Results 31 to 40 of about 3,029 (137)
Ambiguity and area preserving linear transformations in over‐the‐horizon radar
IET Radar, Sonar &Navigation, Volume 19, Issue 1, January/December 2025.The use of recurrent waveforms in over‐the‐horizon radar (OTHR) necessitates techniques for ambiguity resolution and manipulation. In this paper, the authors elucidate methods for systematically transforming any given waveform so that its ambiguity function is transformed by any desired area preserving the linear transformation of the delay‐Doppler ...
Stephen D. Howard, Van Khanh Nguyen
wiley +1 more source
Array self‐calibration for sky‐wave over‐the‐horizon radar with gain‐phase errors
The Journal of Engineering, Volume 2019, Issue 19, Page 6192-6195, October 2019., 2019 This study proposes a novel algorithm for sky‐wave over‐the‐horizon (OTH) radar array self‐calibration with angle‐independent gain‐phase errors. The proposed method exploits backscattered echo from an ionised meteor trail, which can be considered as disjoint sources of opportunity for their spatial and temporal fluctuations during coherent processing ...
Baiqiang Zhang, Junhao Xie
wiley +1 more source
The Journal of Engineering, Volume 2019, Issue 20, Page 6772-6776, October 2019., 2019 Radars operating in the high‐frequency (HF) band can exploit propagation modes other than line‐of‐sight and are hence widely employed to provide over‐the‐horizon surveillance and remote sensing. Most HF radars operating today rely on surface wave propagation; while opportunities for enhancing their performance by adding cognitive features exist, these ...
Stuart Anderson
wiley +1 more source
Do oil and gas platforms off California reduce recruitment of bocaccio (Sebastes paucispinis) to natural habitat? An analysis based on trajectories derived from high-frequency radar [PDF]
, 2006 To investigate the possibility that oil and gas platforms may reduce recruitment of rockfishes (Sebastes spp.) to natural habitat, we simulated drift pathways termed “trajectories” in our model) from an existing oil platform to nearshore habitat using ...
Emery, Brian M. +4 more
core
On the Use of SuperDARN Ground Backscatter Measurements for Ionospheric Propagation Model Validation
Space Weather, Volume 22, Issue 9, September 2024.Abstract Prior to use in operational systems, it is essential to validate ionospheric models in a manner relevant to their intended application to ensure satisfactory performance. For Over‐the‐Horizon radars (OTHR) operating in the high‐frequency (HF) band (3–30 MHz), the problem of model validation is severe when used in Coordinate Registration (CR ...
Joshua J. Ruck +6 more
wiley +1 more source
Geophysical Research Letters, Volume 51, Issue 16, 28 August 2024.Abstract Monitoring the generation and movement of equatorial plasma bubbles (EPBs) in a large longitude region is crucial important for better understanding their day‐to‐day variability. Using the newly developed Low lAtitude long Range Ionospheric raDar (LARID) at Dongfang (19.2°N, 108.8°E, dip lat.
Lianhuan Hu +11 more
wiley +1 more source
Detection and Classification of Sporadic E Using Convolutional Neural Networks
Space Weather, Volume 22, Issue 1, January 2024.Abstract In this work, convolutional neural networks (CNN) are developed to detect and characterize sporadic E (Es), demonstrating an improvement over current methods. This includes a binary classification model to determine if Es is present, followed by a regression model to estimate the Es ordinary mode critical frequency (foEs), a proxy for the ...
J. A. Ellis, D. J. Emmons, M. B. Cohen
wiley +1 more source
Adaptive Transient And Cw Rf Interference Mitigation In Hf Oth Radar: Experimental Results
, 2008 We introduce an adaptive technique for the joint mitigation of transients and continuous-wave radio-frequency co-channel interference (CW RFI) in high-frequency (HF) over-the-horizon radars (OTHRs). The performance of this technique is illustrated using data from an operational surface-wave radar (SECAR) and from recent experimental trials with sky ...
Turcaj, P., Abramovich, Y., Frazer, G.
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Sky and ground - wave high frequency (HF) radars: challenges in modelling, simulation and application preface [PDF]
, 2010 Radar systems operating at high frequency (HF) are able to exploit a variety of propagation mechanisms to achieve line-of-sight (LOS) illumination as well as over-the-horizon coverage, thereby providing many opportunities for long range, wide area multi ...
Sevgi, Levent
core
Transmit And Receive Antenna Array Geometries For Mode Selective Hf Oth Mimo Radar
, 2010 Publication in the conference proceedings of EUSIPCO, Aalborg, Denmark ...
Abramovich, Y.I. +2 more
openaire +1 more source