https://www.dxzone.com/dx36366/great-circle-map-gcm.html
Great Circle Map - GCM - Operating Aids/Distance & Bearing | The DXZone
The page automatically generate a Great Circle Map (GCM) for ham radio operators based on the IP address or by a given QTH locator. The GCM generated, unlike...
great circle mapoperating aidsthe dxzonegcmdistance