RADARSAT-1 Background Mission data for flood monitoring

Demonstrates the value of the global SAR data archives that are being generated as RADARSAT-1 satellite baseline acquisitions called the Background Mission. The RADARSAT-1 Background Mission has now completed two years of SAR data collection by means of multi-mode imaging capabilities. With the help of the wide area ScanSAR beam, a first seasonal snapshot of world continents, continental shelves and polar caps was completed in mid-1997. A second seasonal coverage is in progress over different continents of the world. These seasonal snapshots have furnished valuable reference data that are needed for comparison in the event of unforeseen natural disasters. Bangladesh is a country lying in the delta of the Brahmaputra and the Ganges, which normally flood parts of the country every year following the rainy monsoonal season. However, the monsoonal flooding of 1998 was of historical proportion and covered nearly 2/3rd of the national territory. Monitoring floods of this magnitude is a necessary for planning relief operations, and more importantly, for making long-term flood mitigation strategies. Satellites provide a quick and cost effective way of monitoring floods, though not all satellites are able to deliver timely flood imagery, because of weather conditions that prevail during rainy seasons. RADARSAT is one satellite that is not hampered by weather and day or night conditions. It has the unique capability of furnishing images with variable ground resolution and area covered. Its 500 km-wide ScanSAR swath could capture most of Bangladesh in a single image and thus provide an instantaneous view of the entire flood at a given time. Furthermore, it was possible to reckon the effects of the 1998 flooding by making a comparison with a year of normal flooding.