

Precise Point Positioning with the BeiDou Navigation Satellite System

Directory of Open Access Journals (Sweden)

Min Li

2014-01-01

Full Text Available By the end of 2012, China had launched 16 BeiDou-2 navigation satellites that include six GEOs, five IGSOs and five MEOs. This has provided initial navigation and precise pointing services ability in the Asia-Pacific regions. In order to assess the navigation and positioning performance of the BeiDou-2 system, Wuhan University has built up a network of BeiDou Experimental Tracking Stations (BETS around the World. The Position and Navigation Data Analyst (PANDA software was modified to determine the orbits of BeiDou satellites and provide precise orbit and satellite clock bias products from the BeiDou satellite system for user applications. This article uses the BeiDou/GPS observations of the BeiDou Experimental Tracking Stations to realize the BeiDou and BeiDou/GPS static and kinematic precise point positioning (PPP. The result indicates that the precision of BeiDou static and kinematic PPP reaches centimeter level. The precision of BeiDou/GPS kinematic PPP solutions is improved significantly compared to that of BeiDou-only or GPS-only kinematic PPP solutions. The PPP convergence time also decreases with the use of combined BeiDou/GPS systems.

Precise point positioning with the BeiDou navigation satellite system.

Science.gov (United States)

Li, Min; Qu, Lizhong; Zhao, Qile; Guo, Jing; Su, Xing; Li, Xiaotao

2014-01-08

By the end of 2012, China had launched 16 BeiDou-2 navigation satellites that include six GEOs, five IGSOs and five MEOs. This has provided initial navigation and precise pointing services ability in the Asia-Pacific regions. In order to assess the navigation and positioning performance of the BeiDou-2 system, Wuhan University has built up a network of BeiDou Experimental Tracking Stations (BETS) around the World. The Position and Navigation Data Analyst (PANDA) software was modified to determine the orbits of BeiDou satellites and provide precise orbit and satellite clock bias products from the BeiDou satellite system for user applications. This article uses the BeiDou/GPS observations of the BeiDou Experimental Tracking Stations to realize the BeiDou and BeiDou/GPS static and kinematic precise point positioning (PPP). The result indicates that the precision of BeiDou static and kinematic PPP reaches centimeter level. The precision of BeiDou/GPS kinematic PPP solutions is improved significantly compared to that of BeiDou-only or GPS-only kinematic PPP solutions. The PPP convergence time also decreases with the use of combined BeiDou/GPS systems.

Relativity mission with two counter-orbiting polar satellites

International Nuclear Information System (INIS)

Van Patten, R.A.; Everitt, C.W.F.

1975-01-01

In 1918, J. Lense and H. Thirring calculated that a moon in orbit around a massive rotating planet would experience a nodal dragging effect due to general relativity. An experiment to measure this effect with two counter-orbiting drag-free satellites in polar earth orbit is described. For a 2 1 / 2 year experiment, the measurement accuracy should approach 1 percent. In addition to precision tracking data from existing ground stations, satellite-to-satellite Doppler ranging data are taken at points of passing near the poles. New geophysical information on both earth harmonics and tidal effects is inherent in the polar ranging data. (auth)

Laser experiments in light cloudiness with the geostationary satellite ARTEMIS

Science.gov (United States)

Kuzkov, V.; Kuzkov, S.; Sodnik, Z.

2016-08-01

The geostationary satellite ARTEMIS was launched in July 2001. The satellite is equipped with a laser communication terminal, which was used for the world's first inter-satellite laser communication link between ARTEMIS and the low earth orbit satellite SPOT-4. Ground-to-space laser communication experiments were also conducted under various atmospheric conditions involving ESA's optical ground station. With a rapidly increasing volume of information transferred by geostationary satellites, there is a rising demand for high-speed data links between ground stations and satellites. For ground-to-space laser communications there are a number of important design parameters that need to be addressed, among them, the influence of atmospheric turbulence in different atmospheric conditions and link geometries. The Main Astronomical Observatory of NAS of Ukraine developed a precise computer tracking system for its 0.7 m AZT-2 telescope and a compact laser communication package LACES (Laser Atmosphere and Communication experiments with Satellites) for laser communication experiments with geostationary satellites. The specially developed software allows computerized tracking of the satellites using their orbital data. A number of laser experiments between MAO and ARTEMIS were conducted in partial cloudiness with some amount of laser light observed through clouds. Such conditions caused high break-up (splitting) of images from the laser beacon of ARTEMIS. One possible explanation is Raman scattering of photons on molecules of a water vapor in the atmosphere. Raman scattering causes a shift in a wavelength of the photons.In addition, a different value for the refraction index appears in the direction of the meridian for the wavelength-shifted photons. This is similar to the anomalous atmospheric refraction that appears at low angular altitudes above the horizon. We have also estimated the atmospheric attenuation and the influence of atmospheric turbulence on observed results

Noncoherent Doppler tracking: first flight results

Science.gov (United States)

DeBoy, Christopher C.; Robert Jensen, J.; Asher, Mark S.

2005-01-01

Noncoherent Doppler tracking has been devised as a means to achieve highly accurate, two-way Doppler measurements with a simple, transceiver-based communications system. This technique has been flown as an experiment on the Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) spacecraft, (launched 7 December 2001), as the operational technique for Doppler tracking on CONTOUR, and is baselined on several future deep space missions at JHU/APL. This paper reports on initial results from a series of successful tests of this technique between the TIMED spacecraft and NASA ground stations in the Deep Space Network. It also examines the advantages that noncoherent Doppler tracking and a transceiver-based system may offer to small satellite systems, including reduced cost, mass, and power.

Enhancing the use of Argos satellite data for home range and long distance migration studies of marine animals.

Directory of Open Access Journals (Sweden)

Xavier Hoenner

Full Text Available Accurately quantifying animals' spatial utilisation is critical for conservation, but has long remained an elusive goal due to technological impediments. The Argos telemetry system has been extensively used to remotely track marine animals, however location estimates are characterised by substantial spatial error. State-space models (SSM constitute a robust statistical approach to refine Argos tracking data by accounting for observation errors and stochasticity in animal movement. Despite their wide use in ecology, few studies have thoroughly quantified the error associated with SSM predicted locations and no research has assessed their validity for describing animal movement behaviour. We compared home ranges and migratory pathways of seven hawksbill sea turtles (Eretmochelys imbricata estimated from (a highly accurate Fastloc GPS data and (b locations computed using common Argos data analytical approaches. Argos 68(th percentile error was 4 km for LC ≤ 0. Argos error structure was highly longitudinally skewed and was, for all LC, adequately modelled by a Student's t distribution. Both habitat use and migration routes were best recreated using SSM locations post-processed by re-adding good Argos positions (LC 1, 2 and 3 and filtering terrestrial points (mean distance to migratory tracks ± SD = 2.2 ± 2.4 km; mean home range overlap and error ratio = 92.2% and 285.6 respectively. This parsimonious and objective statistical procedure however still markedly overestimated true home range sizes, especially for animals exhibiting restricted movements. Post-processing SSM locations nonetheless constitutes the best analytical technique for remotely sensed Argos tracking data and we therefore recommend using this approach to rework historical Argos datasets for better estimation of animal spatial utilisation for research and evidence-based conservation purposes.

Differential regulation of adipokines may influence migratory behavior in the white-throated sparrow (Zonotrichia albicollis).

Science.gov (United States)

Stuber, Erica F; Verpeut, Jessica; Horvat-Gordon, Maria; Ramachandran, Ramesh; Bartell, Paul A

2013-01-01

White-throated sparrows increase fat deposits during pre-migratory periods and rely on these fat stores to fuel migration. Adipose tissue produces hormones and signaling factors in a rhythmic fashion and may be controlled by a clock in adipose tissue or driven by a master clock in the brain. The master clock may convey photoperiodic information from the environment to adipose tissue to facilitate pre-migratory fattening, and adipose tissue may, in turn, release adipokines to indicate the extent of fat energy stores. Here, we present evidence that a change in signal from the adipokines adiponectin and visfatin may act to indicate body condition, thereby influencing an individual's decision to commence migratory flight, or to delay until adequate fat stores are acquired. We quantified plasma adiponectin and visfatin levels across the day in captive birds held under constant photoperiod. The circadian profiles of plasma adiponectin in non-migrating birds were approximately inverse the profiles from migrating birds. Adiponectin levels were positively correlated to body fat, and body fat was inversely related to the appearance of nocturnal migratory restlessness. Visfatin levels were constant across the day and did not correlate with fat deposits; however, a reduction in plasma visfatin concentration occurred during the migratory period. The data suggest that a significant change in the biological control of adipokine expression exists between the two migratory conditions and we propose a role for adiponectin, visfatin and adipose clocks in the regulation of migratory behaviors.

Differential regulation of adipokines may influence migratory behavior in the white-throated sparrow (Zonotrichia albicollis.

Directory of Open Access Journals (Sweden)

Erica F Stuber

Full Text Available White-throated sparrows increase fat deposits during pre-migratory periods and rely on these fat stores to fuel migration. Adipose tissue produces hormones and signaling factors in a rhythmic fashion and may be controlled by a clock in adipose tissue or driven by a master clock in the brain. The master clock may convey photoperiodic information from the environment to adipose tissue to facilitate pre-migratory fattening, and adipose tissue may, in turn, release adipokines to indicate the extent of fat energy stores. Here, we present evidence that a change in signal from the adipokines adiponectin and visfatin may act to indicate body condition, thereby influencing an individual's decision to commence migratory flight, or to delay until adequate fat stores are acquired. We quantified plasma adiponectin and visfatin levels across the day in captive birds held under constant photoperiod. The circadian profiles of plasma adiponectin in non-migrating birds were approximately inverse the profiles from migrating birds. Adiponectin levels were positively correlated to body fat, and body fat was inversely related to the appearance of nocturnal migratory restlessness. Visfatin levels were constant across the day and did not correlate with fat deposits; however, a reduction in plasma visfatin concentration occurred during the migratory period. The data suggest that a significant change in the biological control of adipokine expression exists between the two migratory conditions and we propose a role for adiponectin, visfatin and adipose clocks in the regulation of migratory behaviors.

Neural network based satellite tracking for deep space applications

Science.gov (United States)

Amoozegar, F.; Ruggier, C.

2003-01-01

The objective of this paper is to provide a survey of neural network trends as applied to the tracking of spacecrafts in deep space at Ka-band under various weather conditions and examine the trade-off between tracing accuracy and communication link performance.

Distributed Extended Kalman Filter for Position, Velocity, Time, Estimation in Satellite Navigation Receivers

Directory of Open Access Journals (Sweden)

O. Jakubov

2013-09-01

Full Text Available Common techniques for position-velocity-time estimation in satellite navigation, iterative least squares and the extended Kalman filter, involve matrix operations. The matrix inversion and inclusion of a matrix library pose requirements on a computational power and operating platform of the navigation processor. In this paper, we introduce a novel distributed algorithm suitable for implementation in simple parallel processing units each for a tracked satellite. Such a unit performs only scalar sum, subtraction, multiplication, and division. The algorithm can be efficiently implemented in hardware logic. Given the fast position-velocity-time estimator, frequent estimates can foster dynamic performance of a vector tracking receiver. The algorithm has been designed from a factor graph representing the extended Kalman filter by splitting vector nodes into scalar ones resulting in a cyclic graph with few iterations needed. Monte Carlo simulations have been conducted to investigate convergence and accuracy. Simulation case studies for a vector tracking architecture and experimental measurements with a real-time software receiver developed at CTU in Prague were conducted. The algorithm offers compromises in stability, accuracy, and complexity depending on the number of iterations. In scenarios with a large number of tracked satellites, it can outperform the traditional methods at low complexity.

Larger Optics and Improved Calibration Techniques for Small Satellite Observations with the ERAU OSCOM System

Science.gov (United States)

Bilardi, S.; Barjatya, A.; Gasdia, F.

OSCOM, Optical tracking and Spectral characterization of CubeSats for Operational Missions, is a system capable of providing time-resolved satellite photometry using commercial-off-the-shelf (COTS) hardware and custom tracking and analysis software. This system has acquired photometry of objects as small as CubeSats using a Celestron 11” RASA and an inexpensive CMOS machine vision camera. For satellites with known shapes, these light curves can be used to verify a satellite’s attitude and the state of its deployed solar panels or antennae. While the OSCOM system can successfully track satellites and produce light curves, there is ongoing improvement towards increasing its automation while supporting additional mounts and telescopes. A newly acquired Celestron 14” Edge HD can be used with a Starizona Hyperstar to increase the SNR for small objects as well as extend beyond the limiting magnitude of the 11” RASA. OSCOM currently corrects instrumental brightness measurements for satellite range and observatory site average atmospheric extinction, but calibrated absolute brightness is required to determine information about satellites other than their spin rate, such as surface albedo. A calibration method that automatically detects and identifies background stars can use their catalog magnitudes to calibrate the brightness of the satellite in the image. We present a photometric light curve from both the 14” Edge HD and 11” RASA optical systems as well as plans for a calibration method that will perform background star photometry to efficiently determine calibrated satellite brightness in each frame.

Potential spread of highly pathogenic avian influenza H5N1 by wildfowl: dispersal ranges and rates determined from large-scale satellite telemetry

Science.gov (United States)

Gaidet, Nicolas; Cappelle, Julien; Takekawa, John Y.; Prosser, Diann J.; Iverson, Samuel A.; Douglas, David C.; Perry, William M.; Mundkur, Taej; Newman, Scott H.

2010-01-01

1. Migratory birds are major candidates for long-distance dispersal of zoonotic pathogens. In recent years, wildfowl have been suspected of contributing to the rapid geographic spread of the highly pathogenic avian influenza (HPAI) H5N1 virus. Experimental infection studies reveal that some wild ducks, geese and swans shed this virus asymptomatically and hence have the potential to spread it as they move. 2. We evaluate the dispersive potential of HPAI H5N1 viruses by wildfowl through an analysis of the movement range and movement rate of birds monitored by satellite telemetry in relation to the apparent asymptomatic infection duration (AID) measured in experimental studies. We analysed the first large-scale data set of wildfowl movements, including 228 birds from 19 species monitored by satellite telemetry in 2006–2009, over HPAI H5N1 affected regions of Asia, Europe and Africa. 3. Our results indicate that individual migratory wildfowl have the potential to disperse HPAI H5N1 over extensive distances, being able to perform movements of up to 2900 km within timeframes compatible with the duration of asymptomatic infection. 4. However, the likelihood of such virus dispersal over long distances by individual wildfowl is low: we estimate that for an individual migratory bird there are, on average, only 5–15 days per year when infection could result in the dispersal of HPAI H5N1 virus over 500 km. 5. Staging at stopover sites during migration is typically longer than the period of infection and viral shedding, preventing birds from dispersing a virus over several consecutive but interrupted long-distance movements. Intercontinental virus dispersion would therefore probably require relay transmission between a series of successively infected migratory birds. 6. Synthesis and applications. Our results provide a detailed quantitative assessment of the dispersive potential of HPAI H5N1 virus by selected migratory birds. Such dispersive potential rests on the

Deriving animal behaviour from high-frequency GPS: tracking cows in open and forested habitat

NARCIS (Netherlands)

de Weerd, N.; van Langevelde, F.; van Oeveren, H.; Nolet, Bart A.; Kölzsch, Andrea; Prins, H.H.T.; De Boer, W.F.

2015-01-01

The increasing spatiotemporal accuracy of Global Navigation Satellite Systems (GNSS) tracking systems opens the possibility to infer animal behaviour from tracking data. We studied the relationship between high-frequency GNSS data and behaviour, aimed at developing an easily interpretable

Deriving animal behaviour from high-frequency GPS: tracking cows in open and forested habitat

NARCIS (Netherlands)

Weerd, de N.; Langevelde, van F.; Oeveren, van H.; Nolet, B.A.; Kölzsch, A.; Prins, H.H.T.; Boer, de W.F.

2015-01-01

The increasing spatiotemporal accuracy of Global Navigation Satellite Systems (GNSS) tracking systems opens the possibility to infer animal behaviour from tracking data.We studied the relationship between high-frequency GNSS data and behaviour, aimed at developing an easily interpretable

Coupling Between Doppler Radar Signatures and Tornado Damage Tracks

Science.gov (United States)

Jedlovec, Gary J.; Molthan, Andrew L.; Carey, Lawrence; Carcione, Brian; Smith, Matthew; Schultz, Elise V.; Schultz, Christopher; Lafontaine, Frank

2011-01-01

On April 27, 2011, the southeastern United States was raked with several episodes of severe weather. Numerous tornadoes caused extensive damage, and tragically, the deaths of over 300 people. In Alabama alone, there were 61 confirmed tornados, 4 of them produced EF5 damage, and several were on the ground an hour or more with continuous damage tracks exceeding 80km. The use of Doppler radars covering the region provided reflectivity and velocity signatures that allowed forecasters to monitors the severe storms from beginning to end issuing hundreds of severe weather warnings throughout the day. Meteorologists from the the NWS performed extensive surveys to assess the intensity, duration, and ground track of tornadoes reported during the event. Survey activities included site visits to the affected locations, analysis of radar and satellite data, aerial surveys, and interviews with eyewitnesses. Satellite data from NASA's MODIS and ASTER instruments played a helpful role in determining the location of tornado damage paths and in the assessment. High resolution multispectral and temporal composites helped forecasters corroborate their damage assessments, determine starting and ending points for tornado touchdowns, and helped to provide forecasters with a better big-picture view of the damage region. The imagery also helped to separate damage from the April 27th tornados from severe weather that occurred earlier that month. In a post analysis of the outbreak, tornado damage path signatures observed in the NASA satellite data have been correlated to "debris ball" signatures in the NWS Doppler radars and a special ARMOR dual-polarization radar operated by the University of Alabama Huntsville during the event. The Doppler radar data indicates a circular enhanced reflectivity signal and rotational couplet in the radial velocity likely associated with the tornado that is spatially correlated with the damage tracks in the observed satellite data. An algorithm to detect and

75 FR 30483 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures; Amendment 3

Science.gov (United States)

2010-06-01

... and 635 Atlantic Highly Migratory Species; Atlantic Shark Management Measures; Amendment 3; Final Rule... and 635 [Docket No. 080519678-0217-02] RIN 0648-AW65 Atlantic Highly Migratory Species; Atlantic Shark... available to rebuild blacknose sharks and end overfishing of blacknose and shortfin mako sharks, consistent...

Target Detection Based on EBPSK Satellite Passive Radar

Directory of Open Access Journals (Sweden)

Lu Zeyuan

2015-05-01

Full Text Available Passive radar is a topic anti stealth technology with simple structure, and low cost. Radiation source model, signal transmission model, and target detection are the key points of passive radar technology research. The paper analyzes the characteristics of EBPSK signal modulation and target detection method aspect of spaceborne radiant source. By comparison with other satellite navigation and positioning system, the characteristics of EBPSK satellite passive radar system are analyzed. It is proved that the maximum detection range of EBPSK satellite signal can satisfy the needs of the proposed model. In the passive radar model, sparse representation is used to achieve high resolution DOA detection. The comparison with the real target track by simulation demonstrates that effective detection of airborne target using EBPSK satellite passive radar system based on sparse representation is efficient.

Prevalence of West Nile virus in migratory birds during spring and fall migration

Science.gov (United States)

Dusek, Robert J.; McLean, R.G.; Kramer, L.D.; Ubico, S.R.; Dupuis, A.P.; Ebel, G.D.; Guptill, S.C.

2009-01-01

To investigate the role of migratory birds in the dissemination of West Nile virus (WNV), we measured the prevalence of infectious WNV and specific WNV neutralizing antibodies in birds, principally Passeriformes, during spring and fall migrations in the Atlantic and Mississippi flyways from 2001-2003. Blood samples were obtained from 13,403 birds, representing 133 species. Specific WNV neutralizing antibody was detected in 254 resident and migratory birds, representing 39 species, and was most commonly detected in northern cardinals (Cardinalis cardinalis) (9.8%, N = 762) and gray catbirds (Dumetella carolinensis) (3.2%,N = 3188). West Nile virus viremias were detected in 19 birds, including 8 gray catbirds, and only during the fall migratory period. These results provide additional evidence that migratory birds may have been a principal agent for the spread of WNV in North America and provide data on the occurrence of WNV in a variety of bird species. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

EGF-induced expansion of migratory cells in the rostral migratory stream.

Directory of Open Access Journals (Sweden)

Olle R Lindberg

Full Text Available The presence of neural stem cells in the adult brain is currently widely accepted and efforts are made to harness the regenerative potential of these cells. The dentate gyrus of the hippocampal formation, and the subventricular zone (SVZ of the anterior lateral ventricles, are considered the main loci of adult neurogenesis. The rostral migratory stream (RMS is the structure funneling SVZ progenitor cells through the forebrain to their final destination in the olfactory bulb. Moreover, extensive proliferation occurs in the RMS. Some evidence suggest the presence of stem cells in the RMS, but these cells are few and possibly of limited differentiation potential. We have recently demonstrated the specific expression of the cytoskeleton linker protein radixin in neuroblasts in the RMS and in oligodendrocyte progenitors throughout the brain. These cell populations are greatly altered after intracerebroventricular infusion of epidermal growth factor (EGF. In the current study we investigate the effect of EGF infusion on the rat RMS. We describe a specific increase of radixin(+/Olig2(+ cells in the RMS. Negative for NG2 and CNPase, these radixin(+/Olig2(+ cells are distinct from typical oligodendrocyte progenitors. The expanded Olig2(+ population responds rapidly to EGF and proliferates after only 24 hours along the entire RMS, suggesting local activation by EGF throughout the RMS rather than migration from the SVZ. In addition, the radixin(+/Olig2(+ progenitors assemble in chains in vivo and migrate in chains in explant cultures, suggesting that they possess migratory properties within the RMS. In summary, these results provide insight into the adaptive capacity of the RMS and point to an additional stem cell source for future brain repair strategies.

