Results 51 to 60 of about 1,234 (185)

An Improved Coordinate Registration for Over-the-Horizon Radar Using Reference Sources

, 2021
In the target localization of skywave over-the-horizon radar (OTHR), the error of the ionospheric parameters is one main error source. To reduce the error of ionospheric parameters, a method using both the information of reference sources (e.g., terrain ...
Zhen Guo, Yuhang Hao, Quan Pan, Hua Lan, Zengfu Wang   +4 more
core   +1 more source

Transient Interference Suppression Algorithm Based on Time Frequency Sparse Prior for Skywave OTHR

Leida xuebao
The target detection performance of skywave Over-the-Horizon Radar (OTHR) often struggles with transient interference. To address this issue, we have developed a transient interference suppression algorithm that uses Time Frequency Sparsity Prior (TFSP).
Zirui CHEN, Yifei JI, Xiwang LIU, Yongsheng ZHANG, Zhen DONG, Alei CHEN, Weijian LIU   +6 more
doaj   +1 more source

CONSIDERATIONS REGARDING DIFFERENT APPROACHES TO MEASURING LABOR PRODUCTIVITY [PDF]

Journal of Defense Resources Management, 2011
Assessing the productivity of factors of production has been a key issue for economists for many decades, as the development and well-being of a govenrment sector, industry or company have been very early on linked to the way in which inputs are used in ...
Maria CONSTANTINESCU
doaj  

Amyloid PET predicts longitudinal functional and cognitive trajectories in a heterogeneous cohort

Alzheimer's &Dementia, Volume 21, Issue 3, March 2025.
Abstract INTRODUCTION Amyloid positron emission tomography (PET) is increasingly available for diagnosis of Alzheimer`s disease (AD); however, its practical implications in heterogenous cohorts are debated. METHODS Amyloid PET from 890 National Alzheimer`s Coordinating Center participants with up to 10 years post‐PET follow up was analyzed.
Kyan Younes, Emily Johns, Christina B. Young, Gabriel Kennedy, Shubhabrata Mukherjee, Hillary A. Vossler, Joseph Winer, Karly Cody, Victor W. Henderson, Kathleen L. Poston, Tobey J. Betthauser, Bill Bevis, William M. Brooks, Jeffrey M. Burns, Stephen A. Coombes, Charles DeCarli, Frank P. DiFilippo, Ranjan Duara, Audrey P. Fan, Laura E. Gibbons, Todd Golde, Sterling C. Johnson, Rebecca J. Lepping, James Leverenz, Sean McDougall, Emily Rogalski, Elizabeth Sanders, Joshua Pasaye, Jaiashre Sridhar, Andrew J. Saykin, Anjali Sridharan, Russell Swerdlow, Emily H. Trittschuh, David Vaillancourt, Eric Vidoni, Wei‐en Wang, Jesse Mez, Timothy J. Hohman, Duygu Tosun, Sarah Biber, Walter A. Kukull, Paul K. Crane, Elizabeth C. Mormino   +42 more
wiley   +1 more source

An Analysis of the Potential for Using Over-the-Horizon Radar Systems for Space Surveillance [PDF]

, 2004
The Australian Defence Force is investigating the development of a space surveillance system. While several dedicated facilities for space surveillance are in operation around the world, Australia s Over-The-Horizon Radar (OTHR) network has some ...
Colbert, Matthew J.
core   +1 more source

Comparative population genomics of manta rays has global implications for management

Molecular Ecology, Volume 34, Issue 4, February 2025.
Abstract Understanding population connectivity and genetic diversity is of fundamental importance to conservation. However, in globally threatened marine megafauna, challenges remain due to their elusive nature and wide‐ranging distributions. As overexploitation continues to threaten biodiversity across the globe, such knowledge gaps compromise both ...
Emily Humble, Jane Hosegood, Gary Carvalho, Mark de Bruyn, Simon Creer, Guy M. W. Stevens, Amelia Armstrong, Ramon Bonfil, Mark Deakos, Daniel Fernando, Niv Froman, Lauren R. Peel, Stephen Pollett, Alessandro Ponzo, Joshua D. Stewart, Sabine Wintner, Rob Ogden   +16 more
wiley   +1 more source

Data Augmentation and Classification of Sea-Land Clutter for Over-the-Horizon Radar Using AC-VAEGAN [PDF]

, 2023
In the sea-land clutter classification of sky-wave over-the-horizon-radar (OTHR), the imbalanced and scarce data leads to a poor performance of the deep learning-based classification model. To solve this problem, this paper proposes an improved auxiliary
Zhang, Xiaoxuan, Pan, Quan, Wang, Zengfu, Lu, Kun   +3 more
core   +1 more source

EclipseNB: A Network of Low‐Cost GNSS Receivers to Study the Ionosphere

Space Weather, Volume 23, Issue 1, January 2025.
Abstract This work aims to demonstrate that dense networks of low‐cost dual‐frequency global navigation satellite systems (GNSS) receivers can be used to retrieve ionospheric electron content with almost the same level of accuracy as scientific‐grade GNSS receivers.
A. Kashcheyev, B. Nava, C. Watson, P. T. Jayachandran, R. B. Langley   +4 more
wiley   +1 more source

Transient interference excision and spectrum reconstruction for OTHR

Electronics Letters, 2012
High-frequency sky wave over-the-horizon radar (OTHR) suffers performance degradation from transient interference. The segmental subspace projection approach is applied to suppress the clutter and locate the transient interference. After interference excision by adaptive thresholding, the integrated Doppler spectrum is reconstructed based on compressed
Y.H. Quan, M.D. Xing, L. Zhang, Z. Bao
openaire   +1 more source

A Coordinate Registration Method for Over-the-Horizon Radar Based on Graph Matching

Remote Sensing
Coordinate registration (CR) is the key technology for improving the target positioning accuracy of sky-wave over-the-horizon radar (OTHR). The CR parameters are derived by matching the sea–land clutter classification (SLCC) results with prior geographic
Can Li, Zengfu Wang, Quan Pan, Zhiyuan Shi   +3 more
doaj   +1 more source