Monostatic CW SAR Concept for Microsatellites

Abstract:
Currently there is a considerable effort to design and build synthetic aperture radar (SAR) payloads for small (micro-)satellites. This is difficult to achieve with conventional pulsed SARs, as their peak power demands tend to make the payloads heavy and expensive to produce. Recent developments focusing on continuous wave (CW) techniques have proved successful in minimising the cost, weight and power consumption of SARs for small uncrewed air vehicles (UAVs), where the transmitter and receiver can be mounted separately on the same platform. Applying the same technology to space based SARs necessatitates a bi-static dual-spacecraft configuration in order to provide enough isolation between transmitter and receiver. This paper presents an alternative novel concept for using CW SAR in space - switched or interrupted CW SAR; employing a single antenna from a single microsatellite; along with highlighting the associated problems.