50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

Science.gov (United States)

2010-10-01

... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual...

Bottom Pressure Tides Along a Line in the Southeast Atlantic Ocean and Comparisons with Satellite Altimetry

Science.gov (United States)

Ray, Richard D.; Byrne, Deidre A.

2010-01-01

Seafloor pressure records, collected at 11 stations aligned along a single ground track of the Topex/Poseidon and Jason satellites, are analyzed for their tidal content. With very low background noise levels and approximately 27 months of high-quality records, tidal constituents can be estimated with unusually high precision. This includes many high-frequency lines up through the seventh-diurnal band. The station deployment provides a unique opportunity to compare with tides estimated from satellite altimetry, point by point along the satellite track, in a region of moderately high mesoscale variability. That variability can significantly corrupt altimeter-based tide estimates, even with 17 years of data. A method to improve the along-track altimeter estimates by correcting the data for nontidal variability is found to yield much better agreement with the bottom-pressure data. The technique should prove useful in certain demanding applications, such as altimetric studies of internal tides.

Migratory Bone Marrow Edema Syndrome of the Hips: A Case Report

Directory of Open Access Journals (Sweden)

Santoso A

2017-11-01

Full Text Available Migratory bone marrow edema syndrome (BMES of the hip is a rare entity. We report the case of a 41-year old male with migratory BMES of the hip with eight months interval period between onset of the pain and consultation. This patient was successfully treated non-surgically. It is important to always inform the patient with unilateral BMES of the hip regarding the possibility of future involvement of the contralateral hip.

Fixed and flexible: coexistence of obligate and facultative migratory strategies in a freshwater fish

DEFF Research Database (Denmark)

Brodersen, Jakob; Chapman, Ben B.; Nilsson, P. Anders

2014-01-01

of migration/residency, is highly consistent within individuals over time and (2) there is a positive relationship between condition and the probability of migration, but only in individuals that adopt a migratory strategy at some point during their lives. However, life-long residents do not differ...... mechanisms are still heavily debated. One potential mechanism of partial migration is between-individual variation in body condition, where animals in poor condition cannot pay the costs of migration and hence adopt a resident strategy. However, underlying intrinsic traits may overrule such environmental...... fish and monitoring their seasonal migrations over extended periods of time. Our aims were to provide a field test of the role of condition in wild fish for migratory decisions, and also to assess individual consistency in migratory tendency. Our analyses reveal that (1) migratory strategy, in terms...

JPSS Preparations at the Satellite Proving Ground for Marine, Precipitation, and Satellite Analysis

Science.gov (United States)

Folmer, M. J.; Berndt, E.; Clark, J.; Orrison, A.; Kibler, J.; Sienkiewicz, J. M.; Nelson, J. A., Jr.; Goldberg, M.

2016-12-01

The National Oceanic and Atmospheric Administration (NOAA) Satellite Proving Ground (PG) for Marine, Precipitation, and Satellite Analysis (MPS) has been demonstrating and evaluating Suomi National Polar-orbiting Partnership (S-NPP) products along with other polar-orbiting satellite platforms in preparation for the Joint Polar Satellite System - 1 (JPSS-1) launch in March 2017. The first S-NPP imagery was made available to the MPS PG during the evolution of Hurricane Sandy in October 2012 and has since been popular in operations. Since this event the MPS PG Satellite Liaison has been working with forecasters on ways to integrate single-channel and multispectral imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Advanced Very High Resolution Radiometer (AVHRR)into operations to complement numerical weather prediction and geostationary satellite savvy National Weather Service (NWS) National Centers. Additional unique products have been introduced to operations to address specific forecast challenges, including the Cooperative Institute for Research in the Atmosphere (CIRA) Layered Precipitable Water, the National Environmental Satellite, Data, and Information Service (NESDIS) Snowfall Rate product, NOAA Unique Combined Atmospheric Processing System (NUCAPS) Soundings, ozone products from the Atmospheric Infrared Sounder (AIRS), Cross-track Infrared Sounder/Advanced Technology Microwave Sounder (CrIS/ATMS), and Infrared Atmospheric Sounding Interferometer (IASI). In addition, new satellite domains have been created to provide forecasters at the NWS Ocean Prediction Center and Weather Prediction Center with better quality imagery at high latitudes. This has led to research projects that are addressing forecast challenges such as tropical to extratropical transition and explosive cyclogenesis. This presentation will provide examples of how the MPS PG has been introducing and integrating

Satellite accelerometer measurements of neutral density and winds during geomagnetic storms

Science.gov (United States)

Marcos, F. A.; Forbes, J. M.

1986-01-01

A new thermospheric wind measurement technique is reported which is based on a Satellite Electrostatic Triaxial Accelerometer (SETA) system capable of accurately measuring accelerations in the satellite's in-track, cross-track and radial directions. Data obtained during two time periods are presented. The first data set describes cross-track winds measured between 170 and 210 km during a 5-day period (25 to 29 March 1979) of mostly high geomagnetic activity. In the second data set, cross-track winds and neutral densities from SETA and exospheric temperatures from the Millstone Hill incoherent scatter radar are examined during an isolated magnetic substorm occurring on 21 March 1979. A polar thermospheric wind circulation consisting of a two cell horizontal convection pattern is reflected in both sets of cross-track acceleration measurements. The density response is highly asymmetric with respect to its day/night behavior. Latitude structures of the density response at successive times following the substorm peak suggest the equatorward propagation of a disturbance with a phase speed between 300 and 600 m/s. A deep depression in the density at high latitudes (less than 70 deg) is evident in conjunction with this phenomenon. The more efficient propagation of the disturbance to lower latitudes during the night is probably due to the midnight surge effect.

A framework for understanding semi-permeable barrier effects on migratory ungulates

Science.gov (United States)

Sawyer, Hall; Kauffman, Matthew J.; Middleton, Arthur D.; Morrison, Thomas A.; Nielson, Ryan M.; Wyckoff, Teal B.

2013-01-01

1. Impermeable barriers to migration can greatly constrain the set of possible routes and ranges used by migrating animals. For ungulates, however, many forms of development are semi-permeable, and making informed management decisions about their potential impacts to the persistence of migration routes is difficult because our knowledge of how semi-permeable barriers affect migratory behaviour and function is limited. 2. Here, we propose a general framework to advance the understanding of barrier effects on ungulate migration by emphasizing the need to (i) quantify potential barriers in terms that allow behavioural thresholds to be considered, (ii) identify and measure behavioural responses to semi-permeable barriers and (iii) consider the functional attributes of the migratory landscape (e.g. stopovers) and how the benefits of migration might be reduced by behavioural changes. 3. We used global position system (GPS) data collected from two subpopulations of mule deer Odocoileus hemionus to evaluate how different levels of gas development influenced migratory behaviour, including movement rates and stopover use at the individual level, and intensity of use and width of migration route at the population level. We then characterized the functional landscape of migration routes as either stopover habitat or movement corridors and examined how the observed behavioural changes affected the functionality of the migration route in terms of stopover use. 4. We found migratory behaviour to vary with development intensity. Our results suggest that mule deer can migrate through moderate levels of development without any noticeable effects on migratory behaviour. However, in areas with more intensive development, animals often detoured from established routes, increased their rate of movement and reduced stopover use, while the overall use and width of migration routes decreased. 5. Synthesis and applications. In contrast to impermeable barriers that impede animal movement

Satellite Tracking of Humpback Whales in West Greenland

DEFF Research Database (Denmark)

Dietz, R.; Teilmann, J.; Heide-Jørgensen, M.-P.

In June 2000, 6 humpback whales (Megaptere novaeangliae) were tagged with satellite transmitters off West Greenland. Contact remained for up to 42 days. The tagging revealed that within the month of June, humpback whales off West Greenland moved between Fiskenæs Banke, Fyllas Banke, Tovqussaq Banke......, Sukkertop Banke and Lille Hellefiske Banke. The whales showed a preference for the continental slopes with depths less than 200 m, however, few dives were recorded down to 500 m. The whales had a preference for dives lasting 7-8 min. (15%) and no dives lasted longer than 15 min....

Migratory and adhesive properties of Xenopus laevis primordial germ cells in vitro

Directory of Open Access Journals (Sweden)

Aliaksandr Dzementsei

2013-11-01

The directional migration of primordial germ cells (PGCs to the site of gonad formation is an advantageous model system to study cell motility. The embryonic development of PGCs has been investigated in different animal species, including mice, zebrafish, Xenopus and Drosophila. In this study we focus on the physical properties of Xenopus laevis PGCs during their transition from the passive to the active migratory state. Pre-migratory PGCs from Xenopus laevis embryos at developmental stages 17–19 to be compared with migratory PGCs from stages 28–30 were isolated and characterized in respect to motility and adhesive properties. Using single-cell force spectroscopy, we observed a decline in adhesiveness of PGCs upon reaching the migratory state, as defined by decreased attachment to extracellular matrix components like fibronectin, and a reduced adhesion to somatic endodermal cells. Data obtained from qPCR analysis with isolated PGCs reveal that down-regulation of E-cadherin might contribute to this weakening of cell-cell adhesion. Interestingly, however, using an in vitro migration assay, we found that movement of X. laevis PGCs can also occur independently of specific interactions with their neighboring cells. The reduction of cellular adhesion during PGC development is accompanied by enhanced cellular motility, as reflected in increased formation of bleb-like protrusions and inferred from electric cell-substrate impedance sensing (ECIS as well as time-lapse image analysis. Temporal alterations in cell shape, including contraction and expansion of the cellular body, reveal a higher degree of cellular dynamics for the migratory PGCs in vitro.

A Mathematical Model for the Height of a Satellite.

Science.gov (United States)

Thoemke, Sharon S.; And Others

1993-01-01

Emphasizes a real-world-problem situation using sine law and cosine law. Angles of elevation from two tracking stations located in the plane of the equator determine height of a satellite. Calculators or computers can be used. (LDR)

The migratory bird treaty and a century of waterfowl conservation

Science.gov (United States)

Anderson, Michael G.; Alisauskas, Ray T.; Batt, Bruce D. J.; Blohm, Robert J.; Higgins, Kenneth F.; Perry, Matthew; Ringelman, James K.; Sedinger, James S.; Serie, Jerome R.; Sharp, David E.; Trauger, David L.; Williams, Christopher K.

2018-01-01

In the final decades of the nineteenth century, concern was building about the status of migratory bird populations in North America. In this literature review, we describe how that concern led to a landmark conservation agreement in 1916, between the United States and Great Britain (on behalf of Canada) to conserve migratory birds shared by Canada and the United States. Drawing on published literature and our personal experience, we describe how subsequent enabling acts in both countries gave rise to efforts to better estimate population sizes and distributions, assess harvest rates and demographic impacts, design and fund landscape-level habitat conservation initiatives, and organize necessary political and regulatory processes. Executing these steps required large-scale thinking, unprecedented regional and international cooperation, ingenuity, and a commitment to scientific rigor and adaptive management. We applaud the conservation efforts begun 100 years ago with the Migratory Bird Treaty Convention. The agreement helped build the field of wildlife ecology and conservation in the twentieth century but only partially prepares us for the ecological and social challenges ahead. 

Tracking the MJO Convection and its Impact on the Diurnal Cycle over the Maritime Continent Using Satellite Observations

Science.gov (United States)

Kerns, B. W.; Chen, S. S.

2017-12-01

The Indo-Pacific Maritime Continent (MC) is the most active convection center in the tropics, and the most important modes of variability are the diurnal cycle and the Madden-Julian Oscillation (MJO). Previous studies have shown that the MC has strong diurnal variability compared with the rest of the tropics, and the diurnal cycle of convection over the MC is amplified during the passage of an MJO. One outstanding science question is how the passage of the active MJO affects the diurnal cycle. The atmospheric, upper ocean, and land surface forcing factors contributing to the diurnal cycle need to be clarified. In order to address this, large scale precipitation tracking (LPT) is used to identify MJO active and suppressed periods for 2000-2015. To document the diurnal cycle of convection during the active and suppressed periods, TRMM/GPM and mesoscale cloud cluster tracking are used. Finally, the LPT tracking is used to composite the satellite-estimated surface wind, humidity, temperature, cloud cover, and soil moisture over the islands for active versus suppressed MJO periods. In active MJO periods, the diurnal convection in the surrounding marginal seas is enhanced and the diurnal convection over land is decreased. The islands of the MC have greater soil moisture, more cloud cover, and do not warm up as much during the day, leading to a weaker afternoon maximum over land. But how is nocturnal convection over the sea increased? The largest, most mature convective cloud systems are found over the marginal seas in the early morning. This is hypothesized to mainly be a consequence of the longer life cycle of convective systems in the favorable large-scale active MJO. The propagation of the MJO across the MC is facilitated by the enhanced nocturnal deep convection over the sea. In contrast, In the suppressed period the convection is mostly daytime forced convection over land which is locked to the terrain.

78 FR 25758 - Migratory Birds; Eagle Conservation Plan Guidance: Module 1-Land-Based Wind Energy, Version 2

Science.gov (United States)

2013-05-02

...-FXMB123209EAGL0L2] RIN 1018-AX53 Migratory Birds; Eagle Conservation Plan Guidance: Module 1-- Land-Based Wind... Migratory Bird Management, U.S. Fish and Wildlife Service, 4401 North Fairfax Drive, Arlington, Virginia... Act (BGEPA) (16 U.S.C. 668-668c), the Migratory Bird Treaty Act (MBTA) (16 U.S.C. 703-12), and the...

Migratory bats respond to artificial green light with positive phototaxis.

Directory of Open Access Journals (Sweden)

Christian C Voigt

Full Text Available Artificial light at night is spreading worldwide at unprecedented rates, exposing strictly nocturnal animals such as bats to a novel anthropogenic stressor. Previous studies about the effect of artificial light on bats focused almost exclusively on non-migratory species, yet migratory animals such as birds are known to be largely affected by light pollution. Thus, we conducted a field experiment to evaluate if bat migration is affected by artificial light at night. In late summer, we presented artificial green light of 520 nm wavelength to bats that were migrating south along the shoreline of the Baltic Sea. Using a light on-off treatment, we observed that the activity of Pipistrellus nathusii and P. pygmaeus, the two most abundant migratory species at our site, increased by more than 50% in the light-on compared to the light-off treatment. We observed an increased number of feeding buzzes during the light-on compared to the light-off treatment for P. nathusii. However, feeding activity was low in general and did not increase disproportionately during the light-on treatment in relation to the overall echolocation call activity of bats. Further, P. nathusii were attracted towards the green light at a distance of about 23 m, which is way beyond the echolocation detection range for insects of Nathusius' bats. We therefore infer that migratory bats were not attracted to artificial green light because of high insect densities, but instead by positive phototaxis. We conclude that artificial light at night may potentially impact bat migration in a yet unrecognized way.

Enchained territories, migratory displacements and adaptive ruralities

Directory of Open Access Journals (Sweden)

Luis Camarero

2017-05-01

Full Text Available The text is concerned with the ways in which the territories, in this case the different rural areas and localities, are integrated, linked or dissociated into processes and chains of production and economic of a global order. The connection between territories and economic chains occurs through flows of goods, inputs and capital, but also through migratory movements and diverse mobility practices. The process of social division of labor generates new logics of integration / disintegration of the regions in the socioeconomic process, and different mobility demands associated with these changes. The hypothesis that encloses this text is that places and territories will reach to insert in global chains if they develop capacities of adaptability to the productive conditions and especially they manage to reduce the territorial friction guaranteeing the migratory management and mobility of the labor force. With this point of view the socio-agricultural evolution of the rural areas in Spain is contemplated from the end of century XIX

Wind Atlas for the Gulf of Suez Satellite Imagery and Analyses

DEFF Research Database (Denmark)

Hasager, Charlotte Bay

(SAR) data derived from the European Remote Sensing Satellite (ERS) have been used to make wind speed maps for the Gulf of Suez. 2. “Land cover from Landsat TM imagery”. Landsat Thematic Mapper(TM) data have been used to establish true- and false-colour land cover maps, as well as land cover...... classification maps. 3. “Reporting on satellite information for the Wind Atlas for Egypt”. Along-Track Scanning Radiometer (ATSR) data from the European Remote Sensing Satellite (ERS) have been used to map the sea- and land-surface temperatures and albedos....

Stem cell tracking using iron oxide nanoparticles

Directory of Open Access Journals (Sweden)

Bull E

2014-03-01

Full Text Available Elizabeth Bull,1 Seyed Yazdan Madani,1 Roosey Sheth,1 Amelia Seifalian,1 Mark Green,2 Alexander M Seifalian1,31UCL Centre for Nanotechnology and Regenerative Medicine, Division of Surgery and Interventional Science, University College London, London, 2Department of Physics, King’s College London, Strand Campus, London, UK; 3Royal Free London National Health Service Foundation Trust Hospital, London, UKAbstract: Superparamagnetic iron oxide nanoparticles (SPIONs are an exciting advancement in the field of nanotechnology. They expand the possibilities of noninvasive analysis and have many useful properties, making them potential candidates for numerous novel applications. Notably, they have been shown that they can be tracked by magnetic resonance imaging (MRI and are capable of conjugation with various cell types, including stem cells. In-depth research has been undertaken to establish these benefits, so that a deeper level of understanding of stem cell migratory pathways and differentiation, tumor migration, and improved drug delivery can be achieved. Stem cells have the ability to treat and cure many debilitating diseases with limited side effects, but a main problem that arises is in the noninvasive tracking and analysis of these stem cells. Recently, researchers have acknowledged the use of SPIONs for this purpose and have set out to establish suitable protocols for coating and attachment, so as to bring MRI tracking of SPION-labeled stem cells into common practice. This review paper explains the manner in which SPIONs are produced, conjugated, and tracked using MRI, as well as a discussion on their limitations. A concise summary of recently researched magnetic particle coatings is provided, and the effects of SPIONs on stem cells are evaluated, while animal and human studies investigating the role of SPIONs in stem cell tracking will be explored.Keywords: stem cells, nanoparticle, magnetic

Latin-american and maghrebian women migratory process and psychological adjustment: from a gender point of view

Directory of Open Access Journals (Sweden)

Edurne Elgorriaga

2013-02-01

Full Text Available This study examines the migratory process and psychological adjustment of immigrant women currently residing in the Basque Country. Perceived stress is analyzed in relationship with relevant psychosocial variables from a gender perspective.The sample consisted of 206 immigrant women, proceeding from Latin America (61.2% and Maghreb (38.8%.The participants’ self-assessment of migratory and well-beingwas in overall positive, however, the diffi culties derived from thisprocess, and the migratory changes, infl uence the psychologicaladjustment of immigrant women.Results revealed that perceived stress is affected by the migratory process, educational level, residential status, and the balance of their situation, the elements crossed by factors asgender and/or cultural origin.

Network design consideration of a satellite-based mobile communications system

Science.gov (United States)

Yan, T.-Y.

1986-01-01

Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

European Telecommunications Satellite II (EUTELSAT II)

Science.gov (United States)

Laemmel, G.; Brittinger, P.

1991-01-01

EUTELSAT II is a regional public telecommunications system for Europe. The services which will be provided are telephone and television. The satellites will be placed at a geostationary orbit within the arcs of 6 degrees east to 19 degrees east or 26 degrees to 36 degrees east. The designed lifetime is 7 years. After separation of the satellites from the launch vehicles, telemetry, telecommand, and ranging will be performed within the S-band frequencies. After positioning of the satellite at its final geostationary orbit, the Ku-band telecommunication equipment will be activated. From this time on, all satellite control operations will be performed in Ku-band. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. The coverage will consist of the 26-m antennas at Goldstone and Canberra as prime support for the transfer and drift orbits. Maximum support will consist of a 7-day period, plus 14 days of contingency support. Information is given in tabular form for DSN support, frequency assignments, telemetry, command, and tracking support responsibility.

Tracking and Data Relay Satellite System /TDRSS/ telecommunication services

Science.gov (United States)

Deerkoski, L. F.

1975-01-01

The TDRSS and tracking services define the telecommunication performance of the TDRSS between the RF interface with user spacecraft and the data interface with NASCOM at the ground terminal. Attention is given to system constraints, forward link services, multiple-access signal design parameters, S-band single access signal design parameters, multiple-access return link services, and single-access return link services.

Extracting Ocean-Generated Tidal Magnetic Signals from Swarm Data Through Satellite Gradiometry

Science.gov (United States)

Sabaka, Terence J.; Tyler, Robert H.; Olsen, Nils

2016-01-01

Ocean-generated magnetic field models of the Principal Lunar, M2, and the Larger Lunar elliptic, N2, semidiurnal tidal constituents were estimated through a "Comprehensive Inversion" of the first 20.5 months of magnetic measurements from European Space Agency's (ESA) Swarm satellite constellation mission. While the constellation provides important north-south along-track gradiometry information, it is the unique low-spacecraft pair that allows for east-west cross-track gradiometry. This latter type is crucial in delivering an M2 estimate of similar quality with that derived from over 10 years of CHAMP satellite data but over a shorter interval, at higher altitude, and during more magnetically disturbed conditions. Recovered N2 contains nonoceanic signal but is highly correlated with theoretical models in regions of maximum oceanic amplitude. Thus, satellite magnetic gradiometry may eventually enable the monitoring of ocean electrodynamic properties at temporal resolutions of 1 to 2 years, which may have important implications for the inference of ocean temperature and salinity.

Satellite tracking and geospatial analysis of feral swine and their habitat use in Louisiana and Mississippi

Science.gov (United States)

Hartley, Stephen B.; Spear, Kathryn A.; Goatcher, Buddy L.

