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how to convert ALAT/ALON (was Re: Squint)

At 09:43 AM 5/14/2001, Clifford Buttschardt wrote:
>The problem remains-- should we add 180 degrees to this figure and change 
>the signal of ALAT for Instantrack?  Still not clear on this.

Yes.  Change the sign of ALAT, and add 180 degrees to ALON.

To see this, take a globe (a model of the earth, with latitude and 
longitude printed on it), and look at what happens when you go from one 
point on the globe to the point exactly opposite.  You change the sign of 
latitude, and add 180 degrees to longitude.  On AO40, the published ALAT & 
ALON refer to the orientation of the motor, but the antennas (what you're 
likely interested in) are on the opposite side.

In some email, some people have said you should subtract (rather than add) 
180 degrees to ALON.  Of course, adding 180 accomplishes exactly the same 
thing as  subtracting 180, so don't let this confuse you.  Feel free to 
subtract if that suits you.  If someone gives you an ALON of 179, you can 
enter either -1 or +359 .

IT will accept ALON in the range -359 to +359, so you might have to add or 
subtract 360 after you add 180 to put it back in the right range.  I know 
you can all handle that.  If someone gives you a starting ALON of 180, you 
know the point exactly opposite has an ALON of 0 .

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