International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Telemetry Test Station has been developed at the Digital Systems Division, ISRO Satellite Centre, to test House Keeping Telemetry Packages which will be flown onboard satellites. The main feature of the Test Staion is its configurability, since it is intended to be used with different types of (low bit rate) telemetry packages. Other features include automation of test procedure, and reduction in testing time/increase in repeatability due to minimisation of manual interaction. Since the test station comprises GPIB controlled equipment, hardware and software, thf configurability should be built in at all levels and stages, from design to implementation. Thus since the specification is subject to change, the configuration for structure of the system is traosferred from the designer to the user. This results in a large part of the system being devoted to user interface design, since the computer which is an integral part of the setup must be ‘invisible’ to the user. Due to specialised requirements the user and the system are treated at peer level i.e, at any time during the entire test session, the user can override system process and verify/correct it and equally, the system must also verify/correct user input especially with regard to critical test procedures. The test tession itself (after configuration) is divided into three equally important sections: preprocessing, test and analysis. All the data required during the test run should be made ready before the actual test. Since it has been found by experience that this is not always convenient, the preprocessing software is integrated in to the test session so that the user can perform this at any time. Similarly, the results of the test can also be analysed immediately or even during the test to improve subsequent procedures. This paper describes the prototype telemetry test station which has been built and tested over the past two years. This performance has been satisfactory. The system integration features and design problems and solution are high lighted.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper aims to add the information access capabilities to enable user’s mobile terminals in a wireless small satellite telemetry system. The cellular phone-centric mobile network architecture provides wireless communication link; telemetry information is provided to users in a highly personalized form according to the end-user’s range. We choose a reference system-level model of network architecture and compare its performance with common small satellite telemetry network link; evaluation results derived using a known analytical model. The result of original hypotheses, network architecture’s prototype includes both analytical performance evaluation and simulation techniques, are discussed in detail.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The world of data communication and networking has grown rapidly over the last decade, and this growth has been accompanied by the development of standards that reflect and facilitate the need for commercial products that work together in a reliable, robust, and coherent fashion. To a great extent this commercialization, with its increasing performance and diminishing cost, has not been adapted to the data communication needs of satellites. As budgets and mission development and deployment timelines shrink, space exploration and science will require the development of standards and the use of increasing amounts of off-the-shelf hardware and software for integrated satellite ground systems. The Renaissance project at NASA/Goddard Space Flight Center has engaged in rapid prototyping of ground systems using off-the-shelf hardware and software products to identify ways of implementing satellite ground systems "faster, better, cheaper". This paper presents various aspects of these activities, including issues related to the configuration and integration of current off-the-shelf products using telemetry databases for existing spacecraft, an analysis of issues related to the development of standard products for satellite communication, tradeoffs between hardware and software approaches to performing telemetry front-end processing functions, and proposals for future standards and development.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper discusses the design, configuration, and operation of a satellite station built for the Center for Space Telemetering and Telecommunications Laboratory in the Klipsch School of Electrical and Computer Engineering Engineering at New Mexico State University (NMSU). This satellite station consists of a computer-controlled antenna tracking system, 2m/70cm transceiver, satellite tracking software, and a demodulator. The satellite station receives satellite telemetry, allows for voice communications, and will be used in future classes. Currently this satellite station is receiving telemetry from an amateur radio satellite, UoSAT-OSCAR-11. Amateur radio satellites are referred to as Orbiting Satellites Carrying Amateur Radio (OSCAR) satellites.

Tracking an individual species has always been a challenge for scientists, especially when one has to make sure to not change its natural movement pattern. When the number of individuals being tracked is increased and water is added to the equation, the task becomes next to impossible. But thanks to technologies and tracking methods like telemetry, the task of tracking any species without affecting the natural movement pattern has not only become a reality but easily accessible to scientists. Underwater acoustic telemetry has become a standard tool for fisheries biologist to study the movement pattern of the fish (Heupel). This project develops a minimalistic database designed to meet the needs of the telemetry systems. The database is optimized for storing a large number of datasets generated by the telemetry system and also for the most common queries run against the system.

