sarproz-group

E-W, U-D decomposition

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    • #4858
      sjhossene
      Participant

      Hello dear colleagues
      one question
      The following figures show the deformation evaluation of the 2 salt diapirs in the ascending and descending tracks.
      Why are the values ​​inverted in two ascending and descending tracks ?

      The following figure 2 shows Vertical Velocity Displacement along Ascending and Descending tracks

      thanks in advance

      • This topic was modified 2 weeks, 3 days ago by sjhossene.
      • This topic was modified 2 weeks, 1 day ago by periz.
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    • #4866
      periz
      Keymaster

      Those values are not vertical, they are range displacement, which means, along the LOS, inclined w.r.t. the vertical.
      Please read well the basic theory of SAR.
      if you generate TS objects, you can load them in the multisensor module and combine them to estimate vertical and horizontal components
      range movement can have opposite signs in asce/desce datasets if the movement is in fact horizontal
      best

    • #4867
      sjhossene
      Participant

      Hello professor
      Thanks for your quick response.
      That is true.
      These values ​​are along LOS. I generated TS objects for AS&DS and then loaded them in the multi-sensor module and combined them to estimate the vertical components.

      Figure A shows combination of Ascending-Descending TS objects.

      And Figure B shows combination of Ascending -Descending TS
      objects.

      As you can see in the figures below , the values have ​​inverse and opposite signs?!

      Thank you for explaining why they are the opposite!
      Thanks a lot

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    • #4870
      periz
      Keymaster

      you are plotting them together, you are not decomposing them
      please download the last version of the software and use the AD grid
      best

    • #4871
      sjhossene
      Participant

      Hello professor
      Thanks for your quick response.

      How can I decomposing them?
      I downloaded the last version of the software today and did these steps to to estimate the vertical and E-W components.

      1- Imported TS objects for AS&DS tracks and loaded them in the multi-sensor module. In this step PASS and Track in upper table are empty!? while PASS option is in PDF tutorial SW.
      2- To Offsets Estimation: set 5,5 and 20 for “Max Planar Distance” , “Max H Dist” and “Nr Bins”, respectively.

      3- In this Step, The software gives this message
      “”Estimated Offsets: Lat 12.6 [m], Lon 74.2 [m], Height -123.3 [m]
      get_ms_pairs: WARNING!!! reference acquisition pass is empty!! “”

      So how should I do the steps.

      Are there any instructions for doing these steps? Or a PDF training file?

      VERY THANKS

    • #4877
      periz
      Keymaster

      Hi,
      for some reasons it was not recorded if your dataset was ascending or descending.
      We now added the possibility to manually fix this missing info.
      Later today or tomorrow update again your sw with the last version.
      follow these steps:
      1. open the multi-sensor module
      2. load the asce and desce TS objects.
      3. if the pass is missing (3rd field) manually edit the field and input ASCENDING or DESCENDING according to the orbital info of your datasets
      4. the offsets estimation was implemented to work well in urban areas with high resolution. since this is not your case, it might not return the best result. so, plot your points and judge yourself if they are well aligned. if yes, leave offsets to zero. if they are not aligned, you can manually input the shifts (offs lat, offs lon) to try to align them better. Values are in meters.
      5. skip the AD pairs
      6. generate a grid with your preferred step (it’s in meters)
      7. in results visualization, select “grid” and then e/w or u/d velocity or cumulative displacement, other options according to your wishes and plot it. you can also export it. but the time series are not yet implemented. this will come out sometime later on
      best

      • #4881
        sjhossene
        Participant

        Hello professor
        Thank you for your quick response and accurate.

        Please let me ask you three questions in this regard

        1- How can we calculate time series changes along east -west and vertical velocity for a given point?

        2- Is not possible to export e-w velocity and vertical velocity in Multi- Sensor Module or other section of SARPROZ?

        3- What are the positive and negative values ​​in the east-west exit maps?

        Thank you

      • #4892
        periz
        Keymaster

        1. check here https://www.sarproz.com/groups/sarproz-group/forum/topic/combine-different-geometries-for-decomposition-of-los-motion/

        2. e-w, u-d velocities can be exported from the multisensor module

        3. check 1.

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