Ekelund Range

[MarkShot]

I think TMA must be some kind of magical topic.

The other day I was waiting with my wife at a doctor's office and rereading some TMA stuff I had printed. She asked me what I was reading. Normally, I tell her about the various principles of different war games I play, but, for the most part, she just humors me and has no interest.

Surprisingly, when listening to the basic principle and procedures of TMA, she actually seemed curious and for the first time I could see that she felt perhaps one of my various gaming hobbies wasn't a total waste of time.

[Bellman]

Mark,
The 'fairer' can actualy interpret knitting patterns - so I guess they can unravel TMA ?

Another thing they muti-task in a way no guy can. Once behind a barbi or a Wok - notice all those things
we overlook that just get done by........

Hopefully though joint action stops at the study door - the dust in here is my responsibility alone.

[compressioncut]

Originally Posted by PeriscopeDepth

Could someone possibly post what the procedure is for Ekelund ranging? I can't make sense of that web site and my local library doesn't have the book Bill mentioned.

Sorry for being dense.

single leg Ekelund

Range in nautical miles = (RSA x 0.955)/B*

where RSA is the resultant speed across the line of sound, and B* is the bearing rate.

Since you need to have a very good idea as to what the target's speed and course are to find RSA, the single leg Ekelund is pretty much useless, except as a training tool to confirm your understanding of the LOS relationships.

In other words even though it's pretty simple, I wouldn't really worry about it.

A double leg Ekelund is more useful.

Range in nautical miles = (change in OSA x 0.955)/change in B*

OSA being ownship speed across the line of sound, which is sin(OAA) x OS. OAA is ownship aspect angle, which is own course +/- the line of sound (i.e. target bearing).

The caveats with that ranging method are that each leg can't exceed 20 minutes, nor can the bearing rate change more than 15*.

Also, if one of your change in B* ends up at exactly 1*/min, it will not work.



That image has a LOS diagram, which should help a lot.

I'm not sure if the frequency rate Ekelund would work in game, it's been a while since I took a look at the Doppler effects. I think it would if you log the bearings and frequencies carefully, although that would be very tedious.

[PeriscopeDepth]

Thanks compressioncut, that was perfect!