Satellite-based Tracking Research Articles

How liner shipping heals schedule disruption: A data-driven framework to uncover the strategic behavior of port-skipping

Service disruption hurts the reliability of liner shipping schedules and the lack of high-quality data impedes research on schedule recovery in liner shipping. With the support of the Automatic Identification System (AIS), a satellite-based tracking system acquiring real-time records of vessels’ navigation trajectories worldwide, this study develops a novel data-driven framework to uncover the vessel schedule disruption recovery behavior (i.e., port-skipping). The framework consists of a series of independent yet closely related algorithms, which are in turn tasked with screening port calls, estimating closed-loop routes, measuring similarity between different routes, and identifying port-skipping behavior, respectively. Compared with partial proprietary data from the shipping industry and port authorities, the identification results can provide transparent datasets with wide applications and much easier access publicly. The developed data-driven framework is implemented with vessel trajectory information of around 2,000 container vessels worldwide from January 2016 to December 2020, and the results prove its validity and practical value for liner shipping scheduling management.

Defend as You Can, React Quickly: The Effects of the COVID-19 Shock on a Large Fishery of the Mediterranean Sea

This paper presents an analysis of the effect of SARS-CoV-2 coronavirus pandemic and related restrictive measures on the activity of the Italian fleet of trawlers, which represents one of the most important fisheries in the Mediterranean Sea. We integrated multiple sources of information including: (1) Fleet activity data from Vessel Monitoring System, the most important satellite-based tracking device; (2) vessel-specific landing data disaggregated by species; (3) market and economic drivers affecting the effort variation during the lockdown and in the related fishing strategies; (4) monthly landings of demersal species in the main Italian harbors. These data sources are combined to: (1) Assess the absolute and relative changes of trawling effort in the geographical sub-areas surrounding the Italian coasts; (2) integrate and compare these changes with the market and economic drivers in order to explain the observed changes in fishing effort and strategy; (3) analyze the changes of the fishing effort on the Landing-per-unit-effort (LPUE) in order to further understand the strategy adopted by fishers during this crisis and to infer the potential consequence for the different stocks. The results provide an overview of the effects of the “COVID-19 shock,” in terms of fishing activity and socio-economic drivers, demonstrating that the consequences of the pandemic have been very varied. Although the COVID-19 shock has caused a marked overall reduction in activity in the first semester of 2020, in some cases the strategies adopted by fishermen and the commercial network linked to their activity have significantly reduced the impact of the emergency and taken back catch and effort to levels similar to those of previous years. These results could provide insights for management measures based on temporal stops of fishing activities. In particular, if no limits to the fishing effort after the restart of fishing activities are adopted, the benefits of fishing pressure reduction on fishery resources could be nullified. On the other hands, when fishing activities restart, and in the absence of catch control, effort tends to increase on coastal bottoms characterized by greater abundance of resources and longer effective fishing time.

Characterizing Industrial and Artisanal Fishing Vessel Catch Composition Using Environmental DNA and Satellite-Based Tracking Data.

The decline in wild-caught fisheries paired with increasing global seafood demand is pushing the need for seafood sustainability to the forefront of national and regional priorities. Validation of species identity is a crucial early step, yet conventional monitoring and surveillance tools are limited in their effectiveness because they are extremely time-consuming and require expertise in fish identification. DNA barcoding methods are a versatile tool for the genetic monitoring of wildlife products; however, they are also limited by requiring individual tissue samples from target specimens which may not always be possible given the speed and scale of seafood operations. To circumvent the need to individually sample organisms, we pilot an approach that uses forensic environmental DNA (eDNA) metabarcoding to profile fish species composition from the meltwater in fish holds on industrial and artisanal fishing vessels in Ecuador. Fish identified genetically as present were compared to target species reported by each vessel’s crew. Additionally, we contrasted the geographic range of identified species against the satellite-based fishing route data of industrial vessels to determine if identified species could be reasonably expected in the catch.

Stop the global slaughter of sharks

The unsustainable slaughter of millions of sharks for their fins continues unabated even in EU waters, threatening the survival of several species. Meanwhile, new discoveries about the ecology of the top predators illustrate how much we still have to learn about the life we are about to destroy. Michael Gross reports.

