Assessment of the Impact of Long Integration Time in Geosynchronous SAR Imagery of Agricultural Fields by Means of GB-SAR Data

Abstract

Geosynchronous synthetic aperture radar (GeoSAR) missions offer the advantage of near-continuous monitoring of specific regions on Earth, making them essential for applications that require continuous information. However, wind-induced motion along the inherent long integration time can result in image defocusing, with potential degradation of retrieved information. This article aims to investigate the impact of GeoSAR long integration time in synthetic aperture radar (SAR) imaging and derived products (time series of backscatter and coherence) required to extract agriculture-relevant soil or crop parameters of interest. The study is based on the extensive HydroSoil data acquisition campaign carried out over barley and corn crops, funded by the European Space Agency. The collected raw data are used to synthesize equivalent apertures with integration times of up to 4 h, similar to those acquired with a GeoSAR. These ultraslow apertures facilitate the assessment of the impact of agricultural scene decorrelation on the generation of images with extended integration times.

Keywords

• Backscattering
• coherence amplitude
• geosynchronous synthetic aperture radar (GeoSAR)
• integration time
• scene decorrelation