Results 21 to 30 of about 149 (108)

Multistatic Frequency and Polarimetry Adaptive Autofocus for Synthetic Aperture Radar Imaging of a Moving Target

IET Radar, Sonar &Navigation, Volume 20, Issue 1, January/December 2026.
This paper presents a multistatic, frequency‐ and polarimetry‐adaptive autofocus algorithm (F‐Pol) for SAR imaging of moving targets undergoing complex, six‐degrees‐of‐freedom (6‐DoF) motion. Building on Localised Threshold Sharpness (LTS), the method exploits agreement across frequency sub‐bands and polarisation channels to improve pulse‐by‐pulse ...
Anmol Rattan, Daniel Andre, Mark Finnis
wiley   +1 more source

Is GPS telemetry location error screening beneficial?

Wildlife Biology, Volume 2017, Issue 1, Page 1-7, January 2017., 2017
The accuracy of global positioning system (GPS) locations obtained from study animals tagged with GPS monitoring devices has been a concern as to the degree it influences assessments of movement patterns, space use, and resource selection estimates. Many methods have been proposed for screening data to retain the most accurate positions for analysis ...
Kirsten E. Ironside, David J. Mattson, Terence R. Arundel, Jered R. Hansen   +3 more
wiley   +1 more source

Lions (Panthera leo leo) Movement Patterns in a Sudanian Wooded Savannah in Central Africa

African Journal of Ecology, Volume 63, Issue 7, October 2025.
ABSTRACT Understanding the spatial ecology of African lions (Panthera leo) in human‐dominated landscapes is critical for their conservation. Using GPS collar data from three lions monitored between 2024 and 2025, we provide insights into their movement across the Benoue ecosystem in northern Cameroon and potential transboundary links with Chad.
Serge A. Kamgang, Justin G. Didolanvi, Serge P. Tadjo, Paul Bour, Iris Kirsten, Michel Babale, Pricelia N. Tumenta, David W. Macdonald, Murray Stokoe, Hans Bauer   +9 more
wiley   +1 more source

Quantifying spatial habitat loss from hydrocarbon development through assessing habitat selection patterns of mule deer

Global Change Biology, Volume 21, Issue 11, Page 3961-3970, November 2015., 2015
Abstract Extraction of oil and natural gas (hydrocarbons) from shale is increasing rapidly in North America, with documented impacts to native species and ecosystems. With shale oil and gas resources on nearly every continent, this development is set to become a major driver of global land‐use change.
Joseph M. Northrup, Charles R. Anderson Jr., George Wittemyer   +2 more
wiley   +1 more source

Impact of Ionospheric Scintillations on GNSS Availability and Precise Positioning

Space Weather, Volume 23, Issue 2, February 2025.
Abstract For many applications where accuracy, availability, and integrity are essential, such as geodetic positioning and civil aviation, Global Navigation Satellite Systems (GNSS) are indispensable. However, GNSS signal dependability is severely hampered by ionospheric disturbances, especially equatorial plasma bubbles (EPBs), particularly in ...
C. R. Aguiar, J. F. G. Monico, A. O. Moraes   +2 more
wiley   +1 more source

Developing spatially‐explicit weighting factors to account for bias associated with missed GPS fixes in resource selection studies

Wildlife Biology, Volume 19, Issue 3, Page 257-273, September 2013., 2013
Global positioning system (GPS) collars are prone to locational error and missed fixes caused by vegetation and topography, meaning that locational error may be greater, or fix success lower, in certain habitats. These forms of error can lead to bias associated with data loss or censoring. The goals of this paper were to: 1) estimate resource selection
Stephen L. Webb, Matthew R. Dzialak, James P. Mudd, Jeffrey B. Winstead   +3 more
wiley   +1 more source

Distributed angle‐only orbit determination algorithm for non‐cooperative spacecraft based on factor graph

IET Radar, Sonar &Navigation, Volume 18, Issue 9, Page 1494-1514, September 2024.
Two distributed algorithms based on factor graphs are proposed, utilising multiple CubeSats angle measurements for the orbit determination of the non‐cooperative spacecraft. The algorithms are applied to the sub‐parent and distributed cluster spacecraft architectures, respectively.
Zhixun Zhang, Keke Zhang, Leizheng Shu, Zhencai Zhu, Meijiang Zhou   +4 more
wiley   +1 more source

Attitude Determination with Magnetometers and Accelerometers to Use in Satellite Simulator

Mathematical Problems in Engineering, Volume 2013, Issue 1, 2013., 2013
Attitude control of artificial satellites is dependent on information provided by its attitude determination process. This paper presents the implementation and tests of a fully self‐contained algorithm for the attitude determination using magnetometers and accelerometers, for application on a satellite simulator based on frictionless air bearing ...
Helio Koiti Kuga, Valdemir Carrara, Maria Zanardi   +2 more
wiley   +1 more source

The use of anthropogenic areas helps explain male brown bear movement rates and distance travelled during the mating season

Journal of Zoology, Volume 324, Issue 1, Page 83-96, September 2024.
This paper investigated the movement behaviour of GPS‐tracked male brown bears in Finland during the mating vs. non‐mating season and the potential influence of anthropogenic presence. Throughout the year, male bears selected forested/shrub habitats and increased movement rates near main roads, as well as roaming behaviour during the mating season. All
D. Falcinelli, M. del Mar Delgado, I. Kojola, S. Heikkinen, C. Lamamy, V. Penteriani   +5 more
wiley   +1 more source

Testing Global Positioning System performance for wildlife monitoring using mobile collars and known reference points.

, 2007
International audienceTo determine the spatial resolution of Global Positioning System (GPS) receiver data, rigorous testing is essential. We tested performance of the Lotek 3300 GPS collar for medium-sized mammals (Lotek Engineering, Inc., Newmarket, ON,
Angibault, Jean-Marc, Morellet, Nicolas, Cargnelutti, Bruno, Michel, Goulard, Hewison, Mark, Coulon, Aurélie   +5 more
core   +1 more source