[time-nuts] OT - GPS and North

[Gary Chatters]

Iain Young wrote:
> Gary Chatters wrote:
> 
>> I have no idea of how the math works for computing heading.
> 
> Checkout FORWARD and INVERSE (and their 3d equivalents) at
> http://www.ngs.noaa.gov/TOOLS/Inv_Fwd/Inv_Fwd.html
> 
> While these are hosted on a NOAA site, I'm sure I've seen
> it on a NASA site as well. IIRC, there is also a C port
> somewhere.
> 
> 

I am not sure that this would be useful in this application.  Getting
< 1 degree heading error from two positions would require about 8mm 
absolute accuracy.  I suspect that such accuracy requires something like 
the phase measurements as mentioned by Björn.



Gary