/// <summary>
/// Parses the word at the given position to Azimuth.
/// </summary>
/// <param name="position">Position of the Words array that gets parsed to Azimuth.</param>
/// <returns>Invalid if position is outside of Words array or word at the position is empty.</returns>
protected Azimuth ParseAzimuth(int position)
{
if (Words.Length <= position || Words[position].Length == 0)
{
return(Azimuth.Invalid);
}
return(Azimuth.Parse(Words[position], NmeaCultureInfo));
}
/// <summary>
/// Overrides OnSentanceChanged for the GPVTGSentence
/// </summary>
protected override void OnSentenceChanged()
{
// First, process the basic info for the sentence
base.OnSentenceChanged();
// Cache the sentence words
string[] words = Words;
int wordCount = words.Length;
/*
* $GPVTG
*
* Track Made Good and Ground Speed.
*
* eg1. $GPVTG, 360.0, T, 348.7, M, 000.0, N, 000.0, K*43
* eg2. $GPVTG, 054.7, T, 034.4, M, 005.5, N, 010.2, K
*
* 054.7, T True track made good
* 034.4, M Magnetic track made good
* 005.5, N Ground speed, knots
* 010.2, K Ground speed, Kilometers per hour
*
* eg3. $GPVTG, t, T, ,, s.ss, N, s.ss, K*hh
* 0 = Track made good
* 1 = Fixed text 'T' indicates that track made good is relative to true north
* 2 = not used
* 3 = not used
* 4 = Speed over ground in knots
* 5 = Fixed text 'N' indicates that speed over ground in in knots
* 6 = Speed over ground in kilometers/hour
* 7 = Fixed text 'K' indicates that speed over ground is in kilometers/hour
*
*
*
*/
#region Heading
if (wordCount >= 1 && words[0].Length != 0)
{
_heading = Azimuth.Parse(words[0], NmeaCultureInfo);
}
else
{
_heading = Azimuth.Invalid;
}
#endregion Heading
}
/// <summary>
/// Overrides OnSentanceChanged for the GPVTGSentence
/// </summary>
protected override void OnSentenceChanged()
{
// First, process the basic info for the sentence
base.OnSentenceChanged();
// Cache the sentence words
string[] words = base.Words;
int wordCount = words.Length;
/*
* $GPVTG
*
* Track Made Good and Ground Speed.
*
* eg1. $GPVTG,360.0,T,348.7,M,000.0,N,000.0,K*43
* eg2. $GPVTG,054.7,T,034.4,M,005.5,N,010.2,K
*
*
* 054.7,T True track made good
* 034.4,M Magnetic track made good
* 005.5,N Ground speed, knots
* 010.2,K Ground speed, Kilometers per hour
*
*
* eg3. $GPVTG,t,T,,,s.ss,N,s.ss,K*hh
* 1 = Track made good
* 2 = Fixed text 'T' indicates that track made good is relative to true north
* 3 = not used
* 4 = not used
* 5 = Speed over ground in knots
* 6 = Fixed text 'N' indicates that speed over ground in in knots
* 7 = Speed over ground in kilometers/hour
* 8 = Fixed text 'K' indicates that speed over ground is in kilometers/hour
*
*
*
*/
#region Bearing
if (wordCount >= 1 && words[0].Length != 0)
{
_Bearing = Azimuth.Parse(words[0], NmeaCultureInfo);
}
else
{
_Bearing = Azimuth.Invalid;
}
#endregion
#region Magnetic Variation
if (wordCount >= 3 && words[2].Length != 0)
{
_MagneticVariation = new Longitude(double.Parse(words[2], NmeaCultureInfo) - _Bearing.DecimalDegrees);
}
else
{
_MagneticVariation = Longitude.Invalid;
}
#endregion
#region Speed
/* Speed is reported as both knots and KM/H. We can parse either of the values.
* First, try to parse knots. If that fails, parse KM/h.
