Position data is provided as latitude and longitude, to 4-minute resolution, encoded in the PDF-2 of the second protected field (bits 108 – 132) as indicated below.
|
Bits 108 |
109 ———- 115
|
116 ———- 119
|
120
|
121 ———- 128
|
129 ———- 132
|
133 — 144
|
|
Latitude Flag North = 0 South = 1 |
Latitude Degrees (0 to 90) in 1 degree increments |
Latitude Minutes (0 to 56) in 4 minute increments |
Longitude Flag East = 0 West = 1 |
Longitude Degrees (1 to 180) in 1 degree increments |
Longitude Minutes (0 to 56) in 4 minute increments |
BCH 2
|
The default values indicated below should be coded into bits 108 – 119 and bits 120 – 132 when position data is not available or if the beacon radiates a long message in the self-test mode mode:
Bits 108 to 119: 011 111 110 000
Bits 120 to 132: 011 111 111 000 0
Note: Latitude and longitude data are rounded off (i.e. not truncated) to the available resolution. See table below for an example:
| Real Position | Position Encoded in Beacon |
| 43 deg : 31 min : 59 sec North | 43 deg : 32 min North |
| 01 deg : 29 min : 15 sec East | 01 deg : 28 min East |