This is just one approach that happened to come to mind, it's not like I have some hardfast rules that I follow...
There are lots of other things you can do or dream up to analyze the target motion and solve for the target position/vector data.
For instance, you could take the example above and add two or three more predictions for a new bearing at 1550. Then use the advance feature again and do another triangulation at 1550 for a second position fix. Then you'd have two real triangulated positions with time elapsed as a given.
A line between those two positions gives you true course. Distance between the points along with the elapsed time allows you to calculate the target true speed (TSD calcs in MoBo are simple). You can do all this from your stationary location once you have a TMA track that you can use to predict future target bearings.
Good questions and happy hunting.
