Synthetic Aperture PAU: a new instrument to test potential improvements for future SMOSops

This paper describes some potential improvements that could be eventually implemented for future MIRAS (Microwave Imaging Radiometer by Aperture Synthesis) payloads of the follow-on missions of the ESA's SMOS (Soil Moisture and Ocean Salinity) mission. A ground-based instrument concept demonstrator has been designed and it is being implemented to validate these improvements. Both MIRAS and the (Synthetic Aperture Passive Advanced Unit, SA-PAU) are Y shaped arrays, but the receiver topology and the processing unit are significantly different. This paper identifies the elements in the MIRAS's design that could be improved and presents a new instrument (Synthetic Aperture PAU) that could be used to test some potential improvements for future SMOSops (SMOS operational system).