2 easy questions I cant seem to find the answer to

[ikalugin]

Originally Posted by Pisces

You can detect this bearing difference with only one sensor? Or did you find a difference between the bearing of the same target on your own bow sensor and your towed array?

I find that happening a lot (bearing difference between towed and bow), I wonder if one could use it to triangulate the range to target (provided that the point from where the bearing is calculated from for towed is the center of towed array and towed array is long enough).

[Pisces]

Originally Posted by ikalugin

I find that happening a lot (bearing difference between towed and bow), I wonder if one could use it to triangulate the range to target (provided that the point from where the bearing is calculated from for towed is the center of towed array and towed array is long enough).

Yes, you certainly can if the TA is streamed far enough. That is why I wanted to make the distinction between the two. At really close quarters even the bow and hull can be used to triangulate. But bow and TA is obviously better.

On the TMA plot the lines of the Bow, Hull and TA should intersect in the location of the contact (soundsource). But there may be some inaccuracy in the recording of the bearing, so the crossing point might be quite off in distance (as the intersection is so narrow).

Iirc FPSchalzy in his tutorial videos on youtube said it could be due to the timing of the tracker not being synchronised somehow between multiple sensors. Afaik, that only occurs with the first lines when you make a new tracker assignment. Most of the time I find the triangulation between multiple sensors to be spot on. But maybe I missed something he didn't.

[ikalugin]

Dear lord and I have thought that it was possible only with the UUV. That said, doesn't WAA work the same way?

p.s. I do wonder why there isn't some utility availiable that does that automatically (triangulating from towed and bow, or running possible TMA solutions for that matter).

[Pisces]

Originally Posted by ikalugin

Dear lord and I have thought that it was possible only with the UUV. That said, doesn't WAA work the same way?

Launching a UUV gives out a "torpedo in the water" warning to the other units in the area. So not very usefull for stealth in some situations. But yeah, it works similarly in the TMA screen. The bearing lines are plotted from where the UUV is. So this works by lines depicting the direction from where sound comes from and how they intersect.

WAA in real life works I think by analyzing the signal delays between a lot of smaller sensors in the array. And by doing (long-term) signal processing on various frequencies it can figure out the phase (the position in the wave, think of it as the second hand on the clock going round each minute for each wave period) of particular frequencies. From these slight delays it can reconstruct the distance from where it must have originated. As it's exact workings are no doubt classified you might as well consider this magic.

WAA in the game simply gives the bearing and range of the contact with some random noise added to it. Or so it appears. Who knows how Sonalyst calculated this exactly.

[ikalugin]

I know how WAA works IRL (sort of), just was wondering about the game.

The method you have described sounds like generic mono impulse direction finding, ie same as in the modern phased array radars. With several bearings you go and triangulate.

[cemtufekci]

array triangulation.jpg

One example of array triangulation. Sound source is 500 yards away. Sphere, hull, and towed array bearing lines intersect on one point. Notice how far away the fully deployed towed array is.

[Pisces]

What are you trying to say with that image? That looks like an intersection of a UUV and TA bearing. Quite different from your "double soundsource" experience.