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Fix incorrect QNH in spoken ATIS when using live weather fetch

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When using live weather fetch, the QNH should be obtained from
environment/metar/pressure-inhg.

See: http://sourceforge.net/p/flightgear/mailman/message/35037125

Add new method getQnhInHg to ATISInformationProvider and its implementations
to avoid rounding errors converting from hPa back to inches in ATIS reports.

The CurrentWeatherATISInformationProvider (used when live weather fetch is
not in use) continues to use the property environment/pressure-sea-level-inhg.
This produces the incorrect QNH at airports significantly above sea level
but this needs fixing elsewhere to calculate the correct QNH.
This commit is contained in:
Richard Senior 2016-04-26 10:30:15 +01:00
parent f825bb4f3c
commit 29fe6569c4
6 changed files with 18 additions and 4 deletions
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4
src/ATC/ATISEncoder.cxx
View file

@ -565,13 +565,13 @@ string ATISEncoder::getQnh( SGPropertyNode_ptr )
string ATISEncoder::getInhgInteger( SGPropertyNode_ptr )
{
double qnh = _atis->getQnh() * 100 / SG_INHG_TO_PA;
double qnh = _atis->getQnhInHg();
return getSpokenNumber( (int)qnh, true, 2 );
}
string ATISEncoder::getInhgFraction( SGPropertyNode_ptr )
{
double qnh = _atis->getQnh() * 100 / SG_INHG_TO_PA;
double qnh = _atis->getQnhInHg();
int f = int(100 * (qnh - int(qnh)) + 0.5);
return getSpokenNumber( f, true, 2 );
}

1
src/ATC/ATISEncoder.hxx
View file

@ -53,6 +53,7 @@ public:
virtual int getWindSpeedKt() = 0;
virtual int getGustsKt() = 0;
virtual int getQnh() = 0;
virtual double getQnhInHg() = 0;
virtual bool isCavok() = 0;
virtual int getVisibilityMeters() = 0;
virtual std::string getPhenomena() = 0;

7
src/ATC/CurrentWeatherATISInformationProvider.cxx
View file

@ -85,9 +85,16 @@ int CurrentWeatherATISInformationProvider::getGustsKt()
int CurrentWeatherATISInformationProvider::getQnh()
{
// TODO: Calculate QNH correctly from environment
return roundToInt( _environment->getNode("pressure-sea-level-inhg",true)->getDoubleValue() * SG_INHG_TO_PA / 100 );
}
double CurrentWeatherATISInformationProvider::getQnhInHg()
{
// TODO: Calculate QNH correctly from environment
return _environment->getNode("pressure-sea-level-inhg",true)->getDoubleValue();
}
bool CurrentWeatherATISInformationProvider::isCavok()
{
return false;

1
src/ATC/CurrentWeatherATISInformationProvider.hxx
View file

@ -41,6 +41,7 @@ protected:
virtual int getWindSpeedKt();
virtual int getGustsKt();
virtual int getQnh();
virtual double getQnhInHg();
virtual bool isCavok();
virtual int getVisibilityMeters();
virtual std::string getPhenomena();

8
src/ATC/MetarPropertiesATISInformationProvider.cxx
View file

@ -72,10 +72,14 @@ int MetarPropertiesATISInformationProvider::getGustsKt()
return _metar->getIntValue( "gust-wind-speed-kt" );
}
int MetarPropertiesATISInformationProvider::getQnh()
{
return _metar->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
return _metar->getDoubleValue("pressure-inhg") * SG_INHG_TO_PA / 100.0;
}
double MetarPropertiesATISInformationProvider::getQnhInHg()
{
return _metar->getDoubleValue("pressure-inhg");
}
bool MetarPropertiesATISInformationProvider::isCavok()

1
src/ATC/MetarPropertiesATISInformationProvider.hxx
View file

@ -43,6 +43,7 @@ protected:
virtual int getWindSpeedKt();
virtual int getGustsKt();
virtual int getQnh();
virtual double getQnhInHg();
virtual bool isCavok();
virtual int getVisibilityMeters();
virtual std::string getPhenomena();