If Sonalysts made a new game...

[goldorak]

Originally Posted by Rip

Thanks for the refresher. I was an ET but stood sonar watch on occasion. I think I developed most of my TMA techniques from being a geo plot supervisor during tracking stations.

Now I actually wish I had an iPhone, never thought I would say that.

I wish the auto crew were as capable as my shipmates were. Sometimes I don't feel like doing all the work and just want to play captain.

BTW have you done PMS on the compensators this quarter?


Rip

Why would you need and iphone to do basic math ?
Spend 40 $ or so on a good programmable scientific calculator and you're good to go.

Ekelund range in DW !!!!!!!!!!!!!!!!!????????????!!!!!!!!!!!!!!
Do not forget that in the DW Ekelund range is practically unusable. This is because in DW, the Bearing are given as natural numbers without decimal places.
Only with a proper correspondence in the NAVMAP we obtain an accurate Bearing Rate. Even a hundredth of a Deg.

[ASWnut101]

EDIT: Now for some reason I can't get it to work right. Dunno if it's just cause I'm half asleep and missing something or what. Thanks for jinxing me, man. :p

[oscar19681]

I wonder when we are gonna get some news on this.

[streakeagle]

You don't need an iphone... you can program a calculator or use an excel spreadsheet. I can help anyone interested.

Here is a thread all about the Ekelund range: http://www.subsim.com/phpBB_2002/vie...orum=2&start=0

[Kaye T. Bai]

Originally Posted by oscar19681

I wonder when we are gonna get some news on this.

Ten brownie points says that on the first day of April 2011, Neal will come out and shout "April Fools!"

[streakeagle]

While systems displayed bearing to tenths or hundredths, the accuracy was very limited. We logged and plotted to tenths of a degree. For passive ranging equations to have any accuracy, the bearing rate needed to be higher than a few tenths... Especially the difference between the bearing rates when doing multiple legs. A tool we used on the passive broadband waterfall displays was a transparent plastic square with lines drawn at various angles and marked with the corresponding bearing rate.

A way to get a fair bearing rate in the game is to wait for the bearing to change, start a stop watch, then wait for the bearing to change again and stop the watch. 1 degree / measured time in seconds = deg / sec. divide by 60 to get the usual deg / min units used by the Navy. The longer your measurement (i.e. multiple degrees instead of just one) the more accurate the number.

The only problem I have with doing TMA in the game is that I am not getting paid to waste that much time staring at screens with a headset on my ears. I only play DW once in a while. Normally, I play combat flight sims.

[TLAM Strike]

Originally Posted by Kaye T. Bai

Ten brownie points says that on the first day of April 2011, Neal will come out and shout "April Fools!"

... and that will be the last anyone hears from Neal...

As recommended by streakeagle, a tool used on the waterfall display passive broadband is a square of clear plastic with lines drawn at various angles and assigned the corresponding rate of bearing.


You should print it on a transparency and resize to the size of your screen and then the waterfall display passive broadband.

My method:
The only way to calculate a DW Bearing Rate accurate to the nearest hundredth of a DEG is to perform measurements on NAVMap: for example using the function range circle you get a proxy measure to the tenth of DEG, by performing two Measurements for the calculation of the Bearing Rate gives an approximate value to the hundredth of a degree which is even more accurate than the BR that DW can calculate the estimated solution (approximate to a tenth of DEG). By convention, the bearing rate is measured in DEG / min.
To obtain accurate measurements need to make a drop of the contact to show the line of bearing on the nav map at time t1, t2, ... , tn and position of the mark on the end of obtaining so valuable reference for measurement.

Bearing Rate determined both accurate on two LEGS, just replace the values in the formula Ekulund Range Double Leg.

xDMHo1 xDMHo2
----- + / - ----- All That times K.
1DBY 2DBY

it is important that during this analysis, the Target course and speed remain constant in order to get a decent estimate on the Range.
If you use the Iphone, just insert the values of BRG1 & BRG2 obtained along with Bearing, ownship (O/S) course and speed.

[Dr.Sid]

Still in DW it always seemed much faster to just use TMA screen. No numbers needed. Sure you have to know how to do leg. But then it's just a few clicks of the mouse.

Btw. what about full auto ? I heard at least Brits use it. You simple assign tracker, do leg, and firing computer makes all the math .. that's actually what computers should do, right ?