2012-01-01

Feral swine (Sus scrofa) is an invasive species that was first introduced to the continental United States in the 1500s by European explorers. Also known as feral hogs or feral pigs, the animals typically weigh about 200 pounds (up to 400 pounds), have characteristic tusks up to 3 inches long, are territorial, and live in groups, except for the boars, who are solitary and typically interact with sows only to breed. They have an average litter size of 5-6 piglets and occasionally two litters per year, and because they have few natural predators, survival of their young can be nearly 100 percent. Because of the detrimental impacts of this invasive species---including rooting, damaging agricultural lands, competing for food with and destroying the habitats of native animals, and spreading diseases and parasites---many public lands implement feral swine control programs on an annual basis. This activity is not enough to control or prevent an increase in swine populations, however, because of their distribution beyond the boundaries of public lands. Currently, little is known about feral swine populations, their habitat use and movement patterns, and the resulting habitat destruction in Louisiana and Mississippi. To abate this lack of knowledge, researchers at the U.S. Geological Survey National Wetlands Research Center (NWRC)---in cooperation with the U.S. Fish and Wildlife Service, the Louisiana Department of Wildlife and Fisheries, and several large landholding companies---are using collars equipped with Global Positioning System (GPS) receivers to track feral swine in Louisiana and Mississippi to examine population movement patterns, document destruction of habitat and wildlife, and help increase and facilitate removal. The NWRC researchers are using the "Judas pig" system of attaching GPS-satellite telemetry collars to select feral swine to (1) track movement patterns on the landscape, (2) document habitat destruction and effects on native wildlife, and (3) improve

IceBridge GPS L0 Raw Satellite Navigation Data, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — The NASA IceBridge GPS L0 Raw Satellite Navigation Data (IPUTG0) data set contains GPS readings, including latitude, longitude, track, ground speed, off distance,...

Space Solar Power: Satellite Concepts

Science.gov (United States)

Little, Frank E.

1999-01-01

Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

Seasonal climate variation and caribou availability: Modeling sequential movement using satellite-relocation data

Science.gov (United States)

Nicolson, Craig; Berman, Matthew; West, Colin Thor; Kofinas, Gary P.; Griffith, Brad; Russell, Don; Dugan, Darcy

2013-01-01

Livelihood systems that depend on mobile resources must constantly adapt to change. For people living in permanent settlements, environmental changes that affect the distribution of a migratory species may reduce the availability of a primary food source, with the potential to destabilize the regional social-ecological system. Food security for Arctic indigenous peoples harvesting barren ground caribou (Rangifer tarandus granti) depends on movement patterns of migratory herds. Quantitative assessments of physical, ecological, and social effects on caribou distribution have proven difficult because of the significant interannual variability in seasonal caribou movement patterns. We developed and evaluated a modeling approach for simulating the distribution of a migratory herd throughout its annual cycle over a multiyear period. Beginning with spatial and temporal scales developed in previous studies of the Porcupine Caribou Herd of Canada and Alaska, we used satellite collar locations to compute and analyze season-by-season probabilities of movement of animals between habitat zones under two alternative weather conditions for each season. We then built a set of transition matrices from these movement probabilities, and simulated the sequence of movements across the landscape as a Markov process driven by externally imposed seasonal weather states. Statistical tests showed that the predicted distributions of caribou were consistent with observed distributions, and significantly correlated with subsistence harvest levels for three user communities. Our approach could be applied to other caribou herds and could be adapted for simulating the distribution of other ungulates and species with similarly large interannual variability in the use of their range.

Seasonal Climate Variation and Caribou Availability: Modeling Sequential Movement Using Satellite-Relocation Data

Directory of Open Access Journals (Sweden)

Craig Nicolson

2013-06-01

Full Text Available Livelihood systems that depend on mobile resources must constantly adapt to change. For people living in permanent settlements, environmental changes that affect the distribution of a migratory species may reduce the availability of a primary food source, with the potential to destabilize the regional social-ecological system. Food security for Arctic indigenous peoples harvesting barren ground caribou (Rangifer tarandus granti depends on movement patterns of migratory herds. Quantitative assessments of physical, ecological, and social effects on caribou distribution have proven difficult because of the significant interannual variability in seasonal caribou movement patterns. We developed and evaluated a modeling approach for simulating the distribution of a migratory herd throughout its annual cycle over a multiyear period. Beginning with spatial and temporal scales developed in previous studies of the Porcupine Caribou Herd of Canada and Alaska, we used satellite collar locations to compute and analyze season-by-season probabilities of movement of animals between habitat zones under two alternative weather conditions for each season. We then built a set of transition matrices from these movement probabilities, and simulated the sequence of movements across the landscape as a Markov process driven by externally imposed seasonal weather states. Statistical tests showed that the predicted distributions of caribou were consistent with observed distributions, and significantly correlated with subsistence harvest levels for three user communities. Our approach could be applied to other caribou herds and could be adapted for simulating the distribution of other ungulates and species with similarly large interannual variability in the use of their range.

A survey on the automatic object tracking technology using video signals

International Nuclear Information System (INIS)

Lee, Jae Cheol; Jun, Hyeong Seop; Choi, Yu Rak; Kim, Jae Hee

2003-01-01

Recently, automatic identification and tracking of the object are actively studied according to the rapid development of signal processing and vision technology using improved hardware and software. The object tracking technology can be applied to various fields such as road watching of the vehicles, weather satellite, traffic observation, intelligent remote video-conferences and autonomous mobile robots. Object tracking system receives subsequent pictures from the camera and detects motions of the objects in these pictures. In this report, we investigate various object tracking techniques such as brightness change using histogram characteristic, differential image analysis, contour and feature extraction, and try to find proper methods that can be used to mobile robots actually

Assessing allowable take of migratory birds

Science.gov (United States)

Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

2009-01-01

Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was < 3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be < rmax. Further, the ratio of desired harvest rate to 0.5 x rmax may be a useful metric for ascertaining the applicability of specific requirements of the National Environmental Protection Act.

Degree of protandry reflects level of extrapair paternity in migratory songbirds

DEFF Research Database (Denmark)

Coppack, Timothy; Tøttrup, Anders Peter; Spottiswoode, Claire

2006-01-01

Males of most migratory organisms, including many birds, precede female conspecifics on their journey to the breeding areas. Several hypotheses have been proposed to explain the evolution of protandrous migration, yet they have rarely been tested at the interspecific level. Here, we provide...... that the time-lag in spring passage between males and females of five Palearctic migratory songbird species is positively associated with levels of extrapair paternity available from the literature. This suggests that males arrive relatively more in advance of females in species with high sperm competition...

[From Aliya to immigration, or the reading of a migratory continuum].

Science.gov (United States)

Berthomiere, W

1996-01-01

The author aims "to redraw the migratory trajectories which followed one another from the birth of the State [of Israel] until now....[He reads] these mobilities with the idea of [investigating] the migratory continuum in which the dialectic ¿centre-periphery' has with time become more complicated and more diversified. [The] reading presents the main periods of this continuum through a description of the Jewish mobilities and their impacts on the edification of the Israeli national ethos....[The author analyzes] the transformation in the ¿Israel-Diaspora' relations and [identifies] post-Zionist Jewish territoriality." (EXCERPT)

Satellite tagging highlights the importance of productive Mozambican coastal waters to the ecology and conservation of whale sharks

Science.gov (United States)

Richardson, Anthony J.; Jaine, Fabrice R. A.; Bennett, Michael B.; Weeks, Scarla J.; Cliff, Geremy; Robinson, David P.; Reeve-Arnold, Katie E.; Pierce, Simon J.

2018-01-01

The whale shark Rhincodon typus is an endangered, highly migratory species with a wide, albeit patchy, distribution through tropical oceans. Ten aerial survey flights along the southern Mozambican coast, conducted between 2004–2008, documented a relatively high density of whale sharks along a 200 km stretch of the Inhambane Province, with a pronounced hotspot adjacent to Praia do Tofo. To examine the residency and movement of whale sharks in coastal areas around Praia do Tofo, where they may be more susceptible to gill net entanglement, we tagged 15 juveniles with SPOT5 satellite tags and tracked them for 2–88 days (mean = 27 days) as they dispersed from this area. Sharks travelled between 10 and 2,737 km (mean = 738 km) at a mean horizontal speed of 28 ± 17.1 SD km day−1. While several individuals left shelf waters and travelled across international boundaries, most sharks stayed in Mozambican coastal waters over the tracking period. We tested for whale shark habitat preferences, using sea surface temperature, chlorophyll-a concentration and water depth as variables, by computing 100 random model tracks for each real shark based on their empirical movement characteristics. Whale sharks spent significantly more time in cooler, shallower water with higher chlorophyll-a concentrations than model sharks, suggesting that feeding in productive coastal waters is an important driver of their movements. To investigate what this coastal habitat choice means for their conservation in Mozambique, we mapped gill nets during two dedicated aerial surveys along the Inhambane coast and counted gill nets in 1,323 boat-based surveys near Praia do Tofo. Our results show that, while whale sharks are capable of long-distance oceanic movements, they can spend a disproportionate amount of time in specific areas, such as along the southern Mozambique coast. The increasing use of drifting gill nets in this coastal hotspot for whale sharks is likely to be a threat to regional

Birds of a feather winter together: migratory connectivity in the Reed Warbler Acrocephalus scirpaceus

Czech Academy of Sciences Publication Activity Database

Procházka, Petr; Hobson, K. A.; Karcza, Z.; Kralj, J.

2008-01-01

Roč. 149, č. 2 (2008), s. 141-150 ISSN 0021-8375 R&D Projects: GA AV ČR KJB600930508 Institutional research plan: CEZ:AV0Z60930519 Keywords : Acrocephalus scirpaceus * migratory connectivity * migratory divide * ringing recoveries * stable isotopes Sub ject RIV: EH - Ecology, Behaviour Impact factor: 1.465, year: 2008

NOAA-L satellite is mated to Apogee Kick Motor at Vandenberg AFB

Science.gov (United States)

2000-01-01

Inside the B16-10 spacecraft processing hangar at Vandenberg Air Force Base, Calif., workers oversee the mating of the Apogee Kick Motor (below) to the National Oceanic and Atmospheric Administration (NOAA-L) satellite above. NOAA-L is part of the Polar-Orbiting Operational Environmental Satellite (POES) program that provides atmospheric measurements of temperature, humidity, ozone and cloud images, tracking weather patterns that affect the global weather and climate. The launch of the NOAA-L satellite is scheduled no earlier than Sept. 12 aboard a Lockheed Martin Titan II rocket. Concept definition study for recovery of tumbling satellites. Volume 2: Supporting research and technology report

Science.gov (United States)

Cable, D. A.; Derocher, W. L., Jr.; Cathcart, J. A.; Keeley, M. G.; Madayev, L.; Nguyen, T. K.; Preese, J. R.

1986-01-01

A number of areas of research and laboratory experiments were identified which could lead to development of a cost efficient remote, disable satellite recovery system. Estimates were planned of disabled satellite motion. A concept is defined as a Tumbling Satellite Recovery kit which includes a modular system, composed of a number of subsystem mechanisms that can be readily integrated into varying combinations. This would enable the user to quickly configure a tailored remote, disabled satellite recovery kit to meet a broad spectrum of potential scenarios. The capability was determined of U.S. Earth based satellite tracking facilities to adequately determine the orientation and motion rates of disabled satellites.

Records of new or poorly known migratory birds from Laguna del Otun, Los Nevados National Natural Park, Risaralda, Colombia

International Nuclear Information System (INIS)

Acevedo Charry, Orlando; Matta Camacho, Nubia E; Moncada Alvarez, Ligia Ines

2013-01-01

Colombia is important for migratory birds. Despite this, we do not know where they are during their crossing or residency in the country, and which species use paramo. We registered new migratory bird species for Laguna Del Otun, immersed in a complex of wetlands declared a Ramsar site since 2008. The lagoon is located in the Los Nevados National Natural Park at 3932 m asl, in paramo ecosystems of the Central Andes of Colombia. During five field trips between 2010-2012 we recorded four new migratory bird species for the park: Anas acuta, Pandion haliaetus, Riparia riparia, and Dendroica petechia. We also registered an altitudinal range extension for two additional migratory species which had only been recorded below 3500 m: Tringa flavipes and Hirundo rustica. These findings suggest these species could tolerate high mountain conditions and use the paramo. It's needed inquiry about migratory dynamics and high mountain habitat use by migratory birds.

Synchronized oviposition triggered by migratory flight intensifies larval outbreaks of beet webworm.

Directory of Open Access Journals (Sweden)

Yun Xia Cheng

Full Text Available Identifying the reproductive consequences of insect migration is critical to understanding its ecological and evolutionary significance. However, many empirical studies are seemingly contradictory, making recognition of unifying themes elusive and controversial. The beet webworm, Loxostege sticticalis L. is a long-range migratory pest of many crops in the northern temperate zone from 36 °N to 55 °N, with larval populations often exploding in regions receiving immigrants. In laboratory experiments, we examined (i the reproductive costs of migratory flight by tethered flight, and (ii the reproductive traits contributing to larval outbreaks of immigrant populations. Our results suggest that the beet webworm does not initiate migratory flight until the 2nd or 3rd night after emergence. Preoviposition period, lifetime fecundity, mating capacity, and egg hatch rate for adults that experienced prolonged flight after the 2nd night did not differ significantly from unflown moths, suggesting these traits are irrelevant to the severity of beet webworm outbreaks after migration. However, the period of first oviposition, a novel parameter developed in this paper measuring synchrony of first egg-laying by cohorts of post-migratory females, for moths flown on d 3 and 5 of adulthood was shorter than that of unflown moths, indicating a tightened time-window for onset of oviposition after migration. The resulting synchrony of egg-laying will serve to increase egg and subsequent larval densities. A dense population offers potential selective advantages to the individual larvae comprising it, whereas the effect from the human standpoint is intensification of damage by an outbreak population. The strategy of synchronized oviposition may be common in other migratory insect pests, such as locust and armyworm species, and warrants further study.

Tracking an Oil Tanker Collision and Spilled Oils in the East China Sea Using Multisensor Day and Night Satellite Imagery

Science.gov (United States)

Sun, Shaojie; Lu, Yingcheng; Liu, Yongxue; Wang, Mengqiu; Hu, Chuanmin

2018-04-01

Satellite remote sensing is well known to play a critical role in monitoring marine accidents such as oil spills, yet the recent SANCHI oil tanker collision event in January 2018 in the East China Sea indicates that traditional techniques using synthetic aperture radar or daytime optical imagery could not provide timely and adequate coverage. In this study, we show the unprecedented value of Visible Infrared Imaging Radiometer Suite (VIIRS) Nightfire product and Day/Night Band data in tracking the oil tanker's drifting pathway and locations when all other means are not as effective for the same purpose. Such pathway and locations can also be reproduced with a numerical model, with root-mean-square error of days of the tanker's sinking reveals much larger oil spill area (>350 km2) than previous reports, the impact of the spilled condensate oil on the marine environment requires further research.

50 CFR 10.13 - List of Migratory Birds.

Science.gov (United States)

2010-10-01

... Protection of Migratory Birds, August 16, 1916, United States-Great Britain (on behalf of Canada), 39 Stat..., Gallinago stenura Swinhoe's, Gallinago megala Wilson's, Gallinago delicata (the “common” snipe hunted in..., Spizella pusilla Five-striped, Aimophila quinquestriata Fox, Passerella iliaca Golden-crowned, Zonotrichia...

The impact of curved satellite tracks on SAR focusing

DEFF Research Database (Denmark)

Mohr, Johan Jacob; Madsen, Søren Nørvang

2000-01-01

This paper addresses the geometric effect of processing single look complex synthetic aperture radar (SAR) data to a reference squint angle different from that given by the center of the real antenna beam. For data acquired on a straight flight line, the required transformation of radar coordinat...... from one Doppler reference to another is independent of the target elevation but for data acquired from a satellite orbit over a rotating Earth that is not true. Also the effect of ignoring Earth rotation is addressed....

Sea-level trend in the South China Sea observed from 20 years of along-track satellite altimetric data

DEFF Research Database (Denmark)

Cheng, Yongcun; Xu, Qing; Andersen, Ole Baltazar

2014-01-01

The sea-level trend in the South China Sea (SCS) is investigated based on 20 years of along-track data from TOPEX and Jason-1/2 satellite altimetry. The average sea-level rise over all the regions in the study area is observed to have a rate of 5.1 ± 0.8 mm year-1 for the period from 1993 to 2012....... The steric sea level contributes 45% to the observed sea-level trend. These results are consistent with previous studies. In addition, the results demonstrate that the maximum sea-level rise rate of 8.4 mm year-1 is occurring off the east coast of Vietnam and eastern part of SCS. During 2010-2011, the La...... Niña event was highly correlated with the dramatic sea-level rise in the SCS; La Niña events were also associated with the maximum rate of sea rise off the east coast of Vietnam, which occurred during 1993 and 2012. We also evaluated the trends in the geophysical (e.g. dynamical atmospheric correction...

Effects of satellite transmitters on captive and wild mallards

Science.gov (United States)

Kesler, Dylan C.; Raedeke, Andrew H.; Foggia, Jennifer R.; Beatty, William S.; Webb, Elisabeth B.; Humburg, Dale D.; Naylor, Luke W.

2014-01-01

Satellite telemetry has become a leading method for studying large-scale movements and survival in birds, yet few have addressed potential effects of the larger and heavier tracking equipment on study subjects. We simultaneously evaluated effects of satellite telemetry equipment on captive and wild mallards (Anas platyrhynchos) to assess impacts on behavior, body mass, and movement. We randomly assigned 55 captive ducks to one of 3 treatment groups, including a standard body harness group, a modified harness group, and a control group. Ducks in the control group were not fitted with equipment, whereas individuals in the other 2 groups were fitted with dummy transmitters attached with a Teflon ribbon harness or with a similar harness constructed of nylon cord. At the conclusion of the 14-week captive study, mean body mass of birds in the control group was 40–105 g (95% CI) greater than birds with standard harnesses, and 28–99 g (95% CI) greater than birds with modified harnesses. Further, results of focal behavior observations indicated ducks with transmitters were less likely to be in water than control birds. We also tested whether movements of wild birds marked with a similar Teflon harness satellite transmitter aligned with population movements reported by on-the-ground observers who indexed local abundances of mid-continent mallards throughout the non-breeding period. Results indicated birds marked with satellite transmitters moved concurrently with the larger unmarked population. Our results have broad implications for field research and suggest that investigators should consider potential for physiological and behavioral effects brought about by tracking equipment. Nonetheless, results from wild ducks indicate satellite telemetry has the potential to provide useful movement data.

Protected transitional solution to transformational satellite communications

Science.gov (United States)

Brand, Jerry C.

2005-06-01

As the Warfighter progresses into the next generation battlefield, transformational communications become evident as an enabling technology. Satellite communications become even more vital as the battles range over greater non-contiguous spaces. While current satellite communications provide suitable beyond line-of-sight communications and the Transformational Communications Architecture (TCA) sets the stage for sound information exchange, a realizable transition must occur to ensure successful succession to this higher level. This paper addresses the need for a planned escalation to the next generation satellite communications architecture and offers near-term alternatives. Commercial satellite systems continue to enable the Warfighter to reach back to needed information resources, providing a large majority of available bandwidth. Four areas of concentration for transition include encrypted Telemetry, Tracking and Control (or Command) (TT&C), encrypted and covered data, satellite attack detection and protection, and operational mobility. Solution methodologies include directly embedding COMSEC devices in the satellites and terminals, and supplementing existing terminals with suitable equipment and software. Future satellites planned for near-term launches can be adapted to include commercial grade and higher-level secure equipment. Alternately, the expected use of programmable modems (Software Defined Radios (SDR)) enables incorporation of powerful cipher methods approaching military standards as well as waveforms suitable for on-the-move operation. Minimal equipment and software additions on the satellites can provide reasonable attack detection and protection methods in concert with the planned satellite usage. Network management suite modifications enable cohesive incorporation of these protection schemes. Such transitional ideas offer a smooth and planned transition as the TCA takes life.

Sequential Relationship between Profitability and Sustainability: The Case of Migratory Beekeeping

Directory of Open Access Journals (Sweden)

Luciano Pilati

2016-01-01

Full Text Available When beekeeping is managed on a migratory basis, the bee colony produces physical outputs (honey and pollination services on a sequence of forage sites. Forage sites are competitors if their flowering periods overlap, and are complementary otherwise. Viable sequences consist only of complementary forage sites. A part of the bee colony’s production time is spent on each forage site in the period when the crop or wild vegetation covering it is in flower. The total period covered by the sequence of sites, including the base site, must be equal to or less than the duration (365 days of the bee colony’s annual biological cycle. The migratory beekeeper draws up viable sequences of forage sites and calculates their profitability levels. Variations in the profitability of forage sites which alter the composition of the sequence, affecting provision of the non-marketed ecosystem pollination services, impact the biodiversity of the pollinated plants with trickle-down effects on sustainability. In the case of migratory beekeeping, there is, therefore, a sequential relationship between profitability and sustainability.

Long-term GPS tracking of ocean sunfish Mola mola offers a new direction in fish monitoring.

Directory of Open Access Journals (Sweden)

David W Sims

Full Text Available Satellite tracking of large pelagic fish provides insights on free-ranging behaviour, distributions and population structuring. Up to now, such fish have been tracked remotely using two principal methods: direct positioning of transmitters by Argos polar-orbiting satellites, and satellite relay of tag-derived light-level data for post hoc track reconstruction. Error fields associated with positions determined by these methods range from hundreds of metres to hundreds of kilometres. However, low spatial accuracy of tracks masks important details, such as foraging patterns. Here we use a fast-acquisition global positioning system (Fastloc GPS tag with remote data retrieval to track long-term movements, in near real time and position accuracy of <70 m, of the world's largest bony fish, the ocean sunfish Mola mola. Search-like movements occurred over at least three distinct spatial scales. At fine scales, sunfish spent longer in highly localised areas with faster, straighter excursions between them. These 'stopovers' during long-distance movement appear consistent with finding and exploiting food patches. This demonstrates the feasibility of GPS tagging to provide tracks of unparalleled accuracy for monitoring movements of large pelagic fish, and with nearly four times as many locations obtained by the GPS tag than by a conventional Argos transmitter. The results signal the potential of GPS-tagged pelagic fish that surface regularly to be detectors of resource 'hotspots' in the blue ocean and provides a new capability for understanding large pelagic fish behaviour and habitat use that is relevant to ocean management and species conservation.

