Can Radar Interferometry Address Commercial Applications?

This paper addresses a question often asked by industry: can radar interferometry (or InSAR or IFSAR) deliver services on a commercial and/or operational basis? To answer this question two systems based on InSAR for digital elevation model (DEM) generation are considered. One commercial system is the GeoSAR Xand P-band radar aerial mapping system from EarthData. The X-band can deliver digital surface models with 3m resolution while the P-band can provide DEMs at 5m resolution. Another commercial system is the STAR X-band airborne InSAR system from Intermap Technologies. The system can determine DEMs with 2.5m spacing and 1m vertical accuracy. One of the advantages of such systems is that with InSAR installed on fixed-wing aircraft they can operate day or night, in clear or cloudy conditions virtually anywhere on Earth. They can therefore produce high resolution DEMs and radar imagery over regions previously considered inaccessible due to weather, terrain, etc. The paper also considers the commercial potential of spaceborne differential InSAR (DInSAR) for mapping ground surface displacement. Case studies will be given using data from a range of SAR satellites, such as Envisat, Radarsat-1, JERS-1, and ERS-1/2, addressing a range of applications such as subsidence due to underground mining and deformation of urban areas. Sub-centimetre accuracy has been demonstrated using spaceborne repeat-pass DInSAR. With several SAR satellites now operational, and more to be launched in the near future, the authors believe that DInSAR will be used on a commercial and/or operational basis to complement terrestrial surveys for mapping ground surface displacement.