FME Form: 2024.1
Defining New Ellipsoids
Certain sites may require an ellipsoid that is not predefined in the FME. In such a case, a custom ellipsoid may be created. Ellipsoid definitions may occur in an FME mapping file, as well as in the LocalCoordSysDefs.fme.
The syntax of an ellipsoid definition is:
ELLIPSOID_DEF <ellipsoidName> \
DESC_NM
<descriptive name> \
SOURCE
<source> \
E_RAD
<equator radius> \
P_RAD
<polar radius>
Example Ellipsoid Definition
This mapping file fragment defines a sample ellipsoid:
ELLIPSOID_DEF myEllipse \
DESC_NM
“Safe Sample Ellipse” \
SOURCE
“Safe Software Inc.” \
E_RAD
6377340.128 \
P_RAD
63356034.448
Ellipsoid Definition Parameters
Name |
Range | Description | Optional |
---|---|---|---|
<ellipsoidName> |
any string |
The name of the ellipsoid being defined. |
No |
<descriptive name> |
any string |
A descriptive name for the ellipsoid. |
Yes |
<source> |
any string |
The individual or agency providing the ellipsoid parameters. |
Yes |
<equator radius> |
floating-point value |
The radius of the ellipsoid in meters at the equator. |
No |
<polar radius> |
floating-point value |
The radius of the ellipsoid in meters in the polar direction. |
No |