id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
3989	[patch] subprojection implemented in Lambert 4 Zones, Lambert CC9 Zones and UTM 20N France	pieren	team	"Please apply the attached patch (projection.patch) implementing the subprojections for:

- Lambert (Lambert 4 Zones (France))

- LambertCC9Zones (Lambert CC9 Zones (France))

- UTM_20N_France_DOM (UTM 20N (France))

With this subprojection patch, you can remove the three following source files:

- UTM_20N_Guadeloupe_Fort_Marigot.java

- UTM_20N_Guadeloupe_Ste_Anne.java

- UTM_20N_Martinique_Fort_Desaix.java

I also removed all controls of the projection zones limits because of the MapView bug (see ticket #3987). I would like to reintroduce them later when it will be possible.

For the Lambert 4 Zones projection (Lambert.java), I finally implemented the full projection algorithm, means that the geodesic system is also fully translated from the NTF geodesic system used in Lambert 4 zones to the WGS84 geodesic system. For this full implementation, I have to load and parse a grid file (attached) in the NTV2 format, so I also added an extern NTV2 library for this:

- NTV2Grid.bz2 is the archiv of four new classes NTV2GridShift.java, NTV2GridShiftFile.java, NTV2SubGrid.java and NTV2Util.java;

- ntf_r93_b.gsb is the binary file I stored it in josm/core/data . But if you change its location, the file path must be updated in Lambert class constructor.

With this grid, the Lambert 4 Zones projection is accurate at submillimetric level where we have a differential of 1 to 5 meters with the current version, depending of the location. "	enhancement	closed	major		Core	latest	fixed	projection subprojection