One-Bit SAR Imaging Based on Single-Frequency Thresholds
One-Bit SAR Imaging Based on Single-Frequency Thresholds
复制标题
基于单频阈值的一位SAR成像
DOI：
10.1109/tgrs.2019.2910284
复制
发表时间：
2019
影响因子：
8.2
通讯作者：
Bao Weimin
中科院分区：
文献类型：
--
作者：
Zhao Bo;Huang Lei;Bao Weimin
提出了一种基于1比特采样和单频门限的SAR成像新方法。1比特采样方法能够显著降低量化成本。然而，当采样技术通过将每个样本的字长减少到仅1位来简化SAR系统时，SAR回波的幅度信息丢失并引入高次谐波，从而降低了SAR成像质量。单频阈值的策略能够线性地保持幅度信息，并使谐波频谱远离由互调引起的成像分量。因此，可以保证使用1比特采样数据的成像质量。综合考虑频谱混叠、滤波器失配和射频干扰等因素，选择不同的SAR参数组，可以在成像质量和系统简化之间取得较好的折衷。提供了理想散射体和真实的测量场景的实例以供定量分析。利用该方法对真实的RADARSAT-1实测数据进行成像，验证了该方法的有效性。
This paper addresses a novel SAR imaging scheme based on 1-bit sampling assisted with a single-frequency threshold. The 1-bit sampling approach is able to considerably reduce the quantization cost. However, when the sampling technique simplifies the SAR system by reducing the word length of each sample to only 1 bit, amplitude information of the SAR echo is lost and high-order harmonics are introduced, degrading the SAR imaging quality. The strategy of single-frequency threshold is able to linearly maintain the amplitude information and shifts the spectra of the harmonics away from the imaging component caused by the intermodulation. Hence, the imaging quality using 1-bit sampled data can be guaranteed. By selecting different SAR parameter groups according to a comprehensive consideration on spectrum aliasing, filter mismatching, and radio frequency interfering, a good tradeoff can be achieved between imaging quality and system simplification. Examples of ideal scatterers and a real measured scene are provided for quantitative analysis. Real measured RADARSAT-1 data are also imaged using the proposed scheme to validate its effectiveness.