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great circle line from known position and bearing on global map

Hello folks,

in order to do radio diretion finding I would like to visualize great circle lines from four different known positions (waypoints) on the global map. Additional I could specify a 'dummy' distance.

I am looking for a way I can create a route from a specific waypoint following a specific bearing. Where can I enter a bearing (and possibly a distance) to get the great circle line shown on the global map ?

So far all options I found consider a second location as a destination.

Thanks in advance for any hints

greetz from Germany

Andreas

0 Eyelet99 over 3 years ago

Open the Waypoint dialog box and enter a value in the Proximity alert radius field. BC will then show the circle.

0 BTLAAKE over 3 years ago

Eyelet99's reply will create a circle of a fixed distance with the waypoint at the center. My reading is that you want to create a line through a waypoint in a fixed direction.

There is no way to project a waypoint in BaseCamp as far as I know.

The bearing in a Great Ellipse/Circle is constantly changing unless you travel along a meridian or around the equator.

A rhumb line crosses each meridian at a constant bearing. If your not travelling along a meridian or latitude line, it will look like a spiral with ends at each pole.

To create a rhumb line, you will need to create a 2nd waypoint. This can be done on this site: https://geographiclib.sourceforge.io/cgi-bin/RhumbSolve

In BaseCamp you need to create a Direct Route using the two points. This actually gives a Great Ellipse/Circle route. To change it to a rhumb line, convert the route to a track. Then delete all the points except the first and last.