The following table lists the predefined units available to measure coordinates.
For the Latitude/Longitude pseudo-projection, angular measurement units are used to measure the coordinates.
|
FME Unit Name |
Full Name |
Unit Length in Metres |
|
BENOITCHAIN |
Benoit chain |
20.11678249438 |
|
BenoitLink |
Benoit link |
0.2011678249438 |
|
Brealey |
Brealey units |
375.0 |
|
CAGRID |
Canadian grid unit |
0.999738 |
|
CAPEFOOT |
Cape foot |
0.3047972615 |
|
CENTIMETER |
centimeter |
0.01 |
|
CLARKECHAIN |
Clarke chain |
20.1166194976 |
|
CLARKEFOOT |
Clarke foot |
0.3047972651151 |
|
CLARKELINK |
Clarke link |
0.201166194976 |
|
FOOT |
US survey foot |
0.30480060960121920243 |
|
GERMANMETER |
German meter |
1.0000135965 |
|
GUNTERCHAIN |
Gunter chain |
20.11684023368047 |
|
GUNTERLINK |
Gunter link |
0.2011684023368047 |
|
IFOOT |
international foot |
0.3048 |
|
IINCH |
international inch |
0.0254 |
|
IMILE |
international mile |
1609.344 |
|
INCH |
inch |
0.0254000508001016002 |
|
IYARD |
international yard |
0.9144 |
|
KILOMETER |
kilometer |
1000 |
|
METER |
meter |
1.0 |
|
MILE |
mile |
1609.34721869443738887477 |
|
MILLIMETER |
millimeter |
0.001 |
|
NAUTM |
nautical mile |
1852.0 |
|
ROD |
rod |
5.02921005842012 |
|
ROOD |
South African rood |
3.778266898 |
|
SEARSCHAIN |
Sears chain |
20.11676512155 |
|
SEARSLINK |
Sears link |
0.2011676512155 |
|
SEARSYARD |
Sears yard |
0.914398414616029 |
|
YARD |
yard |
0.91440182880365760731 |
Unit Definition
Custom coordinate units are defined when coordinates are measured in units, not in the predefined set of units.
Unit definitions may occur in an FME mapping file, as well as in the LocalCoordSysDefs.fme. The syntax of a unit definition is:
UNIT_DEF <unit name> \
UNIT_TYPE <unit type> \
UNIT_ABBREVIATION <unit abbreviation> \
UNIT_FACTOR <unit size>
Unit Definition Parameters
|
Name |
Range |
Description |
Optional |
|
<unit name> |
any string |
The name of the unit being defined. |
No |
|
<unit type> |
ANGLE | LENGTH |
Specifies whether the unit measures angles or lengths. |
No |
|
<unit abbreviation> |
any string |
This abbreviation represents the unit and may be used in coordinate system definitions instead of the <unitname>. |
No |
|
<unit size> |
Floating point number |
The size of a unit in metres if it measures length. If the unit measures angle, then this is the size in degrees. |
No |
Example Unit Definition
This mapping file fragment defines a unit equivalent to the CAGRID used to perform coordinate conversions from NAD27 Grid to NAD83 Ground:
UNIT_DEF GRIDUNIT \
UNIT_TYPE LENGTH \
UNIT_ABBREVIATION GRD \
UNIT_FACTOR 0.999738