A twenty year mark-recapture dataset from the loggerhead nesting beach on Keewaydin Island, off the southwest coast of Florida, was analyzed using a two-state open robust design model in Program MARK to provide insight into recent nesting declines in the state. A total of 2,292 encounters representing 841 individual tag IDs were used for this analysis. Survival was estimated at 0.73 (95% CI 0.69-0.76), and there was no evidence from remigration rate or clutch frequency to suggest the composition of the nesting assemblage had changed over time. The mark-recapture analysis was supplemented with a satellite tracking component to identify the offshore foraging areas utilized by Keewaydin nesters. Eleven nesting females were outfitted with platform terminal transmitters, which transmitted for 42 to 300+ days including inter-nesting intervals and subsequent migration to foraging grounds. Site fidelity tests and kernel density home range analyses were used to describe foraging habitats. Females foraging in the eastern Gulf of Mexico were within the recent 64 m bottom longline fishery restriction. Areas identified as important habitats during the remigration interval should be used to inform managers in creating targeted management strategies to aid population recovery without the use of broad fishery closures.

Understanding the degree of connectivity among populations, forming migratory links and evaluating factors that influence reproductive fitness is fundamental for the successful management of migratory species of conservation concern. In this thesis I focus on a regionally important rookery of green turtles (Chelonia mydas) at Alagadi beach in northern Cyprus that has been intensively studied since 1992. I employ high resolution genetic markers with different modes of inheritance to reveal fine scale population structuring among four rookeries within a 200 km stretch of shoreline. The relative importance of four foraging areas and the annual contribution from each site to the breeding cohort are evaluated using the stable isotope ratios of the turtles calibrated by satellite telemetry. The stable isotope ratios of the turtles reveal that a previous undisclosed foraging site at Lake Bardawil in Egypt is critical for the population recovery of the Alagadi rookery. The temporal consistency of stable isotope ratios reaffirm that green turtles exhibit high fidelity to foraging sites allowing the evaluation of foraging area effects on reproductive traits to be evaluated over multiple seasons. I investigate the population sub-structuring of the Alagadi nesting aggregation grouped by the foraging area used. The absence of genetic structure supported the Learning Migration Goal Theory and provided evidence that the significant among site phenotypic variability in the body size of recruits, the length of interbreeding intervals and the date that the first nest of the season was made is a result of foraging areas effects. No significant among site phenotypic variability was found for the size or number of clutches laid. Among site variability in interbreeding intervals resulted in substantial variation in the reproductive potential of individuals due to assumed differences in resource availability and environmental factors. The multilocus genotypes generated for 243 nesting females were employed to reconstruct the first wild marine turtle pedigree using a full-likelihood sib-ship reconstruction approach. This revealed that the effective contribution to the next generation was unequal and allowed a minimum age to maturity to be estimated from parent – offspring assignations. However, sample size constraints prevented accurate estimates for the narrow-sense heritability of the five morphological and life-history traits from the quantitative genetic analysis. The multifaceted approach taken here to unravel the cryptic life-history of marine turtles emphasises the importance of long-term individual-based monitoring and the data generated can be employed to advise conservation strategy for this critically endangered regional management unit.

The beaches in the Gandoca-Manzanillo National Wildlife Refuge (GMNWR) in southeastern Costa Rica are known to host nesting critically endangered hawksbill sea turtles (<i>Eretmochelys imbricata</i>). The spatial ecology and movement behaviors of this nesting population has never been observed. Evaluating the spatial ecology of nesting sea turtles allows for a better understanding of their local movement behavior as well as their large scale oceanic movements that inform conservation needs. Satellite tracks reveal internesting, postnesting migration, and foraging behaviors for four nesting hawksbills from the GMNWR. During the internesting behavior, satellite-tracked hawksbills remained in the coastal waters near the nesting beach for 15 to 55 days before making their postnesting migration. Home-range areas occupied by internesting hawksbills vary between 21.9 and 557.9 km². Hawksbill internesting high use areas overlapped with the marine boundary of the GMNWR for an average of 29% of time spent inside the refuge. The beginning of all four turtle’s migrations start with a pelagic circular movement away from the coast into the Caribbean Sea before resuming a northern coastal migration pattern. Migration routes varied in length from 662 to 1,486 km and passed through three or four exclusive economic zones of various neighboring nations. Foraging areas of three hawksbills were situated east of Nicaragua and one was found along the northern coast of Honduras, near Roatan. Foraging home-range areas of satellite-tracked hawksbills varied from 205.1 to 696.1 km². This is the second satellite telemetry study completed on nesting hawksbills in the Costa Rican Caribbean and the first for GMNWR. These results display the use of pelagic and coastal migratory routes for the critically endangered hawksbill. Distant foraging grounds utilized by hawksbills nesting in Costa Rica reveal the importance for the preservation of the Miskito Cays and nearby ecosystems.

