INSAR in Active Landfill

[oguzhannysr]

@Alex-Lewandowski @khogenso @piyushrpt, Hello, first of all, thank you for reopening OSL. I want to monitor a garbage facility until 2024-01, but I couldn't make sense of the results I got. Probably because the coherence values ​​of the area are low, the values ​​of most pixels do not reflect the expected deformation. The garbage area is actively working. While obtaining data from NASA, I left the phase filter as 0.6 as default and also selected the look as 10x2. I need "meaningful" deformations in these areas. Can you help? What do you recommend?

pbaseHistory.pdf
network.pdf
coherenceMatrix.pdf
rms_timeseriesResidual_ramp.pdf
rms_timeseriesResidual_ramp.txt

[Alex-Lewandowski]

Hi @oguzhannysr I agree; it looks like you are running into issues with coherence. There is likely too much surface deformation between acquisitions, due to the fact that this is an active landfill. I do not believe that adjusting the adaptive phase filter or the number of looks will improve coherence. You could try reducing the temporal baseline to 24 days. Given a 12-day repeat-pass cycle, that would reduce the time between acquisitions as much as possible while still maintaining triplicate pairs of interferograms for MintPy. If you are looking at periods when both Sentinel-1A and Sentinel-1B were active, you could potentially reduce your temporal baseline to 12 days.

Looking ahead to NISAR, L-band SAR may help in situations like these due to its longer wavelength. It will accommodate more deformation between scene pairs.

We have recently reorganized and migrated our MintPy workflow to a Jupyter Book in a new repo. If you are still using the notebooks in this repo, you should take a look at the update here: https://github.com/ASFOpenSARlab/opensarlab_MintPy_Recipe_Book

It is also cloned to your OSL account and can be found at: ~/Data_Recipe_Jupyter_Books/opensarlab_MintPy_Recipe_Book

[oguzhannysr]

@Alex-Lewandowski thank you Alex, I made some experiments taking your suggestions into account (24 or 12 day intervals, changing the phase filter value to 0.4 and 0.19, etc.). After lowering the phase filter and obtaining the data from NASA, I produced new results. I took higher deformation values ​​for the garbage area I specified. These are as I expected, but they are very large in value (for example, in the garbage heap area, I detected a total of 30 cm deformation in 9 months in the same date range.). This value is very large, but I am not sure whether it is normal for a garbage facility that is constantly operating actively, and whether these results reflect the correct deformation in value. I need to produce a "meaningful" result for this field.

[oguzhannysr]

@Alex-Lewandowski , I'm waiting for your help..

[Alex-Lewandowski]

Hi @oguzhannysr, I cannot provide insight into the meaningfulness or accuracy of your specific results monitoring landfills. These workflows are designed as examples to help scientists begin to learn about and work with SAR data, but they are only one educational resource. If you are interested in learning more about interferometry and its benefits and limitations for your use case, I recommend Dr. Franz Meyer's courses on EdX, which are available for free if you don't need completion certificates. Here is a link to the first course in the SAR series: https://www.edx.org/learn/data-analysis/university-of-alaska-fairbanks-synthetic-aperture-radar-foundations