ADS-BI: Compressed Indexing of ADS-B Data

The introduction of ADS-B, a satellite-based aircraft tracking technology, and the increasing installation of ADS-B receiver stations around the globe eases the tracking of aircraft, compared with traditional solutions using secondary radar. Given the large scale of ADS-B implementation and the high frequency of data collection, storing and managing ADS-B induced data has become increasingly difficult: The worldwide ADS-B data easily aggregates to several hundreds of terabyte per year, depending on the spatial coverage and temporal resolution. Standard data management solutions do not work well for ADS-B data, since they either require a large uncompressed index structure or cannot be queried efficiently. In this paper, we propose a novel compressed index structure for managing ADS-B data, called ADS-BI. The essential building blocks are spatio-temporal reference partitioning, reordering, and compression. On top of the partitioned, compressed representation, metadata is stored effectively, and exploited during query answering for typical ATM related task such as trajectory adherence evaluation, as well as complexity and safety metrics assessment by only accessing parts of the compressed data as necessary. Our novel index structure is evaluated on worldwide ADS-B data for a week in November 2016. For comparison, we implemented ten standard compression/indexing methods. The experiments reveal that none of these traditional methods can target the sweet spot between a small storage and efficient query answering. Our novel technique provides fast query answering at smallest storage costs. This paper contributes toward efficient handling of the increasing amount of traffic data in air traffic management, and eventually, toward more efficient and safer air transportation.

Invited Commentary: Fifty Years of Raptor Research

This review examines the main developments that have occurred over the past 50 years in our understanding of three aspects of raptor biology: (1) natural factors that limit breeding densities; (2) influences of toxic chemicals; and (3) movements and migrations. Early evidence indicated that raptor breeding densities were limited naturally by the availability of either prey or nest sites, whichever was in shortest supply in the area concerned. More recent evidence has shown that predation can have additional influence, with larger raptors and owls limiting the numbers of smaller ones to below what food or nest sites would permit. In addition, it has become apparent that some migratory raptors, like other migratory birds, can be limited in their migration and wintering areas to levels below those that conditions in breeding areas would permit. As many raptor populations have recovered from the effects of organochlorine pesticides, attention has switched to other limiting agents, including lead (from ammunition), which is currently preventing California Condors (Gymnogyps californianus) from establishing self-sustaining populations in the wild, and anti-inflammatory veterinary drugs, which have caused massive declines in Asia vultures (Gyps spp.). The development of radio-tracking enabled studies of the local movements of individual raptors, providing new information on territories and ranging behavior, while satellite-based tracking has revealed the migration routes, wintering areas, and behavior of hundreds of individual birds.

Emergency Vehicle Positioning, Inc

Emergency Vehicle Positioning, (EVPI), has developed a satellite-based tracking system that continuously updates and displays the location of every vehicle in its network. A recently signed contract presents new technical challenges that may make the normally installed system inadequate. While it is possible to augment the system so that it will definitely work, doing so would entail considerable cost. This case is a modified version of Siting Systems, Inc. (UVA-QA-0441). The only difference is that the QA-0441 provides all possible conditional probabilities, offering a slightly different introduction to Bayes's Theorem. In this case, only the recent conditional probabilities are provided. Indeed, except for the name, date, final paragraph (which mentions the other probabilities), and the exhibit on conditional probabilities, the cases are identical. Therefore, the teaching note for the Integrated Siting Systems case (UVA-QA-0441TN) is also appropriate for this case. Excerpt UVA-QA-0512 Rev. May 23, 2018 Emergency Vehicle Positioning, After the plentiful years of the Reagan military buildup, the defense industry realized that it would have to diversify into nonmilitary applications if it were to survive the contractions of the mid-1990s without losing the capabilities of its highly trained and specialized work force. One result was the spin-off of a variety of small firms, each attempting to commercialize some collection of specialized skills and technologies that had been developed for military use. Emergency Vehicle Positioning, (EVPI), was one such firm. By February 1996, not only had EVPI successfully navigated the system-development phase of its first commercial product—an integrated, real-time, mobile-vehicle-tracking system—but it had already successfully installed its first several systems. The EVPI tracking system continuously updated and displayed the location of every vehicle in its network on centralized maps at any number of dispatch centers. It was designed for use by emergency-services providers, such as ambulances, police, and fire departments. By tracking and routing mobile units to emergency sites, response times could be reduced significantly from those of traditional systems that dispatched centrally housed vehicles. When the system was used with vehicles already in motion, performance time could be further improved by automatically tracking both the location and availability of each vehicle (whether available for a call or currently active). The EVPI system had already demonstrated response-time reductions in excess of 10%. Because improved 911 response time often meant saved lives, and because many emergency-services providers were paid on the basis of realized response time, interest in the system was high. . . .

ALZCARE: an information system for screening, management and tracking of demented patients.

