APS estimation for a part of the area


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

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  • #1552


    Hello Daniele,

    I am processing an area of approx 10×10 km, trying to estimate APS.

    However, the extracted area is much larger in order to improve the S-1 coregistration.

    Is it somehow possible to limit the area for APS estimation? I tried to use scatter plots to save the points and load them in the APS window, but it does not work (seems to have a different format…)

    In my case, maybe I do something wrong (I am not experienced in APS estimation), but the computation seems to take several hours (and it is not necessary to compute the whole area).

    Thank you for an advice, Ivana

  • #1553


    The idea was correct,
    but you should not LOAD the points, you should pick up the file you saved using the menu on the left (menu item: choose a real file).
    Save/Load options use an internal format. While saving a subselection of points from scatter plots writes values in a SxL matrix (the common sw format). Make sure to choose also a parameter for the Color axis in scatter-plots: this will save such parameter in the SxL matrix (instead of just ones). The APS module may use the value for optimization purposes.
    About long time:
    a. check that the process is parallelized. sometimes matlab takes time to start the pool and the process starts in serial way
    b. long time may be taken if u are processing totally noisy points or if NaNs are in the data (in this second case, u get messages).
    I believe that after a few cases u will understand which options to choose to better choose points and limit the time…

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