Interpretation of Almaz‐1A SAR Imagery of the Wairarapa, New Zealand

Abstract

Results from the investigation of an Almaz‐1A S‐band Synthetic Aperture Radar (SAR) image of the Wairarapa region of New Zealand are presented. The data have been studied alongside SPOT multispectral imagery and panchromatic aerial photographs, with the study supported by field work. The study focussed on selected surface phenomena related to roughness characteristics, feature orientation, and signal enhancement due to surface flooding. Orientation dependence was investigated with reference to the detection and omission of linear features oriented at various angles with respect to the SAR flightline, and the investigation of an anomalous bright return from a vineyard. Radar return characteristics from the major rivers in the area allowed the discrimination into two types of rivers, depending on the hydrologic characteristics, size of the channel deposits and the land use/land cover in the adjacent riparian zone. Radar backscatter enhancement from flooded areas under a canopy of tall grasses, reeds and bushes is also noted. Examples of these phenomena are cited, along with attempts to explain their occurrence, and indications of such signal‐target interactions.