Kalman Orbit Optimized Loop Tracking

Science.gov (United States)

Young, Lawrence E.; Meehan, Thomas K.

2011-01-01

Under certain conditions of low signal power and/or high noise, there is insufficient signal to noise ratio (SNR) to close tracking loops with individual signals on orbiting Global Navigation Satellite System (GNSS) receivers. In addition, the processing power available from flight computers is not great enough to implement a conventional ultra-tight coupling tracking loop. This work provides a method to track GNSS signals at very low SNR without the penalty of requiring very high processor throughput to calculate the loop parameters. The Kalman Orbit-Optimized Loop (KOOL) tracking approach constitutes a filter with a dynamic model and using the aggregate of information from all tracked GNSS signals to close the tracking loop for each signal. For applications where there is not a good dynamic model, such as very low orbits where atmospheric drag models may not be adequate to achieve the required accuracy, aiding from an IMU (inertial measurement unit) or other sensor will be added. The KOOL approach is based on research JPL has done to allow signal recovery from weak and scintillating signals observed during the use of GPS signals for limb sounding of the Earth s atmosphere. That approach uses the onboard PVT (position, velocity, time) solution to generate predictions for the range, range rate, and acceleration of the low-SNR signal. The low- SNR signal data are captured by a directed open loop. KOOL builds on the previous open loop tracking by including feedback and observable generation from the weak-signal channels so that the MSR receiver will continue to track and provide PVT, range, and Doppler data, even when all channels have low SNR.

Timing is crucial for consequences of migratory connectivity

NARCIS (Netherlands)

Bauer, Silke; Lisovski, Simeon; Hahn, Steffen

Migratory connectivity can have important consequences for individuals, populations and communities. We argue that most consequences not only depend on which sites are used but importantly also on when these are used and suggest that the timing of migration is characterised by synchrony, phenology,

Hampered foraging and migratory performance in swans infected with low-pathogenic avian influenza A virus.

Directory of Open Access Journals (Sweden)

Jan A van Gils

Full Text Available It is increasingly acknowledged that migratory birds, notably waterfowl, play a critical role in the maintenance and spread of influenza A viruses. In order to elucidate the epidemiology of influenza A viruses in their natural hosts, a better understanding of the pathological effects in these hosts is required. Here we report on the feeding and migratory performance of wild migratory Bewick's swans (Cygnus columbianus bewickii Yarrell naturally infected with low-pathogenic avian influenza (LPAI A viruses of subtypes H6N2 and H6N8. Using information on geolocation data collected from Global Positioning Systems fitted to neck-collars, we show that infected swans experienced delayed migration, leaving their wintering site more than a month after uninfected animals. This was correlated with infected birds travelling shorter distances and fuelling and feeding at reduced rates. The data suggest that LPAI virus infections in wild migratory birds may have higher clinical and ecological impacts than previously recognised.

Authenticated tracking and monitoring system (ATMS) tracking shipments from an Australian uranium mine

International Nuclear Information System (INIS)

Schoeneman, J.L.

1998-01-01

The Authenticated Tracking and Monitoring System (ATMS) answers the need for global monitoring of the status and location of sensitive items on a worldwide basis, 24 hours a day. ATMS uses wireless sensor packs to monitor the status of the items and environmental conditions. A receiver and processing unit collect a variety of sensor event data. The collected data are transmitted to the INMARSAT satellite communication system, which then sends the data to appropriate ground stations. Authentication and encryption algorithms secure the data during communication activities. A typical ATMS application would be to track and monitor the safety and security of a number of items in transit along a scheduled shipping route. The resulting tracking, timing, and status information could then be processed to ensure compliance with various agreements. Following discussions between the Australian Safeguards Office (ASO), the US Department of Energy (DOE), and Sandia National Laboratories (SNL) in early 1995, the parties mutually agreed to conduct and evaluate a field trial prototype ATMS to track and monitor shipments of uranium ore concentrate (UOC) from an operating uranium mine in Australia to a final destination in Rotterdam, the Netherlands, with numerous stops along the way. During the months of February and March 1998, the trial was conducted on a worldwide basis, with tracking and monitoring stations located at sites in both Australia and the US. This paper describes ATMS and the trial

Ground Track Acquisition and Maintenance Maneuver Modeling for Low-Earth Orbit Satellite

Directory of Open Access Journals (Sweden)

Byoung-Sun Lee

1997-12-01

Full Text Available This paper presents a comprehensive analytical approach for determining key maneuver parameters associated with the acquisition and maintenance of the ground track for a low-earth orbit. A livearized model relating changes in the drift rate of the ground track directly to changes in the orbital semi-major axis is also developed. The effect of terrestrial atmospheric drag on the semi-major axis is also explored, being quantified through an analytical expression for the decay rate as a function of density. The non-singular Lagrange planetary equations, further simplified for nearly circular orbits, provide the desired relationships between the corrective in-plane impulsive velocity increments and the corresponding effects on the orbit elements. The resulting solution strategy offers excellent insight into the dynamics affecting the timing, magnitude, and frequency of these maneuvers. Simulations are executed for the ground track acquisition and maintenance maneuver as a pre-flight planning and analysis.

German telecommunications satellite (Deutscher fernmelde satellit) (DFS-1 and -2)

Science.gov (United States)

Hiendlmeier, G.; Schmeller, H.

1991-01-01

The German Telecommunications Satellite (DFS) Program is to provide telecommunications service for high data rate transmission of text and video data to the Federal Republic of Germany within the 11-14 GHz and 20-30 GHz bands. The space segment of this program is composed of three satellites, DFS-1, DFS-2, and DFS-3, which will be located at 23.5 degrees E longitude of the geostationary orbit. The DFS will be launched from the Center Spatial Guyanis in French Giana on an Ariane launch vehicle. The mission follows the typical injection sequence: parking orbit, transfer orbit, and earth orbit. Attitude maneuvers will be performed to orient the spacecraft prior to Apogee Kick Motor (AKM) firing. After AKM firing, drift phase orbital and attitude maneuvers will be performed to place the spacecraft in its final geostationary position. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. Information is presented in tabular form for the following areas: DSN support, compatibility testing, frequency assignments, telemetry, command, and tracking support responsibilities.

Geocenter Motion Derived from GNSS and SLR Tracking Data of LEO

Science.gov (United States)

Li, Y. S.; Ning, F. S.; Tseng, K. H.; Tseng, T. P.; Wu, J. M.; Chen, K. L.

2017-12-01

Space geodesy techniques can provide the monitoring data of global variations with high precision and large coverage through the satellites. Geocenter motion (GM) describes the difference of CF (Center of Figure) respect to CM (Center of Mass of the Earth System) due to the re-distribution and deformation of the earth system. Because satellite tracking data between ground stations and satellites orbit around the CM, geocenter motion is related to the realization of the ITRF (International Terrestrial Reference Frame) origin. In this study, GPS (Global Positioning System) observation data of IGS (International GNSS Service) and SLR (Satellite Laser Ranging) tracking data are applied to estimate the coordinates of observing sites on Earth's surface. The GPS observing sites are distributed deliberately and globally by 15° ×15° grids. Meanwhile, two different global ocean tide models are applied here. The model used in ITRF comparison and combination is parameter transformation, which is a mathematical formula allowing to transform the different frames between ITRF and CM system. Following the parameter transformation, the results of geocenter motion can be determined. The FORMOSAT-7/COSMIC-2 (F7C2) mission is a constellation of LEO (Low-Earth-Orbit) satellites, which will be launched in 2018. Besides the observing system for Meteorology, Ionosphere, and Climate, the F7C2 will be equipped with LRR (Laser Ranging Retroreflector). This work is a pilot survey to study the application of LEO SLR data in Taiwan.

Tracking Climate Effects on Plant-Pollinator Interaction Phenology with Satellites and Honey Bee Hives

Science.gov (United States)

Esaias, Wayne E.; Nickeson, Jaime E.; Tan, Bin; Ma, Peter L.; Nightingale, Joanne M.; Wolfe, Robert E.

2011-01-01

Background/Question/Methods: The complexity of plant-pollinator interactions, the large number of species involved, and the lack of species response functions present challenges to understanding how these critical interactions may be impacted by climate and land cover change on large scales. Given the importance of this interaction for terrestrial ecosystems, it is desirable to develop new approaches. We monitor the daily weight change of honey bee (Apis mellifera) colonies to record the phenology of the Honey Bee Nectar Flow (HBNF) in a volunteer network (honeybeenet.gsfc.nasa.gov). The records document the successful interaction of a generalist pollinator with a variety of plant resources. We extract useful HBNF phenology metrics for three seasons. Sites currently exist in 35 states/provinces in North America, with a concentration in the Mid-Atlantic region. HBNF metrics are compared to standard phenology metrics derived from remotely sensed vegetation indices from NASA's MODIS sensor and published results from NOAA's A VHRR. At any given time the percentage of plants producing nectar is usually a sma11 fraction of the total satellite sensor signal. We are interested in determining how well the 'bulk' satellite vegetation parameters relate to the phenology of the HBNF, and how it varies spatially on landscape to continental scales. Results/Conclusions: We found the median and peak seasonal HBNF dates to be robust, with variation between replicate scale hives of only a few days. We developed quality assessment protocols to identify abnormal colony artifacts. Temporally, the peak and median of the HBNF in the Mid-Atlantic show a significant advance of 0.58 d/y beginning about 1970, very similar to that observed by the A VHRR since 1982 (0.57 d/y). Spatially, the HBNF metrics are highly correlated with elevation and winter minimum temperature distribution, and exhibit significant but regionally coherent inter-annual variation. The relationship between median of the

Avian Influenza in Migratory Birds : Regional Surveillance and ...

International Development Research Centre (IDRC) Digital Library (Canada)

Outbreaks may only occur after transmission from migratory species to domestic flocks through local amplification and secondary spread through the movement of poultry or people, as well as equipment or vehicles contaminated by sick birds. The Asia Partnership for Avian Influenza Research (APAIR) brings together ...

Troublesome transportation concerns can be mitigated - RADMAT tracking system

International Nuclear Information System (INIS)

Harmon, L.H.

1987-01-01

There are three troublesome institutional concerns which face every large-quantity radioactive materials shipment - routing, pre-notification, and emergency response. People want to know: where's the shipment going and how's it getting there? States want to know what's being shipped and when? What kind of response to accidents is needed for this shipment and who'll respond? DOE is developing a transportation tracking system, based on a rapidly developing technology to determine geographical location using geo-positioning satellite systems. This technology will be used to track unclassified radioactive materials shipments in real-time. It puts those charged with monitoring transportation status on top of every shipment. Besides its practical benefits in the areas of logistics planning and execution, it demonstrates emergency preparedness has indeed been considered and close monitoring is possible. This paper will describe the system's technical detail, DOE plans and policy for its implementation, and the state of satellite positioning technology

Proposal of balloon and satellite observations of MeV gammas using Electron Tracking Compton Camera for reaching a high sensitivity of 1 mCrab

Science.gov (United States)

Takada, Atsushi; Tanimori, Toru

2016-04-01

ETCC with a gas Time Projection Chamber (TPC) and pixel GSO scintillators, by measuring electron tracks precisely, provides both a strong background rejection by dE/dx of the track and well-defined 2-dimensional Point Spread Function (PDF) with better than several degrees by adding the arc direction of incident gammas (SPD: Scatter Plane Deviation) with the ARM (angular Resolution Measure) direction measured in standard Compton Camera (CC). In 2006 its background rejection was revealed by SMILE-I balloon experiment with 10cm-cubic ETCC using the dE/dx of tracks. In 2013, 30cm-cube-ETCC has been developed to catch gammas from Crab in next SMILE-II balloon with >5sigma detection for 4 hrs. Now its sensitivity has been improved to 10sigma by attaining the angular resolution of the track (SPD angle) to that determined by multiple scattering of the gas. Thus, we show the ability of ETCC to give a better significance by a factor of 10 than that of standard CCs having same detection area by electron tracking?and we have found that SPD is an essential to define the PSF of Compton imaging quantitatively. Such a well-defined PSF is, for the first time, able to provide reliable sensitivity in Compton imaging without assuming the use of optimization algorithm. These studies uncover the uncertainties of CCs from both points of view of the intense background and the difficulty of the definition of the PSF, and overcome the above problems. Based on this technology, SMILE-II with 3atm CF4 gas is expected to provide a 5times better sensitivity than COMPTEL in one month balloon, and 4modules of 50cm-cube ETCCs would exceed over 10^-12 erg/cm^2s^1 (1mCrab) in satellite. Here we summarize the performance of the ETCC and new astrophysics opened in near future by high sensitive observation of MeV gamma-rays.

Seasonal survival estimation for a long-distance migratory bird and the influence of winter precipitation

Science.gov (United States)

Sarah M. Rockwell; Joseph M. Wunderle; T. Scott Sillett; Carol I. Bocetti; David N. Ewert; Dave Currie; Jennifer D. White; Peter P. Marra

2017-01-01

Conservation of migratory animals requires information about seasonal survival rates. Identifying factors that limit populations, and the portions of the annual cycle in which they occur, are critical for recognizing and reducing potential threats. However, such data are lacking for virtually all migratory taxa. We investigated patterns and environmental correlates of...

Migratory timing, rate, routes and wintering areas of White-crested Elaenia (Elaenia albiceps chilensis, a key seed disperser for Patagonian forest regeneration.

Directory of Open Access Journals (Sweden)

Susana Patricia Bravo

Full Text Available Migratory animals often play key ecological roles within the communities they visit throughout their annual journeys. As a consequence of the links between biomes mediated by migrants, changes in one biome could affect remote areas in unpredictable ways. Migratory routes and timing of most Neotropical austral migrants, which breed at south temperate latitudes of South America and overwinter closer to or within tropical latitudes of South America, have yet to be described in detail. As a result, our understanding about how these birds provide links between South American biomes is almost non-existent. White-crested Elaenia (Elaenia albiceps chilensis is a long-distance austral migrant that breeds in the Patagonian Forest biome and overwinters in tropical South America. Because this small flycatcher plays a key role in the regeneration of this ecosystem, our objective was to describe the annual cycle of White-crested elaenias to evaluate the degree of migratory connectivity between breeding and wintering areas and therefore to determine if there are specific biomes of northern South America linked by elaenias to Patagonian forests. Fifteen individuals were successfully tracked throughout a complete migration cycle using miniature light-level geolocators. All individuals resided and moved through the same general regions. During fall (March-April-May, elaenias were located in the Caatinga and the Atlantic Forest biomes, from Rio de Janeiro to the region near Salvador da Bahia, Brazil. During winter (June-July-Aug., birds were located further inland, within the Cerrado biome. Birds used three different routes during fall migration. Our results indicate that some individuals use a direct route, flying between 500-600 km/day, crossing desert and grasslands, while others took a detour, flying 100-200 km/day through forested areas with refueling opportunities. All birds used the Yunga forest during spring migration, with ten out of 15 individuals

Migration in the Anthropocene: how collective navigation, environmental system and taxonomy shape the vulnerability of migratory species.

Science.gov (United States)

Hardesty-Moore, Molly; Deinet, Stefanie; Freeman, Robin; Titcomb, Georgia C; Dillon, Erin M; Stears, Keenan; Klope, Maggie; Bui, An; Orr, Devyn; Young, Hillary S; Miller-Ter Kuile, Ana; Hughey, Lacey F; McCauley, Douglas J

2018-05-19

Recent increases in human disturbance pose significant threats to migratory species using collective movement strategies. Key threats to migrants may differ depending on behavioural traits (e.g. collective navigation), taxonomy and the environmental system (i.e. freshwater, marine or terrestrial) associated with migration. We quantitatively assess how collective navigation, taxonomic membership and environmental system impact species' vulnerability by (i) evaluating population change in migratory and non-migratory bird, mammal and fish species using the Living Planet Database (LPD), (ii) analysing the role of collective navigation and environmental system on migrant extinction risk using International Union for Conservation of Nature (IUCN) classifications and (iii) compiling literature on geographical range change of migratory species. Likelihood of population decrease differed by taxonomic group: migratory birds were more likely to experience annual declines than non-migrants, while mammals displayed the opposite pattern. Within migratory species in IUCN, we observed that collective navigation and environmental system were important predictors of extinction risk for fishes and birds, but not for mammals, which had overall higher extinction risk than other taxa. We found high phylogenetic relatedness among collectively navigating species, which could have obscured its importance in determining extinction risk. Overall, outputs from these analyses can help guide strategic interventions to conserve the most vulnerable migrations.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Author(s).

New progress of ranging technology at Wuhan Satellite Laser Ranging Station

Science.gov (United States)

Xia, Zhiz-Hong; Ye, Wen-Wei; Cai, Qing-Fu

1993-01-01

A satellite laser ranging system with an accuracy of the level of centimeter has been successfully developed at the Institute of Seismology, State Seismological Bureau with the cooperation of the Institute of Geodesy and Geophysics, Chinese Academy of Science. With significant improvements on the base of the second generation SLR system developed in 1985, ranging accuracy of the new system has been upgraded from 15 cm to 3-4 cm. Measuring range has also been expanded, so that the ETALON satellite with an orbit height of 20,000 km launched by the former U.S.S.R. can now be tracked. Compared with the 2nd generation SLR system, the newly developed system has the following improvements. A Q modulated laser is replaced by a mode-locked YAG laser. The new device has a pulse width of 150 ps and a repetition rate of 1-4 pps. A quick response photomultiplier has been adopted as the receiver for echo; for example, the adoption of the MCP tube has obviously reduced the jitter error of the transit time and has improved the ranging accuracy. The whole system is controlled by an IBM PC/XT Computer to guide automatic tracking and measurement. It can carry out these functions for satellite orbit calculation, real-time tracking and adjusting, data acquisition and the preprocessed of observing data, etc. The automatization level and reliability of the observation have obviously improved.

Economic impotance of flying visitors: migratory birds | Egwumah ...

African Journals Online (AJOL)

... are also capable of producing oil. Nature based tourism and recreation, such as the viewing of wildlife coupled with; management of migratory birds promotes market for other industrial goods such as lead shot, guns and binocular. Keywords: Migration; Recreation and Tourism; Trophies; Ornament; Food; Production of Oil ...

Factors affecting aggressive behaviour of spawning migratory males towards mature male parr in masu salmon Oncorhynchus masou.

Science.gov (United States)

Watanabe, M; Maekawa, K

2010-07-01

This study examined whether dominant migratory males (adopting fighter tactics) of the masu salmon Oncorhynchus masou would more aggressively attack large mature male parr (adopting sneaker tactics) as large mature male parr are expected to have the potential to cause a greater decrease in fertilization success. The frequency of aggressive behaviour was not related to the body size of males, and it increased with the frequency of interactions with mature male parr. The fertilization success of mature male parr was much lower than migratory males, and no relationship was observed between fertilization success and aggressive behaviour. The low fertilization success of mature male parr, despite infrequent aggressive behaviour by migratory males, indicates that there might be little benefit for migratory males to attack mature male parr more aggressively according to their body size.

Heuristic approach to Satellite Range Scheduling with Bounds using Lagrangian Relaxation.

Energy Technology Data Exchange (ETDEWEB)

Brown, Nathanael J. K.; Arguello, Bryan; Nozick, Linda Karen; Xu, Ningxiong [Cornell

2017-03-01

This paper focuses on scheduling antennas to track satellites using a heuristic method. In order to validate the performance of the heuristic, bounds are developed using Lagrangian relaxation. The performance of the algorithm is established using several illustrative problems.

An acoustic system for autonomous navigation and tracking of marine fauna

KAUST Repository

De la Torre, Pedro; Salama, Khaled N.; Berumen, Michael L.

2014-01-01

A marine acoustic system for underwater target tracking is described. This system is part of the Integrated Satellite and Acoustic Telemetry (iSAT) project to study marine fauna. It is a microcontroller-based underwater projector and receiver. A

Tracking change over time

Science.gov (United States)

,

2011-01-01

Landsat satellites capture images of Earth from space-and have since 1972! These images provide a long-term record of natural and human-induced changes on the global landscape. Comparing images from multiple years reveals slow and subtle changes as well as rapid and devastating ones. Landsat images are available over the Internet at no charge. Using the free software MultiSpec, students can track changes to the landscape over time-just like remote sensing scientists do! The objective of the Tracking Change Over Time lesson plan is to get students excited about studying the changing Earth. Intended for students in grades 5-8, the lesson plan is flexible and may be used as a student self-guided tutorial or as a teacher-led class lesson. Enhance students' learning of geography, map reading, earth science, and problem solving by seeing landscape changes from space.

Migratory Insertion of Hydrogen Isocyanide in the Pentacyano(methyl)cobaltate(III) Anion

DEFF Research Database (Denmark)

Kofod, Pauli; Harris, Pernille Hanne; Larsen, Sine

2003-01-01

The preparation of the pentacyano(iminiumacetyl)cobaltate(III) anion and its N-methyl and N,N-dimethyl derivatives is reported. The iminiumacetyl group is formed by migratory insertion of cis hydrogen isocyanide in the pentacyano(methyl)cobaltate(III) anion. The new compounds have been spectrosco......The preparation of the pentacyano(iminiumacetyl)cobaltate(III) anion and its N-methyl and N,N-dimethyl derivatives is reported. The iminiumacetyl group is formed by migratory insertion of cis hydrogen isocyanide in the pentacyano(methyl)cobaltate(III) anion. The new compounds have been...

