TMA while moving problems

[berobispo]

Hi all!

first of all, thanks Aaron for creating such a great app!

I have the following question:

When I try to plot targets passively by TMA while moving, I came across some theoretical problems that don't occur when plotting targets while stationary.

Is there a way to avoid this?

I have attaches some pictures to illustrate:

fig.1
we see the real contact (above) travelling 90°T with 7 kts.
Below is a "fine" TMA, but unfortunately, I have chosen the wrong two points. Of course, I could have been lucky and have chosen the right distance to begin with, but let's assume this is my TMA.



fig. 2
I have connected the two preliminary contacts. TSD shows an unlikely speed.


fig.3
So I adjust the scale, unfortunately I get a fine looking, but wrong analysis


Is there a way to avoid this?

-Maybe by making a preliminary TMA while stationary, then start moving, maybe even triangulate (by plotting future bearings)?

Thanks again and maybe you have a solution!