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Rename equivalent airspeed (EAS) to calibrated airspeed (CAS)

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Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
This commit is contained in:
Silvan Fuhrer
2020-10-06 09:31:58 +02:00
parent f8d5b09b56
commit 8f858d95e6
13 changed files with 78 additions and 80 deletions
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src/lib/airspeed/airspeed.cpp
+4 -4
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@@ -186,17 +186,17 @@ float calc_IAS(float differential_pressure)
}
float calc_TAS_from_EAS(float speed_equivalent, float pressure_ambient, float temperature_celsius)
float calc_TAS_from_CAS(float speed_calibrated, float pressure_ambient, float temperature_celsius)
{
if (!PX4_ISFINITE(temperature_celsius)) {
temperature_celsius = 15.f; // ICAO Standard Atmosphere 15 degrees celcius
}
return speed_equivalent * sqrtf(CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C / get_air_density(pressure_ambient,
return speed_calibrated * sqrtf(CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C / get_air_density(pressure_ambient,
temperature_celsius));
}
float calc_EAS_from_IAS(float speed_indicated, float scale)
float calc_CAS_from_IAS(float speed_indicated, float scale)
{
return speed_indicated * scale;
}
@@ -228,7 +228,7 @@ float get_air_density(float static_pressure, float temperature_celsius)
return static_pressure / (CONSTANTS_AIR_GAS_CONST * (temperature_celsius - CONSTANTS_ABSOLUTE_NULL_CELSIUS));
}
float calc_EAS_from_TAS(float speed_true, float pressure_ambient, float temperature_celsius)
float calc_CAS_from_TAS(float speed_true, float pressure_ambient, float temperature_celsius)
{
return speed_true * sqrtf(get_air_density(pressure_ambient, temperature_celsius) / CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C);
}
src/lib/airspeed/airspeed.h
+11 -13
View File
@@ -86,34 +86,32 @@ __EXPORT float calc_IAS_corrected(enum AIRSPEED_COMPENSATION_MODEL pmodel,
__EXPORT float calc_IAS(float differential_pressure);
/**
* Calculate true airspeed (TAS) from equivalent airspeed (EAS).
* Calculate true airspeed (TAS) from calibrated airspeed (CAS).
*
* Note that the true airspeed is NOT the groundspeed, because of the effects of wind
*
* @param speed_equivalent current equivalent airspeed
* @param speed_equivalent current calibrated airspeed
* @param pressure_ambient pressure at the side of the tube/airplane
* @param temperature_celsius air temperature in degrees celcius
* @return TAS in m/s
*/
__EXPORT float calc_TAS_from_EAS(float speed_indicated, float pressure_ambient,
__EXPORT float calc_TAS_from_CAS(float speed_indicated, float pressure_ambient,
float temperature_celsius);
/**
* Calculate equivalent airspeed (EAS) from indicated airspeed (IAS).
* Note that we neglect the conversion from CAS (calibrated airspeed) to EAS.
* Calculate calibrated airspeed (CAS) from indicated airspeed (IAS).
*
* @param speed_indicated current indicated airspeed
* @param scale scale from IAS to CAS (accounting for instrument and pitot position erros)
* @return EAS in m/s
* @return CAS in m/s
*/
__EXPORT float calc_EAS_from_IAS(float speed_indicated, float scale);
__EXPORT float calc_CAS_from_IAS(float speed_indicated, float scale);
/**
* Directly calculate true airspeed (TAS)
*
* Here we assume to have no instrument or pitot position error (IAS = CAS),
* and neglect the CAS to EAS conversion (CAS = EAS).
* Here we assume to have no instrument or pitot position error (IAS = CAS).
* Note that the true airspeed is NOT the groundspeed, because of the effects of wind.
*
* @param total_pressure pressure inside the pitot/prandtl tube
@@ -132,16 +130,16 @@ __EXPORT float calc_TAS(float total_pressure, float static_pressure, float tempe
__EXPORT float get_air_density(float static_pressure, float temperature_celsius);
/**
* Calculate equivalent airspeed (EAS) from true airspeed (TAS).
* It is the inverse function to calc_TAS_from_EAS()
* Calculate calibrated airspeed (CAS) from true airspeed (TAS).
* It is the inverse function to calc_TAS_from_CAS()
*
*
* @param speed_true current true airspeed
* @param pressure_ambient pressure at the side of the tube/airplane
* @param temperature_celsius air temperature in degrees celcius
* @return EAS in m/s
* @return CAS in m/s
*/
__EXPORT float calc_EAS_from_TAS(float speed_true, float pressure_ambient,
__EXPORT float calc_CAS_from_TAS(float speed_true, float pressure_ambient,
float temperature_celsius);
__END_DECLS