Digital spotlighting filtering optimization for SAR imaging

Abstract

Abstract In this paper, a synthetic aperture radar (SAR) image formation simulator is used to objectively evaluate the parameter selection within the digital spotlighting process. Specifically, recommendations for the filter type and filter order of the low-pass filters used in the range and azimuth decimation processes within the digital spotlighting algorithm are determined to maximize image quality and minimize computational cost. Results show that a finite impulse response low-pass filter with a Taylor (n¯=5) $(\overline {n}=5)$ window applied provides the highest image quality over a wide range of filter orders and decimation factors. Additionally, a linear relationship between filter length and decimation factor is found.

Keywords

• Spotlight SAR simulator
• Digital spotlighting
• Filter order
• Filter windowing