TMA and range determination

TopTorp '92 · Joined: 10 Jan 2002 Posts: 329

You know, this range issue can be reasonably resolved through an exercise with DW's ability to create scenarios. I recommend that one of our full time gammers do this and make a new thread.

Make a series of scenarios with two vessels in the game: own ship and a target. Place the target at a known bearing and range for each scenario and give it zero speed. Place OS on a known course that is perpendicular to the target. You now know what the bearing rate is for a stationary target for the canned range. You can also measure the bearing rate from the broadband display using an index card as a ruler. The bearing line will be less slanted at narrow aspects and at farther distances. Doing this will build judgement about bearing rate behavior and target range given OS speeds and various LOSs.

The next time you do battle with an on-line gammer, you will have the ability to estimate with reasonable precision target range simply based on the bearing rate and the LOS. ADCAP needs no additional information to find its target.

If all you have is a bearing and no bearing rate or even a bearing drift (you don't know yet whether the target draws left or right) then you can snapshot the target using the bearing you have and enable the torpedo at the minimum range. You still have a wire to the weapon that can update its course and other parameters.

Don't waste too much time polishing the TMA cannon ball thinking you're gonna get the best firing solution available or even get a decent range. You only need to get the best bearing available and use it. This is the way it was done in WWII, during the Cold War and I tell you it is the way it can still be done in this computer game.

OKO · Posted: Sun Apr 30, 2006 5:39 pm Post subject:

TopTorp '92 · Joined: 10 Jan 2002 Posts: 329

All good and pure criticisms. However, in the snapshot scenario I envisioned earlier ownship's position had already been compromised by the fact that Troel has used his active sonar and I assumed the range to the target had already diminished well inside say 6,000 yds. The point of the exercise I described was to construct a range of possibilities by which we can reasonably estimate target range given only a few moments of bearing rate data. Combined with other clues from sonar (like getting target blade data), this estimate can help you make tactical choices in an environment where time is the commodity. Combine bearing rate from broadband display along with your LOS, use speed from DEMON and you will have a reasonable range estimate to the target using the position-keeping software that is supplied in the game.

In the scenario you mentioned about the same bearing rate for a target doing 20kts at 40kyds (20nm) as a target doing 10kts at 20kyds (10nm) the best way to get a change in bearing rate without turning ownship is to speed up or slow down. Remember, there are two ways to zig: either turn or change speed. Both take time and both will have an impact on sonar's performance.

Also, for the ranges you cited earlier, although this is a game and DW sonar doesn't come with D/E capability (meaning you won't get a feel about range closure), sonar will still be able to provide SNR data for any contact. So, that 40kyd target will sound different from the 20kyd target based on SNR. Sure, my recommended method will not suffice in isolation. But, nobody makes tactical choices in isolation. All available data must be examined, considered and a tactical picture painted on the CEP.