[streakeagle]

Computers are not aware of all of the variables. The US Navy wants human intelligence to assess that data and correct for factors computers are not aware of. i.e. the computer may be blindly copying data from a tracker that has tracked off. An operator will simply move his cursor to a position and get the bearing he wants regardless of interference that can and does confuse trackers. I am sure sonar has improved in leaps in bounds since I last served, but a human operator on a BQQ-5 can do a better job of TMA than an automatic tracker feeding a manned fire control console under various circumstances. Of course, the operator is supposed to send manual bearing marks if he is able to get information that the tracker cannot. Then you have the best of both worlds, which is the way the Navy wants it: slow, careful, reasoned manual solutions to balance quick and dirty automated ones tempered by the judgement and intuition of the Captain. At least one scenario per visit to the trainers made a point of burning any crew that blindly followed doctrine and automatic systems. The combination of skilled sonar operators working with an equally skilled fire control party can overcome some tricky and difficult tactical/environmental situations. I had the privilege of serving with handpicked crews on SSN-687, some of the best in the entire Navy. As such, I got to see some exceptionally talented and experienced people in action. At the same time, I also saw some personality conflicts and egos cancel out talent and experience. Sonar, TMA, and ASW in general requires a lot of math, which computers excel at, but involves quite a bit of subjective interpretation, which is far beyond computers. Windows speech recognition is a good example. As advanced as it has become, it still makes a lot of mistakes. Add in some background noise, especially other people talking, and it is completely unusuable.

[Dr.Sid]

Don't tell me about computers, I program them
Anyway I don't understand the need for rulers and calculators. At least these days. All data are in the computers already right ? If I want to use these 5 bearings to compute range .. I should be able to just select them and click the button. Which will do all I would otherwise use that programmable calculator for. Those formulas are same since WW2, if not older.
Or slide on the screen ? In seventies, ok .. but today ? I hope not !

[Bubblehead Nuke]

Originally Posted by Dr.Sid

Don't tell me about computers, I program them
Anyway I don't understand the need for rulers and calculators. At least these days. All data are in the computers already right ? If I want to use these 5 bearings to compute range .. I should be able to just select them and click the button. Which will do all I would otherwise use that programmable calculator for. Those formulas are same since WW2, if not older.
Or slide on the screen ? In seventies, ok .. but today ? I hope not !

Computers are fine till they lock up or crash... then you had better have the old fashion mechanical backup on hand as well as the knowledge of how to use them properly.

That is why there is ALWAYS a manual plot (section tracking party) when you are trailing an object of interest. The computer can crunch the numbers, but it is a man you are fighting against. If you know how the computer works, you can outthink it. You can give it data that will result in the outcome YOU want.

Try doing that to someone who is being just as sneaky and calculating and out for YOUR butt. Then it is a whole new situation.

[goldorak]

For those wishing to implement Ekelund ranging on a scientific programmable calculator here is the formula :

The input fields are 8 (4 for the first leg and 4 for the second leg)

• OwnSpeed_1
• OwnCourse_1
• TrgBearing_1
• BearingRate_1
• ---
• OwnSpeed_2
• OwnCourse_2
• TrgBearing_2
• Bearing Rate_2
  

For leg 1 :

OOA_1 :

Calculate X = TrgBearing_1 - OwnCourse_1
If X > 180 then 360 - X
If X < 0 then X + 360
Else X

Once calculated OOA_1, calculate sin (OOA_1)*OwnSpeed_1

The calculation for OOA_2 is the same as OOA_1 mutatis mutandis.

Ekelund Range = 0.955 * [ |sin(OOA_1)*Ownspeed_1 - sin(OOA_2)*OwnSpeed_2| ] / [ |BearingRate_2 - BearingRate_1| ].

Speeds expressed in knots, bearing rate in degrees/min and distance is yards.
Numerator and denominator in the formula have to be positive so absolute values are used.

[Rip]

Originally Posted by Bubblehead Nuke

Computers are fine till they lock up or crash... then you had better have the old fashion mechanical backup on hand as well as the knowledge of how to use them properly.

That is why there is ALWAYS a manual plot (section tracking party) when you are trailing an object of interest. The computer can crunch the numbers, but it is a man you are fighting against. If you know how the computer works, you can outthink it. You can give it data that will result in the outcome YOU want.

Try doing that to someone who is being just as sneaky and calculating and out for YOUR butt. Then it is a whole new situation.

Second that. I coordinated the plot and we were well versed in the loss of just about anything. We could manually plot ownship if the "bug" died. Relay bearings directly from sonar if bearing transmitters and/or fire control failed. We ran drills for mind numbingly numerous casualties. They could manually enter setting into the weapons and launch them from the torpedo room with nothing other than sound powered phones for comms.