The Custom Projection panel

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The Custom Projection panel

The Custom projection panel consists of the following controls to customize the selected projection:


Datum tab



Add favorites: adds the selected projection to the Favorites


Datum tab:


Type of: Select a projection type (algorithm).



Stereographic projection


Transverse Mercator

Oblique Mercator

Hotine Oblique Mercator

Lambert conformal conic

Hungarian stereographic

Hungarian cylindrical

Hungarian Unified projection

Swiss cylindrical

Romania TransDat 2009


Projection tab:


Projection tab



Datum parameters


Spheroid (a, 1/f): Semi-major Axis, Inverse Flattening ratio.


Offset (dx, dy, dz): Offset DX, DY, DZ to WGS84 parameters in meter.

Rotate (rx, ry, rz): Rotate RX, RY, RZ to WGS84  parameters in arc seconds.

Scale (s): Scale Factor in ppm.


Projection parameters


Ref. longitude (la0): Origin Longitude in degree.

Ref. latitude (fi0): Origin Latitude in degree.

1st latitude (fi1): First Latitude in degree.

2nd latitude (fi2): Second latitude in degree.

Scale (m): Scale Factor.

Unit scale: Unit scale value (indicates the unit value in meter).

Origin (fe, fn): False easting, False nothing.


k-tip-iconThe modified Datum and Projection parameters are stored in in TopoLynx topoXplore Map (.EXP) / TopoLynx Map Pack (.DMP) files and in the user.db3 file



Boundaries tab



You can set the boundaries of the projection in degrees (WGS84 coordinates) and you can also edit or copy the Proj4 text which describes the projection.