Western Australian Consolidated Regulations (1) Subject to
regulation 10, the AGD is the prescribed datum for the purposes referred
to in section 27(4) of the Act.
(2) The AGD is defined
by an ellipsoid having a semi-major axis (equatorial radius) of
6 378 160 m and a flattening of 1/298.25 and fixed by the
position of the origin being the Johnston Geodetic Station in the Northern
Territory of Australia.
(3) The Johnston
Geodetic Station is taken to be situated at —
(a)
25° 56′ 54.5515″ south latitude and
133° 12′ 30.0771″ east longitude; or
(b)
where decimal reckoning is used, 25° 56.90919′ south latitude and
133° 12.50129′ east longitude,
and to have a ground
level elevation of 571.2 m above the ellipsoid referred to in
subregulation (2).
(4) An instrument in
force under the Act or these regulations immediately before the commencement
day that contains a reference to the position on the surface of the Earth of a
point, line or area determined by reference to the AGD is to be endorsed, if
it is practicable to do so, with a statement to the effect that the AGD
applied to that determination, but the omission of such a statement does not
affect the validity of the instrument.
(5) If, in relation to
an instrument referred to in subregulation (4), coordinates calculated by
reference to the AGD are to be converted to coordinates calculated by
reference to the GDA, the conversion is to be made using the National
Transformation Version 2 (NTV2) grid file transformation.
[Regulation 11 inserted in Gazette
15 Dec 2000 p. 7215.]