The morphological development of the locomotor and cardiac muscles of the migratory barnacle goose (Branta leucopsis)

NARCIS (Netherlands)

Bishop, CM; Butler, PJ; ElHaj, AJ; Egginton, S; Loonen, MJJE

The masses of the locomotor and cardiac muscles of wild barnacle goose goslings, from a migratory population, were examined systematically during development and their values compared to those of pre-migratory geese. Pre-flight development was typified by approximately linear increases of body, leg,

76 FR 39368 - Migratory Bird Permits; Abatement Regulations

Science.gov (United States)

2011-07-06

... promulgating migratory bird permit regulations for a permit to use raptors (birds of prey) in abatement activities. Abatement means the use of trained raptors to flush, scare (haze), or take birds or other...). Background In response to public interest in the use of trained raptors to haze (scare) depredating and other...

76 FR 67650 - Migratory Bird Permits; Abatement Regulations

Science.gov (United States)

2011-11-02

... and suggestions on migratory bird permit regulations for a permit to use raptors (birds of prey) in abatement activities. Abatement means the use of trained raptors to flush, scare (haze), or take birds or... for a specific permit authorizing the use of raptors in abatement activities (76 FR 39368). The...

Simulation of solar array slewing of Indian remote sensing satellite

Science.gov (United States)

Maharana, P. K.; Goel, P. S.

The effect of flexible arrays on sun tracking for the IRS satellite is studied. Equations of motion of satellites carrying a rotating flexible appendage are developed following the Newton-Euler approach and utilizing the constrained modes of the appendage. The drive torque, detent torque and friction torque in the SADA are included in the model. Extensive simulations of the slewing motion are carried out. The phenomena of back-stepping, step-missing, step-slipping and the influences of array flexibility in the acquisition mode are observed for certain combinations of parameters.

Bicalutamide-Associated Acute Liver Injury and Migratory Arthralgia: A Rare but Clinically Important Adverse Effect

Directory of Open Access Journals (Sweden)

Helga M. Gretarsdottir

2018-06-01

Full Text Available We describe a case of acute liver injury and migratory arthralgia in a patient receiving bicalutamide treatment for prostate cancer. A 67-year-old male with metastatic prostate cancer presented with a 6-day history of migratory arthralgia. He had been undergoing treatment with bicalutamide for 4 months; 3 weeks prior to symptom appearance the bicalutamide dose had been increased. He had no other symptoms. Liver tests and inflammatory markers were markedly elevated. Serology for hepatitis viruses A, B, and C, CMV, and EBV and autoimmune causes were all negative, and an ultrasound of the upper abdomen was normal. There was no history of blood transfusion, intravenous drug abuse, or alcohol abuse. Due to the suspicion of a drug-induced symptomatology, bicalutamide was discontinued and the patient started on 30 mg prednisolone daily. Three weeks later he was symptom free and after 6 weeks his liver tests were almost normal. The Roussel Uclaf Causality Assessment Method (RUCAM suggested a high probability of liver injury. Bicalutamide has very rarely been reported as a causative agent for liver injury and to our knowledge never for migratory polyarthralgia. The migratory polyarthralgia was attributed to bicalutamide due to the absence of other etiological factors and the disappearance of symptoms after discontinuation of the drug. To our knowledge, this is the first published case report of migratory arthralgia and concomitant liver injury attributed to bicalutamide.

Landscape associations of birds during migratory stopover

Science.gov (United States)

Diehl, Robert Howard

The challenge for migratory bird conservation is habitat preservation that sustains breeding, migration, and non-breeding biological processes. In choosing an appropriately scaled conservation arena for habitat preservation, a conservative and thorough examination of stopover habitat use patterns by migrants works back from the larger scales at which such relationships may occur. Because the use of stopover habitats by migrating birds occurs at spatial scales larger than traditional field techniques can easily accommodate, I quantify these relationship using the United States system of weather surveillance radars (popularly known as NEXRAD). To provide perspective on use of this system for biologists, I first describe the technical challenges as well as some of the biological potential of these radars for ornithological research. Using data from these radars, I then examined the influence of Lake Michigan and the distribution of woodland habitat on migrant concentrations in northeastern Illinois habitats during stopover. Lake Michigan exerted less influence on migrant abundance and density than the distribution and availability of habitat for stopover. There was evidence of post-migratory movement resulting in habitats within suburban landscapes experiencing higher migrant abundance but lower migrant density than habitats within nearby urban and agricultural landscapes. Finally, in the context of hierarchy theory, I examined the influence of landscape ecological and behavioral processes on bird density during migratory stopover. Migrant abundance did not vary across landscapes that differed considerably in the amount of habitat available for stopover. As a result, smaller, more isolated patches held higher densities of birds. Spatial models of migrant habitat selection based on migrant proximity to a patch explained nearly as much variance in the number of migrants occupying patches (R2 = 0.88) as selection models based on migrant interception of patches during

Evaluation of the Precision of Satellite-Derived Sea Surface Temperature Fields

Science.gov (United States)

Wu, F.; Cornillon, P. C.; Guan, L.

2016-02-01

A great deal of attention has been focused on the temporal accuracy of satellite-derived sea surface temperature (SST) fields with little attention being given to their spatial precision. Specifically, the primary measure of the quality of SST fields has been the bias and variance of selected values minus co-located (in space and time) in situ values. Contributing values, determined by the location of the in situ values and the necessity that the satellite-derived values be cloud free, are generally widely separated in space and time hence provide little information related to the pixel-to-pixel uncertainty in the retrievals. But the main contribution to the uncertainty in satellite-derived SST retrievals relates to atmospheric contamination and because the spatial scales of atmospheric features are, in general, large compared with the pixel separation of modern infra-red sensors, the pixel-to-pixel uncertainty is often smaller than the accuracy determined from in situ match-ups. This makes selection of satellite-derived datasets for the study of submesoscale processes, for which the spatial structure of the upper ocean is significant, problematic. In this presentation we present a methodology to characterize the spatial precision of satellite-derived SST fields. The method is based on an examination of the high wavenumber tail of the 2-D spectrum of SST fields in the Sargasso Sea, a low energy region of the ocean close to the track of the MV Oleander, a container ship making weekly roundtrips between New York and Bermuda, with engine intake temperatures sampled every 75 m along track. Important spectral characteristics are the point at which the satellite-derived spectra separate from the Oleander spectra and the spectral slope following separation. In this presentation a number of high resolution 375 m to 10 km SST datasets are evaluated based on this approach.

Regional migratory osteoporosis: a review illustrated by five cases

International Nuclear Information System (INIS)

Toms, A.P.; Marshall, T.J.; Becker, E.; Donell, S.T.; Lobo-Mueller, E.M.; Barker, T.

2005-01-01

Regional migratory osteoporosis is an uncommon self-limiting disease characterized by an arthralgia which migrates between the weight-bearing joints of the lower limb. The radiological features of the disease obtained by conventional radiography, CT, MRI and radionuclide scintigraphy are illustrated by means of five case reports. These range from the most common presentation of sequential, proximal to distal spread in the lower limb to the rare intra-articular form, and disease involving the axial skeleton is also recognized. Clinical and radiographical features often overlap with those of diseases such as transient osteoporosis of the hip and transient bone marrow oedema syndrome, which is reflected in confusing terminology. Histological sampling is usually unnecessary; the radiological features are characteristic and the histological findings are not specific. Regional migratory osteoporosis is associated with systemic osteoporosis. This association is probably under-recognized, and has implications for the pathophysiology of the disease and for treatment

Honey buzzards don't always make a beeline.

Science.gov (United States)

Chapman, Jason W

2017-03-01

(a) European honey buzzards breeding in Western Europe primarily use soaring flight to make annual long-range migrations via the Strait of Gibraltar to winter in West Africa; this adult male was photographed on migration near Gibraltar. Photo: Javier Elloriaga. (b) Autumn migration routes of 12 satellite tagged adult European honey buzzards (colour-coded lines); compared with the shortest possible straight-line routes (dashed lines), most routes involved substantial westerly detours in Africa. Adapted from Vansteelant et al. (2016). (c) In contrast, Montagu's harriers predominantly use flapping flight during their migrations; this adult male is carrying a satellite transmitter. Photo: Theo van Kooten. (d) Autumn migration routes of 34 satellite tagged adult Montagu's harriers; migratory tracks more closely approached straight-line routes, and typically involved longer sea crossings, than seen in European honey buzzards. Adapted from Trierweiler et al. (). In Focus: Vansteelant, W.M.G., Shamoun-Baranes, J., van Manen, W., van Diermen, J. & Bouten, W. (2017) Seasonal detours by soaring migrants shaped by wind regimes along the East Atlantic Flyway. Journal of Animal Ecology, 86, 179-191. Migratory birds often make substantial detours from the shortest possible route during their annual migrations, which may potentially increase the duration and energetic cost of their journeys. Vansteelant et al. () investigate repeated migrations of adult European honey buzzards between the Netherlands and sub-Saharan Africa, and find that they make large westerly detours in Africa on both the spring and autumn routes. These detours allow migrants to capitalise on more favourable winds further along the route, thus reducing energy expenditure. Lifelong tracking studies will allow researchers to identify how migration routes have evolved to exploit predictable atmospheric and oceanic circulation patterns. © 2017 The Author. Journal of Animal Ecology © 2017 British Ecological

Are color or high rearing density related to migratory polyphenism in the band-winged grasshopper, Oedaleus asiaticus?

Science.gov (United States)

Cease, Arianne J; Hao, Shuguang; Kang, Le; Elser, James J; Harrison, Jon F

2010-08-01

Locusts represent an impressive example of migratory polyphenism, with high densities triggering a switch from a solitarious, shorter dispersal range, and sometimes greenish phenotype to a gregarious and sometimes darker form exhibiting behavioral, morphological and physiological traits associated with long-distance migratory swarms. While such polyphenism has been well documented in Locusta migratoria and Schistocerca gregaria, the extent to which other grasshoppers exhibit this type of migratory polyphenism is unclear. Anecdotally, the Chinese grasshopper, Oedaleus asiaticus, forms migratory swarms comprised mostly of a darker, brown-colored morph, but also exhibits a non-migratory green-colored morph that predominates at low densities. In a population in Inner Mongolia not currently exhibiting migratory swarms, we found that while green and brown O. asiaticus are found concurrently across our sampled range, only brown grasshoppers were found in high densities. Differences between field-collected brown and green forms matched some but not key predictions associated with the hypothesis that the brown form is morphologically and physiologically specialized for gregarious migration. Controlling for body mass, brown forms had more massive thoraxes, abdomens and legs, and higher metabolic rates, but not more flight muscle or lipid stores. Further, the brown and green grasshoppers did not differ in gregarious behavior, and neither would fly in multiple lab and field trials. Lab or field-rearing at high densities for one-to-multiple juvenile instars caused grasshoppers to exhibit some morphological traits predicted to benefit migration (larger wings and a shift in relative mass from abdomen to thorax), but did not change color or induce flight behavior. One hypothesis to explain these data is that a migratory form of O. asiaticus is partially triggered by high field densities, but that existing ecological conditions blocked full expression of such traits (and outbreak

Recent Korean R&D in Satellite Communications

Science.gov (United States)

Lee, Ho-Jin; Kim, Jae Moung; Lee, Byung-Seub; Lee, Han; Ryoo, Jang-Soo

The R&D in satellite communications in Korea has been driven mainly by KCC (Korea Communications Commission) but in a small scale compared to Korea space development program organized by MEST (Ministry of Education, Science and Technology). Public and civilian satcom sector R&D has been led mainly by ETRI with small/medium companies contrary to rare investment in private sector while military sector R&D has been orchestrated by ADD with defense industry. By the COMS (Communication, Ocean and Meteorological Satellite) experimental Ka-band payload, Korea pursues a space qualification of own technology for national infrastructure evolution as well as industrialization of space R&D results. Once COMS launched and space qualified in 2009, subsequent application experiments and new technology R&D like UHDTV will entail service and industry promotion. The payload technology is expected for the next Korean commercial satellites or for new OBP satellites. The COMS ground control system and GNSS ground station technologies are under development for COMS operation and enhanced GNSS services along with advent of Galileo respectively. Satellite broadband mobile VSAT based on DVB-S2/RCS (+M) and low profile tracking antennas have been developed for trains, ships, and planes. While APSI is developing GMR-1 based Thuraya handset functions, ETRI is designing IMT-Advanced satellite radio interface for satellite and terrestrial dual-mode handheld communication system like Japanese STICS, with universities' satellite OFDM researches. A 21GHz Ka-band higher-availability scalable HD broadcasting technology and SkyLife's hybrid satellite IPTV technology are being developed. In near term Korea will extend R&D programs to upgrade the space communication infrastructure for universal access to digital opportunity and safer daily life from disaster, and to promote space green IT industrialization, national security, and space resources sovereign. Japanese stakeholders are invited to establish

Acquisition, tracking, and pointing; Proceedings of the Meeting, Orlando, FL, Apr. 3, 4, 1986

Science.gov (United States)

Auelmann, Richard R. (Editor); Richard, Herbert L. (Editor)

1987-01-01

The present conference discusses the effect of target signatures on active tracking, the high resolution obtainable with a two-degrees-of-freedom angle sensor having a high update rate, solar object tracking for the Hubble Space Telescope, scaled experiments for the assessment of precise active tracking, and large aperture high-accuracy satellite laser tracking. Also discussed are laboratory test results for the Spaceborne Geodynamic Ranging System's high speed optical tracking system, jitter stabilization for precise optical pointing, scan stabilization and jitter control for an airborne telescope, a simulation of the Solar Optical Telescope's pointing performance, a microprocessor-based dual-speed angle converter, and image localization for alignment by means of adaptive preprocessing.

75 FR 74004 - Atlantic Highly Migratory Species; Advisory Panel

Science.gov (United States)

2010-11-30

... Atlantic Regional Fishery Management Councils, each of the 18 constituent states, both the U.S. Virgin... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA059 Atlantic... nominations for the Advisory Panel (AP) for Atlantic Highly Migratory Species (HMS) Southeast Data, Assessment...

Optimizing conservation of migratory species over their full annual cycle in the Western Hemisphere

OpenAIRE

Bennett, Joseph; Auer, Tom; Fink, Daniel; Arcese, Peter; Rodewald, Amanda; Wilson, Scott; Schuster, Richard

2018-01-01

Strategic plans to conserve migratory species require detailed knowledge on species distribution, abundance, and habitat use over the annual cycle, but such data are lacking for most species. We developed a hemispheric approach to planning using spatiotemporally explicit species abundance models to prioritize land needed to conserve ≥17% of the global populations of 109 species of Neotropical migratory birds. The efficiency of annual cycle plans was evaluated in comparisons to single-season p...

Inference of Altimeter Accuracy on Along-track Gravity Anomaly Recovery

Directory of Open Access Journals (Sweden)

LI Yang

2015-04-01

Full Text Available A correlation model between along-track gravity anomaly accuracy, spatial resolution and altimeter accuracy is proposed. This new model is based on along-track gravity anomaly recovery and resolution estimation. Firstly, an error propagation formula of along-track gravity anomaly is derived from the principle of satellite altimetry. Then the mathematics between the SNR (signal to noise ratio and cross spectral coherence is deduced. The analytical correlation between altimeter accuracy and spatial resolution is finally obtained from the results above. Numerical simulation results show that along-track gravity anomaly accuracy is proportional to altimeter accuracy, while spatial resolution has a power relation with altimeter accuracy. e.g., with altimeter accuracy improving m times, gravity anomaly accuracy improves m times while spatial resolution improves m0.4644 times. This model is verified by real-world data.

The along track scanning radiometer for ERS-1 - Scan geometry and data simulation

Science.gov (United States)

Prata, A. J. Fred; Cechet, Robert P.; Barton, Ian J.; Llewellyn-Jones, David T.

1990-01-01

The first European remote-sensing satellite (ERS-1), due to be launched in 1990, will carry the along track scanning radiometer (ATSR), which has been specifically designed to give accurate satellite measurements of sea surface temperature (SST). Details of the novel scanning technique used by the ATSR are given, and data from the NOAA-9 AVHRR instrument are used to simulate raw ATSR imagery. Because of the high precision of the onboard blackbodies, the active cooling of the detectors, 12-b digitization, and dual-angle capability, the ATSR promises to achieve higher-accuracy satellite-derived SSTs than are currently available.

Status and management of neotropical migratory birds: Introduction

Science.gov (United States)

Deborah M.; Peter W. Stangel

1993-01-01

The future for neotropical migratory birds rests with our commitment and ability to provide them adequate habitat during all periods of their life cycle. Our commitment to this cause is apparent in the groundswell of interest in neotropical migrants and the many proactive and coopemtive partnerships resulting from the Partners in Flight - Aves de las Americas...

77 FR 64318 - Atlantic Highly Migratory Species; Advisory Panel

Science.gov (United States)

2012-10-19

... Fishery Management Plans (FMPs) or FMP amendments for Atlantic tunas, swordfish, sharks, and billfish... membership in the HMS AP (note that there are no Environmental/NGO terms expiring, so no nominations for that...: Jenni Wallace, Highly Migratory Species Management Division, NMFS, 1315 East-West Highway, Silver Spring...

Breeding phenology and winter activity predict subsequent breeding success in a trans-global migratory seabird.

Science.gov (United States)

Shoji, A; Aris-Brosou, S; Culina, A; Fayet, A; Kirk, H; Padget, O; Juarez-Martinez, I; Boyle, D; Nakata, T; Perrins, C M; Guilford, T

2015-10-01

Inter-seasonal events are believed to connect and affect reproductive performance (RP) in animals. However, much remains unknown about such carry-over effects (COEs), in particular how behaviour patterns during highly mobile life-history stages, such as migration, affect RP. To address this question, we measured at-sea behaviour in a long-lived migratory seabird, the Manx shearwater (Puffinus puffinus) and obtained data for individual migration cycles over 5 years, by tracking with geolocator/immersion loggers, along with 6 years of RP data. We found that individual breeding and non-breeding phenology correlated with subsequent RP, with birds hyperactive during winter more likely to fail to reproduce. Furthermore, parental investment during one year influenced breeding success during the next, a COE reflecting the trade-off between current and future RP. Our results suggest that different life-history stages interact to influence RP in the next breeding season, so that behaviour patterns during winter may be important determinants of variation in subsequent fitness among individuals. © 2015 The Authors.

East–West GEO Satellite Station-Keeping with Degraded Thruster Response

Directory of Open Access Journals (Sweden)

Stoian Borissov

2015-09-01

Full Text Available The higher harmonic terms of Earth’s gravitational potential slowly modify the nominal longitude of geostationary Earth orbit (GEO satellites, while the third-body presence (Moon and Sun mainly affects their latitude. For this reason, GEO satellites periodically need to perform station-keeping maneuvers, namely, east–west and north–south maneuvers to compensate for longitudinal and latitudinal variations, respectively. During the operational lifetime of GEO satellites, the thrusters’ response when commanded to perform these maneuvers slowly departs from the original nominal impulsive behavior. This paper addresses the practical problem of how to perform reliable east–west station-keeping maneuvers when thruster response is degraded. The need for contingency intervention from ground-based satellite operators is reduced by breaking apart the scheduled automatic station-keeping maneuvers into smaller maneuvers. Orbital alignment and attitude are tracked on-board during and in between sub-maneuvers, and any off nominal variations are corrected for with subsequent maneuvers. These corrections are particularly important near the end of the lifetime of GEO satellites, where thruster response is farthest from nominal performance.

Tracking change over time: River flooding

Science.gov (United States)

,

2014-01-01

Landsat satellites have been capturing images of Earth from space since 1972. These images provide a long-term record of natural and human-induced changes on the global landscape. Comparing images from multiple years reveals slow and subtle changes as well as rapid and devastating ones. Landsat images are available from the Internet at no charge. Using the free software MultiSpec, students can track changes to the landscape over time—just like remote sensing scientists do!

Angioplastic necrolytic migratory erythema. Unique association of necrolytic migratory erythema, extensive angioplasia, and high molecular weight glucagon-like polypeptide

International Nuclear Information System (INIS)

Franchimont, C.; Pierard, G.E.; Luyckx, A.S.; Gerard, J.; Lapiere, C.M.

1982-01-01

A diabetic patient developed necrolytic migratory erythema with extensive angioplasia and high molecular weight glucagon-like polypeptide. There was no associated neoplasm such as glucagonoma. Lesions in the skin were studied by standard optical microscopy and by radioautography after incorporation of tritiated thymidine. Alterations in the skin begin as focal necrosis in the epidermis and in epithelial structures of adnexa, followed by marked angioplasia and a superficial and deep perivascular dermatitis

Challenges in Visualizing Satellite Level 2 Atmospheric Data with GIS approach

Science.gov (United States)

Wei, J. C.; Yang, W.; Zhao, P.; Pham, L.; Meyer, D. J.

2017-12-01

Satellite data products are important for a wide variety of applications that can bring far-reaching benefits to the science community and the broader society. These benefits can best be achieved if the satellite data are well utilized and interpreted. Unfortunately, this is not always the case, despite the abundance and relative maturity of numerous satellite data products provided by NASA and other organizations. One way to help users better understand the satellite data is to provide data along with `Images', including accurate pixel coverage area delineation, and science team recommended quality screening for individual geophysical parameters. However, there are challenges of visualizing remote sensed non-gridded products: (1) different geodetics of space-borne instruments (2) data often arranged in "along-track" and "across-track" axes (3) spatially and temporally continuous data chunked into granule files: data for a portion (or all) of a satellite orbit (4) no general rule of resampling or interpolations to a grid (5) geophysical retrieval only based on pixel center location without shape information. In this presentation, we will unravel a new Goddard Earth Sciences Data and Information Services Center (GES DISC) Level 2 (L2) visualization on-demand service. The service's front end provides various visualization and data accessing capabilities, such as overlay and swipe of multiply variables and subset and download of data in different formats. The backend of the service consists of Open Geospatial Consortium (OGC) standard-compliant Web Mapping Service (WMS) and Web Coverage Service. The infrastructure allows inclusion of outside data sources served in OGC compliant protocols and allows other interoperable clients, such as ArcGIS clients, to connect to our L2 WCS/WMS.

