sarproz-group

cumulative displacement

This topic contains 1 reply, has 2 voices, and was last updated by  periz 3 months, 1 week ago.

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  • #2394

    leewoneung
    Participant

    I unchecked Linear processing when I did ‘time series processing’ and ‘Sparse point processing’ too.
    and then I tried cumulative displacement,
    but I couldn’t get the cumulative displacement when ‘LOAD MASK’ step.
    Only “0” when I checked cumulative displacement in Load mask.
    How can I get the cumulative displacment??

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  • #2397

    periz
    Keymaster

    1. it is a surprise for me to discover that you can uncheck such option. we will correct it. anyway, it makes no sense. options are: * estimate, * read, * neglect. No checks corresponds to neglecting it.
    2. neglecting a linear estimate (without other options) means not considering any movement. Not considering any movements, means that no cumulative displacement will be calculated.
    3. the cumulative displacement is calculated when you adopt a non-linear movement. A possible non-linear movement is the non-parametric model implemented by Sarproz. Such model is activated when you select the length of the filter with the “smart” field (e.g. smart=5)
    4. I do not suggest you to use such model with 15 images. I suggest you to use a linear model. The velocity is proportional to the cumulative displacement. so, if you get 10mm/year and the observation time is 10 months, the cumulative displacement is 10/12*10=8.3mm. you can get such value also if you export the time series from the csv file. Or you can plot it using the time series module, by calculating the difference between the last image and the first one http://sarproz.com/manual/ts_module.html (“time series space visualization and export”)
    5. you keep saying that you want to select points through the cumulative displacement. that idea makes no sense in first place. firstly, you have to select coherent points. later you will be able to analyze movements and if you want apply a subselection of moving points
    6. I heard from the colleagues in Beijing that you should receive some training in the future. It will be a chance to clarify these concepts.

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