I’m working on estimation of surface deformation using SAR Interferometry with Sentinel-1 IW data. I done my processing and now want to convert Phase Unwrapping to Vertical Displacement. I Use following equation for conversion.
My area lies in IW1 (1st Subswath) with 30 to 36 incident angle range.
My question is that when in applied different angles with range of 30 to 36 at every angle displacement values are totally different.
So any solution of this problem.??
Waiting for your reply
What are these three bands in your table?
In the equation you provided, it tells you that it needs the unwrapped phase to calculate the displacement. The results you derived after using
snaphu and then imported it into SNAP is the layer you need to calculate the displacement.
In the equation, you just replace the letter
phi with your unwrapped phase
@johngan These are not bands. these are the values of deformation on a specific point. Actually when I apply the above equation with incident angle 30 degree. It shows different values of deformation and when I use 33 degree and 36 degree it dhows different values of deformation.
how I can solve this problem and which Incident angle I use .??
don’t enter an incident angle manually. Use it as a variable from the tie-point-grids.
@ABraun Thanks for reply
kindly tell me how to use it in the above equation.??
As ABraun stated, you can import the incedent angle from
tie-point grids. To do that, you just need to,
right click on the product,
band mathsand you type the equation inside the box as shown below.
Make sure you tick the
show tie-point grids box on the left for the incidence angle layer to show up.
The Units of the results will be in cm in that case as the wavelength (5.6) is in cm units
Hi, i have a quastion, pls tell me why my result map are black and white?? I did converting of phase to vertical disp exactly as you mentiond above
@zahra0729 You Means to say in Gray Scale.??
That,s interesting for me if my unwrapped phase is colour map, after converting to vertical displacment,why it appears like gray scale map!!
You can change it from here
Thanks alot for your explanation. But i want to know everything is ok ? And it,s natural if it appears like grayscale after creating?
yes, this is just how SNAP displays the data. It is your choice to apply colours to it.
Hi,I want to analayse ground deformation through a year for a region, so i have created displacment maps by generating interferogeram of all 12 month of year such as slave image and image of the first month such as master image,I mean in whole during of analysing,my master image was the first month image and the other images was slave.but now i,m confused if have i done it right or not!is it possible that I use from two images in different season!!
want to analayse ground deformation through a year for a region, so i have created displacment maps by generating interferogeram of all 12 month of year such as slave image and image of the first month such as master image,I mean in whole during of analysing,my master image was the first month image and the other images was slave.but now i,m confused if have i done it right or not!is it possible that I use from two images in different season!!
Hi, why I cannot see the tie-point-grids folder in my ‘‘unwrapped phase product’’ (the last step, after I import it from snaphu). I want to convert the unwrapped phase to vertical displacement by right click on the product> band math> band math nexpresion editor>
can anyone help me please? thanks
the product you show in the screenshot contains
elevation. That means you already applied “phase to displacement” on this data. Use the product of the previous step, directly after the snaphu import. It contains tie-point grids (as copied from the reference product defined in the first tab of the snaphu import (1-Read-Phase").
Again, Many thanks for your swift reply!
I have one thing else, I did not pin any GCP in my product through the processing of DinSAR, does this mean I missed one big step in the procedure? Do I need necessarily to identify a stable point of X,y coordinates in the image before prior to proceeding? if so, where shall I do that step?
Thank you so much Dear ABraun