The ALZCARE project aims at assisting people at risk or already suffering of dementia, their family and health professionals in the dementia care pathway by providing an integrated ICT-enabled information System. The system consists of a mobile platform for screening people at risk, a Clinical Information System and a satellite-based patient tracking system. The system is currently on the evaluation phase focusing on addressing the needs of citizens of the cross-border areas of Greece and Albania.

Survival of Sooty Falcons (Falco concolor) breeding in Oman

Although the Middle East supports a high level of avian biodiversity, the ecology of relatively few species that use the region has been studied in detail. Despite its restricted breeding distribution in the Middle East, and apparent unfavorable conservation status, little is known about the population ecology of the Sooty Falcon (Falco concolor), one of only two falcon species that breeds in the boreal summer. We applied multi-state models to capture–mark–recapture data collected during 2007–2014 in the Sultanate of Oman to estimate, for the first time, the probabilities of capture, age-specific breeding probabilities, and state-specific apparent survival for Sooty Falcon. Capture probability for breeding adults (±1SE) was 0.443 ± 0.088. Annual apparent survival probability for pre-breeders and for breeding adults was 0.570 ± 0.048 and 0.656 ± 0.069, respectively. The probability that 2-, 3-, and 4-year-old falcons returned as breeders was 0.065 ± 0.036, 0.159 ± 0.069, and 0.339 ± 0.211, respectively. In 2013, we radio-tagged five fledgling falcons, and monitored their fates using satellite-based tracking. All initiated their first migration and survived for 48 days following radio-tagging, but four of the five birds died by 70 days post-tagging; only one survived >100 days. Our results suggest that only about 12 % of fledglings survive to the average age of first breeding (~3.8 years), and that most of first-year mortality occurs during their first migration or soon after they reach their destination. Low apparent survival of pre-breeders could result in low recruitment to the breeding population, and population declines. A comprehensive population-level assessment is urgently needed to accurately determine the status of Sooty Falcons, and to devise flyway-scale conservation plans.

Satellite-Based Tracking of Oil Pollution in the Arabian Gulf and the Sea of Oman

. Two oil spill events were investigated using multisensor satellite images in the Al Khafji and Al Fujairah regions. Oil slicks were characterized with Red-Green-Blue (RGB) and floating algae index (FAI) images. Oil slicks near Al Khafji were detected on April 19, 2014 by Landsat 8 and covered around 29.04 km2. Sequential VIIRS and MODIS/Aqua images collected on the same day observed the same slicks, which indicated different appearances in the RGB images. Another event was recorded near Al Fujairah on May 11, 2014 by both Landsat 8 and Aqua. The total area coverage of oil slicks was 114.6 km2. The estimated slick trajectories from GNOME driven by ocean circulation data from the Regional Ocean Model System (ROMS) and meteorological data were assessed with the movement patterns of satellite-detected oil slicks. The average absolute percentage error of velocity of slick movement between satellite observation and GNOME simulation was 33% for both events. The directions of slick movement showed an agreement between satellite observation and model simulation in 5 out of 7 trajectories' cases. This implies that the integration of multisensor satellite measurements and spill trajectory modeling is very helpful to forecast and predict the fate and transport of oil spills.Résumé. Deux déversements d'hydrocarbures ont été étudiés en utilisant des images satellitaires multicapteurs dans les régions d'Al Khafji et d'Al Fujairah. Les nappes de pétrole ont été caractérisées avec des images rouge-vert-bleu (RVB) « red-green-blue (RGB) » et avec l'indice d'algues flottantes « floating algae index » (FAI). Les nappes de pétrole près d'Al Khafji ont été détectées le 19 avril 2014 par Landsat 8 et elles couvraient environ 29,04 km2. Les images séquentielles VIIRS et MODIS/Aqua acquises le même jour ont observé les mêmes nappes, indiquées par différents aspects dans les images RVB. Un autre évènement a été détecté près d'Al Fujairah le 11 mai 2014 à la fois par Landsat 8 et Aqua. La superficie totale de ces nappes était de 114,6 km2. Les trajectoires des déversements d'hydrocarbure estimées à partir de GNOME, en utilisant les données de la circulation océanique du Regional Ocean Model System (ROMS) et les données météorologiques, ont été évaluées en utilisant les déplacements des nappes de pétrole détectées par satellite. Le pourcentage d'erreur absolue moyenne de la vitesse de mouvement de la nappe entre l'observation par satellite et la simulation de GNOME était de 33% pour les 2 évènements. Les directions de mouvements des nappes ont montré un accord entre l'observation par satellite et la simulation du modèle dans 5 des 7 cas de trajectoires. Ceci implique que l'intégration de mesures satellitaires multicapteurs et la modélisation des trajectoires des déversements sont très utiles pour prévoir et prédire le devenir et le transport des déversements de pétrole.

