InSAR DEM generation

Microwave Toolbox
1

Hello everyone! need help:slightly_smiling_face:
I have created a DEM using sentinel 1 data using InSAR analysis and finally did the phase to elevation and terrain corrected using range dopler terrain correction. The result was fine but i need to clarify these three questions.

1).What is the purpose of using SRTM DEM in the process of DEM making using inteferometry.
2).The elevation made from Insar DEM, based on geoid height or ellisoidal height??
3).when finally doing the terrain correction for the Insar dem, it is projected to WGS84. is it affecting to the height model.(will it change to ellisoidal to geoid or geoid to ellipsoidal) ???

thanks!!

2

Not sure about other questions, I guess the experts will reply. But, you should not use SRTM or any other DEM on the DInSAR (but yes on the BackGeocoding), just remove the FlatEarth (reference phase). If you apply TopoPhaseRemoval you will never get close to a DEM as you would be unwrapping only deformation+atmosphere+noise.

I hope this helps

3

Hi, @chathumal , the DEM that you get finally will be in elipsoidal reference. @Responders: I wish to know the answers to some of the questions raised by chathumal.

Also i have a few questions of my own:

  1. When you generate the DEM through INSAR, how much accuracy can it get? and what should be the ideal temporal and perpendicular criteria to select INSAR pair?
  2. I wish to create a DEM with a centimeter level vertical accuracy. is that possible? is so can you tell me or provide me with a tutorial ?
4

Here is a good reference for DEM-generation from Sentinel-1 data:

Retrieval of digital elevation models from Sentinel-1 radar data – open applications, techniques, and limitations.

Regarding your questions, for 1) I would say that the answer depends on the satellite/satellites you will be using, while for 2) the answer is a clear no, at least from space or from an aircraft.