Bistatic Synthetic-Aperture Radar Imaging of Rotating Objects

2011 IEEE RadarCon (RADAR)

2011

Abstract-We consider synthetic aperture radar (SAR) imaging using ultranarrowband continuous waveforms (CWs). Because of the high Doppler resolution of CW signals, we refer to this imaging modality as Doppler synthetic aperture radar (DSAR). We present a novel model and an image formation method for the bistatic DSAR for arbitrary imaging geometries. Our bistatic DSAR model is formed by correlating the translated version of the received signal with a scaled or frequency-shifted version of the transmitted CW signal over a finite time window. High-frequency analysis of the resulting model shows that the correlated signal is the projections of the scene reflectivity onto the bistatic iso-Doppler curves. We next use microlocal techniques to develop a filtered-backprojection (FBP) type image reconstruction method. The FBP inversion results in the backprojection of the correlated signal onto the bistatic iso-Doppler curves as opposed to the bistatic iso-range curves used in the traditional wideband SAR imaging. We show that our method takes advantage of the velocity, as well as the acceleration of the antennas in certain directions, to form a high-resolution SAR image. Our bistatic DSAR imaging method is applicable for arbitrary flight trajectories and nonflat topography, and can accommodate system-related parameters. We present resolution analysis and extensive numerical experiments to demonstrate the performance of our imaging method.

“…2 The determinant of the Hessian matrix of K is (2π) 2 f 2 0 . Thus, the stationary points are nondegenerate.…”

Section: B Psf Of the Imaging Operatormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Bistatic Synthetic Aperture Radar imaging using ultranarrow-band continuous waveforms

2011 IEEE RadarCon (RADAR)

2011

“…Radar imaging with ultra-narrowband waveforms has received interest before [1][2][3][4][5][6][7][8][9]. In [1,2], the imaging of rotating objects using a single-frequency continuous wave (CW) illumination was investigated theoretically.…”

Section: Introductionmentioning

confidence: 99%

“…In [1,2], the imaging of rotating objects using a single-frequency continuous wave (CW) illumination was investigated theoretically. The same approach was recently studied experimentally in [3].…”

Section: Introductionmentioning

confidence: 99%

Doppler synthetic aperture radar imaging

2011

SPIE Proceedings

We consider synthetic aperture radar system using ultra-narrowband continuous waveforms, which we refer to as Doppler Synthetic Aperture Radar (DSAR). We present a novel image formation method for bi-static DSAR. Our method first correlates the received signal with a scaled or frequency-shifted version of the transmitted signal over a finite time window, and then uses microlocal analysis to reconstruct the scene by a filtered-backprojection of the correlated signals. Our approach can be used under non-ideal imaging scenarios such as arbitrary flight trajectories and non-flat topography. Furthermore, it is an analytic reconstruction technique which can be made computationally efficient. We present numerical experiments to demonstrate the performance of the proposed method.

“…The imaging of rotating objects using a single-frequency continuous wave (CW) illumination has been investigated before in [1], [2]. This work was recently studied experimentally in [3].…”

Section: Introductionmentioning

confidence: 99%

Ultranarrow-band synthetic aperture radar imaging for arbitrary flight trajectories

Wang

2011 17th International Conference on Digital Signal Processing (DSP)

2011

Abstract-We present a novel image formation method for synthetic aperture radar (SAR) using ultra-narrowband continuous waveforms. Considering the high Doppler resolution nature of the ultra-narrowband continuous wave (CW) signals, we refer to the SAR system using ultra-narrowband CW signals as Doppler Synthetic Aperture Radar (DSAR). We first correlate the translated version of the received signal with a scaled or frequency-shifted version of the transmitted signal over a finite time window, and then use microlocal analysis to reconstruct the scene by a filtered-backprojection (FBP) of the correlated signals. We show that the resolution of the image is directly related to the length of the support of the windowing function, the carrier-frequency of the transmitted waveform, and the sampling rate of the aperture. Unlike the previous approaches in the literature, our approach backprojects the correlated received signal onto iso-Doppler curves as opposed to iso-range curves, and takes advantage of the velocity, as well as the acceleration of the antennas in a certain direction to form a high resolution SAR image. Furthermore, it can accommodate arbitrary flight trajectories. We present numerical experiments to demonstrate the performance of the new image formation method.