[FWTools] gdal_translate, -a_srs, -a_ullr, and Projections with Rotations

[Peter Willis]

Hello,

Well, I tried with GCPs but no UTM geography is applied to
the output unless I supply the '-a_ullr' option. Using
-a_ullr causes the GCPs to be ignored and the same pixel
size calculation errors occur due to the rotation and
the actual bottom right coordinates with respect to the
upper left.

gdal_translate appears to be calculating the pixel size
based on the UL and LR corners, which is normal. However,
with GCPs there should be more of a rotation/translation
applied to the geography.

Perhaps an option to override the pixel size calculations
in each dimension should be added to the utility...

Peter


Peter Willis wrote:
> Hello,
> 
> I just noticed the '-gcp' option for gdal_translate.
> It occurs to me that this should provide the required projection
> adjustments.
> 
> Peter
> 
> 
> Peter Willis wrote:
>> Hello,
>>
>> I am applying geography to some UTM based images.
>> The images have a 1.9 degree rotation.
>>
>> Is there a way to assign a rotation to the projection
>> using gdal_translate?
>>
>> If not, is there a way to assign the rotation using
>> any other GDAL tools?
>>
>> Thanks
>>
>> Peter
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>>
>>
>>
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