DEM resolution influence on S1 TOPS corregistration quality

Microwave Toolbox
#1

Hi,

I was wondering how the quality (resolution) of the DEM used for back-geocoding during the S-1 TOPS Coregistration affects the accuracy of the of the process.

I have to work over an area in Finland and of course SRTM is not available. I am considering using ASTER or the DEMs provided by a national authority (2, 10, 25 or 200m)

Any idea on that? From my experience, the DEM resolution should be as closed as possible to the pixel size of the image.

M

#2

Even a very coarse DEM like the the GETASSE30 is sufficient - there is no degradation of accuracy.

#3

@mengdahl, If the DEM is used to provide better prediction of the offset vectors (pixel by pixel correspondence between master and slave acquisitions using using orbital data and a reference DEM).

Why the resolution of the DEM is not relevant if the process is done pixel by pixel?

M