Radar Remote Sensing and Interferometry
In radar remote sensing, electromagnetic pulses are emitted from aircraft- or satellite-mounted sensors, which then record and process the radiation backscattered from the earth’s surface. In doing so, various frequencies (X-band, C-band or L-band) are used for different application areas. This active process allows for Earth observation at any time of the day and in all weather conditions.
The recorded signals represent a complex combination of backscatter intensity and wave phases. These not only allow conclusions to be drawn about the properties of the earth’s surface (roughness, humidity) but also enable the recording of the terrain height. Radar interferometry includes various measuring methods for the comparative analysis of image pairs and time series.
Classic differential SAR interferometry uses recordings of two points in time to detect changes in the height of the earth’s surface. With the advanced methods of interferometric stacking, monitoring tasks can also be accomplished by analyzing data of entire time series. After the reduction of interferences, it is possible to identify ground movements in the cm to mm range.