Preliminary results from the soil moisture active/passive (SMAP) radiometer digital electronics engineering test unit (ETU)

SMAP is one of four Tier-1 missions recommended by the National Research Council´s Committee on Earth Science and Applications from Space [1]. The mission consists of a spacecraft with two instruments: an active L-band 1.26 GHz synthetic aperture radar and a passive L-band radiometer that operates in the 1.400 to 1.427 GHz microwave band. The goal of the mission is to use data derived from both instruments to construct high-resolution, high-accuracy global maps of soil moisture and freeze/thaw states over a 3 year mission duration. The SMAP radiometer has an entirely digital back-end processor that builds upon the findings by Misra et. al. [2], [3] for its digital signal processing (DSP) and radio frequency interference (RFI) mitigation. The implementation of this radiometer is currently under way and the mission is scheduled to launch in 2015. This paper summarizes the design and performance results of the RDE engineering test unit (ETU).