Results 41 to 50 of about 280 (161)
Surface Clutter Suppression Techniques for Ice Sounding Radars: Analysis of Airborne Data [PDF]
For the ice sounding of Antarctica from space, a P-band radar at 435 MHz is the only option which complies with present ITU regulations. At this frequency the ice surface cannot be considered smooth, leading to high ambiguous returns.
Hélière, Florence +2 more
core
Research on Polarization Cancellation of Nonstationary Ionosphere Clutter in HF Radar System [PDF]
Oblique projection polarization filter (OPPF) can be applied as an effective approach for interference cancellation in high-frequency surface wave radar (HFSWR) and other systems. In order to suppress the nonstationary ionosphere clutter further, a novel OPPF based clutter suppressing scheme is proposed in this paper. The polarization and nonstationary
Xingpeng Mao +3 more
openaire +2 more sources
Enhancing Low‐Latitude Ionospheric Irregularity Prediction With Generalized Linear Models
Abstract The ionosphere poses challenges for accurate forecasting due to its complexity and variability. Irregularities in the lower ionosphere are influenced by local time, season, geographic location, solar activity and space weather, complicating precise predictions.
Alysson Brhian +4 more
wiley +1 more source
Deep Learning Aided Time–Frequency Analysis Filter Framework for Suppressing Ionosphere Clutter
In a heterogeneous environment, the ionosphere is dynamically changing in the Earth’s middle latitude, and backscatter from fast-moving irregularities in the plasma can cause ionosphere clutter to extend. Suppressing varying ionosphere clutter and exploring obscured targets are challenging tasks for high frequency surface wave radar (HFSWR).
Xiaowei Ji +5 more
openaire +2 more sources
Abstract The radar surface echo can be separated into coherent and incoherent components by statistical approaches, and the coherent component can be described by a backscattering model related to the RMS height. According to backscattering models for fractal surfaces, the coherent power in decibels decreases with RMS height on a scale independent of ...
Tiansheng Hong +9 more
wiley +1 more source
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.
Stuart Anderson
doaj +1 more source
Low Frequency Oscillation Observed in the Ionosphere Around the Substorm Onsets
Abstract Three substorm events in which Defense Meteorological Satellite Program (DMSP) spacecraft are geomagnetically co‐located with substorm onset locations in IMAGE far ultraviolet auroral images are analyzed. A Hilbert‐Huang Transform is used to decompose the DMSP B⊥ ${B}_{\perp }$ in the ionosphere to its intrinsic mode functions. A dominant mode
Simon Wing +4 more
wiley +1 more source
Ionospheric clutter models for high frequency surface wave radar [PDF]
High frequency surface wave radar (HFSWR), operating at frequencies between 3 and 30 MHz, has long been employed as an important ocean remote sensing device.
Chen, Shuyan
core
Abstract Incoherent scatter radar probing of the topside F‐region ionosphere with reduced electron densities residing at relatively large radar ranges requires the use of uncoded long pulse (ULP) transmissions. In these ULP measurements the range resolution is necessarily poor, rendering the inference of ionospheric state parameters such as composition,
Binghui Wang +3 more
wiley +1 more source
Abstract The Martian lava plains are characterized by their extensive, low‐relief surfaces, which are the result of numerous basaltic eruptions and feature a variety of volcanic landforms, including vents, cones, pits, and skylights. The combination of these features and impact craters yields a significant understanding of the planet's geological past ...
G. Nodjoumi +4 more
wiley +1 more source

