GSV - Satellites in view

               1 2 3 4 5 6 7     n
        | | | | | | |     |
 $--GSV,x,x,x,x,x,x,x,...*hh<CR><LF>

 Field Number: 
  1) total number of messages
  2) message number
  3) satellites in view
  4) satellite number
  5) elevation in degrees
  6) azimuth in degrees to true
  7) SNR in dB
  more satellite infos like 4)-7)
  n) checksum