jeudi 26 février 2015

Worldfile incorrect? Puzzler: all resources supplied!


Trying to manually create a worldfile for gif images of surface currents supplied by the navy here. I have QGIS and am decent at using it but the world file tool is failing without error on me (even after recompiling GDAL).


So I have both been manually calculating world files and using this website. Repeatedly, I am coming up with the same numbers, but they can not be correct, at least not in the vertical. The resulting world file places the four corners in the correct spot, but pixels are incorrectly distorted in the vertical, and I believe it is only wrong in the vertical-see image of georeferenced TIF vs world file oriented GIF with Gulf lease areas for reference (those boundaries should not be on the coast). I have gone back to square one and georeferenced the source image several times, checked my calculations, and attempted to track down any copy of Arc I could borrow or a QGIS expert to help get the tool working. I now turn to you all. Can anyone help me generate the correct numbers for this world file? What gets me is that I've been able to correctly do this for other images from the NRL site.... this one is just always slightly off.


enter image description here


Current (almost correct but at least line 4 is wrong) world file:

1) 0.02271210592255126

2) 0.00000

3) 0.00000

4) -0.02039280161507402

5) -98.38164194703873

6) 33.08804759959623


GCP file from QGIS if anyone wants a look: http://ift.tt/1vE9Ev2





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