Life doesn't get any easier - one answer brings up a bunch of questions :)
At this moment I am certain that our whole country uses CS-63 for cadastral purposes. BTW, I've done some research and here's what I've found out. It seems that the soviets invented this system to supposedly make it harder for NATO to target their ballistic missiles at the soviet territory. Basically CS-63 is the same Krasovski ellipsoid, Pulkovo datum and Gauss-Krueger coordinate system only with a different nomenclature. The land is split in 1:100'000 zones but these zones have an irregular spape. Also, these zones intersect (SIC!). In our cadastral exchange file specs four zones are mentioned as valid - X, C, P, T. Also 10'000 maps use 3-degree zones instead of 6-degree, hence the coordinate center is shifted 250 Km west (as opposed to 500 Km). Axis meridian of every zone is shifted 30 minutes west. Finally, every zone has its own additional shift of both latitude and longitude several minutes and coodrinate center shift of about 10 Km. The magnitude of these shifts is classified info. It seems that conversion from CS-63 to CS-42 requires different coefficients for every zone. Similarly, I'd need a different SRID for every CS-63 zone. But is that really necessary for our cadastral purposes? I am pretty sure that we're going to have a separate "project" for every town surveyed. Does it really matter what kind of reference system we are using if the project will be isolated and never used with other projects, and its coordinates are consistent within the project? So if I make a PostGIS DB, I guess I can ignore the SRID (set it to -1)? Do you think it's OK to ignore the SRID? -- View this message in context: http://www.nabble.com/Quantum-GIS-and-cadastre-tp14477338p14771556.html Sent from the qgis-user mailing list archive at Nabble.com. _______________________________________________ Qgis-user mailing list Qgis-user@lists.qgis.org http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
