Characterization of SAR type payloads on-board Spacecraft

SAR payloads are generally used on-board all-weather imaging satellites. When compared to optical payloads they are found more suitable for target detection applications in absence of sunlight. Their working principle is based on transmission and reception of pulses of predefined pulse characteristics. The reflected pulse from earth terrain is analysed and processed based on the changes in the transmitted pulses. This analysis provides all the necessary information regarding the terrain. The effectiveness of the image generation depends on the accuracy of the desired pulse that is transmitted. Thus there is a need for characterizing the transmitted pulses for all the relevant parameters. This paper provides an automated scheme to characterize the transmit receive modules in a typical LFM (Liner Frequency Modulation) SAR payload. This scheme includes a test set up comprising of various COTS measurement instruments. It also includes an automation software which conducts all the measurements using the test set up and presents the results in a standard form.