Document ID: chunk:federal_register_of_legislation:F2023C00611:body:0:p10
Version: federal_register_of_legislation:F2023C00611
Segment Type: other
Provision Reference: 
Character Range: 24949–27776

implementing the method in section 4.5.2 of Recommendation ITU-R P.526-15, the path profile is developed by sampling the DEM-3S at 100 metre increments along each radial. At each increment along the path profile, the procedure for determining the average ground height described in Part 2 of Schedule 3 is implemented.

4. In implementing the method in section 3.2 of Recommendation ITU-R P.2108-0:
         (a) the percentage of locations is set at 0.08% and the correction is applied at only one end of the path; and
         (b) if the loss calculated using the method in section 3.2 of Recommendation ITU-R P.2108-0 is less than 0 dB, the calculated loss value is replaced with 0 dB; and
         (c) if the loss calculated using the method in section 3.2 of Recommendation ITU-R P.2108-0 is greater than 8 dB, the calculated loss value is replaced with 8 dB.
Schedule 3 Antenna height and average ground height
(section 10, Schedule 2)

Part 1 Antenna height of a transmitter

       1. The antenna height of a fixed transmitter, is the vertical height in metres of the phase centre of the transmitter's antenna measured with an error of less than 5 parts in 100 and relative to the point:
             (a) located on the line of intersection between the external surface of the structure supporting the antenna and the surface of the ground or sea; and
             (b) having the lowest elevation on that line.

      2.                            For a group of radiocommunications transmitters, the antenna height for the group is the greatest of the heights of each individual transmitter in the group, calculated in accordance with this Part.

      Part 2 Average ground height

      1.  The average ground height for the mth increment on the nth radial is calculated as follows:

              Step 1: determine the associated latitude and longitude (lmn,Lmn) of the mth increment on the nth radial as calculated in Part 3.
                    Step 2:  identify the DEM-3S cell represented by the latitude and longitude of the mth increment on the nth radial.
                    Step 3:  bound the identified DEM-3S cell with the 8 adjacent DEM-3S cells in a 3x3 matrix and obtain each DEM-3S cell height attribute (as shown in Diagram 1).
             Step 4:  determine the average value of height from the 3x3 matrix.

      2.  If the seconds component of (lmn,Lmn), plus 1.5, has a modulus of zero when divided by 3, then the corresponding DEM-3S cell, for the purposes Step 2 in item 1, is the adjacent DEM-3S cell with the minimum height.

Diagram 1 Calculating average ground height

Part 3 Vincenty's Formulae

    Note This implementation of Vincenty's Direct Formulae uses the parameters {a, f1, b} from the GRS80 ellipsoid as referenced by the Geocentric Datum of Australia 1994 (GDA94).

    1.  In