Bird migration and avian influenza: A comparison of hydrogen stable isotopes and satellite tracking methods

Satellite-based tracking of migratory waterfowl is an important tool for understanding the potential role of wild birds in the long-distance transmission of highly pathogenic avian influenza. However, employing this technique on a continental scale is prohibitively expensive. This study explores the utility of stable isotope ratios in feathers in examining both the distances traveled by migratory birds and variation in migration behavior. We compared the satellite-derived movement data of 22 ducks from 8 species captured at wintering areas in Bangladesh, Turkey, and Hong Kong with deuterium ratios (δD) in the feathers of these and other individuals captured at the same locations. We derived likely molting locations from the satellite tracking data and generated expected isotope ratios based on an interpolated map of δD in rainwater. Although δD was correlated with the distance between wintering and molting locations, surprisingly, measured δD values were not correlated with either expected values or latitudes of molting sites. However, population-level parameters derived from the satellite-tracking data, such as mean distance between wintering and molting locations and variation in migration distance, were reflected by means and variation of the stable isotope values. Our findings call into question the relevance of the rainfall isotope map for Asia for linking feather isotopes to molting locations, and underscore the need for extensive ground truthing in the form of feather-based isoscapes. Nevertheless, stable isotopes from feathers could inform disease models by characterizing the degree to which regional breeding populations interact at common wintering locations. Feather isotopes also could aid in surveying wintering locations to determine where high-resolution tracking techniques (e.g. satellite tracking) could most effectively be employed. Moreover, intrinsic markers such as stable isotopes offer the only means of inferring movement information from birds that have died as a result of infection. In the absence of feather based-isoscapes, we recommend a combination of isotope analysis and satellite-tracking as the best means of generating aggregate movement data for informing disease models.

Flow-Specific Medium Access for Networked Satellite System

Prior work in modeling the satellite-based detection and tracking components of the ballistic missile defense system as a large-scale, wireless sensor network relies on a medium access scheme that can accommodate the large propagation delays encountered in these networked satellite systems. While existing satellite-based systems typically employ a form of time division multiple access, recent efforts have begun to explore contention-based approaches. In this work, we quantify the effect of the large propagation delays on both contention-based and contention-free solutions and propose a flow-specific medium access solution that provides improved delay performance by dynamically adapting the networked satellite medium access scheme to changes in both individual flow and link characteristics. A comparison with CSMA and TDMA is provided through simulation results using a version of the traffic-adaptive cooperative wireless sensor medium access control protocol that has been modified to accommodate large propagation delays.

GPS tracking and the right of privacy

Government authorities and law enforcement agencies start using the satellite-based GPS tracking technology more often for various purposes. Due to its unique technical features, GPS tracking poses a much greater threat to the right of privacy compared with traditional electronic tracking techniques, such as the Beeper. Comparisons are extensively analyzed and a number of the US cases are quoted for illustrations. In the end, several key principles are proposed to facilitate the supervision of investigation behaviors in China.

Year-Round Tracking of Small Trans-Saharan Migrants Using Light-Level Geolocators

Since 1899 ringing (or banding) remained the most important source of information about migration routes, stopover sites and wintering grounds for birds that are too small to carry satellite-based tracking systems. Despite the large quantity of migrating birds ringed in their breeding areas in Europe, the number of ring recoveries from sub-Saharan Africa is very low and therefore the whereabouts of most small bird species outside the breeding season remain a mystery. With new miniaturized light-level geolocators it is now possible to look beyond the limits of ring recovery data. Here we show for the first time year round tracks of a near passerine trans-Saharan migrant, the European Hoopoe (Upupa epops epops). Three birds wintered in the Sahel zone of Western Africa where they remained stationary for most of the time. One bird chose a south-easterly route following the Italian peninsula. Birds from the same breeding population used different migration routes and wintering sites, suggesting a low level of migratory connectivity between breeding and wintering areas. Our tracking of a near passerine bird, the European Hoopoe, with light-level geolocators opens a new chapter in the research of Palaearctic-African bird migration as this new tool revolutionizes our ability to discover migration routes, stopover sites and wintering grounds of small birds.

