How can i effectively measure bearing rate?

[phil21]

Hello guys,

here is another typical "noob-question" :
How do i get a precise bearing rate for a contact? I know in the Navmap you can find one, but this one only appears after i've done my TMA and its also influenced by it, so its useless for what i had in mind.
I also know that you can just sit there with a stopwatch and calculate it yourself but i would like to know if there's another, faster (and perhaps more reliable) way...

I'm asking this in a new thread because the threads i find with 'Search' do not really answer the question(s) i have. Right now i'm working on a simple program to calculate Target range (and maybe more later) via´Ekelund with OwnShip data plus LOB (Bearing Rate). So if theres another way to do this (getting a good TMA with (as few as possible) bearings only) this would be also of interest for me...especially if theres already a program for it.

Phil

[jmr]

Great question. It's a shame you DW doesn't give you a bearing rate on the subs sonar displays but you can find it manually.

One method involves using a utitlity called Mobo in which you overlay it on top of the TMA screen and plot a bearing line over the bearing in question to get it's measurement. You'll have to run DW in a window if you wish to overlay Mobo on top of your DW screen otherwise if you run DW in fullscreen you'll have to grab a screenshot, alt-tab to Mobo and dump the screenshot into it.

I can post a screenshot later if what I said didn't make sense.

Keep in mind Mobo won't give you the bearing rate, it only allows you to get a more precise bearing reading (to how many decimal places you'd like) than you would get by simply looking at your bearing display on the sonar screens. Once you have your bearings you can find the rate manually or dump into Excell and find it using the "data analysis ----> regression" tool.

[phil21]

Thank you,

I use Mobo then if theres no other precise method.
My wish for the next Patch/Addon/Game/whatever: Give More Sonardata like Bearingrate etc...and make it accessable for TMA. So we can skip all these additional programs...

Maybe i should also work on a Excell table for most of these 'basic' things...

[jmr]

A nice Excell sheet would be pretty cool to have. Do you need the Ekelund range formula?

[phil21]

I just finished the Program for calculating range with Ekelund (double-leg). It only needs to be tested, i think i do that tomorrow...if its ok i polish it one last and maybe i upload it somewhere (if its needed). Perhaps i also add the other stuff for a full TMA...but this will need some more time.

After this the next thing to do will be an Excell sheet with all this stuff for the differen Platforms plus the easy calculating stuff....

@jmr: you integrated it in Excell? Or just the plain formulas? I still need the Formulas for "full TMA" (Speed & Course) in combination with Ekelund range....i have seen them in this forum a while ago but i cant find them right now. Would be nice if you have those.

Phil

[phil21]

I've done a few tests with the Ekelund calculator and the results are disappointing: First of all, it seems to work as it should, but you need very precise data for it. It seems that you need at least two decimal places for bearing rate and one decimal place for all the other data for this formula to make it work reliable.
This makes the use of this method unpractical, since you don't have a reliable Bearing rate indicator in DW (e.g. using Mobo helps alot, but its hardly acurate enough for two decimal places) nor the possibility to process these data in real time.

But theres also one other possibility: i've got the wrong formula for this. I dont think that this is the point but i keep looking. Maybe i find something more "sturdy" formula that can use more unprecise data to produce at least a limited solution...

Phil