Knowledge of species distribution and habitat associations are essential for conservation measures. Such information is lacking for many marine species due to their occupancy of broad and ephemeral habitats that are difficult to access for study. Sea turtles, specifically the surface-pelagic juvenile stage of some species, are a group for which significant knowledge gaps remain surrounding their distribution and habitat use. Recent research has confirmed the long-standing hypothesis that the surface-pelagic juvenile stage occurs within surface-pelagic drift communities (SPDC). Within the North Atlantic and surrounding basins, the holopelagic macroalgae Sargassum spp. dominates SPDC and serves as a remotely-detectable indicator of SPDC. The present study focuses on surface-pelagic habitats of four sea turtle species and addresses knowledge gaps using two approaches: habitat mapping and behavioral examination. Remote sensing techniques were used to identify SPDC, and satellite telemetry to examine behavior. This work was conducted in three parts and is presented in three chapters. Imagery collected from the Landsat satellites (5 and 7) was used to quantify the area of SPDC (km2). Approximately 1,800 Landsat images collected from 2003–2011 were examined for SPDC. The first chapter discusses the abundance, seasonality, and distribution of SPDC within the eastern Gulf of Mexico waters where surface-pelagic green, hawksbill, Kemp’s ridley, and loggerhead turtles are known to occur. SPDC was found year-round within the eastern Gulf of Mexico, and the amount of habitat peaked during summer months. The amount of SPDC within the eastern Gulf of Mexico varied annually with peaks in 2005, 2009, and 2011. High concentrations of SPDC were discovered within offshore waters of the northeastern Gulf of Mexico and southern West Florida Shelf. Within the second chapter, the behavior of 10 surface-pelagic juvenile Kemp’s ridleys was examined using satellite telemetry. Using remotely-sensed imagery, the sea surface habitats used by tracked turtles were examined. Surface-pelagic juveniles are hypothesized to be principally passive drifters. The behavior of tracked turtles was examined to determine if they exhibited periods of active and passive behavior, which may indicate periods of swim and drift. The proximity of tracked turtles to remotely-detected SPDC was examined when coincident Landsat imagery was available (within one day of the turtle’s position). Turtles were tracked for 36.5 days (mean) and exhibited primarily passive behavior during the tracking period. The satellite transmitters messaged frequently and reported temperatures significantly higher than sea surface temperatures. Landsat imagery was available coincident to the tracks of nine individuals. SPDC was present within 74% of images, and the mean distance between tracked turtles and SPDC was 54 km. Close associations between tracked turtles and SPDC were documented for four individuals. Results suggest that the tracked turtles spent a majority of the time drifting within SPDC. The final chapter discusses the density of SPDC within northern and western Gulf of Mexico waters from 2009–2011. Seasonal abundance peaks occurred throughout the study area, but the timing varied. SPDC peaked earlier (late spring) within the northwestern Gulf of Mexico. Moving eastward, the timing of seasonal peaks shifted progressively later during the year. Within the western portions of the study area, SPDC was found to be significantly higher than in the eastern Gulf of Mexico. The eastern Gulf of Mexico may provide critical developmental habitats for several North Atlantic sea turtle species. Additional study is necessary to determine if portions of the western Gulf of Mexico could serve in a similar capacity. SPDC is extremely vulnerable to anthropogenic impacts, specifically oil spills and the occurrence of persistent marine debris. Conservation of SPDC may be challenged by its ephemeral nature; however, the results presented herein could advise conservation efforts (e.g., delineation of critical habitat). The present study described spatial patterns of SPDC occurrence, regions of high abundance, and seasonality. The description of the behavior surface-pelagic sea turtles offers refinements to the spatial distribution of this life stage. These results, coupled with information on circulation patterns and the distribution of sea turtle nesting beaches, can be used to better predict when and where sea turtles and SPDC may be found. For example, the year-round persistence of SPDC within the eastern Gulf of Mexico and the location of major nesting beaches located upstream support the area’s designation as critical habitat for surface-pelagic green, hawksbill, Kemp’s ridley, and loggerhead turtles.

