An implementation of a fast backprojection image formation algorithm for spotlight-mode SAR

Wahl, Daniel E.; Yocky, David A.; Jakowatz, Charles V.

doi:10.1117/12.779401

Cited by 40 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In its absence, it is common to assume flat terrain. However, if the scene is not suitably flat, distortion effects and defocussing can results in loss of image resolution [10].…”

Section: A Sar Imaging Geometrymentioning

confidence: 99%

“…The PFA requires assumptions of constant terrain elevation and flat wavefronts (far-field scenario) which are not required in the (re/back)-projection algorithms. Using techniques from the tomography literature it has been shown that the (re/back)-projection algorithms can also be implemented in O N 2 log N operations without the approximations of the PFA [9], [10]. Also, more recently another approach has been shown to provide similar speedup with additional theoretical guarantees regarding the quality of the reconstruction [11].…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Iterative image formation using fast (Re/Back)-projection for spotlight-mode SAR

Kelly

Rilling

Davies

et al. 2011

2011 IEEE RadarCon (RADAR)

View full text Add to dashboard Cite

Iterative SAR image formation can visually improve image reconstructions from under-sampled phase histories by approximately solving a regularised least squares problem. For iterative inversion to be computationally feasible, fast algorithms for the observation matrix and its adjoint must be available. We demonstrate how fast, N 2 log 2 N complexity, (re/back)-projection algorithms can be used as accurate approximations for the observation matrix and its adjoint, without the limiting assumptions of other N 2 log 2 N methods, e.g. the polar format algorithm. Experimental results demonstrate the effectiveness of iterative methods using a publicly available SAR dataset. Matlab/C code implementations of the fast (re/back)-projection algorithms used in this paper have been made available.

show abstract

“…In its absence, it is common to assume flat terrain. However, if the scene is not suitably flat, distortion effects and defocussing can results in loss of image resolution [10].…”

Section: A Sar Imaging Geometrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Iterative image formation using fast (Re/Back)-projection for spotlight-mode SAR

Kelly

Rilling

Davies

et al. 2011

2011 IEEE RadarCon (RADAR)

View full text Add to dashboard Cite

show abstract

“…We currently partition the image into rectangular strips for distribution, although we have tested several image partitioning strategies with little resulting performance difference. Furthermore, a fully optimized SAR image formation framework would likely utilize hierarchical backprojection algorithms that reduce the computational complexity from O(N 3 ) to O(N 2 log N ) by downsampling the phase history data corresponding to a certain image space region to the sampling rate required for that image space region [8], [9]. When implementing such approaches, it is important to balance the computation associated with the resampling operations with those associated with backprojection.…”

Section: A Backprojection Parallelizationmentioning

confidence: 99%

Gigapixel spotlight synthetic aperture radar backprojection using clusters of GPUs and CUDA

Benson

Campbell

Cook

2012

2012 IEEE Radar Conference

View full text Add to dashboard Cite

Synthetic aperture radar (SAR) image formation via backprojection offers a robust mechanism by which to form images on general, non-planar surfaces, without often restrictive assumptions regarding the planarity of the wavefront at the locations being imaged. However, backprojection presents a substantially increased computational load relative to other image formation algorithms that typically depend upon fast Fourier transforms. In this paper, we present an image formation framework for accelerated SAR backprojection that utilizes a cluster of computing nodes, each with one or more graphics processing units (GPUs). We address the parallelization of the backprojection process among multiple nodes and the scalability thereby obtained, several optimization approaches, and performance as a function of both allocated resources and desired precision. Finally, we demonstrate the achieved performance on a simulated gigapixel-scale data set.

show abstract

“…In theory, the complexity of back-projection method is O(N 3 ), where N × N gives the SAR image size. 2 To address this issue, methods have been developed 3 and some of which leverage multi-core systems to improve the computational efficiency. 4 Many of these algorithms use approximation and sacrifice image quality in trade for reduced processing time.…”

Section: Introductionmentioning

confidence: 99%

Improved image reconstruction from sub-apertures of circular spotlight SAR

Yuan

Ternovskiy

2015

SPIE Proceedings

View full text Add to dashboard Cite

Reconstructing images from SAR returns is usually a time consuming task. In addition it is often desired to use as many returns as possible to achieve better image quality. However, the high computational resources demand by the conventional methods hinders the reconstruction process. In this article, we propose a simple method to reconstruct SAR image that is built upon the back-projection algorithm using multiple sub-aperture imagery to attain both greater processing efficiency and improved image quality. Instead of aggregating all the available pulses into one single image following the backprojection algorithm, our proposed method creates multiple SAR image reconstructions from a relatively small number of pulses to exploit variations in sub-aperture views of the scene. The heterogeneity among these sub-aperture views exhibits an exceptional difference between various objects and presents a reconstruction with much less noise. Our proposed method is evaluated with circular spotlight GOTCHA data sets and it demonstrates much improved computational performance and image quality compared to the conventional back-projection algorithm.

show abstract

An implementation of a fast backprojection image formation algorithm for spotlight-mode SAR

Cited by 40 publications

References 0 publications

Iterative image formation using fast (Re/Back)-projection for spotlight-mode SAR

Iterative image formation using fast (Re/Back)-projection for spotlight-mode SAR

Gigapixel spotlight synthetic aperture radar backprojection using clusters of GPUs and CUDA

Improved image reconstruction from sub-apertures of circular spotlight SAR

Contact Info

Product

Resources

About