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Signal Quality Window
The Signal Quality Window uses the GPGSV NMEA message to extract the signal to
noise ratio (SNR C/No) which is specified as a number from 0 - 99 dB. Depending on
the number of satellites in view, the number of SNR bars will vary. At the top of each
SNR bar, the raw SNR value is displayed. Full scale is considered any SNR value of
50 dB or above. At the bottom of each bar shows the satellite ID or Pseudo Random
Number.
The signal quality bar will change its color depending if the satellite is used in the
navigation solution returned by the GPGSA NMEA message. If the satellite is not
used in the position fix solution, the signal quality bar will be in gray. If the satellite is
used in the solution, the signal quality bar will be blue.
Azimuth and Elevation window
The Azimuth and Elevation window shows satellite position and the physical antenna
mask angle. The satellite position is denoted using azimuth, 0° to 359°, and elevation,
0° to 90° where 90° is the horizon. The satellites are also color coded to show which
is part of the navigation solution and tracked. When the satellite is highlighted in color
shows that it is being used for a navigation solution and tracked. When the satellite is
gray shows that the satellite is not tracked.
Like the Signal Quality Window, the Azimuth & elevation Window will use the
GPGSV NMEA command to extract azimuth and elevation for each satellite that is in
view. Each satellite is identified by its Pseudo Random Number (PRN) with the
azimuth as the letter ‗A‘ and elevation by the letter ‗E‘.
