Hello, I am referring to the reprojection problem of GRASS6.x described here: http://www.intevation.de/rt/webrt?display=History&serial_num=3630
To sum up, the GRASS version 5.3+ (i.e., the current version 6.2, too; I'v not tested CVS version) incorrectly reprojects the maps between coordinate system using gnomonic projection (using only sphere as a reference body) and any other coordinate system with projection using ellipsoid. There is obvious erroneous north-south shift of approx 0.19 degree (at 50 deg latitude), very likely due to the different reference body (and mayby because of the mix of of geodetic/geometric latitude - ?). The system proj (http://proj.maptools.org/) works OK, there is not a problem. The old [vr].proj in GRASS 5.0.3 is reprojecting perfectly, without any shift, obviously handling the reference body correctly. I think that there could be some possibility to fix the problem if this old version works OK. Maybe the problem could have been connected with the introduction of the datum transformation function in grass5.3 (http://grass.itc.it/devel/roadmap.php). I would like to ask if there is a possibility to fix the shortcoming. As a workaround, I still have to maintain the old version of GRASS 5.0.3 at one computer just for the reprojections using gnomonic projection. For some reprojection tasks I have available external programs, but the correction of the above mentioned error would be very helpful. If the correction of the error (or feature?) :o) is not planned in the future, let me know, too, please. BTW, is anywhere a repository of old GRASS 5.0.3 for cygwin? I'v found only GRASS 5.4. Thanks in advance for any response. Milan Salek -- ___________ \ o o / Milan Salek \ ^ / Regionalni predpovedni pracoviste \ ~ / Regional Forecasting Office Brno ( ( ) ) Czech Hydrometeorological Institute ( ( . ) ) Kroftova 43, 616 67 Brno, Czech Republic ( ( . ) ) (____________) ) tel.: +420-541 421 072 //// fax : +420-541 421 018 //// E-mail: [EMAIL PROTECTED] cell phone: +420-724 185 618 http://www.chmi.cz Ceska meteor. spolecnost / Czech Meteorological Society: http://www.chmi.cz/poboc/BR/metspol/metspol.html ------------------------------------------------------------ _______________________________________________ grassuser mailing list [email protected] http://grass.itc.it/mailman/listinfo/grassuser
