Temperature variation compensation in engineering model of MIRAS reference radiometer

Abstract

We present a compensation method for the temperature variation of the reference radiometer (NIR) of the MIRAS instrument on the SMOS mission. A similar study done for the prototype of the reference radiometer has been reported at IGARSS'04. Novelty of this study, compared to the previous, lies on the facts that (1) it is based on more thorough temperature cycling, (2) it includes also the antenna and (3) the analysed model (EM) is representative to Flight Model of NIR. We present a thermal model for the NIR front-end and noise source that further improves the stability so that the desired performance, which arises from the requirements for the measurement of soil moisture and ocean salinity, can be met.