Preparing data for SBAS processing

Added by Sven Borgstrom over 7 years ago

Hi Piyush,
I'm collecting the ifgs (TSX/TDX, StripMap, ROI_PAC processing) for SBAS processing and I have some questions on this:

1) I added in "PrepIgramStack.py", in the "rdict" section, one more line: "rdict['TSX-wvl'] = 0.0310665" for TSX processing: is this correct?

2) Some ifgs are a combination of TSX and TDX: should I need one more line in the same section, let's say...TDX-wvl...? As far as I remember, TSX and TDX have exactly the same wavelenght, so this probably makes no sense...

3) In the "ifg.list" file I used the acronym "TSX" for the 4th column: is this ok? Also for TSX/TDX or TDX/TSX ifgs?

4) As indicated in the Manual, I put into my working directory also a "SIM_8rlks.hgt" file (renamed into "SIM.hgt") for my DEM in radar coordinates (which is the way I'm working now): which is the right location and name for this? And where is the right place to indicate this? In "prepxml_SBAS.py" at "hgtfile=...?

5) The mean size of my ifgs is, let's say, 30 MB, anyway I got also larger ifgs: how can I crop larger ifgs to the mean size? Automatically through the "example.rsc" file?

6) Anyway I started using "prepxml_SBAS.py" (see the attached file) but I got an 'HEADING_DEG' error: how can I fix this?

Sorry for disturbing you,
Sven.


Replies (3)

RE: Preparing data for SBAS processing - Added by Piyush Agram over 7 years ago

1) I added in "PrepIgramStack.py", in the "rdict" section, one more line: "rdict['TSX-wvl'] = 0.0310665" for TSX processing: is this correct?

-> This is fine but is not necessary. The rdict section is meant to be used when combining data from multiple sensors with different wavelengths - example ERS and Envisat. If only one sensor is specified, the wavelength from the example.rsc is used. This change should not affect anything if you have only one sensor type in ifg.list.

2) Some ifgs are a combination of TSX and TDX: should I need one more line in the same section, let's say...TDX-wvl...? As far as I remember, TSX and TDX have exactly the same wavelenght, so this probably makes no sense...

-> See answer to Qn 1.

3) In the "ifg.list" file I used the acronym "TSX" for the 4th column: is this ok? Also for TSX/TDX or TDX/TSX ifgs?

-> This is absolutely fine. The name of the sensor is only used to determine if you are mixing data from multiple sensors. Since TSX and TDX have same wavelength, I would recommend using TSX for sensor name for all data.

4) As indicated in the Manual, I put into my working directory also a "SIM_8rlks.hgt" file (renamed into "SIM.hgt") for my DEM in radar coordinates (which is the way I'm working now): which is the right location and name for this? And where is the right place to indicate this? In "prepxml_SBAS.py" at "hgtfile=...?

-> This should be specified in data.xml. data.xml has facilities for latitude, longitude and height files. Then these files will be read in, cropped and multilooked in the same manner as your data. You should modify inputs to prepare_data_xml in prepxml_SBAS.py.

5) The mean size of my ifgs is, let's say, 30 MB, anyway I got also larger ifgs: how can I crop larger ifgs to the mean size? Automatically through the "example.rsc" file?

-> Are all your interferograms coregistered? The current code assumes that all of them are of the same size. If not, all the files should at least have the same width and their top left pixels must be aligned. If that is the case, there should be no problem if the dimensions in example.rsc are smaller than the images. If the image is smaller than the dimensions in example.rsc it will generate an error.

If you want this code to behave differently, you will need to keep track of sizes of each interferogram (maybe pass it through ifg.list) and modify the read statements in the loop to read and align it the way you want.

6) Anyway I started using "prepxml_SBAS.py" (see the attached file) but I got an 'HEADING_DEG' error: how can I fix this?

-> The example.rsc should include a heading field if it was generated using ROI_PAC. If this doesn't exist, just include a HEADING_DEG field with the correct value in degrees.

Piyush

RE: Preparing data for SBAS processing - Added by Sven Borgstrom over 7 years ago

Hi Piyush,
thanks for answering.
I'll follow your suggestions and then I'll let you know.
Sven.

RE: Preparing data for SBAS processing - Added by leopoldo petricelli about 7 years ago

Ciao
Dopo tutto il lavoro fatto insieme mi sorge spontaneo chiedere se è finalmente riuscita una buona TIme Series?

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