Vertical Velocity Displacement along Ascending and Descending tracks
Hello dear colleagues
one question
The following figures show the deformation evaluation of the 2 salt diapirs in the ascending and descending tracks.
Why are the values inverted in two ascending and descending tracks ?
The following figure 2 shows Vertical Velocity Displacement along Ascending and Descending tracks
thanks in advance
I think it would be helpful for us to undestand how you generated these maps. Different velocity patterns for ascending/descending results are possible if the displacement was measured along the line of sight. So how did you convert the displacement to absolute vertical velocities?
Hi ABraun, Dear colleague
Thanks for the quick reply
The first images show the measurements along LOS
But 2 images below show the vertical displacement are calculated by considering the incident angle.
How in the above Figs the pattern are opposite?
thanks
now I understand, thank you. Which equation did you use to calculate the vertical velocity
There are many error sources which could be responsible, atmospheric disturbances in one of the images, unwrapping errors, changed environmental conditions.
Are the image pairs from the same time?
Hi
Yes, All images both AS%DS pairs are the same time (2014-2019, about 85 images).
so you followed a persistent scatterer approach?
I guess this equation is not precise enough for your purpose.
You can try to implement the formula suggested by @mdelgado, also for a Sentinel-1 persistent scatterer approach:
Hi ABraum and Dear colleagues
The above method was used. But the results are not the same.
Pay Attention To:
The area is a salt dome and is elongated along NE-SW
So how to interpret the opposite signs (+ and _) results?
Best
can you please show the results? I don’t think they will be the same.
Hi
Excuse me please
The above method was used. But the results are not the same.
So how to interpret the opposite signs (+ and _) results?
https://forum.step.esa.int/uploads/default/original/3X/9/5/956da5b83c42f3724aa33d61fd85b05c01f08820.jpeg
I the results bin ascending and descending orbits during the same period show different up/down in LOS means that the main phenomenon is not subsiding or uplifting but lateral displacement.
Could this explain bit?
