2_2_step01_5

2.2. Step 01-05: Prepare Stack of UNW Data

For more details of the commands, use -h option to see the usage.

Step 03-05 are optional and in no particular order.

Step 01: Download GeoTIFF from COMET-LiCS web

LiCSBAS01_get_geotiff.py [-f FRAME] [-s start_date] [-e end_date]

This script downloads GeoTIFF files of unw (unwrapped interferogram) and cc (coherence) for the specified frame ID from COMET-LiCS web. The -f option is not necessary because the frame ID can be automatically identified from the name of the working directory.

Step 02: Convert (and downsample)

LiCSBAS02_ml_prep.py -i GEOCdir [-o GEOCmldir] [-n nlook] [-f FRAME]

This script converts GeoTIFF files to float format for further time series analysis, and also downsamples (multilooks) data if specified by -n option.

Step 03: GACOS correction (optional)

LiCSBAS03op_GACOS.py -i in_dir -o out_dir -z ztddir

This script applies a tropospheric correction to unw data using GACOS data. GACOS data must be prepared beforehand by requesting on GACOS web. This step is optional.

Step 04: Mask UNW (optional)

LiCSBAS04op_mask_unw.py -i in_dir -o out_dir [-r x1/x2/y1/y2] [-f txtfile]

This script masks some parts of unw data. The masking is effective when the unw data include areas which have many unwrapping errors and are not of interest, and can improve the result of step 12 (loop closure).

Step 05: Clip UNW (optional)

LiCSBAS05op_clip_unw.py -i in_dir -o out_dir [-r x1/x2/y1/y2] [-g lon1/lon2/lat1/lat2]

This script clips a specified rectangular area of interest from unw and cc data. The clipping can make the data size smaller and processing faster, and improve the result of step 12 (loop closure).