Got my brain sorted.. here's the action clip.. and there's a slightly longer clip coming up explaining how it all works...
I did this slowly so to make it easy to understand- took me 6 minutes to get ship speed, closest range, bearings ..ect.. at a range of 6500m..
It can take no less than 30 seconds after the 1 degree reading, and you don't have to limit yourself to a 1 degree reading (a 0.25 degree will do - longer readings are more accurate)
In the meantime study your trigonometry...
https://www.dropbox.com/s/65o25wnfast6ppc/VansWheel.mp4 (113MB=06:40)