Codan Radio Radio Repeater Systems Training Guide - Manual (Page 47)

RADIO REPEATER SYSTEM | TRAINING GUIDE
Appendix B: Drawing Path Profi les Page 39
APPENDIX B: DRAWING PATH PROFILES
In Appendix A, coverage maps were drawn for the BRIDGE Base Station (Offi ce) and BRIDGE A.R.S.
showing the expected coverage of those sites. To determine if the BRIDGE A.R.S. site will communicate
with the Base Station a path profi le must be drawn. If any two sites (base station to repeater or repeater
to repeater) are to be linked together, a path profi le between those two sites must be drawn.
On a 1:50,000 map covering the area between the two sites, draw a straight line between the two points
as shown in Figure B-1. Find the center and scale off from that point at 1 km intervals to each end.
Prepare the 4/3 earth curvature profi le paper with names, date, and any other pertinent information as
shown in Figures B-2 and B-3.
From the 1:50,000 map which you have marked and again starting at the center, working your way
out to each end in turn, transfer the elevations from the map, one kilometer at a time. You may wish
to interpolate highs and lows between points as shown on the map. Although the example shows the
points marked in heights for each kilometer, you will fi nd that marking is unnecessary after you have
done one or two profi les. You can now see whether or not the path is line-of-sight. Once the path profi le
has been drawn, path calculations need to be made for path loss characteristics and signal levels.