Document ID: chunk:federal_register_of_legislation:F2023L00277:reg:2
Version: federal_register_of_legislation:F2023L00277
Segment Type: reg
Provision Reference: reg 2
Character Range: 23599–24570

2  Average ground height
   (1) The average ground height at the mth increment on the nth radial is calculated as follows:
    Step 1: Determine the associated latitude and longitude of the mth increment on the nth radial (lmn, Lmn) as calculated in item 3 of this Schedule.
     Step 2: Identify the DEM-3S cell represented by (lmn, Lmn).
Note: See subitem (2) below for identifying the DEM-3S cell in a particular case.
    Step 3: Bound the identified DEM-3S cell with the 8 adjacent DEM-3S cells in a 3 x 3 matrix and obtain each DEM-3S cell height attribute (as shown in Diagram 2).
    Step 4: Determine the average value of the 9 DEM-3S cell heights for each cell in the the 3 x 3 matrix.
Diagram 2 Calculating average ground height
   (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 of Step 2 in subitem (1), is the adjacent DEM-3S cell with the minimum height.