[time-nuts] OT - GPS and North

[Gary Chatters]

Mark Spencer wrote:
> Would Time Difference of Arrival techniques combined with an array of four closely spaced antennas work with Gps signals as a means of determing the orentation of the antenna array vs the gps satellites ? (I'm thinking traditional TDOA techniques may not work with gps signals.)
> 

There are commercial products available: 
http://www.hemispheregps.com/Default.aspx?tabid=379
http://www.hemispheregps.com/Default.aspx?tabid=412


These devices claim less than 1 degree RMS heading accuracy.

Here the antennas are integrated and a fixed 0.5 meter apart.  They do 
(or did) make a board that could be used with separate antennas, but I 
can not find it right now.

I have no idea of how the math works for computing heading.

Gary