Multi-static synthetic aperture radar image formation

IEEE Trans. Geosci. Remote Sensing

2013

Abstract-We present a novel method for ground moving target imaging using a synthetic aperture radar system transmitting ultranarrowband continuous waveforms (CW). Our method exploits the high Doppler resolution provided by ultranarrowband CW signals to image both the scene reflectivity and to determine the velocity of multiple moving targets. We develop a new forward model based on the temporal Doppler induced by the movement of antennas and moving targets. The forward model relates reflectivity and velocity information at each location to a correlated received signal. We form the reflectivity images of the moving targets and estimate their motion parameters using a filtered-backprojection (FBP) technique combined with the contrast or gradient optimization method. The method results in focused reflectivity images of moving targets and their velocity estimates, regardless of the target location, speed, and velocity direction. We show that the amplitude and visible edges of the targets can be correctly reconstructed when the correct target velocity estimate is used in the FBP imaging. We present the resolution analysis of the reflectivity images. Extensive numerical simulations demonstrate the performance of our method and validate the theoretical results.

Section: Discussionmentioning

confidence: 99%

Ground Moving Target Imaging Using Ultranarrowband Continuous Wave Synthetic Aperture Radar

IEEE Trans. Geosci. Remote Sensing

2013

“…Since the derivation of the filters, B 1 , B 3 and B 4 are similar to that of B 2 , we present the derivation of B 2 following the methods of [5], [13].…”

Section: Image Reconstructionmentioning

confidence: 99%

“…As a consequence, we use the methods developed in [5], [13] to develop FBP type image reconstruction operators. We design FBP type image reconstruction operator for each transmitter-receiver pair that suppresses artifacts in the reconstructed image due to FBP of the data received from different scattering paths.…”

Section: Image Reconstructionmentioning

confidence: 99%

“…Similar to our previous work [5], [13], we use microlocal analysis in a statistical setting to design our image reconstruction method. Microlocal techniques lead to inversion methods that have the desirable property that visible edges in the scene will appear in the reconstructed image at the correct location and orientation [4], [10], [11].…”

Section: Introductionmentioning

confidence: 99%

“…We employ the techniques introduced in [5], [13] to reconstruct the image of the target while suppressing the artifacts caused by data interference from different scattering paths. As in [5], our method involves backprojecting the received data with respect to each transmitter-receiver pair. We assume that we have a priori knowledge of the second-order statistics of the target to be reconstructed.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

SAR imaging exploiting multi-path

Krishnan

Yarman

2010 IEEE Radar Conference

2010

Self Cite

Abstract-We present a new filtered-backprojection (FBP) type image reconstruction method for synthetic aperture radar (SAR) that exploits multi-path in the presence of a perfectly reflecting wall. The new method is designed to take advantage of multiple scattering and incorporates the multiple scattered waves in the image reconstruction process enhancing the reconstructed image. We present numerical simulation to demonstrate the performance of the new method. While the focus of this paper is on radar applications, our image formation method is also applicable to other problems arising in fields such as acoustic, geophysical and medical imaging.

Synthetic aperture radar imaging exploiting multiple scattering

Krishnan

2011

Inverse Problems

In this paper, we consider an imaging scenario, where a bi-static synthetic aperture radar (SAR) system is used in a multiple scattering environment. We consider a ray-theoretic approximation to the Green's function to model a multiple scattering environment. This allows us to incorporate the multiple paths followed by the transmitted signal, thereby providing different views of the object to be imaged. However, the received signal from the multiple paths and additive thermal noise may interfere and produce artifacts when standard backprojection-based reconstruction algorithms are used. We use microlocal analysis in a statistical setting to develop a novel filtered-backprojection type image reconstruction method that not only exploits the multi-paths leading to enhancement of the reconstructed image but also suppresses the artifacts due to interference. We assume a priori knowledge of the secondorder statistics of the target and noise to suppress the artifacts due to interference in a mean-square error sense. We present numerical simulations to demonstrate the performance of our image reconstruction method. While the focus of this paper is on radar applications, our image formation method is also applicable to other problems arising in fields such as acoustic, geophysical and medical imaging.