*/
if (wordCount > 6 && words[5].Length != 0)
{
_Speed = new Speed(
// Parse the numeric portion
double.Parse(words[5], NmeaCultureInfo),
// Use knots
SpeedUnit.Knots);
}
else if (wordCount > 8 && words[7].Length != 0)
{
_Speed = new Speed(
// Parse the numeric portion
double.Parse(words[7], NmeaCultureInfo),
// Use knots
SpeedUnit.KilometersPerHour);
}
else
{
// Invalid speed
_Speed = Speed.Invalid;
}
#endregion
}
/// <summary>
/// Corrects this classes properties after the base sentence was changed.
/// </summary>
private new void SetPropertiesFromSentence()
{
// Cache the words
string[] words = Words;
int wordCount = words.Length;
/* $GPGSV
*
* GPS Satellites in view
*
* eg. $GPGSV, 3, 1, 11, 03, 03, 111, 00, 04, 15, 270, 00, 06, 01, 010, 00, 13, 06, 292, 00*74
* $GPGSV, 3, 2, 11, 14, 25, 170, 00, 16, 57, 208, 39, 18, 67, 296, 40, 19, 40, 246, 00*74
* $GPGSV, 3, 3, 11, 22, 42, 067, 42, 24, 14, 311, 43, 27, 05, 244, 00, ,, ,*4D
*
*
* $GPGSV, 1, 1, 13, 02, 02, 213, ,03, -3, 000, ,11, 00, 121, ,14, 13, 172, 05*62
*
*
* 1 = Total number of messages of this type in this cycle
* 2 = Message number
* 3 = Total number of SVs in view
* 4 = SV PRN number
* 5 = Elevation in degrees, 90 maximum
* 6 = Azimuth, degrees from true north, 000 to 359
* 7 = SNR, 00-99 dB (null when not tracking)
* 8-11 = Information about second SV, same as field 4-7
* 12-15= Information about third SV, same as field 4-7
* 16-19= Information about fourth SV, same as field 4-7
*/
// Example (signal not acquired): $GPGSV, 1, 1, 01, 21, 00, 000, *4B
// Example (signal acquired): $GPGSV, 3, 1, 10, 20, 78, 331, 45, 01, 59, 235, 47, 22, 41, 069, ,13, 32, 252, 45*70
// Get the total message count
if (wordCount > 0 && words[0].Length != 0)
{
TotalMessageCount = int.Parse(words[0], NmeaCultureInfo);
}
// Get the current message number
if (wordCount > 1 && words[1].Length != 0)
{
CurrentMessageNumber = int.Parse(words[1], NmeaCultureInfo);
}
// Get the total message count
if (wordCount > 2 && words[2].Length != 0)
{
SatellitesInView = int.Parse(words[2], NmeaCultureInfo);
}
// Make a new list of satellites
Satellites = new List <Satellite>();
// Now process each satellite
for (int index = 0; index < 6; index++)
{
int currentWordIndex = index * 4 + 3;
// Are we past the length of words?
if (currentWordIndex > wordCount - 1)
{
break;
}
// No. Get the unique code for the satellite
if (words[currentWordIndex].Length == 0)
{
continue;
}
int pseudorandomNumber = int.Parse(words[currentWordIndex], NmeaCultureInfo);
Elevation newElevation;
Azimuth newAzimuth;
SignalToNoiseRatio newSignalToNoiseRatio;
// Update the elevation
if (wordCount > currentWordIndex + 1 && words[currentWordIndex + 1].Length != 0)
{
newElevation = Elevation.Parse(words[currentWordIndex + 1], NmeaCultureInfo);
}
else
{
newElevation = Elevation.Empty;
}
// Update the azimuth
if (wordCount > currentWordIndex + 2 && words[currentWordIndex + 2].Length != 0)
{
newAzimuth = Azimuth.Parse(words[currentWordIndex + 2], NmeaCultureInfo);
}
else
{
newAzimuth = Azimuth.Empty;
}
// Update the signal strength
if (wordCount > currentWordIndex + 3 && words[currentWordIndex + 3].Length != 0)
{
newSignalToNoiseRatio = SignalToNoiseRatio.Parse(words[currentWordIndex + 3], NmeaCultureInfo);
}
else
{
newSignalToNoiseRatio = SignalToNoiseRatio.Empty;
}
// Add the satellite to the collection
Satellites.Add(new Satellite(pseudorandomNumber, newAzimuth, newElevation, newSignalToNoiseRatio, false));
}
}