The next generation of ESA Earth Observation satellites include a series of ‘Sentinel Missions’ to be developed and operated with the framework of GMES (Global Monitoring for Environment and Security). These will include SAR and Optical satellites with new imaging configurations and spectral bands, and much improved capabilities for frequent repeat coverage.
The AGRISAR 2006 campaign was collecting in-situ, airborne SAR and optical measurements in support of decisions being taken on satellite instrument configurations for the first Sentinel Missions, as well as providing an important database for the study of longer term mission concepts.
E-SAR polarimetric C-band image
Agricultural and land use mapping are important applications for the new satellites and the test site selected for AGRISAR 2006 is in the Demmin area of north-east Germany where there is a well established research arrangement working with practising farmers. Ground data collection activities on the site where detailed measurements of plant and soil parameters are obtained. Ground radiometer measurements were also carried out.
The DLR E-SAR airborne radar system was used to acquire SAR data at X-, C- and L-Band, and in polarimetric SAR and interferometric SAR modes. A total of 16 flights were carried out over the main growing season from April to August, to provide the frequent repeat coverage which is an important feature of the new Sentinel SAR satellites.
Imaging spectrometer data acquisition was carried out by INTA, Spain, in close collaboration with Itres Research Ltd, Canada. An Airborne Hyperspectral System (AHS) from INTA was installed onboard a CASA-212-200 aircraft to collect hyperspectral imagery over the whole optical spectrum. Additionally, a VNIR hyperspectral imaging sensor, a CASI-1500, owned by Itres, was installed in the CASA aircraft and will operate jointly with the AHS. Positioning and orientation of both sensors were achieved with separate INS/GPS modules (Applanix POS/AV 410), through direct geo-referencing techniques. A complete and valuable hyperspectral data set was acquired to support the definition of spectral configurations for the Sentinel-2 optical satellite mission. Two optical airborne surveys were done in June and July 2006, synchronized with ground measurements and E-SAR acquisitions.