Detection of terrain changes in southern Denmark using persistent scatterer interferometry

Since 1991, a number of European satellites have acquired data of the Earth’s surface for environmental monitoring. In general, a satellite will orbit the Earth in about 1½ hours and it takes 35 days before an ERS or ENVISAT satellite repeats radar scanning of the same position. For younger generations of satellites, such as RADARSAT and TERRA, the scanning repeat interval has decreased to 24 and 11 days, respectively, so that hundreds of radar scenes of the same place, produced over the past c. 20 years, are now available.