Martin Suess

Technology developments for the next generation of spaceborne SAR instruments based on digital beamforming

During the past ten years a number of research groups around the world have been investigating the use of digital beamforming for spaceborne SAR instruments. The separate optimization of the effective transmit and receive aperture sizes together with the splitting of the receive side into multiple receive sub-apertures which can be combined on board by means of digital beamforming allows for a number of new SAR modes. With this it is for example possible to overcome the principle swath width and azimuth resolution limitation known in classical SAR instrument designs. ESA has performed and initiated a number of systems studies to identify the critical technologies needed for this type of instrument. Based on these system studies a number of technology development activities have been started. This paper gives an overview on the studies and technology developments performed in this context.

Digital beam forming for C-Band SAR and technological elements

ESA has initiated several studies to enhance the performance of next generation of C-Band SAR. This paper provides an overview of the on-going demonstration activity for critical technology in C-band as required for a next generation Sentinel-1 SAR instrument with enhanced performance in terms of coverage and resolution. The new instrument will use digital beam forming (DBF) capabilities to achieve the performance improvement by a new combined analogue/digital beam forming unit called TRIM (Transmit/Receive Interface Module). The paper reports on the status of ongoing developments at subsystem level including required technological elements as European GaN and deep sub-micron silicon semiconductor technology.

Lessons learnt from SMOS after 7 years in orbit

ESAs Soil Moisture and Ocean Salinity (SMOS) mission has been in orbit for over 7 years, with its Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) functioning well. This 7 year period has provided a wealth of information which has enabled us to understand and consolidate the performance of the payload in great detail. More importantly, we know now the things that work well, those that need improvement, and how the instrument could be enhanced if we were to build it again. This paper presents the lessons learnt from SMOS after 7 years in orbit.

Impact of new technologies on future space-borne radar design

In the 1990s radar instruments for Earth observation started to generate continuous streams of high quality data for scientific and commercial applications alike. Now that these instrument concepts have been proven and the demand for their data has become apparent, the next generation must provide even better quality with increased temporal and spatial coverage but, as ever, at a reduced price. Fortunately advances in new technology developments have continued apace and these are set to transform space-borne radar design, increasing capabilities whilst at the same time reducing unit costs.