High Bandwidth Optical Links for Micro-Satellite Support

Science.gov (United States)

Chao, Tien-Hsin (Inventor); Wilson, Keith E. (Inventor); Coste, Keith (Inventor)

2016-01-01

A method, systems, apparatus and device enable high bandwidth satellite communications. An onboard tracking detector, installed in a low-earth orbit satellite, detects a position of an incoming optical beam received/transmitted from a first ground station of one or more ground stations. Tracker electronics determine orientation information of the incoming optical beam based on the position. Control electronics receive the orientation information from the tracker electronics, and control a waveguide drive electronics. The waveguide drive electronics control a voltage that is provided to an electro-optic waveguide beam steering device. The electro-optic waveguide beam steering device steers an outgoing optical beam to one of the one or more ground stations based on the voltage.

50 CFR 21.42 - Authority to issue depredating orders to permit the killing of migratory game birds.

Science.gov (United States)

2010-10-01

... permit the killing of migratory game birds. 21.42 Section 21.42 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD PERMITS Control of Depredating and Otherwise Injurious Birds § 21.42 Authority to issue depredating orders to...

North/south Station Keeping of Geostationary Satellite Using Mft

Directory of Open Access Journals (Sweden)

Woong-Young Ahn

1997-06-01

Full Text Available A precise determination of the fuel efficiency is important because North/South station keeping ,which controls the inclination of the geostationary orbit, consumes most of the satellite fuel. We estimate the amount of fuel required during the lifetime of the KOREASAT when MFT(Minimum Fuel Target technique is adopted, and the result is compared to those when MCT(Maximum Compensation Target and TBCT(Track-Back Chord Target technique are applied. From this computation, we find that if MFT technique is adopted, the lifetime of the satellite can be extended at least 45 and 15 days, respectively, compared to those consumed with MCT and TBCT technique.

High Dynamic Optimized Carrier Loop Improvement for Tracking Doppler Rates

Directory of Open Access Journals (Sweden)

Amirhossein Fereidountabar

2015-01-01

Full Text Available Mathematical analysis and optimization of a carrier tracking loop are presented. Due to fast changing of the carrier frequency in some satellite systems, such as Low Earth Orbit (LEO or Global Positioning System (GPS, or some planes like Unmanned Aerial Vehicles (UAVs, high dynamic tracking loops play a very important role. In this paper an optimized tracking loop consisting of a third-order Phase Locked Loop (PLL assisted by a second-order Frequency Locked Loop (FLL for UAVs is proposed and discussed. Based on this structure an optimal loop has been designed. The main advantages of this approach are the reduction of the computation complexity and smaller phase error. The paper shows the simulation results, comparing them with a previous work.

Technical Description of Radar and Optical Sensors Contributing to Joint UK-Australian Satellite Tracking, Data-fusion and Cueing Experiment

Science.gov (United States)

Eastment, J.; Ladd, D.; Donnelly, P.; Ash, A.; Harwood, N.; Ritchie, I.; Smith, C.; Bennett, J.; Rutten, M.; Gordon, N.

2014-09-01

DSTL, DSTO, EOS and STFC have recently participated in a campaign of co-ordinated observations with both radar and optical sensors in order to demonstrate and to refine methodologies for orbit determination, data fusion and cross-sensor cueing. The experimental programme is described in detail in the companion paper by Harwood et al. At the STFC Chilbolton Observatory in Southern England, an S-band radar on a 25 m diameter fully-steerable dish antenna was used to measure object range and radar cross-section. At the EOS Space Systems facility on Mount Stromlo, near Canberra, Australia, an optical system comprising a 2 m alt / az observatory, with Coude path laser tracking at 400W power, was used to acquire, lock and laser track the cued objects, providing accurate orbit determinations for each. DSTO, located at Edinburgh, Australia, operated an optical system consisting of a small commercial telescope and mount, measuring the direction to the objects. Observation times were limited to the evening solar terminator period. Data from these systems was processed independently, using DSTL-developed and DSTO / EOS-developed algorithms, to perform orbit determination and to cross-cue: (i) the radar, based on the optical measurements; (ii) the optical system, based on the radar measurements; and (iii) the radar, using its own prior observations (self-cueing). In some cases, TLEs were used to initialise the orbit determination process; in other cases, the cues were derived entirely from sensor data. In all 3 scenarios, positive results were obtained for a variety of satellites in low earth orbits, demonstrating the feasibility of the different cue generation techniques. The purpose of this paper is to describe the technical characteristics of the radar and optical systems used, the modes of operation employed to acquire the observations, and details of the parameters measured and the data formats.

TAGGING, TRACKING AND LOCATING WITHOUT GPS

Energy Technology Data Exchange (ETDEWEB)

Cordaro, J.; Coleman, T.; Shull, D.

2012-07-08

The Savannah River National Laboratory (SRNL) was requested to lead a Law Enforcement Working Group that was formed to collaborate on common operational needs. All agencies represented on the working group ranked their need to tag, track, and locate a witting or unwitting target as their highest priority. Specifically, they were looking for technologies more robust than Global Positioning Satellite (GPS), could communicate back to the owner, and worked where normal cell phone communications did not work or were unreliable. SRNL brought together multiple technologies in a demonstration that was held in in various Alaska venues, including metropolitan, wilderness, and at-sea that met the working group's requirements. Using prototypical technologies from Boeing, On Ramp, and Fortress, SRNL was able to demonstrate the ability to track personnel and material in all scenarios including indoors, in heavily wooden areas, canyons, and in parking garages. In all cases GPS signals were too weak to measure. Bi-directional communication was achieved in areas that Wi-Fi, cell towers, or traditional radios would not perform. The results of the exercise will be presented. These technologies are considered ideal for tracking high value material such has nuclear material with a platform that allows seamless tracking anywhere in the world, indoors or outdoors.

Automated cloud tracking system for the Akatsuki Venus Climate Orbiter data

Science.gov (United States)

Ogohara, Kazunori; Kouyama, Toru; Yamamoto, Hiroki; Sato, Naoki; Takagi, Masahiro; Imamura, Takeshi

2012-02-01

Japanese Venus Climate Orbiter, Akatsuki, is cruising to approach to Venus again although its first Venus orbital insertion (VOI) has been failed. At present, we focus on the next opportunity of VOI and the following scientific observations.We have constructed an automated cloud tracking system for processing data obtained by Akatsuki in the present study. In this system, correction of the pointing of the satellite is essentially important for improving accuracy of the cloud motion vectors derived using the cloud tracking. Attitude errors of the satellite are reduced by fitting an ellipse to limb of an imaged Venus disk. Next, longitude-latitude distributions of brightness (cloud patterns) are calculated to make it easy to derive the cloud motion vectors. The grid points are distributed at regular intervals in the longitude-latitude coordinate. After applying the solar zenith correction and a highpass filter to the derived longitude-latitude distributions of brightness, the cloud features are tracked using pairs of images. As a result, we obtain cloud motion vectors on longitude-latitude grid points equally spaced. These entire processes are pipelined and automated, and are applied to all data obtained by combinations of cameras and filters onboard Akatsuki. It is shown by several tests that the cloud motion vectors are determined with a sufficient accuracy. We expect that longitude-latitude data sets created by the automated cloud tracking system will contribute to the Venus meteorology.

Prevalence of Brucella Antibodies in Migratory Fulani Cattle Herds ...

African Journals Online (AJOL)

Brucellosis is a major cause of economic losses such as abortion, infertility, low conception rate and low survival rate of neonates in the livestock industry and zoonoses of great public health significance. The prevalence of Brucella antibodies in migratory Fulani cattle in Kaduna State was determined using the Milk Ring ...

Elephant (Loxodonta africana home ranges in Sabi Sand Reserve and Kruger National Park: a five-year satellite tracking study.

Directory of Open Access Journals (Sweden)

Bindi Thomas

Full Text Available During a five-year GPS satellite tracking study in Sabi Sand Reserve (SSR and Kruger National Park (KNP we monitored the daily movements of an elephant cow (Loxodonta africana from September 2003 to August 2008. The study animal was confirmed to be part of a group of seven elephants therefore her position is representative of the matriarchal group. We found that the study animal did not use habitat randomly and confirmed strong seasonal fidelity to its summer and winter five-year home ranges. The cow's summer home range was in KNP in an area more than four times that of her SSR winter home range. She exhibited clear park habitation with up to three visits per year travelling via a well-defined northern or southern corridor. There was a positive correlation between the daily distance the elephant walked and minimum daily temperature and the elephant was significantly closer to rivers and artificial waterholes than would be expected if it were moving randomly in KNP and SSR. Transect lines established through the home ranges were surveyed to further understand the fine scale of the landscape and vegetation representative of the home ranges.

Elephant (Loxodonta africana) home ranges in Sabi Sand Reserve and Kruger National Park: a five-year satellite tracking study.

Science.gov (United States)

Thomas, Bindi; Holland, John D; Minot, Edward O

2008-01-01

During a five-year GPS satellite tracking study in Sabi Sand Reserve (SSR) and Kruger National Park (KNP) we monitored the daily movements of an elephant cow (Loxodonta africana) from September 2003 to August 2008. The study animal was confirmed to be part of a group of seven elephants therefore her position is representative of the matriarchal group. We found that the study animal did not use habitat randomly and confirmed strong seasonal fidelity to its summer and winter five-year home ranges. The cow's summer home range was in KNP in an area more than four times that of her SSR winter home range. She exhibited clear park habitation with up to three visits per year travelling via a well-defined northern or southern corridor. There was a positive correlation between the daily distance the elephant walked and minimum daily temperature and the elephant was significantly closer to rivers and artificial waterholes than would be expected if it were moving randomly in KNP and SSR. Transect lines established through the home ranges were surveyed to further understand the fine scale of the landscape and vegetation representative of the home ranges.

Migratory and resident blue tits Cyanistes caeruleus differ in their reaction to a novel object

Science.gov (United States)

Nilsson, Anna L. K.; Nilsson, Jan-Åke; Alerstam, Thomas; Bäckman, Johan

2010-11-01

Individuals differ consistently in their behavioural reactions towards novel objects and new situations. Reaction to novelty is one part of a suit of individually consistent behaviours called coping strategies or personalities and is often summarised as bold or shy behaviour. Coping strategies could be particularly important for migrating birds exposed to novel environments on their journeys. We compared the average approach latencies to a novel object among migrants and residents in partially migratory blue tits Cyanistes caeruleus. In this test, we found migrating blue tits to have shorter approach latencies than had resident ones. Behavioural reactions to novelty can affect the readiness to migrate and short approach latency may have an adaptive value during migration. Individual behaviour towards novelty might be incorporated among the factors associated with migratory or resident behaviour in a partially migratory population.

Exposure of nonbreeding migratory shorebirds to cholinesterase-inhibiting contaminants in the western hemisphere

Science.gov (United States)

Strum, K.M.; Hooper, M.J.; Johnson, K.A.; Lanctot, Richard B.; Zaccagnini, M.E.; Sandercock, B.K.

2010-01-01

Migratory shorebirds frequently forage and roost in agricultural habitats, where they may be exposed to cholinesterase-inhibiting pesticides. Exposure to organophosphorus and carbamate compounds, common anti-cholinesterases, can cause sublethal effects, even death. To evaluate exposure of migratory shorebirds to organophosphorus and carbamates, we sampled birds stopping over during migration in North America and wintering in South America. We compared plasma cholinesterase activities and body masses of individuals captured at sites with no known sources of organophosphorus or carbamates to those captured in agricultural areas where agrochemicals were recommended for control of crop pests. In South America, plasma acetylcholinesterase and butyrylcholinesterase activity in Buff-breasted Sandpipers was lower at agricultural sites than at reference sites, indicating exposure to organophosphorus and carbamates. Results of plasma cholinesterase reactivation assays and foot-wash analyses were inconclusive. A meta-analysis of six species revealed no widespread effect of agricultural chemicals on cholinesterase activity. however, four of six species were negative for acetylcholinesterase and one of six for butyrylcholinesterase, indicating negative effects of pesticides on cholinesterase activity in a subset of shorebirds. Exposure to cholinesterase inhibitors can decrease body mass, but comparisons between treatments and hemispheres suggest that agrochemicals did not affect migratory shorebirds' body mass. Our study, one of the first to estimate of shorebirds' exposure to cholinesterase-inhibiting pesticides, suggests that shorebirds are being exposed to cholinesterase- inhibiting pesticides at specific sites in the winter range but not at migratory stopover sites. future research should examine potential behavioral effects of exposure and identify other potential sitesand levels of exposure. ?? The Cooper Ornithological Society 2010.

Satellite laser ranging to low Earth orbiters: orbit and network validation

Science.gov (United States)

Arnold, Daniel; Montenbruck, Oliver; Hackel, Stefan; Sośnica, Krzysztof

2018-04-01

Satellite laser ranging (SLR) to low Earth orbiters (LEOs) provides optical distance measurements with mm-to-cm-level precision. SLR residuals, i.e., differences between measured and modeled ranges, serve as a common figure of merit for the quality assessment of orbits derived by radiometric tracking techniques. We discuss relevant processing standards for the modeling of SLR observations and highlight the importance of line-of-sight-dependent range corrections for the various types of laser retroreflector arrays. A 1-3 cm consistency of SLR observations and GPS-based precise orbits is demonstrated for a wide range of past and present LEO missions supported by the International Laser Ranging Service (ILRS). A parameter estimation approach is presented to investigate systematic orbit errors and it is shown that SLR validation of LEO satellites is not only able to detect radial but also along-track and cross-track offsets. SLR residual statistics clearly depend on the employed precise orbit determination technique (kinematic vs. reduced-dynamic, float vs. fixed ambiguities) but also reveal pronounced differences in the ILRS station performance. Using the residual-based parameter estimation approach, corrections to ILRS station coordinates, range biases, and timing offsets are derived. As a result, root-mean-square residuals of 5-10 mm have been achieved over a 1-year data arc in 2016 using observations from a subset of high-performance stations and ambiguity-fixed orbits of four LEO missions. As a final contribution, we demonstrate that SLR can not only validate single-satellite orbit solutions but also precise baseline solutions of formation flying missions such as GRACE, TanDEM-X, and Swarm.

Bayesian estimation of animal movement from archival and satellite tags.

Directory of Open Access Journals (Sweden)

Michael D Sumner

Full Text Available The reliable estimation of animal location, and its associated error is fundamental to animal ecology. There are many existing techniques for handling location error, but these are often ad hoc or are used in isolation from each other. In this study we present a Bayesian framework for determining location that uses all the data available, is flexible to all tagging techniques, and provides location estimates with built-in measures of uncertainty. Bayesian methods allow the contributions of multiple data sources to be decomposed into manageable components. We illustrate with two examples for two different location methods: satellite tracking and light level geo-location. We show that many of the problems with uncertainty involved are reduced and quantified by our approach. This approach can use any available information, such as existing knowledge of the animal's potential range, light levels or direct location estimates, auxiliary data, and movement models. The approach provides a substantial contribution to the handling uncertainty in archival tag and satellite tracking data using readily available tools.

First direct evidence of long-distance seasonal movements and hibernation in a migratory bat

Science.gov (United States)

Weller, Theodore J.; Castle, Kevin T.; Liechti, Felix; Hein, Cris D.; Schirmacher, Michael R.; Cryan, Paul M.

2016-01-01

Understanding of migration in small bats has been constrained by limitations of techniques that were labor-intensive, provided coarse levels of resolution, or were limited to population-level inferences. Knowledge of movements and behaviors of individual bats have been unknowable because of limitations in size of tracking devices and methods to attach them for long periods. We used sutures to attach miniature global positioning system (GPS) tags and data loggers that recorded light levels, activity, and temperature to male hoary bats (Lasiurus cinereus). Results from recovered GPS tags illustrated profound differences among movement patterns by individuals, including one that completed a >1000 km round-trip journey during October 2014. Data loggers allowed us to record sub-hourly patterns of activity and torpor use, in one case over a period of 224 days that spanned an entire winter. In this latter bat, we documented 5 torpor bouts that lasted ≥16 days and a flightless period that lasted 40 nights. These first uses of miniature tags on small bats allowed us to discover that male hoary bats can make multi-directional movements during the migratory season and sometimes hibernate for an entire winter.

Performance analysis of an IMU-augmented GNSS tracking system on board the MAIUS-1 sounding rocket

Science.gov (United States)

Braun, Benjamin; Grillenberger, Andreas; Markgraf, Markus

2018-05-01

Satellite navigation receivers are adequate tracking sensors for range safety of both orbital launch vehicles and suborbital sounding rockets. Due to high accuracy and its low system complexity, satellite navigation is seen as well-suited supplement or replacement of conventional tracking systems like radar. Having the well-known shortcomings of satellite navigation like deliberate or unintentional interferences in mind, it is proposed to augment the satellite navigation receiver by an inertial measurement unit (IMU) to enhance continuity and availability of localization. The augmented receiver is thus enabled to output at least an inertial position solution in case of signal outages. In a previous study, it was shown by means of simulation using the example of Ariane 5 that the performance of a low-grade microelectromechanical IMU is sufficient to bridge expected outages of some ten seconds, and still meeting the range safety requirements in effect. In this publication, these theoretical findings shall be substantiated by real flight data that were recorded on MAIUS-1, a sounding rocket launched from Esrange, Sweden, in early 2017. The analysis reveals that the chosen representative of a microelectromechanical IMU is suitable to bridge outages of up to thirty seconds.

Shared wilderness, shared responsibility, shared vision: Protecting migratory wildlife

Science.gov (United States)

Will Meeks; Jimmy Fox; Nancy Roeper

2011-01-01

Wilderness plays a vital role in global and landscape-level conservation of wildlife. Millions of migratory birds and mammals rely on wilderness lands and waters during critical parts of their life. As large, ecologically intact landscapes, wilderness areas also play a vital role in addressing global climate change by increasing carbon sequestration, reducing...

Satellite tagging of rehabilitated green sea turtles Chelonia mydas from the United Arab Emirates, including the longest tracked journey for the species.

Science.gov (United States)

Robinson, David P; Jabado, Rima W; Rohner, Christoph A; Pierce, Simon J; Hyland, Kevin P; Baverstock, Warren R

2017-01-01

We collected movement data for eight rehabilitated and satellite-tagged green sea turtles Chelonia mydas released off the United Arab Emirates between 2005 and 2013. Rehabilitation periods ranged from 96 to 1353 days (mean = 437 ± 399 days). Seven of the eight tagged turtles survived after release; one turtle was killed by what is thought to be a post-release spear gun wound. The majority of turtles (63%) used shallow-water core habitats and established home ranges between Dubai and Abu Dhabi, the same area in which they had originally washed ashore prior to rescue. Four turtles made movements across international boundaries, highlighting that regional cooperation is necessary for the management of the species. One turtle swam from Fujairah to the Andaman Sea, a total distance of 8283 km, which is the longest published track of a green turtle. This study demonstrates that sea turtles can be successfully reintroduced into the wild after sustaining serious injury and undergoing prolonged periods of intense rehabilitation.

On the choice of orbits for an altimetric satellite to study ocean circulation and tides

Science.gov (United States)

Parke, Michael E.; Stewart, Robert H.; Farless, David L.; Cartwright, David E.

1987-01-01

The choice of an orbit for satellite altimetric studies of the ocean's circulation and tides requires an understanding of the orbital characteristics that influence the accuracy of the satellite's measurements of sea level and the temporal and spatial distribution of the measurements. The orbital characteristics that influence accurate calculations of the satellite's position as a function of time are examined, and the pattern of ground tracks laid down on the ocean's surface as a function of the satellite's altitude and inclination is studied. The results are used to examine the aliases in the measurements of surface geostrophic currents and tides. Finally, these considerations are used to specify possible orbits that may be useful for the upcoming Topex/Poseidon mission.

Testing the gravitational interaction in the field of the Earth via satellite laser ranging and the Laser Ranged Satellites Experiment (LARASE)

International Nuclear Information System (INIS)

Lucchesi, D M; Peron, R; Visco, M; Anselmo, L; Pardini, C; Bassan, M; Pucacco, G

2015-01-01

In this work, the Laser Ranged Satellites Experiment (LARASE) is presented. This is a research program that aims to perform new refined tests and measurements of gravitation in the field of the Earth in the weak field and slow motion (WFSM) limit of general relativity (GR). For this objective we use the free available data relative to geodetic passive satellite lasers tracked from a network of ground stations by means of the satellite laser ranging (SLR) technique. After a brief introduction to GR and its WFSM limit, which aims to contextualize the physical background of the tests and measurements that LARASE will carry out, we focus on the current limits of validation of GR and on current constraints on the alternative theories of gravity that have been obtained with the precise SLR measurements of the two LAGEOS satellites performed so far. Afterward, we present the scientific goals of LARASE in terms of upcoming measurements and tests of relativistic physics. Finally, we introduce our activities and we give a number of new results regarding the improvements to the modelling of both gravitational and non-gravitational perturbations to the orbit of the satellites. These activities are a needed prerequisite to improve the forthcoming new measurements of gravitation. An innovation with respect to the past is the specialization of the models to the LARES satellite, especially for what concerns the modelling of its spin evolution, the neutral drag perturbation and the impact of Earth's solid tides on the satellite orbit. (paper)

Testing General Relativistic Predictions with the LAGEOS Satellites

International Nuclear Information System (INIS)

Peron, Roberto

2014-01-01

The spacetime around Earth is a good environment in order to perform tests of gravitational theories. According to Einstein’s view of gravitational phenomena, the Earth mass-energy content curves the surrounding spacetime in a peculiar way. This (relatively) quiet dynamical environment enables a good reconstruction of geodetic satellites (test masses) orbit, provided that high-quality tracking data are available. This is the case of the LAGEOS satellites, built and launched mainly for geodetic and geodynamical purposes, but equally good for fundamental physics studies. A review of these studies is presented, focusing on data, models, and analysis strategies. Some recent and less recent results are presented. All of them indicate general relativity theory as a very good description of gravitational phenomena, at least in the studied environment.

