Is Magnetic Declination in DCS static?

[Nealius]

In real life, magnetic declination changes every year, but is this change modeled in DCS? The reason I ask is because I noticed moon phases seem to be accurately modeled to the mission date and even year; i.e. the moon phase on 9/5/2018 will be different than on 9/5/2004. If such a change is modeled, I'm wondering if changes in magnetic declination is modeled as well, as such a change would affect some of our modules and just general navigation.

[eaglecash867]

Magnetic variation changes an average of roughly 0.1 degrees per year in real life, and in DCS its not really modeled correctly anyway.

[Frederf]

Yes, magnetic declination varies with both location and date in DCS terrain. How well? You'd have to compare with history and some of the better predictions but it seems at extremes to go a bit bonkers like they only included the first term or two.

 

Any module that samples the magnetic value directly would be fine. Perhaps some do some things weirdly by deriving magnetic from true when the real system was the other way around (or the reverse) and that might be noticeable.

[Nealius]

Magnetic variation changes an average of roughly 0.1 degrees per year in real life, and in DCS its not really modeled correctly anyway.

 

Depends on region. According to NOAA, Las Vegas declination changes +0°6' every year. Batumi -0°5' every year.

 

Any module that samples the magnetic value directly would be fine. Perhaps some do some things weirdly by deriving magnetic from true when the real system was the other way around (or the reverse) and that might be noticeable.

 

My main concern is any module that requires the user to input declination for INS alignment. If the charts we have for Nevada say +12° declination, is it going to remain +12° for every date setting in the mission, or will things get screwy if I make a mission set in 1991?

[eaglecash867]

Depends on region. According to NOAA, Las Vegas declination changes +0°6' every year. Batumi -0°5' every year.

 

Pretty much what I said, just different terms. 6 minutes is roughly 0.1 degrees. Regardless of the direction of change, that's still an average of 0.1 degrees of change. ;)

[Frederf]

Depends on region. According to NOAA, Las Vegas declination changes +0°6' every year. Batumi -0°5' every year.

 

My main concern is any module that requires the user to input declination for INS alignment. If the charts we have for Nevada say +12° declination, is it going to remain +12° for every date setting in the mission, or will things get screwy if I make a mission set in 1991?

 

 

I don't know of any modules are actually require (or even allow) user input of magnetic variation with maybe exception of L-39. But L-39 is automatic sample from mission (correct for starting date, location, map position). If there was some theoretical module first you'd line up against a known true heading reference and then compare to magnetic compass.

[Nealius]

Harrier currently needs magnetic variation input for INS align. All of my Harrier missions are set in the 90s or early 00s. Our nav charts where we get magnetic variation in DCS are from 2013.

Edited September 5, 2018 by Nealius

[Frederf]

Charts also have yearly change rates so even a 2013 chart is valid +- some years. And what really happens if you enter a deliberately wrong magvar during align? Is gyrocompassing increased in time or the heading tape is off relative to true?