Dear Syed Ahatsham Haider The best technique to work on the landslides or land deformation with vegetation cover is to employ Small Baseline Subset (SBAS) approach; where SBAS approaches account for signal decorrelations by partitioning the data set into several subsets with short spatial and temporal baseline possible (i.e., excluded large baseline interferograms). Within the subsets, the interferograms are spatially multilooked and unwrapped.

he SBAS analysis can be considered as a linear model inversion problem. For each pixel, based on the equation given below:

φ=Ax+Δw

Now coming to coherence, the area as you mentioned is covered with vegetation so there is high probability of decorrelation (within 30 days or less). To overcome this issues you have to use SAR stacks with minimum temporal baseline (incerease the number of SAR images)

Secondly, if your target area is within mountainous region then you have to account for errors due to topographic phase.

The residual topographic phase consists of the height-to-phase factor, elevation error; normal baseline relative to the n-th image with respect to the reference (master) image; local incidence angle; carrier wavelength; zero-Doppler distance between the target and the n-th orbit acquisition.

Gomal Amin Many thanks for your valuable input

Hello,

You can check out the SqueeSAR method:

https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=squeesar&btnG=#d=gs_qabs&u=%23p%3DihZQTKhGU44J

It is very useful, especially on low coherence areas.