P band data collection and investigations utilizing the RAMSES SAR facility

ONERA, the French aerospace research agency, has developed a multi-frequency, full polarimetric and high resolution airborne SAR facility named RAMSES, which has been expanded with a P-band (435 MHz) capability at the end of year 2000. The Gironde area was chosen as a suitable test-site for fieldwork validation of P-band capabilities in coordination with the "low frequency radar working group" set up by CNES (French Space Agency), the DGA (DOD Procurement Agency) and the CEV (French Flight Test Center). This experiment has explored the capabilities of this low frequency band for sub-surface moisture detection (on the "Pyla" sand dune), biomass assessment (on the Nezer forest), mapping of the ocean bathymetry/salinity (on the "bassin d\´Arcachon", estuary of the Gironde), and archaeology (imaging of buried Roman-era artifacts). After a short description of the radar P and of the experience feedback of campaign "PYLA 2001" on the P-band radar, we present a preliminary synthesis of the results on the different sites. The "PYLA 2001" campaign results are encouraging. We therefore plan further experiments at the beginning of 2004 over Egypt (with simultaneous band P+L). In conclusion, we present the future research trend at ONERA in the domain of lower frequency (VHF/UHF) SAR.