The most basic InSAR technique is differential InSAR (D-InSAR), which uses just two SAR images. Surface movement is determined by the spatial variation of phase across the image over a number of pixels. D-InSAR removes topographic noise by use of a Digital Elevation Model (DEM) and removes phase noise caused by atmospheric water vapour by using MDA’s advanced spatial filtering techniques. MDA’s basic wide area monitoring uses the D-InSAR technique.
D-InSAR is best suited to areas of interest where:
- Limited data is available
- Noise from atmospheric water vapour is low
- Noise from surface changes is low, such as in desert regions with little vegetation