Generating DEM by using SLC Sentinel1 TOPS


I’ve been testing some Sentinel tiles to generating DEMs by interferomety, however the results are really poor when compared to SRTM 1arc sec images. It seams that the problem is related with the scenes since I’ve followed exactly the steps presented in the tutorials. Is there any tool that allows a previous visualization of the interfarogram as available for ERS scenes in EOLI (ESA)? The process is really time consuming, which makes it difficult the choice of suitable tiles for DEM generation.

Thank you!

The quality of the DEMs is expected to be poor unless your coherence is very high (like in a desert) and even then the atmospheric artefacts in the InSAR phase cause errors in the generated DEM. Averaging over many generated DEMs reduces the effect of the atmospheric artefacts but you cannot mitigate difficulties caused by low coherence.

Thank you.
I figured that now after a series of tests in my studied area. I guess my only option would be using stereoscopic techniques based on passive remote sensing systems.

I have a problem like osvaldoguax
but i want to work in urban area that has a high coherence but I can’t get a good DEM!
what should I do?
is there any difference between DEM generation with TOPS data or Strip data ?
what kind of data is better?
and is there any software for reduce atmospheric effect?

The phase in urban areas is often not smooth due to scatterers being at varying heights from one pixel to the next, which makes phase unwrapping impossible. InSAR is not the right tool for urban DEMs I’m afraid.

but i see some DEM from urban area with good accuracy using interferometry
but there was a difference that they use TanDEM data
i want to try repeat pass data
do you think that it is impossible?

No please try it, nobody knows yet how well it will work with S-1 :slight_smile:

Hi mengdahl

I did an DEM with S1 for an urban area about my country, but I don’t have any validation for this, if someone want help me with the validation I should be is thankful!!! :grin:

hi gabriela
I do like you and I want to know answer of your question too
do you know what the reference height is for computing elevation from this method?

Hi mengdahl
Could you please explain how to ‘average over many generated DEMs’.

My DEM generated from S1A IW SLC produces very poor results