# Precision of interferometric deformation analysis

Hi
How precise it is possible på measure land deformation with sentinel-1 data?
I live in Denmark, and we have area called Thy which is lifted approximately 2 mm per year.
Is it possible to see that with interferometry? The last sentinel-1 was launched in 2016, so i guess i will have 4 years of data resultning in a total diffence of appriximately 8 mm.

I read that “the interferometric technique measures ground deformation
with a precision of 2.8 centimeters” in the EO-college course on interferometry", but when i search the internet, it looks like some people can obtain better precision in their projects.

Does anyone know something about this project, or has an idea about where to search for more information?

Best Regards, Michael

Hi,

Deformation analysis applies to your application (detecting subsidence or uplift). Sentinel-1 data can be used for that purpose. The magnitude of the subsidence/uplift that can be detected depends on the sensor. For instance, TeraSAR-X satellite can detect ground subsidence down to 1cm (if i am not mistaken) compared to Sentinel-1 due to its shorter wavelength.

The conventional interferoemtry, unfortunately suffers from atmospheric noise which means you cannot accurately detect any ground subsidence as the atmospheric noise, in most case, is higher than the magnitude of the subsidence. Using conventional interferometric analysis, you can get an overview of your AOI as to whether it subsidence or there is an uplift.

What you need to do is to think about more advanced analysis such as Persistent Scatteres Interferoemtry (PSI) where you can get very reliable measurements. More info on that have a look in the PSI/SBAS topic

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Yes, PSI-analysis will eventually see the uplift and it’s probably visible alreeady, at least if the movement is linear. Long time-series enable detecting very slow movements.

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Thanks a lot for the reply, ill look more into PSI.

or it follows a trend, not being the movement necessary linear.
For example:

or

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how to make unit displacement to cm mate? and how you make a time series graphic like that?