[osg-users] [vpb] Correct way to get texture data from USGS or any other source?

[Sebastian Messerschmidt]

Am 09.06.2015 um 23:05 schrieb Elias Tarasov:
> Hello!
> Thanks for quick reply, it helped to solve a problem.
>
> SMesserschmidt wrote:
>> Am 09.06.2015 um 11:35 schrieb Elias Tarasov:
>>
>>> ...
>>> there is a bunch of links to get data. Since --geocentric option allows not to use elevation data, then only textures are needed.
>>>
>> Who told you this? Of course you can use elevation data in geocentric
>> mode ...
>> Simply use -t for imagery and -d for digitial elevation data
>> ...
>> Don't doubt the arguments we used this time. Yes, there is no -d option and thus no
>> elevation map specified. As we have already indicated to use the geocentric system
>> to build from the source, VPB will automatically use flat sea-level elevation data and
>> construct the earth geometry according to the given GeoTiff imagery.

Yes but you still CAN use elevation data relative to the ellipsoid.
>
>>
>>> And here is a problem: i can't get georeferenced textures from USGS.
>>>
>> They are referenced, but in a non-supported coordinate frame. I never
>> had problems of this kind yet.
>> But there are definitively geo-referenced data-sets on USGS, as I'm
>> using them myself.
>>
> Yes, they are. Just in a different projection, it seems.
>
>> Use LandSAT imagery, which is WGS84 projected, so there should no
>> problems here.
>>
> Actually, problems are exist. This is the LandSat image from USGS
> ...
>
> Now datum is WGS84, but vpbmaster shows again
> Error: vpbmaster can not run without all source data being in the correct destination coordinates system, please reproject them.
>
> Maybe because PROJCS["WGS 84 / UTM zone 33N", not just WGS84?
That is UTM with reference datum WGS84*. Don't mix them up. One is the 
projection (UTM at the zone 33North) using the reference ellipsoid WGS84.
Usually it will be transformed/reprojected automatically. Can you try 
osgdem instead of vpbmaster? I think the distributed version (vpbmaster) 
indeed won't work on data not being "adapted".
Also make sure you have the gdal/proj libraries  accessible for the 
osgdem application.

*(WGS84 defines the "sea level" by approximating the earth's shape by an 
ellipsoid)
>
>
>> If you need some sample data I can share a small set on googledrive etc.
>>
> That's very kind, Sebastian, but the problem seems to have been solved already.
>
> To use data with vpb i need to reproject them.
>
> gdalwarp -s_srs EPSG:2238 -t_srs EPSG:4326 src.tif dst.tif
>
> Now produced *.osgb image looks correctly into OSG viewer. However, it also looks quite plain. So elevation data is needed?
If you need elevation data or not is totally up to you. Usually you 
don't need to re-project manually (see above).

Cheers
Sebastian