Sea surface wind streak is one of many geophysical phenomena in synthetic aperture radar (SAR) images, which often used to obtain sea direction. At present, the recognition streaks mainly depends on artificial experience, and efficiency accuracy are not high. In this study, transfer learning based convolutional neural network architecture Inception v3 was introduced streaks. Four categories imaged by gaofen-3 (GF-3) SAR from 2019 2020 were chosen for retraining full pre-retrained model....

The detection performances of MIMO radar can be improved by waveform diversity technology. gain depends on the correlation side-lobe level orthogonal set. Generally, peak (PSL) and integrated (ISL) are two most important performance metrics level. Few existing set design algorithms minimize PSL ISL simultaneously. To tackle this problem, article first proposes a metric in form <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -norm,...

Nonlinear radar has a unique advantage in finding nonlinear targets, like RF electronics and harmonic tags, under clutter circumstances, among which intermodulation-based schemes are usually favored for their resistance to self-harmonics interference. Currently, intermodulations produced by multiple large signals dominantly used target characterization detection. However, this work proposes exploit the intermodulation generated small signals, referred as localized conjugate component (LCC)....

A pair of sequences lengthLis called a Z-complementary (ZCP) with zero correlation zone (ZCZ)Zif the have aperiodic autocorrelation sums at eachof non-zero time-shifts smaller thanZ. Such is denoted byan(L,Z)-ZCP for short. In this letter, we propose construction ofZCPs via properly cascading from Golay complemen-tary (GCP). The proposed leads to(3N,2N)-ZCPs,(5N,3N)-ZCPs,(7N,4N)-ZCPs,(9N,5N)-ZCPs,(11N,6N)-ZCPs,(12N,10N)-ZCPs,(13N,7N)-ZCPsand(14N,12N)- ZCPs, whereNis length chosen GCP....

Abstract A knowledge of melting layer (ML) is crucial for the accurate estimation rainfall and study microphysical characterization cloud. Based on 5 years (2016–2020) measurements cyclones over Western North Pacific from dual‐frequency precipitation radar board Global Precipitation Measurement satellite, characteristics processes ML are investigated. Our research shows that height top boundary higher than freezing level (0 degrees centigrade level, FL), Z e larger ML. The result combined...

C-band synthetic aperture radar (SAR) with all-weather observation capability is gradually being used for the high-resolution of hurricane. The extreme wind speed in hurricanes retrieved by combining co- and cross-polarized SAR signals. However, heavy precipitation associated will seriously affect retrieval sea surface speed. In this study, effects precipitation-related parameters phenomena on under strong hurricane conditions were examined using data from co-located global measurement...

Nonlinear radar has attracted considerable attention in recent years due to its unique advantage detecting nonlinear targets, such as radio frequency (RF) electronics, under strong clutter conditions. However, the low RF-to-RF conversion efficiency (RRCE) severely limits operational range and application scenarios. So far, research community mainly focused on improving RRCE from hardware aspects while ignoring signal design. In this article, we study waveform design problem that maximizes...

The auto-correlation is not sufficient for the complete statistical characterization of a complex sequence, especially in applications involving nonlinear systems. Therefore, this letter addresses sequence design problem considering local shaping second-order correlation, which controls sidelobe level both and conjugate correlation over specific lags. An efficient algorithm based on Majorization-Minimization technique proposed, only consists close-form iterations with full fast Fourier...

In view of the lack fine ground detection data freezing rain clouds, using high sensitivity Ka band cloud radar for small-scale precipitation particle detection, combined with meteorological automatic observation equipment, a joint quantitative experiment was carried out on vertical structure in whole process Changsha, Hunan Province from 00:00 February 5 to 24:00 7,2024 (for simplicity, it is called "2.5" process). On basis quality control basic data, spatiotemporal four physical parameters...

Due to the sparsity of inverse synthetic aperture radar (ISAR) images, compressive sensing (CS) has been introduced ISAR imaging for resolution improvement. However, conventional CS algorithms assume that target scatterers are on predefined range-Doppler grid, which will cause performance degradation in practical applications as generally off-grid. In this paper, we investigate technique targets with off-grid scatterers. Based adaptive grids, a two dimensional sparse algorithm is presented....

Abstract This letter formulates a high‐dimensional multi‐objective optimization model to minimize all correlation function values for multiple input output (MIMO) radar waveforms. Then, solve this problem, proposes an adaptive weighted cyclic algorithm‐new (CAN), named p ‐norm ( ‐WeCAN). Specifically, the weight updating is constructed using peak side‐lobe level (PSL) and integrated (ISL) simultaneously. Numerical results show that obtains similar PSL as best minimization algorithm low close...

Abstract To improve the accuracy of sea surface wind speed under rain based on data obtained from U.S. spaceborne fully polarimetric microwave radiometer (WindSat), a correction model statistical algorithm is constructed. First, coupled samples 2003 to 2014 are considered as training sample set, and 2015 2020 used test set. Then, WindSat Results show that overestimated severely. The higher speed, larger overestimated. experimental results reveal standard deviation 2.6 m/s. However, decreases...