DEM vertical resolution

Microwave Toolbox Interferometry
#1

Dear all,
I have constructed a DEM from sentinel-1 with the Snap application. I want to know the vertical resolution of my product. How I can find it?

#2

you can select “DEM” as an additional output during the Range Doppler Terrain Correction which writes you the SRTM (1Sec at best) into the final product. It will cover elevation_VV (the one from Sentinel-1) and elevation (SRTM). Now you can calculate the difference between both, for example the RMSE between the Sentinel-1 heights and the SRTM heights. But this is just a number which doesn’t tell you much about systematic errors, for example if the quality is bad only in a part of the image.

#3

Thanks. It means somehow to compare the results with SRTM. So, you mean DEM generated from sentinel 1 is always less accurate than SRTM?

#4

in 99% of the cases, SRTM is more accurate, yes.

Sentinel-1 may provide a higher spatial resolution, but is more sensitive to errors from phase decorrelation, short baseline and unwrapping over noise phase areas.

#5

Thank you so much!

#6

have you seen this tutorial? DEM generation with Sentinel-1 - Workflow and challenges

1 Like
#7

yes, I did my DEM generation based on this tutorial. Now, I see what you mean. The last page is exactly what you mentioned comparing STRM and DEM generated. Apparently, I skipped that part. Thank you for mentioning that.

#8

happy to hear that.