/// <summary>
/// Handle GPS GPGSV Notifications - Satellites In View
/// </summary>
/// <param name="notification">GPGSV packet notification</param>
private void GpGsvHandler(gps.GpGsvNotification notification)
{
/*
* GSV - Satellites in View shows data about the satellites that the unit might be able to find based on its viewing mask and almanac data.
* It also shows current ability to track this data. Note that one GSV sentence only can provide data for up to 4 satellites and thus there may need to be 3 sentences for the full information.
* It is reasonable for the GSV sentence to contain more satellites than GGA might indicate since GSV may include satellites that are not used as part of the solution.
* It is not a requirment that the GSV sentences all appear in sequence.
* To avoid overloading the data bandwidth some receivers may place the various sentences in totally different samples since each sentence identifies which one it is.
*
* The field called SNR (Signal to Noise Ratio) in the NMEA standard is often referred to as signal strength.
* SNR is an indirect but more useful value that raw signal strength.
* It can range from 0 to 99 and has units of dB according to the NMEA standard, but the various manufacturers send different ranges of numbers with different starting numbers
* so the values themselves cannot necessarily be used to evaluate different units. The range of working values in a given gps will usually show a difference of about 25 to 35 between the lowest and highest values,
* however 0 is a special case and may be shown on satellites that are in view but not being tracked.
*
* $GPGSV,2,1,08,01,40,083,46,02,17,308,41,12,07,344,39,14,22,228,45*75
*
* Where:
* GSV Satellites in view
* 2 Number of sentences for full data
* 1 sentence 1 of 2
* 08 Number of satellites in view
*
* 01 Satellite PRN number
* 40 Elevation, degrees
* 083 Azimuth, degrees
* 46 SNR - higher is better
* for up to 4 satellites per sentence
* 75 the checksum data, always begins with *
*/
if (!_mapperVicinity.robotState.ignoreGps)
{
if (!notification.Body.IsValid)
{
Tracer.Error("the GPS reported GPGSV with IsValid=false");
}
else
{
if (traceGps)
{
Tracer.Trace(string.Format("the GPS reported GPGSV: {0} Satellites in View: {1} {2}", notification.Body.LastUpdate, notification.Body.GsvSatellites.Count, notification.Body.SatellitesInView));
}
GpsState state = _state.gpsState;
// Number of Satellites In View
state.GPGSV_SatellitesInView = notification.Body.SatellitesInView;
// Last Updated:
state.GPGSV_LastUpdate = notification.Body.LastUpdate;
if (!_testBumpMode && !_state.Dropping && !_doUnitTest)
{
Decide(SensorEventSource.Gps);
}
}
}
}
/// <summary>
/// Handle GPS GPGSV Notifications - Satellites
/// </summary>
/// <param name="notification">GPGSV packet notification</param>
private void GpGsvHandler(gps.GpGsvNotification notification)
{
Tracer.Trace(string.Format("the GPS reported GPGSV: {0} Satellites in View: {1} {2}", notification.Body.LastUpdate, notification.Body.GsvSatellites.Count, notification.Body.SatellitesInView));
}