Apparent survival of the salamander Salamandra salamandra is low because of high migratory activity

Directory of Open Access Journals (Sweden)

Schaub Michael

2007-09-01

Full Text Available Abstract Background Understanding the demographic processes underlying population dynamics is a central theme in ecology. Populations decline if losses from the population (i.e., mortality and emigration exceed gains (i.e., recruitment and immigration. Amphibians are thought to exhibit little movement even though local populations often fluctuate dramatically and are likely to go exinct if there is no rescue effect through immigration from nearby populations. Terrestrial salamanders are generally portrayed as amphibians with low migratory activity. Our study uses demographic analysis as a key to unravel whether emigration or mortality is the main cause of "losses" from the population. In particular, we use the analysis to challenge the common belief that terrestrial salamanders show low migratory activity. Results The mark-recapture analysis of adult salamanders showed that monthly survival was high (> 90% without a seasonal pattern. These estimates, however, translate into rather low rates of local annual survival of only ~40% and suggest that emigration was important. The estimated probability of emigration was 49%. Conclusion Our analysis shows that terrestrial salamanders exhibit more migratory activity than commonly thought. This may be due either because the spatial extent of salamander populations is underestimated or because there is a substantial exchange of individuals between populations. Our current results are in line with several other studies that suggest high migratory activity in amphibians. In particular, many amphibian populations may be characterized by high proportions of transients and/or floaters.

Gravity model development for precise orbit computations for satellite altimetry

Science.gov (United States)

Marsh, James G.; Lerch, Francis, J.; Smith, David E.; Klosko, Steven M.; Pavlis, Erricos

1986-01-01

Two preliminary gravity models developed as a first step in reaching the TOPEX/Poseidon modeling goals are discussed. They were obtained by NASA-Goddard from an analysis of exclusively satellite tracking observations. With the new Preliminary Gravity Solution-T2 model, an improved global estimate of the field is achieved with an improved description of the geoid.

Migratory connectivity of american woodcock using band return data

Science.gov (United States)

Moore, Joseph D.; Krementz, David G.

2017-01-01

American woodcock (Scolopax minor) are managed as a Central and an Eastern population in the United States and Canada based on band return data showing little crossover between populations or management regions. The observed proportion of crossover between management regions, however, depends on the criteria used to subset the band return data. We analyzed the amount of crossover between management regions using only band return records that represent complete migrations between the breeding and wintering grounds by using only band return records in which the capture took place during the breeding season and the band recovery took place during the wintering season or vice versa (n = 224). Additionally, we applied spatial statistics and a clustering algorithm to investigate woodcock migratory connectivity using this subset of migratory woodcock band return records. Using raw counts, 17.9% of records showed crossover between management regions, a higher proportion than the <5% crossover reported in studies that did not use only migratory band returns. Our results showed woodcock from the breeding grounds in the Central Region largely migrate to destinations within the Central Region, whereas woodcock from the breeding grounds in the Eastern Region migrate to destinations across the entire wintering range and mix with individuals from the Central Region. Using the division coefficient, we estimated that 54% of woodcock from the breeding grounds of the Eastern Region migrate to the Central Region wintering grounds. Our result that many woodcock from separate regions of the breeding grounds mix on the wintering grounds has implications for the 2-region basis for woodcock management. Elucidating finer scale movement patterns among regions provides a basis for reassessing the need for separate management regions to ensure optimal conservation and management of the species.

Wide dispersal of aphid-pathogenic Entomophthorales among aphids relies upon migratory alates.

Science.gov (United States)

Feng, Ming-Guang; Chen, Chun; Chen, Bin

2004-05-01

Entomophthoralean mycoses are of general importance in the natural control of aphids, but mechanisms involved in their dissemination are poorly understood. Despite several possible means of fungal survival, the dispersal of the mycoses in aphids has never been related to the flight of their migratory alates that are able to locate suitable host plants. In this study, aphid-pathogenic fungi proved to be widely disseminated among various aphids by their alates through migratory flight based on the following findings. First, up to 36.6% of the 7139 migratory alates (including nine species of vegetable or cereal aphids) trapped from air > 30 m above the ground in three provinces of China were found bearing eight species of fungal pathogens. Of those, six were aphid-specific Entomophthorales dominated in individual cases by Pandora neoaphidis, which occurs globally but has no resting spores discovered to date. Secondly, infected alates were confirmed to be able to fly for hours, to initiate colonies on plants after flight and to transmit fungal infection to their offspring in a laboratory experiment, in which 238 Sitobion avenae alates were individually flown in a computer-monitoring flight mill system after exposure to a spore shower of P. neoaphidis and then allowed to colonize host plants.

76 FR 23427 - General Provisions; Revised List of Migratory Birds

Science.gov (United States)

2011-04-26

... most aspects of the taking, possession, transportation, sale, purchase, barter, exportation, and..., transportation, sale, purchase, barter, exportation, and importation of migratory birds. An accurate and up-to... Solicitor has determined that the proposed rule would not unduly burden the judicial system and meets the...

Satellite in transit metastases in rapidly fatal conjunctival melanoma: implications for angiotropism and extravascular migratory metastasis (description of a murine model for conjunctival melanoma).

Science.gov (United States)

Barnhill, Raymond L; Lemaitre, Stéphanie; Lévy-Gabrielle, Christine; Rodrigues, Manuel; Desjardins, Laurence; Dendale, Rémi; Vincent-Salomon, Anne; Roman-Roman, Sergio; Lugassy, Claire; Cassoux, Nathalie

2016-02-01

Little information is currently available concerning loco-regional metastases such as satellite and in transit metastases and their natural history in conjunctival melanoma as compared to cutaneous melanoma. Angiotropism, a marker of extravascular migration of melanoma cells along vascular channels, often appears responsible for microscopic satellite, satellite and in transit metastases development in cutaneous melanoma. In addition, diffuse tissue microscopic satellites are correlated with widespread melanoma dissemination and death. Herein we report rapid conjunctival melanoma progression and a fatal outcome in four of five patients following recurrence as satellite in transit metastases. Five patients aged 31, 60, 63, 56, and 67 years developed primary conjunctival melanoma, histologically characterised by tumour thicknesses of 4, 4, 1.1, 3, and 2 mm. Two or more conjunctival melanomas manifested ulceration, significant mitotic rates, necrosis, angiotropism, and intralesional transformation. The conjunctival melanoma recurred in a matter of months as one or more discrete satellite in transit lesions in the vicinity of the primary melanoma. Histological examination revealed well-defined micronodules containing atypical melanocytes in the subepithelial connective tissue stroma. All lesions were extravascular and most appeared angiotropic. Four of five patients subsequently developed parotid or other loco-regional nodal disease and rapidly ensuing widespread metastases and death. The time course from diagnosis to the demise of the patients averaged about 13 (range 7-20) months. Our findings suggest that satellite in transit metastases constitute an important new risk marker for possible rapid metastatic disease progression and death in patients with conjunctival melanoma. This finding appears to take on even greater significance if such lesions develop rapidly, i.e., in a matter of weeks or months following diagnosis of primary conjunctival melanoma, and if the

Design and control of the precise tracking bed based on complex electromechanical design theory

Science.gov (United States)

Ren, Changzhi; Liu, Zhao; Wu, Liao; Chen, Ken

2010-05-01

The precise tracking technology is wide used in astronomical instruments, satellite tracking and aeronautic test bed. However, the precise ultra low speed tracking drive system is one high integrated electromechanical system, which one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. The precise Tracking Bed is one ultra-exact, ultra-low speed, high precision and huge inertial instrument, which some kind of mechanism and environment of the ultra low speed is different from general technology. This paper explores the design process based on complex electromechanical optimizing design theory, one non-PID with a CMAC forward feedback control method is used in the servo system of the precise tracking bed and some simulation results are discussed.

Space Time – Track Circuits with Trellis Code Modulation

Directory of Open Access Journals (Sweden)

Marius Enulescu

2017-07-01

Full Text Available The track circuits are very important equipments used in the railway transportation system. Today these are used to send vital information, to the running train, in the same time with the integrity checking of the rail. The actual track circuits have a small problem due to the use of the same transmission medium by the signals containing vital information and the return traction current, the running track rails. But this small problem can produce big disturbances in the train circulation, especially in the rush hours. To improve the data transmission to the train on-board equipment, the implementation of new track circuits using new communication technology were studied. This technology is used by the mobile and satellite communications and applies the principle of diversity encoding both time and space through the use of multiple transmission points of the track circuit signal for telegram which is sent to the train. Since this implementation does not satisfy the intended purpose, other modern communication principles such as 8PSK signals modulation and encoding using Trellis Coded Modulation were developed. This new track circuit aims to solve the problems which appeared in the current operation of track circuits and theoretically manages to transmit vital information to the train on board equipment without being affected by disturbances in electric traction transport systems.

Visualizing Cloud Properties and Satellite Imagery: A Tool for Visualization and Information Integration

Science.gov (United States)

Chee, T.; Nguyen, L.; Smith, W. L., Jr.; Spangenberg, D.; Palikonda, R.; Bedka, K. M.; Minnis, P.; Thieman, M. M.; Nordeen, M.

2017-12-01

Providing public access to research products including cloud macro and microphysical properties and satellite imagery are a key concern for the NASA Langley Research Center Cloud and Radiation Group. This work describes a web based visualization tool and API that allows end users to easily create customized cloud product and satellite imagery, ground site data and satellite ground track information that is generated dynamically. The tool has two uses, one to visualize the dynamically created imagery and the other to provide access to the dynamically generated imagery directly at a later time. Internally, we leverage our practical experience with large, scalable application practices to develop a system that has the largest potential for scalability as well as the ability to be deployed on the cloud to accommodate scalability issues. We build upon NASA Langley Cloud and Radiation Group's experience with making real-time and historical satellite cloud product information, satellite imagery, ground site data and satellite track information accessible and easily searchable. This tool is the culmination of our prior experience with dynamic imagery generation and provides a way to build a "mash-up" of dynamically generated imagery and related kinds of information that are visualized together to add value to disparate but related information. In support of NASA strategic goals, our group aims to make as much scientific knowledge, observations and products available to the citizen science, research and interested communities as well as for automated systems to acquire the same information for data mining or other analytic purposes. This tool and the underlying API's provide a valuable research tool to a wide audience both as a standalone research tool and also as an easily accessed data source that can easily be mined or used with existing tools.

Cyclone track forecasting based on satellite images using artificial neural networks

OpenAIRE

Kovordanyi, Rita; Roy, Chandan

2009-01-01

Many places around the world are exposed to tropical cyclones and associated storm surges. In spite of massive efforts, a great number of people die each year as a result of cyclone events. To mitigate this damage, improved forecasting techniques must be developed. The technique presented here uses artificial neural networks to interpret NOAA-AVHRR satellite images. A multi-layer neural network, resembling the human visual system, was trained to forecast the movement of cyclones based on sate...

Effect of large weirs on abundance and diversity of migratory ...

African Journals Online (AJOL)

Lake Tana has a remarkable fish diversity, including 17 endemic Labeobarbus species, of which nine spawn in the inflowing rivers. Three of the migratory species are threatened, namely the endangered Labeobarbus macrophtalmus and the vulnerable L. acutirostris and L. platydorsus. In July–November 2016 during the ...

Understanding the stopover of migratory birds: a scale dependent approach

Science.gov (United States)

Frank R. Moore; Mark S. Woodrey; Jeffrey J. Buler; Stefan Woltmann; Ted R. Simons

2005-01-01

The development of comprehensive conservation strategies and management plans for migratory birds depends on understanding migrant-habitat relations throughout the annual cycle, including the time when migrants stopover en route. Yet, the complexity of migration makes the assessment of habitat requirements and development of a comprehensive...

Positioning Reduction of Deep Space Probes Based on VLBI Tracking

Science.gov (United States)

Qiao, S. B.

2011-11-01

In the background of the Chinese Lunar Exploration Project and the Yinghuo Project, through theoretical analysis, algorithm study, software development, data simulation, real data processing and so on, the positioning reductions of the European lunar satellite Smart-1 and Mars Express (MEX) satellite, as well as the Chinese Chang'e-1 (CE-1) and Chang'e-2 (CE-2) satellites are accomplished by using VLBI and USB tracking data in this dissertation. The progress is made in various aspects including the development of theoretical model, the construction of observation equation, the analysis of the condition of normal equation, the selection and determination of the constraint, the analysis of data simulation, the detection of outliers in observations, the maintenance of the stability of the solution of parameters, the development of the practical software system, the processing of the real tracking data and so on. The details of the research progress in this dissertation are written as follows: (1) The algorithm is analyzed concerning the positioning reduction of the deep spacecraft based on VLBI tracking data. Through data simulation, it is analyzed for the effects of the bias in predicted orbit, the white noises and systematic errors in VLBI delays, and USB ranges on the positioning reduction of spacecraft. Results show that it is preferable to suppress the dispersion of positioning data points by applying the constraint of geocentric distance of spacecraft when there are only VLBI tracking data. The positioning solution is a biased estimate via observations of three VLBI stations. For the case of four tracking stations, the uncertainty of the constraint should be in accordance with the bias in the predicted orbit. White noises in delays and ranges mainly result in dispersion of the sequence of positioning data points. If there is the systematic error of observations, the systematic offset of the positioning results is caused, and there are trend jumps in the shape of

Burrowing Owl and Other Migratory Bird Mitigation for a Runway Construction Project at Edwards AFB

OpenAIRE

Hoehn, Amber L.; Hagan, Mark; Bratton, Mark

2009-01-01

Edwards Air Force Base (AFB) scheduled the construction of a runway in the spring of 2007. The runway would be in an area that contained migratory birds and their habitat. The construction project would be near Edwards AFB main runway and had the potential not only to impact species protected under the Migratory Bird Treaty Act (MBTA), including the burrowing owl (Athene cunicularia), but also to increase bird and wildlife–aircraft strike hazards in the active flightline areas. To discourage ...

Assimilation of GMS-5 satellite winds using nudging method with MM5

Science.gov (United States)

Gao, Shanhong; Wu, Zengmao; Yang, Bo

2006-09-01

With the aid of Meteorological Information Composite and Processing System (MICAPS), satellite wind vectors derived from the Geostationary Meteorological Statellite-5 (GMS-5) and retrieved by National Satellite Meteorology Center of China (NSMC) can be obtained. Based on the nudging method built in the fifth-generation Mesoscale Model (MM5) of Pennsylvania State University and National Center for Atmospheric Research, a data preprocessor is developed to convert these satellite wind vectors to those with specified format required in MM5. To examine the data preprocessor and evaluate the impact of satellite winds from GMS-5 on MM5 simulations, a series of numerical experimental forecasts consisting of four typhoon cases in 2002 are designed and implemented. The results show that the preprocessor can process satellite winds smoothly and MM5 model runs successfully with a little extra computational load during ingesting these winds, and that assimilation of satellite winds by MM5 nudging method can obviously improve typhoon track forecast but contributes a little to typhoon intensity forecast. The impact of the satellite winds depends heavily upon whether the typhoon bogussing scheme in MM5 was turned on or not. The data preprocessor developed in this paper not only can treat GMS-5 satellite winds but also has capability with little modification to process derived winds from other geostationary satellites.

Loop migration in adult marsh harriers Circus aeruginosus, as revealed by satellite telemetry

DEFF Research Database (Denmark)

H. G. Klaassen, Raymond; Strandberg, Roine; Hake, Mikael

2010-01-01

level, for example by analysing ring recoveries. Here we study loop migration of individual marsh harriersCircus aeruginosus tracked by satellite telemetry. We show that despite a generally narrow migration corridor the harriers travelled in a distinct clockwise loop through Africa and southern Europe...

The Along Track Scanning Radiometer (ATSR) for ERS1

Science.gov (United States)

Delderfield, J.; Llewellyn-Jones, D. T.; Bernard, R.; de Javel, Y.; Williamson, E. J.

1986-01-01

The ATSR is an infrared imaging radiometer which has been selected to fly aboard the ESA Remote Sensing Satellite No. 1 (ERS1) with the specific objective of accurately determining global Sea Surface Temperature (SST). Novel features, including the technique of 'along track' scanning, a closed Stirling cycle cooler, and the precision on-board blackbodies are described. Instrument subsystems are identified and their design trade-offs discussed.

Intercomparison of Satellite Derived Gravity Time Series with Inferred Gravity Time Series from TOPEX/POSEIDON Sea Surface Heights and Climatological Model Output

Science.gov (United States)

Cox, C.; Au, A.; Klosko, S.; Chao, B.; Smith, David E. (Technical Monitor)

2001-01-01

The upcoming GRACE mission promises to open a window on details of the global mass budget that will have remarkable clarity, but it will not directly answer the question of what the state of the Earth's mass budget is over the critical last quarter of the 20th century. To address that problem we must draw upon existing technologies such as SLR, DORIS, and GPS, and climate modeling runs in order to improve our understanding. Analysis of long-period geopotential changes based on SLR and DORIS tracking has shown that addition of post 1996 satellite tracking data has a significant impact on the recovered zonal rates and long-period tides. Interannual effects such as those causing the post 1996 anomalies must be better characterized before refined estimates of the decadal period changes in the geopotential can be derived from the historical database of satellite tracking. A possible cause of this anomaly is variations in ocean mass distribution, perhaps associated with the recent large El Nino/La Nina. In this study, a low-degree spherical harmonic gravity time series derived from satellite tracking is compared with a TOPEX/POSEIDON-derived sea surface height time series. Corrections for atmospheric mass effects, continental hydrology, snowfall accumulation, and ocean steric model predictions will be considered.

Migratory Patterns of Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-flowing River Basin

Science.gov (United States)

Eiler, John H.; Evans, Allison N.; Schreck, Carl B.

2015-01-01

Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, virtually pristine river basin. These returns have declined dramatically since the late 1990s, and information is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio tagged during 2002–2004. Most (97.5%) of the fish tracked upriver to spawning areas displayed continual upriver movements and strong fidelity to the terminal tributaries entered. Movement rates were substantially slower for fish spawning in lower river tributaries (28–40 km d-1) compared to upper basin stocks (52–62 km d-1). Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between “hares” (faster fish becoming slower) and “tortoises” (slow but steady fish) explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 16 days to pass a site 872 km upriver. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southerly drainages, but may reflect the pristine conditions within the Yukon River, wild origins of the fish, and discrete run timing of the returns. Movement data can provide numerous insights into the status and management of salmon returns, particularly in large river drainages with widely scattered fisheries where management actions in the lower river potentially impact harvests and escapement farther upstream. However, the substantial variation

How can present and future satellite missions support scientific studies that address ocean acidification?

Science.gov (United States)

Salisbury, Joseph; Vandemark, Douglas; Jonsson, Bror; Balch, William; Chakraborty, Sumit; Lohrenz, Steven; Chapron, Bertrand; Hales, Burke; Mannino, Antonio; Mathis, Jeremy T.; Reul, Nicolas; Signorini, Sergio; Wanninkhof, Rik; Yates, Kimberly K.

2016-01-01

Space-based observations offer unique capabilities for studying spatial and temporal dynamics of the upper ocean inorganic carbon cycle and, in turn, supporting research tied to ocean acidification (OA). Satellite sensors measuring sea surface temperature, color, salinity, wind, waves, currents, and sea level enable a fuller understanding of a range of physical, chemical, and biological phenomena that drive regional OA dynamics as well as the potentially varied impacts of carbon cycle change on a broad range of ecosystems. Here, we update and expand on previous work that addresses the benefits of space-based assets for OA and carbonate system studies. Carbonate chemistry and the key processes controlling surface ocean OA variability are reviewed. Synthesis of present satellite data streams and their utility in this arena are discussed, as are opportunities on the horizon for using new satellite sensors with increased spectral, temporal, and/or spatial resolution. We outline applications that include the ability to track the biochemically dynamic nature of water masses, to map coral reefs at higher resolution, to discern functional phytoplankton groups and their relationships to acid perturbations, and to track processes that contribute to acid variation near the land-ocean interface.

Desired Mobility or Satisfied Immobility? Migratory Aspirations among Knowledge Workers

Science.gov (United States)

Ferro, Anna

2006-01-01

Among the aspects discussed within the globalisation process, the international mobility of professional workers assumes considerable relevance. This paper focuses on migratory aspirations among knowledge workers within the context of economic globalisation and market restructuring in Romania. Due to a lack of literature dealing with these issues,…

Death and danger at migratory stopovers: Problems with "predation risk"

NARCIS (Netherlands)

Lank, D.B.; Ydenberg, R.C.

2003-01-01

Dierschke (2003) recently published a paper entitled, ``Predation hazard during migratory stopover: are light or heavy birds under risk?¿¿ He measured the body condition of 11 species of passerine migrants depredated by feral cats and raptors at an offshore stopover site, and used these data to

75 FR 33531 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

Science.gov (United States)

2010-06-14

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 635 RIN 0648-XW79 Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine..., recent Large Pelagics Survey estimates indicate that charter/headboat BFT landings constitute...

WGS 84 Coordinate Validation and Improvement for the NIMA and Air Force GPS Tracking Stations

National Research Council Canada - National Science Library

Cunningham, James

1996-01-01

Using 10 days of Global Positioning System (GPS) pseudorange and carrier phase data collected in 1995 from 31 stations and 24 Block II/IIA satellites, estimates of GPS clocks, orbits, and tracking station coordinates were generated...

Satellite data sets for the atmospheric radiation measurement (ARM) program

Energy Technology Data Exchange (ETDEWEB)

Shi, L.; Bernstein, R.L. [SeaSpace Corp., San Diego, CA (United States)

1996-04-01

This abstract describes the type of data obtained from satellite measurements in the Atmospheric Radiation Measurement (ARM) program. The data sets have been widely used by the ARM team to derive cloud-top altitude, cloud cover, snow and ice cover, surface temperature, water vapor, and wind, vertical profiles of temperature, and continuoous observations of weather needed to track and predict severe weather.

