NNavigationUtilities Namespace Reference

Classes
class	CGeoConstants
class	CMathConstants

Functions
float	HeightFromPressure (float fPressurePascals)
	Compute height above mean sea level from pressure. Valid input range [22700.0 127780.0]. The range corresponds to height from approximately -2000m to 11000m.
float	PartialDerivativeHeightWrtPressure (float fPressurePascals)
	Compute a partial derivative of height above mean sea level with respect to pressure. Valid input range [22700.0 127780.0]. The range corresponds to height from approximately -2000m to 11000m.
void	EulerFromSpecificForce (const Eigen::Vector3f &korSpecificForce, float &frRoll, float &frPitch)
	Compute Euler angles (roll and pitch) from specific force measurements. The function does not check for static conditions. Aerospace sequence of Euler angles is assumed.
void	EulerFromQuaternion (const CQuaternion &korQuaternion, float &frRoll, float &frPitch, float &frYaw)
	Convert a quaternion to Euler angles. Quaternion's norm shall be 1, otherwise usage of this function does not make sense. The function does not vefify the input, it shall be done by a caller.
float	HeadingFromMagnetometer (const Eigen::Vector3f &korMagneticFieldVectorInGauss, float fRoll, float fPitch)
	Compute magnetic heading given known attitude and a magnetometer measurement.
CQuaternion	QuaternionFromEuler (float fRoll, float fPitch, float fYaw)
	Convert Euler angles to a quaternion.
Eigen::Matrix3f	DcmFromQuaternion (const CQuaternion &korQuaternion)
	Convert a quaternion to a rotation matrix.
template<typename tUnsignedType >
int32_t	DiffOfUnsigned (tUnsignedType uTimestamp1, tUnsignedType uTimestamp2)
	Computes a signed difference of two unsigned numbers. The function asserts if the diff is greater than the max value of the return type.

Function Documentation

DcmFromQuaternion()

Eigen::Matrix3f NNavigationUtilities::DcmFromQuaternion

(

const CQuaternion &

korQuaternion

)

Convert a quaternion to a rotation matrix.

Parameters

korQuaternion

Input quaternion.

Returns

Rotation matrix.

DiffOfUnsigned()

template<typename tUnsignedType >

int32_t NNavigationUtilities::DiffOfUnsigned ( tUnsignedType  uTimestamp1, tUnsignedType  uTimestamp2  )

inline

Computes a signed difference of two unsigned numbers. The function asserts if the diff is greater than the max value of the return type.

Template Parameters

tUnsignedType

Unsigned type

Parameters

[in]	uTimestamp1
[in]	uTimestamp2

Returns

uTimestamp1 minus uTimastamp2

EulerFromQuaternion()

void NNavigationUtilities::EulerFromQuaternion	(	const CQuaternion &	korQuaternion,
		float &	frRoll,
		float &	frPitch,
		float &	frYaw
	)

Convert a quaternion to Euler angles. Quaternion's norm shall be 1, otherwise usage of this function does not make sense. The function does not vefify the input, it shall be done by a caller.

Parameters

korQuaternion	A quaternion to be converted.
frRoll	Output roll angle, [rad], from -pi to pi
frPitch	Output pitch angle, [rad], from -pi/2 to pi/2
frYaw	Output yaw angle, [rad], from -pi to pi

EulerFromSpecificForce()

void NNavigationUtilities::EulerFromSpecificForce	(	const Eigen::Vector3f &	korSpecificForce,
		float &	frRoll,
		float &	frPitch
	)

Compute Euler angles (roll and pitch) from specific force measurements. The function does not check for static conditions. Aerospace sequence of Euler angles is assumed.

Parameters

korSpecificForce	The specific force measurement.
frRoll	Output roll angle.
frPitch	Output pitch angle.

HeadingFromMagnetometer()

float NNavigationUtilities::HeadingFromMagnetometer	(	const Eigen::Vector3f &	korMagneticFieldVectorInGauss,
		float	fRoll,
		float	fPitch
	)

Compute magnetic heading given known attitude and a magnetometer measurement.

Roll must be between +-pi, pitch must be between +-pi/2. The function returns NaN if inputs are not in the expected range. Rturns NaN in gimbal lock, i. e. when pitch is exactly +pi/2 or -pi/2

Parameters

korMagneticFieldVectorInGauss	Magnetometer measurement.
fRoll	Roll angle, [rad], must belong to the closed interval [-pi, pi]
fPitch	Pitch angle, [rad]

Returns

Magnetic heading in radians, from -pi to pi.

HeightFromPressure()

float NNavigationUtilities::HeightFromPressure

(

float

fPressurePascals

)

Compute height above mean sea level from pressure. Valid input range [22700.0 127780.0]. The range corresponds to height from approximately -2000m to 11000m.

Parameters

fPressurePascals

Measured pressure.

Returns

Height above mean sea level when input is from the valid range, quiet NaN otherwise.

PartialDerivativeHeightWrtPressure()

float NNavigationUtilities::PartialDerivativeHeightWrtPressure

(

float

fPressurePascals

)

Compute a partial derivative of height above mean sea level with respect to pressure. Valid input range [22700.0 127780.0]. The range corresponds to height from approximately -2000m to 11000m.

Parameters

fPressurePascals

Measured pressure.

Returns

A value of a partial derivative of height with respect to pressure when input is from the valid range, quiet NaN otherwise.

QuaternionFromEuler()

CQuaternion NNavigationUtilities::QuaternionFromEuler	(	float	fRoll,
		float	fPitch,
		float	fYaw
	)

Convert Euler angles to a quaternion.

Parameters

fRoll	Roll angle.
fPitch	Pitch angle.
fYaw	Yaw angle.

Returns

Quaternion.