Positioning Algorithm With Joint Space–Time Constraints for Unmanned Network-Flying Vehicles

Unmanned network-flying vehicles (UNFVs), regarded as special remote-sensing platforms, are affected by attitude maneuvering, gravity, climatic change, and atmospheric turbulence. To improve the positioning precision of the UNFVs and accomplish autonomous navigation in the case of communication and/or tracking failure, a tracking positioning algorithm with joint space-time constraints (PAST) is proposed. In particular, the adaptive truncated normal distribution model is adopted to describe the distribution of the vehicle maneuvering acceleration with reduced delay effect of the vehicle tracking. Then, according to the spatial correlation of the UNFVs in adjacent moment, a spatial adjustment datum is combined with a time-domain strong tracking filter by Lagrange method of multipliers. As such, the rank deficiency in the measurement equation is resolved while the spatial correlation of the UNFV tracking enhanced. Furthermore, for the autonomous navigation of the UNFVs which depends little on the Earth- or satellite-based tracking, telemetry, and command, we utilize an ldquoanchorrdquo technology to further improve the PAST algorithm. Monte Carlo simulation results show that, compared with existing positioning methods, the proposed algorithm may continuously track sudden motion, rapidly respond to network communication failure, and greatly increase positioning precision for slowly moving vehicles.

A Virtual University for the Semi‐Arid Tropics: A Concept Note

1.1 Purpose This concept note serves as a springboard for discussions on the establishment of a Virtual University for the Semi-Arid Tropics (VUSAT) for India, South Asia and sub-Saharan Africa. The VUSAT aims to develop climate literacy and drought preparedness among rural communities, development workers, service providers, policy makers, and other strategic sectors through the integrated use of contemporary information and communication technology (ICT), open and distance learning (ODL), and other communication media. It will also communicate information on climatic trends like monsoon behavior and methods of drought management for community mobilization and disaster preparedness. Likewise, this initiative will promote and explore the innovative interface of new tools (space technology, the Internet, satellite-based tracking of ground events, etc.) and conventional communication media (print, radio and television) for mass-based learning and social mobilization.

Large-scale space object tracking using APL2

The number of space objects in earth orbit has increased steadily from the launch of the first space object (Sputnik) to the current level of approximately 10,000. The North American Defense Cheyenne Mountain Operations Center (CMOC), operated by the United States and Canada, provides continuous tracking of this growing constellation of space objects, including active and inactive satellites and space debris. This mission is accomplished for the most part using radar stations and ground-based optical tracking stations, with centralized orbit determination and satellite catalog maintenance performed at CMOC. The United States plans to augment this capability with satellite-based optical tracking. In this paper we discuss aspects of an extensive APL2 prototyping capability that we have developed to evaluate concepts for satellite-based tracking of space objects.Over the last 25 years, we have developed a library of APL prototyping and simulation capabilities to handle various aspects of space-based infrared sensor surveillance of missile launches (Ref. 1 and 2). In recent years we have expanded these capabilities to address the space object surveillance mission as well as Global Positioning System applications (Ref. 3). In this paper we discuss development of algorithms and simulations for the space object surveillance mission of a generic constellation of low-altitude surveillance satellites.In general, surveillance satellites can be equipped with several different kinds of infrared and visible wavelength sensors to accommodate a variety of surveillance missions. A given satellite platform may contain one or more acquisition sensors having a wide field of view for global coverage, in order for the satellite system to detect the occurrence of a space launch or a missile launch anywhere in the world. The same platform may also contain narrow field of view sensors that operate in different parts of the spectral band, in order to enhance detection of objects at various altitudes within the atmosphere or outside the atmosphere, and to enhance the system's ability to identify targets of different types.Finally, a given satellite platform may contain visible wavelength sensors with very small fields of view but very high resolution that are designed to track targets with greater precision. The "track sensors" that are used to detect and track objects in space are of this general type.The mission of tracking space objects includes maintaining orbital ephemerides for active satellites, inactive satellites, spent boosters and space debris primarily in earth orbit. This paper describes how our group (Lockheed Martin Mission Systems in Boulder, Colorado) has simulated the relevant aspects of this mission in considerable detail using APL2. We also discuss our simulation approach compared with other approaches, such as using COTS products. We also describe some of the data sources we used, with particular emphasis on capabilities available through the Internet. We also show examples of APL2 functions that we crafted for this work.This approach has effectively capitalized on the rich algorithm library we have developed over the years that enables us to evaluate new concepts and designs in a rapid and confident manner.

First satellite-based tracking in the Atlantic Ocean of a leatherback turtle Dermochelys coracea: Duron-Dufrenne, Michèle, 1987. C. r. Acad. Sci., Paris, (Sér. III)304(15):399–402

First satellite-based tracking in the Atlantic Ocean of a leatherback turtle Dermochelys coracea: Duron-Dufrenne, Michèle, 1987. C. r. Acad. Sci., Paris, (Sér. III)304(15):399–402