Layer shifting a fixed distance

When the default image coordinates of an image is not accurate enough, the "Layer shifting a fixed distance" function is extremely useful. Sometimes, however, it seems not to work properly, and it also changes the projection. This is illustrated below with an ASTER image, which I have  in ENVI format. The first image (in red) is to be moved 70 m east and 15 m south so that it pefectly fits the second ASTER image, below.




But when I am shifting it by any distance in meters, either by specifying offset "as fixed X/Y distance offsets" or "as distance and bearing", the whole image is reprojected, as you can see below:


 Looking at the layer projection tab, the projection was not modified.
I could not figure out what is the logics behind this behaviour...
a.jpg 149.7K
b.jpg 185.9K
c.jpg 162.4K

Answers

  • tikhpetrtikhpetr Posts: 46
    Seti Check the coordinate systems of both images. Take any image and try moving it using the function "Shift".
    If this is not confidential data, post it (link). I would like to see.
  • SetiSeti Posts: 6
    Hi tikhpetr; thansk for your response. The coordinate system is for both Lat/Lon, with WGS84 as the projection, but the issue is independent of the second image. I am showing it here mainly to illustrate how the first image should look like after shifting, both should be perfectly superimposed. Shifting the first image without anything else on the screen leads to a similar result. 
    It is true, however, that in the algorithm, which contains several tens of satellite images (I need all of them for time series monitoring), some are in UTM. 
    tikhpetr said:Take any image and try moving it using the function "Shift".
    For some images it works, for some it does not, but I have not found the logics. For instance, I could shift a majority of ASTER images very easily, as well as images from other sources. OrbView-3 imported from USGS Earth Explorer is fine. But some ASTER images area reluctant.
    tikhpetr said:
    If this is not confidential data, post it (link). I would like to see.
    It is not confidential, one of the reluctant images is here:
    https://uncloud.univ-nantes.fr/index.php/s/xQqoZWMKm3La9qn
     I might also give you access to the algorithm through TeamViewer.

    Many thanks for helping!
     
  • tikhpetrtikhpetr Posts: 46
    Hi, Seti!
    I looked at your image. Committed action:
    1.
    - moved the source raster over your distances and according to my azimuth and distance - 0 result
    - export source raster to format GeoTiff and previous actions - 0 result
    - Changed the projection to UTM 37N - 0 result
    - Created a polygon at the corner points of the source raster and downloaded this territory from another resource - result OK!
    2. Opened source raster in ArcGIS result - OK! 
    Total:
    In GM i unfortunately can not help you. Sorry!

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