The Custom Projection panel

Top  Previous  Next

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 DigiTerra Explorer Map (.EXP) / DigiTerra Map Pack (.DMP) files and in the user.db3 file


On the Source Datum tab you can define the GPS Datum when using Real Time Corrections with different Source Datum (not WGS 84)


Source Datum tab