In this chapter, we presented two algorithms, that is, the PQIHT algorithm and the E-BIHT algorithm, for enhancing the radar imaging quality with coarsely quantized data. The first algorithm, PQIHT, is basically the combination of the original QIHT algorithm and the PSR framework. It aims to eliminate the negative effect of the model uncertainty caused by the target motion and the quantization error on the SAR imaging quality. Experimental results demonstrate that the PQIHT algorithm can achieve moving target refocusing for coarsely quantized data and even 1 -bit data, with little sacrifice of the image quality compared to that generated from precise data. The second algorithm, E-BIHT, is based on the combination of the original BIHT algorithm and the two -level block sparsity model. Experimental results demonstrate that the E-BIHT algorithm can enhance the quality of radar imaging of stationary targets with 1 -bit data, by effectively removing the isolated artifacts and clustering the dominant pixels, at the cost of the increase in computational complexity. It is worth emphasizing that similar extensions can be also applied to other CS algorithms based on coarsely quantized data. The combination of the advance sparse signal models with 1 -bit CS algorithms has great potential in simplifying hardware implementation without severe degradation in radar imaging quality.

Chapter Contents:

• 6.1 Introduction
• 6.2 Parametric quantized iterative hard thresholding for SAR refocusing of moving targets with coarsely quantized data
• 6.2.1 Signal model
• 6.2.2 Description of the PQIHT algorithm
• 6.2.3 Experimental results
• 6.2.3.1 Simulations
• 6.2.3.2 Experiments on real SAR data
• 6.3 Enhanced 1-bit radar imaging by exploiting two-level block sparsity
• 6.3.1 Signal model
• 6.3.2 Description of the E-BIHT algorithm
• 6.3.2.1 Joint sparsity
• 6.3.2.2 Clustered sparsity
• 6.3.2.3 The E-BIHT algorithm
• 6.3.3 Experimental results
• 6.3.3.1 Simulations
• 6.3.3.2 Experiments on real radar data
• 6.4 Conclusion
• References

Inspec keywords: synthetic aperture radar; image coding; radar imaging; computational complexity; data compression; pattern clustering; compressed sensing; image enhancement

Other keywords: model uncertainty; SAR imaging quality; quantization error; radar imaging quality enhancement; advanced sparse signal models; E-BIHT algorithm; PQIHT algorithm; dominant pixel clustering; PSR framework; two-level block sparsity model; CS algorithms; computational complexity

Subjects: Radar equipment, systems and applications; Image and video coding