[Gdal-dev] ENVISAT data comes out left-right fliped

[Frank Warmerdam]

On 2/3/06, Julien Demaria <dem at acri-st.fr> wrote:
> Joaquim,
>
> This isn't a bug.
> MERIS Envisat files are geolocated using a GCPs list (in fact one GCP
> every 16 pixels). In the swath the file is left-right fliped, but it's
> the specifications. If you want apply the GCPs projection and then flip
> LR the file, you should use the gdalwarp GDAL utility:
> gdalwarp MER_RR__1_Mediterranean.n1 MER_RR__1_Mediterranean.tif
> (tested on Linux with FWTools-linux-1.0.0a7).
>
> I've successfully viewed your file using FWTools OpenEV (FWTools1.0.0a8
> on Windows). With it you can directly display (unflipped) your .n1 file
> since OpenEV reproject on-the-fly the file using GCPs :)

Joaquim,

Julien is dead-on in his analysis.  The images are
stored in a manner related to how they are collected,
but the geolocation info (GCPs) should allow you to
warp the image to north up if that is what you need.

Best regards,
--
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