| Number | Meaning |
|---|---|
| 0 |
Earth assumed spherical with radius = 6,367,470.0 m |
| 1 |
Earth assumed spherical with
radius specified by data producer |
| 2 |
Earth assumed oblate spheriod
with size as determined by IAU in 1965 (major axis = 6,378,160.0 m, minor axis = 6,356,775.0 m, f = 1/297.0) |
| 3 |
Earth assumed oblate spheriod
with major and minor axes specified by data producer |
| 4 |
Earth assumed oblate spheriod
with definedin IAG-GRS80 model (major axis = 6,378,137.0 m, minor axis = 6,356,752.314 m, f = 1/298.257222101) |
| 5 |
Earth assumed represented by
WGS84 (as used by ICAO since 1998) (Uses IAG-GRS80 as a basis) |
| 6 |
Earth assumed spherical with radius = 6,371,229.0 m |
| 7-191 |
Reserved |
| 192-254 | Reserved for Local Use |
| 255 |
Missing |