An evaluation of ERS-1 PRI data in the context of the rapid estimation of crop acreages in Europe

The Pilot Project for Remote Sensing applied to agricultural statistics includes a specific action aimed at crop acreage forecasting (ACTION 4). For 53 European test-sites optical imagery from TM or SPOT is nominally acquired four times during the growing season. This data is then successively analyzed by computer aided photo-interpretation techniques. Within 10 days after data reception an updated forecast bulletin for the main crops is published. Due to the unfavourable weather conditions in northern Europe a sufficient coverage from optical sensors is a problem. These time and weather constraints emphasize the interest in working with ERS-1 PRI data. An analysis of a 18-date ERS-1 (PRI-format) and 4-date SPOT data set on JRC´s Seville (Spain) and Great Driffield site showed that the inherent geometric accuracy and spatial resolution are sufficient to create multidate and multisensor datasets. Together with ancillary information (DEM, climatic parameters, crop survey etc.) stored on the author´s GIS and after an adequate preprocessing of the satellite imagery the author was able to evaluate the potential of the ERS-1 data for the application. SPOT derived information is essential for both, the evaluation as well as the operational phase.