I’m trying to carry out a time-series analysis on the basis of Beta0 coefficient in Sentinel-1.
My area of interest has a revisit frequency of 12 days (Only S1A is available) and hence I decided to use both Ascending and Descending passes of S1A. But the values I get from these passes keep varying abruptly and hence I cannot draw any conclusion out of the combined time-series.
Is there any way through which I can get Beta0 values by making use of both Ascending and Descending passes?
Here are the preprocessing steps that I have followed and parameters that I have used in SNAP:
- Apply Orbit File
- Thermal Noise Removal
- Calibration => Create beta0 virtual band
- Speckle Filter => Median (3x3 Window)
- Terrain Correction =>
- DEM => SRTM 3sec
- DEM Resampling Method => Nearest Neighbour
- Image Resampling Method => Nearest Neighbour
Please let us know if these are the correct steps to get the Beta0 values.
Images Used (All images are S1A_IW_GRDH_1SDV):
- subset_20210601_Orb_NR_Cal_Spk_TC - Ascending Pass
- subset_20210609_Orb_NR_Cal_Spk_TC - Descending Pass
- subset_20210613_Orb_NR_Cal_Spk_TC - Ascending Pass
- subset_20210621_Orb_NR_Cal_Spk_TC - Descending Pass
- subset_20210625_Orb_NR_Cal_Spk_TC - Ascending Pass