Simrad SU90 - HDG Heading, Deviation and Variation

SimradSU90
3llll.ll=latitudenorth/south,positionindegrees,minutesandhundredths.Characters
N(North)orS(South)identiesthebearing.
4a=North/South.CharactersN(North)orS(South)identiesthebearing.
5yyyyy.yy,a=longitudeeast/west,positionindegrees,minutesandhundredths.
6a=West/East.CharactersW(West)orE(East)identiesthebearing.
7hhmmss.ss=coordinateduniversaltime(UTC)ofposition.
8A=status,charactersA(datavalid)orV(datanotvalid)areused.
9a=modeindicator.
Note
TheGLLtelegrammaybereceivedfromintegratedinstrumentsusingthe“ii”talker
identier.TheSimradITIsystemusesthesametalkeridentier“ii”,andthishascaused
someconfusionforsomeofourusers.Inordertorectifythis,theITIGLLtelegram
hasbeeninhibited.
HDGHeading,deviationandvariation
Thistelegramcontainstheheadingfromamagneticsensor,whichifcorrectedfor
deviationwillproducemagneticheading,whichifoffsetbyvariationwillprovidetrue
heading.
Format
$--HDG,x.x,z.z,a,r.r,a*hh<CR><LF>
Headingconversions
Toobtainmagneticheading:Addeasterlydeviation(E)tomagneticsensorreading,or
subtractwesterlydeviation(W)frommagneticsensorreading.
Toobtaintrueheading:Addeasterlyvariation(E)tomagneticheading,orsubtract
westerlyvariation(W)frommagneticheading.
Formatdescription
1––=talkeridentier
2HDG=telegramidentier
3x.x=magneticsensorheading,degrees
4z.z,a=magneticdeviation,degreeseast/west
5r.r,a=magneticvariation,degreeseast/west
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