Compass Rose
A compass rose is a circle graduated in degrees (0° to 360°) or in points (N, NE, E, etc.) used to indicate direction. In aviation, compass roses appear on navigation charts at VOR/VORTAC stations and on aeronautical charts to show magnetic variation. The VOR compass rose shows radials emanating from the station.
Compass Rose on Charts
VOR stations on enroute charts are depicted with a compass rose aligned to magnetic north at that location. The alignment accounts for magnetic variation — the rose is not aligned to true north. When reading radials from a VOR compass rose on a chart, the values shown are magnetic bearings from the station.
VOR Radials and the Compass Rose
Each VOR transmits on 360 radials (magnetic bearings from the station). The compass rose around the VOR on the chart shows the orientation of these radials. To determine which radial you are on, observe the TO/FROM flag on your CDI and read the magnetic bearing from the OBS.