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View Full Version : Ekelund range formula, a question.


banryu79
02-25-15, 11:51 AM
I'm trying to use (inside a spredsheet) the double leg Ekelund range formula as detailed by Goldorack in this post: here (http://www.subsim.com/radioroom/showpost.php?p=1590236&postcount=284)
My questions are:
#1 - Is the variable "TrgBearing_1" the faired (by least squared method) bearing of all the bearings plotted for the fisrt leg?
#2 - Is the Bearing Rate also a faired value?

EDIT#1: Some time later...
I found this post (http://www.subsim.com/radioroom/showpost.php?p=247943&postcount=12) by SeaQueen, maybe there lies the answer to my question, but I'm not clever/mathematically skilled enough to sort this out... If there is anybody reading that knows or is able to come up with the answer, please, I will be happy to know it :)

EDIT#2: Even more time later...
I found explanations about the TMA process in general and about time/bearing plot, in particular, starting from page 17, chapter 10 of the "Operations Specialist - Volume 1" Nonresident Training Course, anybody can consult it here (http://www.globalsecurity.org/military/library/policy/navy/nrtc/14308.htm).
The time/bearing plot contains the answers to my questions above, but in graphical terms.

Mmmm... some solutions had come to my mind:

[1] Spreadsheet + formula solution.
I'm thinking that the time/bearing plot could be easly recorded in a spreadsheet, while the graphical process of fairing bearing values and measure the bearing rate could be easly translated (for those math-inclined) in a mathematical process (a formula). Now I think I understand what SeaQueen (and probably more DW users in the past) had done.

[2] Pen, paper and Bearing Rate template solution.
I think I could use an A4 squared sheet and a pen and make myself the time/bearing plot. But then I will need to use a Bearing Rate template to measure the bearing rate... Any idea on how to build one?

[3] Custom software with a GUI (let me dream...)
The more advanced solution, would be a custom software in which to input the time/bearing values for a segment and then get the faired bearing and the bearing rate as output. Well, at this point, of course, step #2 would be to give the software the ability to record/store a set of segments (TMA legs) and to compute the Ekelund range and maybe some other stuff... I've dreamed about a LOS interactive display to formulate and test multiple hypotetical solutions concurrently...

The largest obstacle inside DW, AFAIK, is the ability to take precise time/bearing readings cause the game basically gives you:
a) bearing values rounded to the nearest integer unit;
b) timed bearing reads every 2 minutes (every even game minute, to be precise).

Fortunatley I have found a solution for issue 'a' (a not-too-cumbersome technique to precisley measure bearings to the nearest decimal) but I've notyet found a solution for issue 'b'.

FPSchazly
02-25-15, 08:00 PM
I have no idea what this is, but as an engineer, my curiosity with numbers is killing me haha I must investigate this!

banryu79
02-26-15, 04:33 AM
I have no idea what this is, but as an engineer, my curiosity with numbers is killing me haha I must investigate this!
Just make and "advanced" search in the Dangerous Water section for the string "Ekelund" or "TMA" (select the oprion "in titles only") and prepare yourself for a ton of info.

I've found very intresting info in this way, especially when I identified several users who had real Navy experience to share and looking for threads started by them. It's time consuming, but very valuable.

EDIT: First post updated.

banryu79
02-27-15, 05:39 AM
Another question for those who knows... (unreleted to the current topic).
Do you know if (and how) DW models knuckles in the water produced by sudden maneuvers?

EDIT: First post updated, again.

NavyUSA
03-18-15, 08:24 AM
Mmmm... some solutions had come to my mind:

[1] Spreadsheet + formula solution.
I'm thinking that the time/bearing plot could be easly recorded in a spreadsheet, while the graphical process of fairing bearing values and measure the bearing rate could be easly translated (for those math-inclined) in a mathematical process (a formula). Now I think I understand what SeaQueen (and probably more DW users in the past) had done.

[2] Pen, paper and Bearing Rate template solution.
I think I could use an A4 squared sheet and a pen and make myself the time/bearing plot. But then I will need to use a Bearing Rate template to measure the bearing rate... Any idea on how to build one?

[3] Custom software with a GUI (let me dream...)
The more advanced solution, would be a custom software in which to input the time/bearing values for a segment and then get the faired bearing and the bearing rate as output. Well, at this point, of course, step #2 would be to give the software the ability to record/store a set of segments (TMA legs) and to compute the Ekelund range and maybe some other stuff... I've dreamed about a LOS interactive display to formulate and test multiple hypotetical solutions concurrently...


The most efficient solution in dangerous waters is:

i) Determine the bearings from NAVmap every 2 (1 in new RAmod) minutes.
ii) Calculate the bearing rate with a pocket calculator.
ii) Knowing how to interpret the data.

ps: double leg Ekelund range formula, requires at least 16 minutes.
It's better determine the solution in tma station.