doppler effect = range rate x frequency line/speed of sound

OSL(own speed along) cos rel brg x own sp

TSL ( target speed along) cos atb x vt ( target speed)

OSL OR TSL kts to hz osl or tsl x freq line/3000 gives hz

OSL OR TSL hz to kts osl or tsl x 3000 / freq line gives kts

base frequency cos atb x vt


atb tsl(kts)/vt inv cos

speed tsl/cos atb = kts


1959 range 110.85 x rate of change of range rate / bearing rate squared


all these are only relevent to tracking a tonal to two decimal places on a paper plot although some can be done on the TDHS computer

Ahhhh, the joys of tonal tracking :rotfl:

For 59's just use the +10% ;)

I have a lot to add here, but we americans are not allowed to, even if the math can be googled. Sorry. I will tell you that these are great tools for tracking in game.

Question: Does range rate analysis (frequency tracking using doppler) actually work properly in game? I just assumed that it was beyond the model and never tried.

There is no doppler in the game, as far as I know.
Can you give some more info about how it should work ? As much as you dare :up:

I can't give specifics, but if you think about the doppler effect very long you'll understand that it isn't a high-level concept. When I walk towards you, the sine wave making up my particular tonal compresses, causing the frequency to increase. The amount of that increase (or decrease) gives me a lot of useful information, especially for detecting contact zigs.

Range rate analysis gives the piece of the puzzle that is missing from bearings-only TMA. Bearing rate shows relative speed across the line of sight, and frequency rate shows relative speed in the line of sight. Since what we do is basically a vector problem, put 'em together with one in the x axis and the other in the y and you have course.

I see .. I understand you as if there is some way to determine distance from doppler alone.

To get speed 'in-line' you have to know 'no Doppler' frequency of the line you are looking at right ? If targets makes circle, it's the middle frequency. Simple. But what if the target does not make the circle ?

How many NB lines are known to be fixed and their frequency is know exact enough ? If I understand it correctly, there is not so many of them as in DW (where all are fixed). Many of the lines are machinery based and these change with RPM of corresponding parts.

Yeah. It's complicated, and I'm on thin ice as it is. I'm sorry.

(How the hell did I get this tagline???)

You've got the tagline because you spoke too much :rotfl:

I'm always careful to google before I speak. :up: