Differential InSAR (D-InSAR)

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
California Oil Field
Basic ​wide ​area ​monitoring (D-InSAR) Interferogram over an oil field producing area of California.
A single SAR image of the oil area in California.
Image Stack
Advanced ​wide ​area ​monitoring using a stack of images (more than 2) allows improved estimation and removal of the atmospheric noise caused by water vapour.