Geodetic Systems

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Geodetic Systems by Island

The geodetic control infrastructure of the Cayman Islands is currently based on four Continuously Operating Reference Stations (CORS); one in Cayman Brac (CBMD), one in Little Cayman (LCSB) and two in Grand Cayman (GCFS and GCEA).

Data are stored in RINEX format and are available free for post processing. Real time corrections for RTK surveying are available as a subscription package.

For more information on subscribing for real time corrections, please contact the Chief Surveyor.


SystemCayman BracLittle CaymanGrand Cayman
Global Geodectic DatumCIGD11CIGD11CIGD11
Datum TransformationCIGD11-SIGD61CIGD11-SIGD61CIGD11-GCGD59
Local Geodetic DatumSIGD61SIGD61GCGD59
ProjectionTM (UTM Zone 17N)TM (UTM Zone 17N)TM (UTM Zone 17N)
National GridSING61SING61GCNG59
Verical DatumCBVD61LCVD61GCVD54
Geoid ModelCBGM0811LCGM0811GCGM0811

Grand Cayman & Sister Islands

The Cayman Islands Geodetic Datum 2011 (CIGD11) is in use on Grand Cayman, Cayman Brac and Little Cayman. CIGD11 is based on ITRF05(2011.0) positions.

In order to convert GPS Latitude Longitude Heights referenced to CIGD11 into the current Grand Cayman national grid (GCNG59), while Sister Islands national grid (SING61). The seven parameter transformation for Grand Cayman CIGD11-GCGD59 (Sister Islands CIGD11-SIGD6) and UTM projection parameters for zone 17 north are required.

The Grand Cayman Geoid Model (GCGM0811) facilitates GNSS observation of ground elevations. Expected accuracy is 0.1 feet RMSE.

Both the Cayman Brac Geoid Model (CBGM0811) and the Little Cayman Geoid Model (LCGM0811) are now in use on their respective islands. Expected accuracy of GNSS observed elevations is 0.1 feet RMSE.