Create Stack error in filter images

s1tbx
#1

I have applied these steps in order to process the data:

  1. Thermal noise removal
  2. Apply Orbit file
  3. Calibration to Beta0
  4. MultiTemp filtering
  5. Radiometric terrain flattening — SRTM 1Sec HGT (Auto Download)
  6. Sub-setting the images
  7. Coregistration — here is the problem!!!
  8. Range Doppler Terrain Correction — it would be the next step

I have attached the outcome of the stack.

Untitled.png1922×1157 333 KB

Terrain flattening co-registered images
#2

I don’t know if this causes the problem but filtering before coregistering doesn’t seem good to my. How can you perform step 4 MultiTemporal filtering without coregistering?

#3

You are right in fact I have read the help file of MultiTemp filter which says “For a sequence of N registered multitemporal images, with intensity at position (x, y) in the kth image denoted by Ik(x, y), the temporal filtered images are given by…”
Therefore, the images should be first co-registered.
I have worked a lot on single image analysis with the steps (without subset and coregistration) but I need to test my model (which is not related to interferometry or polarimetry) for time series data sets as well.

I have tried this as well:

  1. Thermal noise removal
  2. Apply Orbit file
  3. Calibration to Beta0
  4. Lee 3x3 filtering ---- single image
  5. Radiometric terrain flattening — SRTM 1Sec HGT (Auto Download)
  6. Sub-setting the images
  7. Coregistration — here is the problem!!!
  8. Range Doppler Terrain Correction — it would be the next step

but still I have the error. So based on your suggestion it should be as follow:

  1. Thermal noise removal
  2. Apply Orbit file
  3. Calibration to Beta0
  4. Radiometric terrain flattening — SRTM 1Sec HGT (Auto Download)
  5. Sub-setting the images
  6. Coregistration — here is the problem!!!
  7. filtering ------ single or MultiTemp
  8. Range Doppler Terrain Correction — it would be the next step

correct ?

#4

as coregistration automatically searches for significant pairs of points in the images, I would personally leave out the filtering and apply a real multi-temporal filter on the stack after coregistration. Would be worth a try.

#5

Thanks Andreas, I will try as you have suggested.

But what about the subset phase. I generally subset the images after Range Doppler Terrain Correction but now I have to process about 100 images soo what do you think, can I do the subset before Radiometric terrain flattening in order to save some more time?

#6

Yes, should be no problem. You can create a graph using a polygon encoded in wkt.