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Australian Geodetic Datum 1966 (AGD66) in PNG and Transformation Parameters

The Australian Geodetic Datum 1966 (AGD66) EPSG Code 4202 was the geodetic datum used in Papua New Guinea until 1998 when it was superseded by PNG94. While PNG94 is the mandated geodetic datum for all new surveys conducted in PNG, some PNG legislation (e.g. Mining and Oil & Gas) still refers to AGD66 as the legal geodetic datum for reporting of coordinates and lease boundaries. The PNG Oil and Gas leglislation identifies AA 070 Bevan Rapids as the geodetic origin for AGD66 in Papua New Guinea. It is defined as follows:

Reference Ellipsoid: ANS
Map Projection: Australian Map Grid 1966 (AMG66)
Projection type: Universal Transverse Mercator (UTM)

AGD66 is still required for well location reporting and lease boundary definition by PNG Oil and Gas legislation. The existing 1:100,000 topographic map sheets are still defined in terms of AGD66, however these maps will be updated to PNG94/WGS84 in the near future (2015). AGD66 is also still used on projects commenced before 1998. AGD66 is not recommended for any other purpose as it is now superseded by PNG94

Transformation of coordinates between AGD66 and PNG94
AGD66 to PNG94 coordinate transformation parameters are currently only estimated for the PNG Mainland, the Papuan Fold and Thrust Belt Area (PFTB) and the North Fly Area. The listed parameters are all traceable to the AGD66 geodetic origin AA 070 at Bevan Rapids in Gulf Province. The PFTB is the location of the main PNG oilfields (Hides, Kutubu, Gobe, Purari). PFTB parameters are valid between Latitude -5.59 deg and -8.28 deg and Longitude 142.24 deg and 144.75 deg. The North Fly area is the location of the Ok tedi mine and Stanley/Elevala gas fields. The North Fly parameters are valid between Latitude -5.04 deg and -6.36 deg and west of Longitude 141.32 deg to the PNG border. The 7 parameter PFTB and North Fly transformations are recommended for use in those areas. Accurate parameters for other PNG islands will be estimated once more surveys on AGD66 primary control on those islands are completed.

Important usage note: The rotation convention used is the "Position Vector" method. If the "Coordinate Frame" method is used, the signs of the rotation parameters will need to be changed.

AGD66 to PNG94 transformation parameters
 Area of Use  EPSG Code  Accuracy (m)  Tx (m)  Ty (m)  Tz (m)  Rx (sec)  Ry (sec)  Rz (sec)  Sc (ppm)
Medium accuracy - 7 parameter Position Vector convention
PNG Mainland69371.0-0.41-2.372.003.5923.6983.9898.843
PFTB 69391.0-131.876-54.554453.346-5.2155-8.20420.09005.02
North Fly 69410.545.928-177.212336.867-4.6039-3.09210.572936.796
Medium accuracy - 7 parameter Coordinate Frame rotation convention
PNG Mainland69371.0-0.41-2.372.00-3.592-3.698-3.9898.843
PFTB 69391.0-131.876-54.554453.3465.21558.2042-0.09005.02
North Fly 69410.545.928-177.212336.8674.60393.0921-0.572936.796
Lower accuracy - 3 parameter
PNG Mainland69384.0-129-58152
North Fly69422.5-137.4-58.9150.4

AGD66 to WGS84 transformation parameters (3 parameter) in PNG
 Area of Use  EPSG Code  Accuracy (m)  Tx (m)  Ty (m)  Tz (m)
PNG Mainland69435.0-129-58152
North Fly69454.0-137.4-58.9150.4

Coordinate transformations:
The map projection for AGD66 is the Australian Map Grid 1966 (AMG66). AMG66 is a UTM projection (Southern Hemisphere) with three Zones in Papua New Guinea:
AMG66 Zone 54 (west of 144 degrees E) EPSG Code 20254
AMG66 Zone 55 (between 144 and 150 degrees E) EPSG Code 20255
AMG66 Zone 56 (east of 150 degrees E) EPSG Code 20256
0.5 degree zone overlaps are permissable for projects located on a UTM zone boundary.

Datum precision:
In PNG, AGD66 Horizontal Coordinates of AGD66 have a Positional Uncertainty of 5 metres

Technical Questions and enquiries:
Contact Richard Stanaway richard.stanaway@quickclose.com.au for any technical information regarding PNG94, transformations and vertical datums.

2010-2014, Association of Surveyors of Papua New Guinea. All rights reserved
Maintained by: Richard Stanaway, Quickclose Pty. Ltd.
Last Updated: 17th December 2014