Attribute: Shift parameters

Acronym: SHIPAM

Code: 138

Attribute type: A

Definition:

Latitude and longitude offsets required to shift a position from one geodetic datum to another.

References:

Indication:

• Lat: Shift parameter in latitude from the specified horizontal datum to the horizontal datum of the data.
• Unit: minutes ('), negative south.
• Resolution: 0.001 minute.

• Lon: Shift parameter in longitude from the specified horizontal datum to the horizontal datum of the data.
• Unit: minutes ('), negative west.
• Resolution: 0.001 minute.

Format:

sxx.xxx, syy.yyy

sxx.xxx: lat syy.yyy: lon s: sign, negative values only.

Example:

-0.03,0.07 in the following case:

Position on specified datum: 20 40 .36 (N) 085 20 .05 (E)

Shift parameters (-0.03,0.07): -0.03 (S) 0.07 (E) ========== ===========

Position on datum of data: 20 40 .33 (N) 085 20 .12 (E)

Remarks

All necessary information for conversion of geographic coordinates from most of the Geodetic Datums in the above list to WGS-84 is contained in the "User's Handbook on Datum Transformations involvin g WGS-84", prepared by the US Defense Mapping Agency and which is available from the IHB as IHO Publication S-60 (English and French Versions), along with an associated standard datum t ransformation software on floppy disk called "MADTRAN". The resulting latitude and longitude offsets can be encoded in the attribute SHIPAM.

Additional information on the transformation as indicated in IHO Publication S-60, e.g. TOY-M (Mean Solution), TOY-A (Japan), TOY-B (South Korea) or TOY-C (Okinawa) in relation to Tokyo Datum, may be encoded in the attribute INFORM or NINFORM.