This paper delves into the problem of moving-target detection in partially homogeneous environments (PHE) with unknown Gaussian disturbance using a frequency diverse array multiple-input multiple-output (FDA-MIMO) radar. Using training data, we have derived expressions for four adaptive detectors, including one-step and two-step generalized likelihood ratio test (GLRT), Rao (TRao) test, Wald (TWald) criteria, respectively. All proposed detectors are characterized by constant false-alarm rate...

In multichannel high-resolution and wide-swath (HRWS) synthetic aperture radar (SAR) systems, Doppler centroid (DC) is essential for SAR focusing. However, conventional phase-dependent DC estimators single-channel systems face many problems in HRWS because of the azimuth undersampling each channel mismatches phase. To estimate baseband DC, spatial cross-correlation coefficients (SCCCs) signals are exploited, a novel estimator named SCCC method proposed this letter. Validation demonstrated...

Ground surface deformation must be monitored to understand and prevent geological hazards. Global navigation satellite system (GNSS) technology has been widely used in monitoring; however, current GNSS station layout strategies are often subjective lack theoretical guidance. Therefore, this study, a observation network optimization method was developed based on interferometric synthetic aperture radar (InSAR) prior assistance. This considers the distribution, cost, accuracy, topography,...

For long baseline in a network, the traditional combined ionosphere-free (IF) + wide-lane (WL) strategy is commonly used, but residual tropospheric delays and larger noise hamper basic ambiguity resolution (AR). With completion of BeiDou global navigation satellite system (BDS-3) quad-frequency signals provided by BDS-3 satellites, we can construct more combinations that are conducive to resolution. Compared with linear combinations, estimated ionospheric delay using three independent WL...

This paper presents a water body detection framework with an automatic threshold determination procedure. Water bodies in SAR image often appear dark and homogeneous due to specular reflection. Therefore, the can easily be detected thresholding method. However, needs adjusted interactively for every data backscatter differences between data. The recursive Otsu method is used determine automatically. normalized between-class variance introduced select optimal from set generated by...

Microscopic and ultra-microscopic vascular sutures are indispensable in the surgical procedures such as arm transplantation finger reattachment. The state of blood vessels after suturing, patency, narrow, blocked, determines success rate operation. If we can grasp golden window period vessel suture before muscle tissue to achieve accurate objective assessment status, it not only reduce medical costs but also improve social benefits. Doppler optical coherence tomography enables high-speed,...

Random stepped-frequency chirp waveform (RSFCW) is capable of achieving high-resolution synthetic aperture radar (SAR) imagery as well certain electronic countermeasure capabilities. The Doppler-dependent phase incoherence due to the platform motion leads degradation frequency synthesis RSFCW. In this letter, a coherence processing algorithm for RSFCWSAR developed with full cell Doppler correction (FCDC). structure RSFCW exploited decompose signal into different cells, which paves way FCDC...

Theoretical or numerical progressive collapse analysis is necessary for important civil structures in case of unforeseen accidents. However, currently, most analytical research carried out under the assumption material elasticity problem simplification, leading to deviation results from actual situations. On this account, a procedure truss proposed, based on elastoplastic materials. A plastic importance coefficient was defined express members entire system. The deformations were involved...

For change detection in remote sensing images, supervised learning always relies on bi-temporal images as inputs and 2-class/multi-class classifiers outputs. On the other hand, can be viewed a metric problem, i.e., changed areas should dissimilar while unchanged similar. In this paper, we study several formulations for detection. A strong baseline is achieved by training pair-wise with Reverted Contrastive Loss (RCL) hard mining. Motivated success of triplet loss, seek two sources pairs from...

Abstract In this paper, the effects of transverse boundary conditions, specifically bias voltage on wall and gap width, electron beam-generated plasmas (EBPs) confined in a narrow gap, are investigated using particle-in-cell/Monte Carlo collision (PIC/MCC) simulations. Simulation results reveal that application causes beam deflections, leading to formation band structures velocity space. Three branches electrostatic waves, including mode, Langmuir wave, acoustic identified. Increasing...

Microscopic and ultramicroscopic vascular sutures are indispensable in surgical procedures such as arm transplantation finger reattachment. The state of the blood vessels after suturing, which may feature patency, narrowness, blockage, determines success rate operation. If we can take advantage golden window opportunity vessel suture before muscle tissue to achieve an accurate objective assessment status, this will not only reduce medical costs but also offer social benefits. Doppler optical...

This paper proposes a method against bi-static synthetic aperture radar (SAR) jamming based on frequency diversity array (FDA). Firstly, we present the geometry model of signal FDA-bistatic SAR. Then, introduce two-dimensional non-uniform fast Fourier transform (2D-NUFFT) for SAR imaging. Via simulation results, find that FDA has deceptive effect

High-squint multichannel synthetic aperture radar (SAR) in azimuth can overcome the constraint of minimum antenna area traditional single-channel classical SAR system, and thereby it would be much more flexible to achieve high-resolution wide-swath (HRWS) imaging than broadside SAR. However, for high-squint mode, squint angle causes Doppler centroid varying with range frequency, which further result complicated problem spectral folding after down-sampled low PRF. Meanwhile, frequency is...

Dual-functional radar-communication (DFRC) attracts extensive attention recently, given its potential to integrate the sensing and communication processes for enhancing spectrum efficiency hardware utilization. Due co-channel interference, effective resource allocation is a critical issue DFRC, which typically relies on accurate channel estimation. However, conventional estimate-then-optimize algorithms may not work well due inaccurate estimation, high computation complexity, inconsistent...

For high resolution sliding spotlight SAR (HRSS-SAR) on agile platform, its beam steering can be achieved by satellite attitude maneuver. In designing the attitude, variation of Doppler centroid and azimuth should considered, along with illuminated scene width shape. We proposed a feasible maneuver strategy for HRSS-SAR. The developed conventional geometry moderate resolution. This paper conceive that rotation center HRSS-SAR moves time, range direction minimized. strategy, is realized...

An improved imaging algorithm is proposed for processing high resolution spaceborne squinted sliding spotlight SAR data in this paper, which includes four steps, namely, azimuth preprocessing, coarse focusing, fine focusing and geometry correction. In the a linear range walk correction (LRWC) filter used to mitigate two-dimensional (2-D) spectral skew, modified subaperture method performed increase size of data, obtain 2-D without aliasing. Then ω-k kernel realize focusing. However,...

The X-band coherence statistical characteristics related to the height of ambiguity, polarisation and resolution in two typical forested areas are investigated, using multi-baseline polarimetric synthetic aperture radar interferometry (PolInSAR) data acquired by an automobile-based interferometric (InSAR) system. influences on carefully analysed. results show that volume decorrelation is independent decreases with reduction resolution. In addition, empirical model relation resolution, forest...