Post-breeding migration of Dutch-breeding black-tailed godwits: timing, routes, use of stopovers, and nonbreeding destinations

Science.gov (United States)

Hooijmeijer, Jos C. E. W.; Senner, Nathan R.; Tibbitts, T. Lee; Gill, Robert E.; Douglas, David C.; Bruinzeel, Leo W.; Wymenga, Eddy; Piersma, Theunis

2014-01-01

Conservation of long-distance migratory shorebirds is complex because these species use habitats spread across continents and hemispheres, making identification of critical habitats and potential bottlenecks in the annual cycle especially difficult. The population of Black-tailed Godwits that breeds in Western Europe, Limosa limosa limosa, has declined precipitously over the past few decades. Despite significant efforts to identify the root causes of this decline, much remains unclear. To better understand the migratory timing, use of stopover and nonbreeding sites, and the potential impact of breeding success on these parameters, we attached 15 Argos satellite transmitters and 10 geolocation tracking devices to adult godwits nearing completion of incubation at breeding sites in southwest Friesland, The Netherlands during the spring of 2009. We successfully tracked 16 adult godwits for their entire southward migration and two others for part of it. Three migration patterns and four regions of use were apparent. Most godwits left their breeding sites and proceeded south directly to stopover sites in the Mediterranean — e.g. Spain, Portugal, and Morocco — before flying on to non-breeding sites in West Africa. Other individuals spent the entire nonbreeding season in the Mediterranean. A third pattern included a few individuals that flew nonstop from their Dutch breeding sites to nonbreeding sites in West Africa. Tracking data from this study will be immediately useful for conservation efforts focused on preserving the dispersed network of sites used by godwits during their southward migration.

Variation in immune parameters and disease prevalence among Lesser Black-backed Gulls (Larus fuscus sp. with different migratory strategies.

Directory of Open Access Journals (Sweden)

Elena Arriero

Full Text Available The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus with different migratory strategies. We found higher activity of natural antibodies in long distance migrants from the nominate subspecies L.f.fuscus. Circulating levels of IgY showed large variation at the population level, while immune parameters associated with antimicrobial activity showed extensive variation at the individual level irrespective of population or migratory strategy. Pathogen prevalence showed large geographical variation. However, the seroprevalence of one of the gull-specific subtypes of avian influenza (H16 was associated to the migratory strategy, with lower prevalence among the long-distance migrants, suggesting that migration may play a role in disease dynamics of certain pathogens at the population level.

The precision of today's satellite laser ranging systems

Science.gov (United States)

Dunn, Peter J.; Torrence, Mark H.; Hussen, Van S.; Pearlman, Michael R.

1993-06-01

Recent improvements in the accuracy of modern satellite laser ranging (SLR) systems are strengthened by the new capability of many instruments to track an increasing number of geodetic satellite targets without significant scheduling conflict. This will allow the refinement of some geophysical parameters, such as solid Earth tidal effects and GM, and the improved temporal resolution of others, such as Earth orientation and station position. Better time resolution for the locations of fixed observatories will allow us to monitor more subtle motions at the stations, and transportable systems will be able to provide indicators of long term trends with shorter occupations. If we are to take advantage of these improvements, care must be taken to preserve the essential accuracy of an increasing volume of range observations at each stage of the data reduction process.

Seasonal and circadian biases in bird tracking with solar GPS-tags.

Directory of Open Access Journals (Sweden)

Rafa Silva

Full Text Available Global Positioning System (GPS tags are nowadays widely used in wildlife tracking. This geolocation technique can suffer from fix loss biases due to poor satellite GPS geometry, that result in tracking data gaps leading to wrong research conclusions. In addition, new solar-powered GPS tags deployed on birds can suffer from a new "battery drain bias" currently ignored in movement ecology analyses. We use a GPS tracking dataset of bearded vultures (Gypaetus barbatus, tracked for several years with solar GPS tags, to evaluate the causes and triggers of fix and data retrieval loss biases. We compare two models of solar GPS tags using different data retrieval systems (Argos vs GSM-GPRS, and programmed with different duty cycles. Neither of the models was able to accomplish the duty cycle programed initially. Fix and data retrieval loss rates were always greater than expected, and showed non-random gaps in GPS locations. Number of fixes per month of tracking was a bad criterion to identify tags with smaller biases. Fix-loss rates were four times higher due to battery drain than due to poor GPS satellite geometry. Both tag models were biased due to the uneven solar energy available for the recharge of the tag throughout the annual cycle, resulting in greater fix-loss rates in winter compared to summer. In addition, we suggest that the bias found along the diurnal cycle is linked to a complex three-factor interaction of bird flight behavior, topography and fix interval. More fixes were lost when vultures were perching compared to flying, in rugged versus flat topography. But long fix-intervals caused greater loss of fixes in dynamic (flying versus static situations (perching. To conclude, we emphasize the importance of evaluating fix-loss bias in current tracking projects, and deploying GPS tags that allow remote duty cycle updates so that the most appropriate fix and data retrieval intervals can be selected.

Migratory Prostitution with Emphasis on Europe.

Science.gov (United States)

M&oring;rdh; Genç

1995-03-01

In many European countries, foreigners constitute the majority of certain groups of prostitutes, e.g., approximately 90% of the window prostitutes in the red light district of Amsterdam are not native to the Netherlands. The same is true for prostitutes working in bars in Vienna. In cities where registered prostitution is legal, unregistered prostitutes, most of whom are foreigners, often outnumber the registered ones. Central European countries often receive "sex workers" from eastern Europe, e.g., from Bulgaria, the Czech Republic, Slovakia, Hungary, and Romania, whereas the majority of migratory prostitutes in Great Britain and continental western Europe come from Africa, the Caribbean, and South America. In northern Europe, women from Russia, the Czech Republic, Slovakia, Poland, and the Baltic states are prostituting themselves in increasing numbers. Scandinavia has so far been affected relatively less by this mobility. In Spain, France, and Italy, women from Arabic and subSaharan countries are common among prostitutes. Foreign prostitutes move into Turkey along two main routes: women from the Balkan countries come to the western part of the country, whereas those from the former Soviet Union cross the border from Georgia, where they usually operate at resorts along the eastern Black Sea coast. Prostitutes are also mobile within the former communist bloc. For instance, women from Russia prostitute themselves in Lithuania, the Czech Republic, Slovakia, and Hungary. the customers are locals, particularly those with "hard currency", such as businessmen and "sex tourists" from the West. Following the outbreak of civil war in the former Yugoslavia, women from that country are now more frequently seen among the population of migratory prostitutes in Europe.

Satellites

International Nuclear Information System (INIS)

Burns, J.A.; Matthews, M.S.

1986-01-01

The present work is based on a conference: Natural Satellites, Colloquium 77 of the IAU, held at Cornell University from July 5 to 9, 1983. Attention is given to the background and origins of satellites, protosatellite swarms, the tectonics of icy satellites, the physical characteristics of satellite surfaces, and the interactions of planetary magnetospheres with icy satellite surfaces. Other topics include the surface composition of natural satellites, the cratering of planetary satellites, the moon, Io, and Europa. Consideration is also given to Ganymede and Callisto, the satellites of Saturn, small satellites, satellites of Uranus and Neptune, and the Pluto-Charon system

Multicriteria assessment in restoring migratory fish stocks in the river Iijoki; Monitavoitearviointi Iijoen vaelluskalakantojen palauttamisen tukena

Energy Technology Data Exchange (ETDEWEB)

Karjalainen, T.P.; Rytkoenen, A.-M.; Marttunen, M.; Maeki-Petaeys, A.; Autti, O.

2011-05-15

The Iijoki is one of Finland's most important former salmon rivers. Construction of multiple main stem dams on the river in the 1960s effectively blocked the migration corridors of migratory fish. Suitable spawning and nursery habitats above the dams span an estimated 600-800 hectares. With riverside residents are very much in favour of the return of migratory fish, watershed planning for this has been set as a target. Such measures are rendered urgent by the fact that there is still a possibility of replenishing the Iijoki's own salmon stock, thereby restoring the fishes' natural lifecycle and natural selection. This report has been completed as part of the project 'The return of migratory fish to the River Iijoki (2008-2010)', where the main object was reconciling the target of enhancing the natural life cycle of migratory fish with the continued generation of hydropower. Under a multicriteria assessment, various alternatives and measures for improving migratory fish stocks were clarified and their desirability, costs and benefits systematically and transparently evaluated. Furthermore, interest groups' views of the three options and their effects (as distinct from the expert evaluation) were clarified with the help of computer aided interviews. The alternatives were transferring salmon above the main stem dams and two fish-ladder options. The multicriteria assessment viewed the construction of fish ladders, alongside other large-scale support measures, as the best option. Based on all of the criteria applied in a cost-benefit analysis, the stock transfer alternative was the most economically viable, because its net product value was positive in all cases. The fish ladder options were the most expensive due to the construction costs involved, but they also provided the greatest benefits. Above all, fish ladder construction is supported by the fact that it would return migratory fish to their natural lifecycle and attain the EU

Spatio-temporal hotspots of satellite-tracked arctic foxes reveal a large detection range in a mammalian predator.

Science.gov (United States)

Lai, Sandra; Bêty, Joël; Berteaux, Dominique

2015-01-01

The scale at which animals perceive their environment is a strong fitness determinant, yet few empirical estimates of animal detection ranges exist, especially in mammalian predators. Using daily Argos satellite tracking of 26 adult arctic foxes (Vulpes lagopus) during a single winter in the High Canadian Arctic, we investigated the detection range of arctic foxes by detecting hotspots of fox activity on the sea ice. While maintaining territories in the tundra, these solitary foragers occasionally used the sea ice where they sometimes formed spatio-temporal hotspots, likely scavenging on marine mammal carcasses. We detected 35 movements by 13 individuals forming five hotspots. Foxes often traveled more than 10 km, and up to 40 km, to reach hotspots, which lasted one-two weeks and could gather up to 12 individuals. The likelihood of a fox joining a hotspot was neither influenced by its distance from the hotspot nor by the distance of its home range to the coast. Observed traveling distances may indicate a high detection range in arctic foxes, and our results suggest their ability to detect food sources on the sea ice from their terrestrial home range. While revealing a wide knowledge gap regarding resource detection abilities in mammalian predators, our study provides estimates of detection range useful for interpreting and modeling animal movements. It also allows a better understanding of foraging behavior and navigation capacity in terrestrial predators.

Satellite-Observed Black Water Events off Southwest Florida: Implications for Coral Reef Health in the Florida Keys National Marine Sanctuary

OpenAIRE

Zhao, Jun; Hu, Chuanmin; Lapointe, Brian; Melo, Nelson; Johns, Elizabeth; Smith, Ryan

2013-01-01

A “black water” event, as observed from satellites, occurred off southwest Florida in 2012. Satellite observations suggested that the event started in early January and ended in mid-April 2012. The black water patch formed off central west Florida and advected southward towards Florida Bay and the Florida Keys with the shelf circulation, which was confirmed by satellite-tracked surface drifter trajectories. Compared with a previous black water event in 2002, the 2012 event was weaker in terms...

Using Satellite Remote Sensing to assist the National Weather Service (NWS) in Storm Damage Surveys

Science.gov (United States)

Schultz, L. A.; Molthan, A.; McGrath, K.; Bell, J. R.; Cole, T.; Burks, J.

2016-12-01

In recent years, the NWS has developed a GIS-based application, called the Damage Assessment Toolkit (DAT), to conduct storm surveys after severe weather events. At present, the toolkit is primarily used for tornado damage surveys and facilitates the identification of damage indicators in accordance with the Enhanced Fujita (EF) intensity scale by allowing surveyors to compare time- and geo-tagged photos against the EF scale guidelines. Mobile and web-based applications provide easy access to the DAT for NWS personnel while performing their duties in the field or office. Multispectral satellite remote sensing imagery has demonstrated benefits for the detection and mapping of damage tracks caused by tornadoes, especially for long-track events and/or areas not easily accessed by NWS personnel. For example, imagery from MODIS, Landsat 7, Landsat 8, ASTER, Sentinel 2, and commercial satellites, collected and distributed in collaboration with the USGS Hazards Data Distribution System, have been useful for refining track location and extent through a "bird's eye" view of the damaged areas. The NASA Short-term Prediction Research and Transition (SPoRT) Center has been working with the NWS and USGS to provide imagery and derived products from polar-orbiting satellite platforms to assist in the detection and refinement of tornado tracks as part of a NASA Applied Science: Disasters project. Working closely with select Weather Forecast Offices (WFOs) and Regional Operations Centers (ROCs) in both the NWS Central and Southern regions, high- and medium-resolution (0.5 - 30 m and 250 m - 1 km resolutions, respectively) imagery and derived products have been provided to the DAT interface for evaluation of operational utility by the NWS for their use in both the field and in the office during post event analysis. Highlighted in this presentation will be case studies where the remotely sensed imagery assisted in the adjustment of a tornado track. Examples will be shown highlighting

Migratory birds are the source of highly toxic organic pollutants for indigenous people in the Russian Arctic

Science.gov (United States)

Pesiakova, A. A.; Gusakova, E. V.; Trofimova, A. N.; Sorokina, T. Yu

2018-01-01

Polychlorinated biphenyls are highly toxic organic contaminants. Due to their chemical properties they had wide application in industry and agriculture in the 20th century. In 2001 the production of PCBs has been prohibited almost worldwide. Environmental contamination has been found in soils, water, and air where there were PCB production sites. They have been detected in fish, birds and animals of migratory species, retaining transboarding transfer. Several migratory species of birds (Taiga bean goose, greater white-fronted goose, lesser white fronted goose and barnacle goose) are a diet for indigenous people. PCBs accumulating in the human body affect all systems and organs. This article reviews the contribution of migratory bird species in transboarding transfer of highly toxic contaminants in the Nenets Autonomous Area, Kolguev island (Russian Arctic).

Plumage quality mediates a life-history trade-off in a migratory bird.

Science.gov (United States)

Podlaszczuk, Patrycja; Kamiński, Maciej; Włodarczyk, Radosław; Kaczmarek, Krzysztof; Janiszewski, Tomasz; Minias, Piotr

2016-01-01

Moult is one of the most costly activities in the annual cycle of birds and most avian species separate moult from other energy-demanding activities, such as migration. To this end, young birds tend to undergo the first post-juvenile moult before the onset of migration, but in some species the time window for the pre-migratory feather replacement is too narrow. We hypothesized that in such species an increased investment in the structural quality of juvenile feathers may allow to retain juvenile plumage throughout the entire migratory period and delay moult until arriving at wintering grounds, thus avoiding a moult-migration overlap. The effect of juvenile plumage quality on the occurrence of moult-migration overlap was studied in a migratory shorebird, the common snipe Gallinago gallinago . Ca. 400 of first-year common snipe were captured during their final stage of autumn migration through Central Europe. The quality of juvenile feathers was assessed as the mass-length residuals of retained juvenile rectrices. Condition of migrating birds was assessed with the mass of accumulated fat reserves and whole-blood hemoglobin concentration. Path analysis was used to disentangle complex interrelationships between plumage quality, moult and body condition. Snipe which grew higher-quality feathers in the pre-fledging period were less likely to initiate moult during migration. Individuals moulting during migration had lower fat loads and hemoglobin concentrations compared to non-moulting birds, suggesting a trade-off in resource allocation, where energetic costs of moult reduced both energy reserves available for migration and resources available for maintenance of high oxygen capacity of blood. The results of this study indicate that a major life-history trade-off in a migratory bird may be mediated by the quality of juvenile plumage. This is consistent with a silver spoon effect, where early-life investment in feather quality affects future performance of birds during

Satellite tracking of two Montagu's Harriers (Circus pygargus) : Dual pathways during autumn migration

NARCIS (Netherlands)

Trierweiler, Christiane; Koks, Ben J.; Drent, Rudi H.; Exo, Klaus-Michael; Komdeur, Jan; Dijkstra, Cor; Bairlein, Franz

2007-01-01

Autumn migration routes of two Dutch female Montagu's Harriers (Circus pygargus) were documented for the first time using satellite telemetry. Both migrated to their African wintering area-one via the Straits of Gibraltar through the Mediterranean and the other via Italy/Tunisia. The rate of travel

76 FR 23935 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures

Science.gov (United States)

2011-04-29

.... 110120049-1144-01] RIN 0648-BA69 Atlantic Highly Migratory Species; Atlantic Shark Management Measures... retention, transshipping, landing, storing, or selling of hammerhead sharks in the family Sphyrnidae (except for Sphyrna tiburo) and oceanic whitetip sharks (Carcharhinus longimanus) caught in association with...

76 FR 72383 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures

Science.gov (United States)

2011-11-23

...-BA17 Atlantic Highly Migratory Species; Atlantic Shark Management Measures AGENCY: National Marine... plan (FMP) amendment that would consider catch shares for the Atlantic shark fisheries. The comment... potential catch shares programs in the Atlantic shark fisheries. Additionally, NMFS is extending the comment...

Migration confers survival benefits against avian predators for partially migratory freshwater fish

DEFF Research Database (Denmark)

Skov, Christian; Chapman, Ben B.; Baktoft, Henrik

2013-01-01

The importance of predation risk in shaping patterns of animal migration is not well studied, mostly owing to difficulties in accurately quantifying predation risk for migratory versus resident individuals. Here, we present data from an extensive field study, which shows that migration...... in a freshwater fish (roach, Rutilus rutilus) that commonly migrates from lakes to streams during winter confers a significant survival benefit with respect to bird (cormorant, Phalacrocorax carbo spp.) predation. We tagged over 2000 individual fish in two Scandinavian lakes over 4 years and monitored migratory...... behaviour using passive telemetry. Next, we calculated the predation vulnerability of fish with differing migration strategies, by recovering data from passive integrated transponder tags of fish eaten by cormorants at communal roosts close to the lakes. We show that fish can reduce their predation risk...

Linear feature detection algorithm for astronomical surveys - II. Defocusing effects on meteor tracks

Science.gov (United States)

Bektešević, Dino; Vinković, Dejan; Rasmussen, Andrew; Ivezić, Željko

2018-03-01

Given the current limited knowledge of meteor plasma micro-physics and its interaction with the surrounding atmosphere and ionosphere, meteors are a highly interesting observational target for high-resolution wide-field astronomical surveys. Such surveys are capable of resolving the physical size of meteor plasma heads, but they produce large volumes of images that need to be automatically inspected for possible existence of long linear features produced by meteors. Here, we show how big aperture sky survey telescopes detect meteors as defocused tracks with a central brightness depression. We derive an analytic expression for a defocused point source meteor track and use it to calculate brightness profiles of meteors modelled as uniform brightness discs. We apply our modelling to meteor images as seen by the Sloan Digital Sky Survey and Large Synoptic Survey Telescope telescopes. The expression is validated by Monte Carlo ray-tracing simulations of photons travelling through the atmosphere and the Large Synoptic Survey Telescope telescope optics. We show that estimates of the meteor distance and size can be extracted from the measured full width at half-maximum and the strength of the central dip in the observed brightness profile. However, this extraction becomes difficult when the defocused meteor track is distorted by the atmospheric seeing or contaminated by a long-lasting glowing meteor trail. The full width at half-maximum of satellite tracks is distinctly narrower than meteor values, which enables removal of a possible confusion between satellites and meteors.

NASA to launch second business communications satellite

Science.gov (United States)

1981-01-01

The two stage Delta 3910 launch vehicle was chosen to place the second small business satellite (SBS-B) into a transfer orbit with an apogee of 36,619 kilometers and a perigee of 167 km, at an inclination of 27.7 degrees to Earth's equator. The firing and separation sequence and the inertial guidance system are described as well as the payload assist module. Facilities and services for tracking and control by NASA, COMSAT, Intelsat, and SBS are outlined and prelaunch operations are summarized.

Implementing telemetry on new species in remote areas: Recommendations from a large-scale satellite tracking study of African waterfowl

Science.gov (United States)

Cappelle, J.; Iverson, S.A.; Takekawa, John Y.; Newman, S.H.; Dodman, T.; Gaidet, N.

2011-01-01

We provide recommendations for implementing telemetry studies on waterfowl on the basis of our experience in a tracking study conducted in three countries of sub-Saharan Africa. The aim of the study was to document movements by duck species identified as priority candidates for the potential spread of avian influenza. Our study design included both captive and field test components on four wild duck species (Garganey, Comb Duck, White-faced Duck and Fulvous Duck). We used our location data to evaluate marking success and determine when signal loss occurred. The captive study of eight ducks marked with non-working transmitters in a zoo in Montpellier, France, prior to fieldwork showed no evidence of adverse effects, and the harness design appeared to work well. The field study in Malawi, Nigeria and Mali started in 2007 on 2 February, 6 February and 14 February, and ended on 22 November 2007 (288 d), 20 January 2010 (1 079 d), and 3 November 2008 (628 d), respectively. The field study indicated that 38 of 47 (81%) of the platform transmitter terminals (PTTs) kept transmitting after initial deployment, and the transmitters provided 15 576 locations. Signal loss during the field study was attributed to three main causes: PTT loss, PTT failure and mortality (natural, human-caused and PTT-related). The PTT signal quality varied by geographic region, and interference caused signal loss in the Mediterranean Sea region. We recommend careful attention at the beginning of the study to determine the optimum timing of transmitter deployment and the number of transmitters to be deployed per species. These sample sizes should be calculated by taking into account region-specific causes of signal loss to ensure research objectives are met. These recommendations should be useful for researchers undertaking a satellite tracking program, especially when working in remote areas of Africa where logistics are difficult or with poorly-known species. ?? NISC (Pty) Ltd.

Satellite Contributions to Global Change Studies