The inversion of ocean currents is a significant challenge and area interest in remote sensing. Spaceborne along-track interferometric synthetic aperture radar (ATI-SAR) has several advantages benefits, including precise observations, extensive swath coverage, high resolution. However, limited number spaceborne (InSAR) systems are operating orbit. Among these, the baseline length generally suboptimal, resulting low accuracy difficulty achieving operational stability. One approaches involves...

To achieve precise detection of target geometric features, Ka/W/sub-terahertz band imaging radar systems with ultra-wide instantaneous bandwidth have been developed. Although dechirp-based receiver architectures allow for low-sampling-rate signal acquisition, they require linearity in chirp signals, often necessitating precompensation nonlinear errors. While most research addresses polynomial-based error correction, periodic errors remain underexplored, despite their potential to obscure...

Repositioning error (RE) compensation is one of the key steps in discontinuous ground-based synthetic aperture radar (D-GBSAR) monitoring. The traditional RE to perform 2-D phase unwrapping, and then remove based on least squares method, thereby introducing an extra unwrapping error. Specifically, due wrapped discrete permanent scatterers (PS), method intractable be performed directly. Hence, core idea this paper propose a new likelihood function model, straightforwardly estimate baseline...

A new powerful constant false-alarm rate (CFAR) method is proposed for detecting moving ships in along-track interferometric synthetic aperture radar (ATI-SAR) images, based on the sea interferogram's magnitude and phase (SIMP) metric, presented Part I of this paper. First, within structure product model, a statistical model (hereafter simply termed Nq) square root SIMP metrics clutter was developed by assuming cross-sectional (RCS) components return follow commonly used gamma distribution....

Synthetic aperture radar (SAR), in along-track interferometry mode, is extensively used sensing oceanic surface. Detecting moving ships becoming an increasingly important requirement global monitoring of environment and maritime security. To realize this requirement, we first constructed a metric for detecting SAR images by combining sea interferogram's magnitude phase (SIMP). Second, the performance SIMP was evaluated through simulations investigation several key issues, such as azimuth...

The nonlinearity in the transmitted signal of Frequency-modulated continuous-wave (FMCW) radar has become a bottleneck to its utilization. This paper presents new method conduct correction for wideband FMCW radars. is first modeled as polynomial phase function, whose coefficients are then estimated with proposed regression algorithm (PRA). Combined Match Fourier Transform, finally corrected. Simulation results show feasibility algorithm. Echo processing result an X-band indicates that can be...

This paper introduces a method for quantifying the three-dimensional deformation of ground targets and outlines associated process. Initially, ground-based synthetic aperture radar was employed to monitor radial targets, optical equipment monitored pixel-level in vertical plane line sight. Subsequently, regression model established transform into two-dimensional based on fundamental length unit, monitoring data were merged with data. Finally, fused underwent deformation, resulting...

In this article, we propose a dual-frequency synthetic aperture radar tomography (TomoSAR) method with fewer flights for efficient urban building reconstruction. By utilizing signals, our overcomes the limitations of traditional single-frequency TomoSAR in terms data acquisition time and temporal decoherence. The proposed can achieve imaging results comparable to methods only half number required. We present an model derive theoretical accuracy model. A analysis shows that are approximately...

In order to compensate for the repositioning error introduced by radar position offset in discontinuous GBSAR monitoring, a new mathematical framework modeling baseline based on Taylor expansion is developed this letter. And then, novel three-dimensional model called Multiparameter Nonlinear Trigonometric Model (MNTM) proposed accurately error. Furthermore, improve compensating efficiency, we further develop an efficient two-dimensional Linear (LTM). Both simulation and field experiments...

As a new deformation monitoring method, Discontinuous Ground-Based Synthetic Aperture Radar (D-GBSAR) has gradually attracted people's attention, and the key problem it faces is how to compensate for repositioning error caused by radar position offset. To address above issue, this paper studies geometric relationship between spatial baseline target, proposes novel compensation method based on trigonometric model least squares parameter estimation. The feasibility of proposed verified...

Atmospheric phase is the main factor affecting accuracy of ground-based synthetic aperture radar. The atmospheric screen (APS) may be very complicated, due to drastic changes in conditions, and conventional correction methods based on regression models cannot fit correct it effectively. Partition a feasible path improve (APC) for complicated APS, but overfitting problem ignored. In this article, we propose clustering partition method, normal vector which can APS more reasonably, then perform...

Ground-based synthetic aperture radar (GB-SAR) has been developed rapidly in ground deformation measurement technology and its accuracy improved gradually. However, atmospheric effects greatly affect the of measurement. That how to effectively reduce impact atmosphere on results become an important research direction. This paper firstly introduces that affects GB-SAR Then, some common correction methods, based physical characteristic internal characteristics images, are summarized. Further,...

Folded lenses offer advantages in terms of lightness and thinness, but they have limitations when it comes to correcting aberrations. In this paper, we propose a novel approach address issue by incorporating metasurfaces the design folded optical systems. Specifically, refractive-metasurface hybrid annular aperture lens (AFL) is introduced. The structural characteristics AFL imaging system are analyzed investigate blocking ratio, thickness, light collection capability ring system....

Quasi-continuous wave radar is an attempt to give consideration the performance of pulse and continuous signals. However, it also has shortcomings both. This paper aims add a new quasi-continuous-wave coding method spaceborne synthetic aperture (SAR) system. The technology improving SAR imaging by pulses studied, some this algorithm are improved. Firstly, application in system reconstruction scheme provided so that can be successfully applied SAR. Secondly, effects different methods on...

The traditional jammer uses an architecture of superheterodyne receiver and a method direct sampling intermediate frequency (IF) signal, which is costly difficult for implementation. A new based on dechirp reception that can significantly reduce the rate, further cost signal processing complexity proposed in this paper. In response to problem mirror interference inverse transmission, novel solution using local oscillator (LO) with fixed offset introduced, experimental system constructed...

MIMO ground-based synthetic aperture radar (GB-SAR) have experienced rapid development in recent years because they can rapidly acquire echo data from observed scenes neglecting mechanical motion and thus monitor the entire geological deformation process ranging slow changes to instabilities. However, unique alternating transceiver configuration of GB-SAR systems presents varying periodic characteristics channel amplitude phase errors, leading severe paired false targets imaging results....