gps-satellite sky-plot

Hi All,

i'm starting to learn matplotlib,
for my study i need to parse the nmea sentence from a gps
and plot a "sky graphic" to plot satellite visibility.

(i tried to write code from scratch ... it works  but my teacher  
suggest me to not reinvent the well, so, to have a good nema parser, i  
installed gpsd ... it has in the source code a nice python code that  
allow me to retrieve satellite constallation iformation).

now i need to learn how to produce a sky plot,
have you any suggestion on how to produce such kind of graphic ?

thanks to all for any suggestion!

Massimo.

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