I am currently working on a time-series of Sentinel 1-GRD data.
This is my workflow:
Read -> Thermal Noise Removal -> Apply Orbit file -> Subset -> Calibration -> Speckle-Filtering (Lee 5x5) -> Terrain-Correction (Range-Doppler).
Afterwards I tried to stack those subsets, but somehow this does not work properly. The images are not perfectly overlapping, since some parts of the Lake I am looking at are not on every image:
The red part is the whole lake, whereas the other colours should represent other images.
If I just stack them like I did, the images that are not fullfilling the whole subset are really strange in terms of form etc. Any possibility to solve this?
Did you maybe use different UTM zones for the Terrain Correction?
If all are projected to WGS84 the stacking should be able to correctly align them. Can you maybe upload a screenshot to clarify how they are wrong after the stacking?
If you use the coregistration for the terrain corrected products (this makes sense because they are of different tracks and orbits), you have to select “product geolocation” in the offset method instead of “orbit”.
It worked perfectly for the three Scenes/four Pins I used this time. I will now try to stack all my images and more Pins.
Hopefully, you will not here something from me in the near future, which means everything works (I do not really believe it though )
conversion to dB simply changes the distribution of your histogram. The values stay calibrated and therefore comparable. It really depends if you need high contrasts in the low value regions or in the high value regions.