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Option to Define Magnetic Correction

Posted: Sat May 24, 2014 4:20 pm
by Aardvark
I only noticed this last night as I was listening to JFK ROBER approach, noted the heading an aircraft was told to fly and what was being reported on the VRS map. For example, an aircraft was told by controllers to fly on a heading of 310 degrees. VRS reported the plane flying 297 when it finished turning. This correctly corresponds to the west 13 degree positive magnetic offset here in the New York City metro area. I researched and saw that this is correct per ADS-B reporting the magnetic heading. I am curious if it would be possible to add an option in the configuration settings to set the magnetic correction so that the headings reported by VRS correspond to true north instead of magnetic north. If the user chooses not to define a setting than behavior would be as always.

Re: Option to Define Magnetic Correction

Posted: Sun May 25, 2014 3:53 am
by agw
With things like that it would be nicer if it could be calculated as-at the aircraft's position (or somewhere near to the aircraft's position) rather than being a global value. 14.3 would only hold good for aircraft in your area, if you were taking a shared feed from another part of the world then applying a global value could end up showing the wrong heading for aircraft on that feed. Also there's the problem of looking up what the deviation is in your area, it'd be nicer if the software did it for you.

It turns out that NOAA publish a bunch of tables and C source that uses them to calculate the magnetic deviation when given a position. I'll look into porting the relevant bits to C# and incorporating it into VRS, then it can just be a "Convert headings to true north" switch in the settings rather than a global value.

Re: Option to Define Magnetic Correction

Posted: Sun May 25, 2014 1:30 pm
by Aardvark
Definitely a better idea. I had not investigated whether or not there were resources that could translate a longitude and latitude to magnetic declination. Makes sense considering all the data that is available these days!

Re: Option to Define Magnetic Correction

Posted: Sun Nov 01, 2015 12:40 am
by ricreig
agw wrote:With things like that it would be nicer if it could be calculated as-at the aircraft's position (or somewhere near to the aircraft's position) rather than being a global value. 14.3 would only hold good for aircraft in your area, if you were taking a shared feed from another part of the world then applying a global value could end up showing the wrong heading for aircraft on that feed. Also there's the problem of looking up what the deviation is in your area, it'd be nicer if the software did it for you.

It turns out that NOAA publish a bunch of tables and C source that uses them to calculate the magnetic deviation when given a position. I'll look into porting the relevant bits to C# and incorporating it into VRS, then it can just be a "Convert headings to true north" switch in the settings rather than a global value.
Any updates on this topic?? It would be very helpfull to have this option enabled on the settings?

Please!? and Thanks!!

Re: Option to Define Magnetic Correction

Posted: Tue Nov 03, 2015 10:58 pm
by agw
I'm on NOAA's mailing list but aside from that no, I've not yet implemented it. Soon. Ish.