激光与光电子学进展, 2013, 50 (7): 072801, 网络出版: 2013-06-07
一种适用于合成孔径激光雷达非线性啁啾校正的频率变标成像方法
Frequency Scaling Algorithm for Nonlinearity Chirp Correction of Synthetic Aperture Ladar Imaging
遥感 合成孔径激光雷达 非线性啁啾校正 频率变标算法 调频连续波 剩余视频相位滤波 remote sensing synthetic aperture ladar nonlinearity chirp correction frequency scaling algorithm frequency modulated continuous wave residual visual phase filtering
摘要
合成孔径激光雷达(SAL)的激光光源啁啾非线性会严重恶化距离向分辨率,无法清晰成像。针对这一问题,建立了存在非线性啁啾误差的SAL回波信号模型,分析认为非线性啁啾误差影响成像的本质为成对回波效应,并提出一种校正光源啁啾非线性的改进频率变标算法。该方法应用傅里叶变换时移特性估计非线性大小,基于剩余视频相位滤波原理“三步法”完成非线性啁啾的校正处理,实现目标的精确成像。仿真实验表明分辨率和成像质量获得明显改善,从而验证了该算法的可行性和高效性。
Abstract
The presence of nonlinearity chirp in the transmitted synthetic aperture ladar (SAL) signal badly deteriorates the range resolution. The signal model with nonlinearity chirp is established in this paper, by which the pair-echo effect induced by the nonlinearity term is analyzed. By estimating the nonlinearity chirp using the time-shift characteristic of the Fourier transform, a novel modified frequency scaling algorithm is proposed to correct the ladar nonlinearity based on the residual visual phase filter. Through simulation experiments, the modified algorithm confirms its superiority in terms of resolution and image quality.
于雯, 赵思伟, 宋小全. 一种适用于合成孔径激光雷达非线性啁啾校正的频率变标成像方法[J]. 激光与光电子学进展, 2013, 50(7): 072801. Yu Wen, Zhao Siwei, Song Xiaoquan. Frequency Scaling Algorithm for Nonlinearity Chirp Correction of Synthetic Aperture Ladar Imaging[J]. Laser & Optoelectronics Progress, 2013, 50(7): 072801.