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This paper introduces the concept of a fractionated MirrorSAR which is based on a set of mutually separated transmitter and receiver satellites. As opposed to previously published bi- and multistatic SAR systems, the receiver satellites are considerably simplified, as their main functionality is reduced to a kind of microwave mirror (or space transponder) which routes the radar echoes towards the...
The paper reports on an extensive set of outdoor measurements aimed at characterizing the polarimetric radar backscatter response of vehicles at 222 GHz. This effort supports the future application of high frequency radars operating around 230 GHz in autonomous vehicle navigation and collision avoidance. It is observed that radar backscatter is primarily from the outer surfaces of the vehicle and...
The Calaveras fault passes directly through Coyote Dam located near Gilroy, California. The earthen structure of the dam was constructed to withstand the expected deformation due to fault creep at a rate of 10 to 15 mm/year. As part of a possible dam retrofit, the Santa Clara Valley Water District initiated a series of measurements using a Ku-Band terrestrial interferometer to accurately localize...
The basal topography of most of the glaciers that drain the ice caps of the Canadian Arctic Archipelago is largely unknown. To measure the basal topography, NASA Operation IceBridge flew a radar depth sounder in a wide swath mode with three transmit beams to image the glacier beds during three flights over the archipelago in 2014. We describe the measurement setup of the radar system, the algorithms...
A new ground moving target indication algorithm for single channel Circular Synthetic Aperture Radar (CSAR) is presented and evaluated by airborne CSAR dataset. The algorithm is based on overlap subaperture magnitude images. The subaperture image can be regarded as the background image (clutter) plus the foreground image (moving target). The background image is obtained by median filter. Then the...
In this paper a forward looking (end fire) synthetic aperture radar (SAR) system is described for the Very deep Autonomous Laser-powered Kilowatt-class Yo-yoing Robotic Ice explorer (VALKYRIE) project. Design and analysis of novel conformal log periodic antennas for the radar and the forward looking SAR ambuguity function is presented. Fabrication and laboratory characterization of the antennas system...
This paper presents a method for estimating the three dimensional (3D) position of Persistent Scatterers (PSs) for Persistent Scatterer Interferometric SAR (PS-InSAR) and a PS-InSAR analysis system. PSs are useful to monitor deformation of manmade structures with accuracy of millimeter range. However, SAR images include geometric distortions such as layovers or foreshortenings. These distortions cause...
Airborne synthetic aperture radar (SAR) image quality considerably degrades because of motion errors. High-precision motion compensation (MOCO) is necessary in an advanced SAR data processing scheme. Operation complexity and computation burden are both increased as development of ultra-high resolution SAR. There are two main disadvantages for conventional MOCO. Firstly, accurate envelope correction...
Angular super-resolution imaging plays a significant role in the area of the scanning radar imaging. Some deconvolution methods are used to realize the angular super-resolution on scanning radar. However, the ill-posed nature of the deconvolution problem means difficulties and inaccuracies in the search for the solution. In this paper, we present a novel method for angular super-resolution imaging...
Monitoring the soil moisture level of crop fields is one of the most important things to do for having an optimal crop yield. In this paper we investigate the capabilities of Sentinel-1 to soil moisture states. Aspects of modeling the map of soil moisture by the radar scene from Sentinel-1 on the example of a territory having undergone intensive precipitation have been considered. Representations...
Three dimensional (3-D) synthetic aperture radar (SAR) image formation provides the scene reflectivity estimation along azimuth, range and elevation co-ordinates. For 3-D image focusing multiple signals, acquired along different orbits, are required. In order to obtain the tomographic resolution, this paper apply a novel strategy into geosynchronous synthetic aperture radar (GEO SAR), which allow...
Performance of ship detection is influenced by synthetic aperture radar (SAR) imaging characteristics and environmental conditions. In this paper, aiming at evaluating vessel detectability for Sentinel-1 SAR data, a model based on a large-scale Sentinel-1A vessel chips database is established. The model sensitivity is analyzed by simulation data. In the experiment, by inputting the parameters of imaging...
Floods rank among the most devastating and deadly disasters likely to occur. Each year, thousands of people die as a result of rising river water levels and spring snow melts. Minimizing the impact of these events and providing necessary information to rescue teams on the ground requires the mobilization of all humanitarian stakeholders. This work aims to automate the extraction of flooded areas from...
With more degrees of freedom in the along-track axis, multichannel SAR systems are widely investigated for the purpose of ground moving target indication and motion parameter estimation. However, since conventional multichannel SAR system usually works at the side-looking mode and only the radial velocity is considered, it fails to detect targets only moving in azimuth. In this paper, the variable-boresight...
This paper presents novel results of active/passive microwave retrievals of ocean surface wind speed and path average rain rate for hurricane Patricia in the Pacific Ocean on October 22, 2015. These observations are the result of coordinated near-simultaneous flights between a high-altitude NASA aircraft operating the Hurricane Imaging Radiometer (HIRAD), and a NOAA “hurricane hunter” lower-altitude...
Target recognition based on forward-looking imaging has many potential applications. However, the conventional algorithms fail to locate targets accurately due to the low resolution of forward-looking radar images. Meanwhile, the conventional algorithms always suffer from high computational complexity and cannot satisfy the requirement of real-time processing for high-speed platform. This paper proposes...
Regularization technology can be utilized to improve the azimuth resolution for forward-looking scanning radar (FLSR). Among various regularization methods, L1 norm constrained method is usually adopted for its strong ability in resolving the sparse targets. Nevertheless, the solution of L1-norm constrained regularization method (L1-CRM) is sensitive to noise and the iterations would quickly diverge...
Recently, sparse radar imaging has drawn more and more attentions, which has the superiority of feature enhancement, super-resolution and so on. In this paper, we focus on sparse moving target imaging (MTIm) using a SAR sensor from sparse aperture (SA) data. For maneuvering targets, their strong motion tends to introduce migration through range cell (MTRC), which increases the difficulty of SA imaging...
Recent analyses have showed that moving target smears in synthetic aperture radar (SAR) imagery are not constrained to have the shapes of simple parabolas but instead can have a wide variety of two-dimensional (2D) shapes, including self-crossing signatures. The current study investigates the properties of the central smear contour under the conditions of varying the target speed difference for targets...
We developed a SFCW sparse array radar system for 3D imaging, which consists from 16 transmitters and 16 receivers and operates at the frequency range from 270MHz to 8GHz. The 2D antenna array layout was optimized using the middle point approximation. Several image reconstruction methods, which include the least square, Compressive Sampling Matching Pursuit and Regularized Orthogonal Matching Pursuit...
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