[time-nuts] How can I measure GPS Antenna quality?

David J Taylor david-taylor at blueyonder.co.uk
Wed Nov 23 09:56:24 EST 2016

The interpolation does not spread the data to where sats have not 
appeared...  what it effectively does is intelligently make the dots 
bigger...  but only along the azimuth "axis".

For each elevation angle, it starts at azimuth 0 degrees and searches 
forward until it sees a point with signal.  It then searches forward up to 
22.5 degrees looking for the next azimuth point at that elevation that has 
seen signals.  If it finds one, it colors in the arc between those two 
points (providing that the arc lies inside the clipping boundaries which 
prevents spreading the interpolation to areas that have not seen signals). 
As more sky data is collected over time  the space between adjacent azimuth 
points at a given elevation narrows and less "filling in" occurs.

Attached are two gifs,  one of the raw data from 24 hours and the other the 
interpolated data.  Note that areas near the horizon and to the north where 
no sats are seen are not colored.  The interpolation gives an excellent 
representation of your sky coverage.


This looks to be a most useful and helpful display.  Will the program do the 
same from any serial NMEA source?

SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor at blueyonder.co.uk
Twitter: @gm8arv 

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