Some georeferencing fails for some images from NGA

[jdfergason]

In nitfimage.c there is little bit of code that appears to break georeferencing for *SOME* files from NGA. Basically the georeference shows up way off target. Older versions of GDAL (1.3.0 and back) do not have this issue and I tracked the culprit down to bug fix #1750 in nitfimage.c When I remove this bit of code it works just fine for all the files that I have. The code I removed is listed below.

    /* Bug #1750 */
    /* Fix for cjnc/cjncz01/000k1023.jn1 (and similar) from NIMA GNCJNCN CDROM: */
    /* this product is crossing meridian 180deg and the upper and lower right longitudes are negative (<-170) */
    /* while the upper and lower left longitudes are positive (> 170) which causes problems in OpenEV, etc... */
    /* So we are adjusting the upper and lower right longitudes by setting them above +180 */
    if( (psImage->chICORDS == 'G' || psImage->chICORDS == 'D') &&
        (psImage->dfULX > 170 && psImage->dfLLX > 170 && psImage->dfURX < -170 && psImage->dfLRX < -170 &&
         psImage->dfULY > psImage->dfLLY && psImage->dfURY > psImage->dfLRY) )
    {
        psImage->dfURX += 360;
        psImage->dfLRX += 360;
    }

[rouault]

If you hit the special case of that "if", it should mean that you have an image with meridian 180° in the middle of it. The 360 shift to the upper and lower right longitudes is supposed to avoid that they are negative. It is preferable in many applications that they are a bit above 180° rather than negative.

Can you provide more info on the expected georeferencing of your image ?

[rouault]

jdfergason, any news on that topic ?

[warmerdam]

jdfergason,

I'm closing now for lack of followup. If you can provide more information please just reopen this ticket.

Thanks.