<p>Sea turtles have experienced dramatic population declines during the last century as a consequence of direct harvest, by-catch in fisheries, and habitat loss. Despite almost 50 years of partial international protection, several populations of sea turtles are still at imminent risk of extinction. Our knowledge of their complex life histories is still far from complete; these knowledge gaps hinder our ability to provide scientific advice regarding their conservation and management. It is the very complexity of their life histories, which allows them to exploit widely separated habitats during development, often over the course of decades, which makes them inherently difficult to study. I used satellite telemetry (n=60) to investigate the movements and habitat use patterns of juvenile loggerhead (<italic>Caretta caretta</italic>), green (<italic>Chelonia mydas</italic>), and Kemp's ridley (<italic>Lepidochelys kempii</italic>) sea turtles on their summer feeding grounds in North Carolina estuaries. These turtles migrate into and out of the estuarine waters each spring and autumn, encountering a gauntlet of fishing gear on each journey. The by-catch of sea turtles is an important conservation issue in North Carolina, and throughout the world's oceans. I evaluated conservation measures established to reduce the by-catch of sea turtles in Pamlico Sound's autumnal large-mesh gill net fishery for southern flounder (<italic>Paralichthys lethostigma</italic>), using a spatially explicit predator/prey model. My findings indicated that species-specific habitat preferences contributed to a turtles' risk of encountering fishing gear and that areas of high by-catch are predictable from patterns of overlap between sea turtle habitat use and flounder fishing effort. I then examined how the behavior of green turtles affected their vulnerability to incidental capture in estuarine commercial fisheries. Individual green turtles interact with multiple gears per season as a result of strong site fidelity to habitats also preferred by fishers. Telemetry also allowed me to examine individual variation in movements, habitat use, and site fidelity patterns of juvenile loggerhead turtles, both within the estuary and as the turtles migrated out into the North Atlantic. I used these observations to test the hypothesis of a discrete ontogenetic shift in habitat and diet in juvenile loggerheads. Approximately one-third of large juvenile loggerheads tagged in North Carolina estuaries return to oceanic habitat, sometimes for several years, where they are vulnerable to by-catch in pelagic fisheries. This led me to conclude that the long held notion of a discrete ontogenetic habitat shift between the oceanic and neritic habitat was incorrect for juvenile loggerheads (and possibly also for green turtles). Finally, I explored variation in migratory destinations in these animals through multivariate analyses of carbon and nitrogen stable isotope ratios in blood plasma and red blood cells, and through analysis of sex, genetic, haplotype, body size, and remigration records, and described the trophic niche of these turtles with Bayesian isotope mixing models. Variation in migratory destination (oceanic or neritic habitat) was best described by stable isotope ratios of nitrogen and remigration tendency. Turtles that returned to the open ocean had significantly lower nitrogen ratios than those animals that remained in the neritic zone and their diets retained a substantial contribution of epipelagic prey items. The diet composition of neritic turtles, on the other hand, consisted primarily of estuarine benthic invertebrates during the summertime and autumn foraging season but shifted toward pelagic jellyfish, fish, and <italic>Sargassum</italic> during the overwintering period. Oceanic turtles likely came from open ocean regions prior to entering the summer foraging grounds while neritic turtles likely overwintered at the edge of the Gulf Stream. The agreement between the dietary compositions and migration patterns between the two groups of turtles suggest that these feeding and habitat use strategies were persistent characteristics in the turtles I sampled. My work has improved our understanding of sea turtle habitats in North Carolina estuaries and identified their migratory destinations and overwintering habitats. I hope that this work lays the groundwork for future studies that will explore how variation in habitat use and feeding strategies are manifested in life history traits that affect fitness directly, such as survivorship, growth rates, stage durations, and fecundity.</p> / Dissertation