ALOS-2 InSAR and Ionospheric Correction package released

Added by Cunren Liang 10 months ago

The ALOS-2 Multi-Mode InSAR and Ionospheric Correction Processors have now been fully integrated into ISCE. Check out the tutorials here
https://github.com/isce-framework/isce2/tree/master/examples/input_files/alos2

The package described below is no longer recommended.

Cunren Liang





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Dear ISCE users and colleagues,

We have got permission from JPL to release the InSAR Processor for ALOS-2 Multi-Mode SAR Data and Ionospheric Correction. You can download the package from github at: https://github.com/CunrenLiang/insarzd

Currently it is still a separate package. We are working on fully incorporating it into ISCE with improved efficiency and robustness. This will be done in a couple of months. Key features of this package include:

ONE APP TO PROCESS THEM ALL
  • Support all ALOS-2 acquisition modes (except spotlight, to be added shortly)
  • Combinations include ScanSAR-ScanSAR, ScanSAR-stripmap and stripmap-stripmap
  • Support making interferograms across all the three wavelengths of ALOS-2
  • Automatic mosaicking of multiple subswaths and frames
  • Ionospheric corrections

You can find more from the readme.txt file of the package, where you will find that many advanced techniques are implemented. For details of these techniques, refer to:
1. InSAR processing:
C. Liang and E. J. Fielding, "Interferometry with ALOS-2 full-aperture ScanSAR data,"
IEEE Transactions on Geoscience and Remote Sensing, vol. 55, no. 5, pp. 2739-2750,
May 2017.
2. Ionospheric correction:
C. Liang and E. J. Fielding, "Measuring azimuth deformation with L-band ALOS-2
ScanSAR interferometry," IEEE Transactions on Geoscience and Remote Sensing, vol.
55, no. 5, pp. 2725-2738, May 2017.
C. Liang, Z. Liu, E. J. Fielding, and R. Bürgmann, “InSAR time series analysis
of L-band wide-swath SAR data acquired by ALOS-2,” IEEE Transactions on Geoscience
and Remote Sensing, vol. 56, no. 8, pp. 4492-4506, Aug. 2018.

Attached is the 2015 Nepal earthquake deformation imaged by ALOS-2 multi-mode InSAR with ionospheric corrections.

Cunren Liang and Eric J. Fielding

nepal_example.jpg (898.1 kB)


Replies (4)

RE: ALOS-2 InSAR and Ionospheric Correction package released - Added by wfm m 9 months ago

Dear Liang,
I wonder how "MAI" is implemented in your package,which has been mentioned in your article 《Measuring azimuth deformation with L-band ALOS-2
ScanSAR interferometry》.I hope to hear from you soon,than kou!
yours sincerely!
Wenfei MAO.

RE: ALOS-2 InSAR and Ionospheric Correction package released - Added by Yahui Chong 4 days ago

Dear Liang
when I used the split range spectrum to deal with the ALOS1.0 data, I can get the right outcomes, but when I used the TerraSAR data, I can't get the right high/low band SLCs, I suspect that the split range spectrum is not support the TerraSAR data, I want to know whether you have applied the split range spectrum module to the TerrasAR data? Does the split range spectrum module support the TerraSAR data? I am looking forward to your reply! Thank you very much!

RE: ALOS-2 InSAR and Ionospheric Correction package released - Added by Cunren Liang 3 days ago

Hi Yahui,

Range split-spectrum method is implemented for all sensors and acquisition modes supported by ISCE in different applications. I guess you are using stripmapApp.py. Check your paramters in your input file.

Ionospheric correction is not recommended for X-band TerraSAR-X data. First of all, ionospheric effects at X-band is only about 1/64 that at L-band, which, in nearly all cases, only causes negligible errors. Second of all, the performance of range split-spectrum method depends on coherence. The shorter wavelength X-band data have much worse coherence, which might lead to significant errors in ionospheric phase computation. Therefore, eventually you might get worse result after ionospheric correction.

Cunren

RE: ALOS-2 InSAR and Ionospheric Correction package released - Added by Yahui Chong 1 day ago

Hi Cunren

Thank you very much for your recommendation! The purpose of I do range split spectrum to TerraSAR data is not to do the ionospheric correction, but to obtain lower resolution SLC data.As you have said,the signal-to-noise ratio of the data will decreases after split spectrum,I am not sure whether I can get the right interferograms through the high/low band SLC data.

Yahui

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