[Help]: Removal topography

[kjz1997]

Hello Doctor, I would like to know if pygmtsar can generate terrain phases and remove them?

[AlexeyPechnikov]

If you’re referring to the topography phase, then yes, absolutely! Almost all PyGMTSAR examples include calculations for removing the topography phase.

[kjz1997]

Is the phase-diff function used to implement this function? if it is. I am confused about the returned results， According to the interference formula, shouldn't it be np.angle (data1 * np. conj (data2)) - topo_phaseIf my understanding is wrong, please forgive me
the returned result:
data1 = data.sel(date=pairs[:,0]).drop_vars('date').rename({'date': 'pair'}) data2 = data.sel(date=pairs[:,1]).drop_vars('date').rename({'date': 'pair'}) out = (data1 * phase_topo * np.exp(-1j * phase_real) * da.conj(data2)).astype(np.complex64).rename('phase')

[AlexeyPechnikov]

In PyGMTSAR, we work with complex phases and apply interferogram() (e.g., np.arctan2 or np.angle) at the final stage. You can use Stack.interferogram() on the topographic phase for plotting, or utilize it in the Stack.phasediff() function to remove the topographic phase from your interferograms.