Document ID: chunk:federal_register_of_legislation:F2023L00279:reg:3
Version: federal_register_of_legislation:F2023L00279
Segment Type: reg
Provision Reference: reg 3
Character Range: 25005–25838

3  Vincenty's Direct Formulae
Note: This implementation of Vincenty's Direct Formulae uses the parameters {a, fl, b} from the GRS80 ellipsoid as referenced by GDA94.
 (1) In calculating (lmn, Lmn):

lt     is the latitude of the fixed transmitter (decimal radians)

Lt     is the longitude of the fixed transmitter (decimal radians)

α      is the azimuth angle (decimal radians)

d      is the separation distance to required point (m×100 metres)

a      is the semi-major axis with value 6378137 metres

fl     is the flattening of the value 1/298.25722210

b      is the semi-minor axis of (a×(1-fl))

 (2) Using an initial value , iterate the following three equations until the change in φ is less than 10-12.

 (3) Then:

Note: Use the four-quadrant inverse tangent, atan2.
Note: Use the four-quadrant inverse tangent, atan2.