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Hi,
There’s simple approach for LOS decomposition published here (see Appendix):
https://earth.esa.int/workshops/fringe09/proceedings/papers/s12_3esfa.pdfThe strategy is further described and applied for example here (Section 4. Results, end of page 4):
https://reader.elsevier.com/reader/sd/pii/S1877050916324346?token=771278C7AFAA466F3FEEF289F7DDE6C8713E460ECCAC46B1744B76C398E13CFE4F2CCE6624E6054633DA8418CD70D520Although, east-west component refers to “azimuth look direction” here and only 2 orbit tracks are used, for obtaining east-west component and more robust transformation 3 or more satellite tracks should be used (some details can be found here: https://www.springer.com/la/book/9781402094279). Obtaining vertical component should be even easier as you just need to multiply LOS displacement with cosine of an incidence angle.
Cheers
Matus
Hi Iza,
for now, you should use only one type of the orbit – ascending or descending. Generally, minimum of 20 images is advised to perform PSInSAR analysis, but you might find also lower number of images suitable, however as you said – the more the better.
Cheers
Matus
Yasser, “Custom Mask Generation” under Sparse Points Selection in Site Processing window could help you also.
I would consider KML export from Small Area quite handy as well. The best part of it are possible fast changes of Ref. Point since exporting through Sparse Points Processing requires APS processing until Ref. Point is selected and playing with Load Mask/Scatter plots.
Hi Nader,
I would suggest to be patient. As in other processing windows you have to be familiar with what you are doing. Any of us that started with SARproZ has been experimenting with it for months until obtaining some reliable results, as its not a magic box where you press buttons and get outputs (like any other InSAR related software). First of all you are trying to estimate APS with 6 images? APS is estimated upon connections of the points (arcs) that you have defined by thresholding on Spatial Coherence. By including all zero values under Graph Creation you are using Delaunay graph, i.e try to exchange those values for 0 90 0 0 and you’ll see other type of graph – Flowered Tree – with the PSs in centers that are connected to the surrounding points in radius 90 [pix]. If you’ll change all the values e.g. Min Nr of points (e.g. 5) found within Minimum radius (25 [pix]) and Maximum radius (100 [pix]) with Radius step (25 [pix]) you’ll get user defined graph. What are the advantages of such types of connections? Then within network created upon such rules you are estimating Linear Trend without Height and without External DEM as reference? Is there any particular reason for that? In the end there are different types of APS you can deal with – Inverted Parameters (I.P.), Inverted Residuals (I.R.), Triangular Inverted Residuals (Tri I.R.), etc. I am sure you’ll find some comment on each option included in this window on this Forum as you’ve been allowed to research through it and for the second time advised to use it, see for example this:
http://www.sarproz.com/groups/sarproz-group/forum/topic/aps-processing-parameters/Good luck and keep going on!
Matus