sarproz-group

GCP and SPS decision

This topic contains 4 replies, has 2 voices, and was last updated by  anarizka 2 years, 1 month ago.

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  • #812

    anarizka
    Participant

    Dear Mr.Daniele

    I have some problem lists below:
    1. I make GCP itself from google earth, in left-below from interest area but in Refl.map value why the GCP still in right-below of image? It looks like I don’t geocoding yet. But from your tutorial, you have not done geocoding too. I think, GCP point in Refl.map must in left-below. Am I miss some steps?

    2. If I want to close SPS windows, the Matlab always deliver message “All temporary files will be deleted”. and If I click “OK” option, some files from SPS processing deleted directly. What must I have done to avoid deleted files?

    Please, find attach file below
    Thanks,
    Ana

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  • #815

    periz
    Keymaster

    Hi Ana

    1) if you plot the GCP in geographic and in SAR coordinates, the 2 pictures will not be matching, because SAR images are plotted with the range in the vertical direction and azimuth in the horizontal one. If you want to plot the SAR image in geographic coordinates, you can press the “Mean Kml” button (in the GCP selection module): you will see (in Google Earth) that everything matches. All these steps are shown in the tutorials

    2) the temporary files in the Multi-Image Sparse-Points (MISP) processing module are used to spare memory and also to allow recovery of possible broken operations. However, you do not need them in normal conditions. In normal conditions, you should save your results in a permanent way through the different “save” buttons you find at the different processing steps (the most important ones are “Save Param” and “Save Coher”, but you may also want to save the read phase and APS for further use). So, if you saved your results, and if you do not want to further process the data with different options, do not worry about closing that window…

    let me know this clears your doubts…
    d

  • #816

    anarizka
    Participant

    Dear Mr.Daniele

    In your tutorial you say that if we are not really satisfied with the automatically selected point. Therefore, we are going to select one manually. Depending on the available data and the resolution, there are different strategies for selecting good tie-points for geo-coding.

    For GCP point problem , I want to make sure that Refl.map value has geocode, right? though it is on right-below of image (in attach file before). Because I am sure that I make good GCP point selection (SAR coordinate point close to geo Coordinate point in GE)
    Please, find attached file below.

    Best Regards,

    Ana

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  • #818

    periz
    Keymaster

    Hi Ana,
    from the pictures you are attaching here I cannot see your problem.
    Did you generate the kmz file of the Reflectivity Map? Only with that kmz you can see if your image has been geocoded well.
    Please consider one factor more: for precise geocoding, you (the software) need to consider also the external DEM.
    if you geocode the reflectivity map using the “Mean kml” button in the GCP selection window, the data will be geocoded without a DEM. In fact, the DEM in SAR coordinates is generated only at the next step. So, for a final accurate geocoding, after selecting a GCP, you need to generate the DEM in SAR coordinates and then use the “extended geocoding” function in “site processing”.
    But you can appreciate the difference only if you have a significant topography in your area.
    Anyway, to check your GCP, generate a kmz map…
    d

  • #819

    anarizka
    Participant

    Dear Prof.Daniele

    I just solve my problem. Now, I can understand why the SAR image (Refl.map) like that.
    Thanks very much

    Best Regards,

    Ana

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