# The phase shift originates from horizontal or vertical displacements

Dear friends
please look at regular formula here (you can see this one in this paper´SAR interferometry over
Baltic Sea ice´):

From equation ( 3 ) we see that measurements of both surface elevations and small displacements (Delta h) are possible from a repeat-pass interferogram. The temporal surface movement, Delta eta , is measured in the radar look direction and can be either horizontal, vertical or a combination of both.
Dear friends, I am working on fast ice, something that does not have topography part and this is something that you delete from earthquake by helping ´Topographic Phase Removal´ (please look at TOPS Interferometry Tutorial manual) but as you know, The temporal surface movement, Delta eta , is measured in the radar look direction and can be either horizontal, vertical or a combination of both.
How you can understand that the phase shift originates from horizontal or vertical displacements.
Please guide me in this process.
Cheers,
Marjan

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Hello Marjan, the phase-patterns on sea-ice are difficult to understand since they are caused by horizontal and vertical movement caused by tides and displacement of blocks of ice including rotation. If I were you I would generate synthetic blocks of ice and simulate the phase-pattern that is generated by vertical/horizontal/rotational movement of the block according to formula (3). This should help you understand where translation/rotation/tidal effect are happening and how they are combining in your scenes.

Dear Mengdal
Yes you are right. It is difficult but I think you have in earthquake part, horizontal and vertical movement and displacements, so, How you separate them? Is there any software for that?
I saw one example that it told about separating horizontal and vertical movement in earthquake.
I do not know why we can not do that with fast ice because in both (fast ice and earthquake after topography removing) we have displacements?
What is the meaning by blocks of ice including rotation?
Cheers,
Marjan

Sea ice moves so quickly and unpredictably that even if you had ascending and descending interferograms (needed for 3D-movement detection) separation might still be very difficult.

By “rotation” I mean you should simulate the phase-ramp generated on a block of (synthetic) ice that is rotated around its center or corner and compare to simple translation.

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