Global Mapper Pro

|Metadata, extent different in GM and in QGIS

alberto_fr
alberto_fr Global Mapper UserTrusted User
Hello,
Im dealing with QC and i have to make some calculations related to a combination of extent coordinates and resolution, the question is that i find differences in Gm 22.0 b101920 challenged to QGIS extent... I thought there was just an extent...
Could you please let me  know what do you think about it?

https://www.dropbox.com/s/hpsajp8trd2ydg3/dtm.rar?dl=0

GM 22 QGIS
UPPER LEFT X=724882.500 724880.000
UPPER LEFT Y=2686897.500 2686900.000
LOWER RIGHT X=745452.500 745455.000
LOWER RIGHT Y=2665647.500 2665645.000


Thanks in advance,
Alberto

Best Answer

  • bmg_bob
    bmg_bob Global Mapper Programmer
    Accepted Answer
    Hello,

    In the metadata for a DTM, the UPPER LEFT and LOWER RIGHT values represent the center of the upper left and lower right pixels in your data. Since each pixel is 5 meters square, the true boundary would be found by expanding the rectangle by 2.5 meters in each direction. To see the actual bounds:
    • Right-click on the layer in the Control Center 
    • Choose Layer > BBOX/COVERAGES... Click the Yes button to create a rectangular area feature. 
    • After the new layer is added to the Control Center, view its Metadata to see the bounding coordinates.
    Cheers,
    Bob

Answers

  • alberto_fr
    alberto_fr Global Mapper User Trusted User
    Thank you Bob,
    I think i can step forward with this answer,
    Thanks again,
    Regards,
    Alberto
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