[gdal-dev] gdal_translate for nc --> tiff. Coords seem to change?

[Even Rouault]

Apologies, I misread your original question. I don't observe a 
difference in min x between the .nc file you observe and the .tif I get 
from gdal_translate. However I see the .tif you uploaded has indeed a 
difference in x, but it also has a UTM CRS, whereas the original .nc 
file has no CRS information, so I'm a bit confused if you attached the 
right .nc file.

Le 29/06/2021 à 00:07, Hill, David Foster a écrit :
> Thank you for the reply. I still don’t understand why the minimum x 
> values from the grids are so different between the .nc and the .tif 
> files. I will continue to try and figure it out.
>
> Regards,
>
> ---------------------------------------------------
> David F. Hill
> Professor
> Civil and Construction Engineering
> Oregon State University
> 220 Owen Hall
> Corvallis, OR 97331
> 541.737.4939
> david.hill at oregonstate.edu <mailto:david.hill at oregonstate.edu>
> http://www.engr.oregonstate.edu/~dfh
> ---------------------------------------------------
>
>
>
>> On Jun 28, 2021, at 2:56 PM, Even Rouault <even.rouault at spatialys.com 
>> <mailto:even.rouault at spatialys.com>> wrote:
>>
>> [This email originated from outside of OSU. Use caution with links 
>> and attachments.]
>>
>> As far as I can see, the netCDF driver behaves as designed. It 
>> reports as the origin the top-left corner of the raster.
>>
>> Le 28/06/2021 à 22:42, Hill, David Foster a écrit :
>>> Here is a link to the .tif:
>>>
>>> https://drive.google.com/file/d/1ZxNdoURdLZS1HRUQUhF-evD1NpuIDcvk/view?usp=sharing 
>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1ZxNdoURdLZS1HRUQUhF-evD1NpuIDcvk%2Fview%3Fusp%3Dsharing&data=04%7C01%7C%7C2968bf9723694d852d0708d93a7f9c9e%7Cce6d05e13c5e4d6287a84c4a2713c113%7C0%7C0%7C637605142036202941%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=TEV9ZAhk1Si3JbX9YJeqCI0unDgOjrxRYxoOIQqnrdk%3D&reserved=0>
>>>
>>> And here is a link to the .nc:
>>>
>>> https://drive.google.com/file/d/1pcXklnup5AxYe3DQfGfsZ3mwwe8WI8mf/view?usp=sharing 
>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1pcXklnup5AxYe3DQfGfsZ3mwwe8WI8mf%2Fview%3Fusp%3Dsharing&data=04%7C01%7C%7C2968bf9723694d852d0708d93a7f9c9e%7Cce6d05e13c5e4d6287a84c4a2713c113%7C0%7C0%7C637605142036212935%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=dx1yLb2i6YCPjnXudnE1JyPHKG1Wywt3IFv%2Foa7Q%2BQc%3D&reserved=0> 
>>>
>>>
>>>
>>> ---------------------------------------------------
>>> David F. Hill
>>> Professor
>>> Civil and Construction Engineering
>>> Oregon State University
>>> 220 Owen Hall
>>> Corvallis, OR 97331
>>> 541.737.4939
>>> david.hill at oregonstate.edu <mailto:david.hill at oregonstate.edu>
>>> http://www.engr.oregonstate.edu/~dfh
>>> ---------------------------------------------------
>>>
>>>
>>>
>>>> On Jun 28, 2021, at 12:53 PM, Even Rouault 
>>>> <even.rouault at spatialys.com <mailto:even.rouault at spatialys.com>> wrote:
>>>>
>>>> [This email originated from outside of OSU. Use caution with links 
>>>> and attachments.]
>>>>
>>>> David,
>>>>
>>>> providing a link to a such file could be useful for investigation
>>>>
>>>> Even
>>>>
>>>> Le 28/06/2021 à 20:59, Hill, David Foster a écrit :
>>>>> Hello.
>>>>>
>>>>> I am new to GDAL, and have spent the past two weeks exploring its use for (largely) nc —> tiff conversions. I am puzzled by a few things, however. I have a .nc file and when I use
>>>>>
>>>>>>> ncdump -c file.nc
>>>>> the coords are shown to me. The min x is 487200 and the min y is 4690100. The grid size is 100 m. If I then do:
>>>>>
>>>>>>> gdal_translate -of GTiff file.nc file.tif
>>>>> and then
>>>>>
>>>>>>> gdalinfo file.tif,
>>>>> it shows the ‘lower left’ corner coordinates as
>>>>>
>>>>> 486790, 4690050
>>>>>
>>>>> For the y coord, I can see how this makes sense…assume that ncdump is giving coords of the grid cell centers, not the ‘corner’ of the grid cells. Thus, the 50 m difference. For the x coord, the values are like 410 m different, so I am puzzled about that.
>>>>>
>>>>> I am sure this is an overly simple question, but I would welcome any tips / guidance on what I am doing wrong. Thank you.
>>>>> ---------------------------------------------------
>>>>> David F. Hill
>>>>> Professor
>>>>> Civil and Construction Engineering
>>>>> Oregon State University
>>>>> 220 Owen Hall
>>>>> Corvallis, OR 97331
>>>>> 541.737.4939
>>>>> david.hill at oregonstate.edu
>>>>> http://www.engr.oregonstate.edu/~dfh
>>>>> ---------------------------------------------------
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> gdal-dev mailing list
>>>>> gdal-dev at lists.osgeo.org
>>>>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>> -- 
>>>> http://www.spatialys.com
>>>> My software is free, but my time generally not.
>>>
>> -- 
>> http://www.spatialys.com
>> My software is free, but my time generally not.
>
-- 
http://www.spatialys.com
My software is free, but my time generally not.

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