Class GeodeticLibrary

Namespace

NominalSystems.Universe

Assembly

NominalSystems.Universe.dll

Library for converting between different planet coordinates, including: PCI, PCPF, LLA and SEZ

public static class GeodeticLibrary

Inheritance

object

GeodeticLibrary

Methods

DistanceBetweenGeodeticElements(double, GeodeticElements, GeodeticElements)

Determines the Distance between two Geodetic elements

public static double DistanceBetweenGeodeticElements(double planetRadius, GeodeticElements LLA1, GeodeticElements LLA2)

Parameters

planetRadius double

[m] The radius of the planet

LLA1 GeodeticElements

The first Geodetic element

LLA2 GeodeticElements

The second Geodetic element

Returns

double

[m] The calculated distance between the two elements

GeodeticElem2VectorElem(GeodeticElements, Matrix3, double, double)

Converts from a Lat/Long/Altitude coordinates to planet-centered, planet-fixed coordinates given a planet radius. This assumes that the object is located at the peak of the orbit equal to the lat and lon of the object. This also assumes a circular orbit.

public static VectorElements GeodeticElem2VectorElem(GeodeticElements llaPosition, Matrix3 j20002Pfix, double planetRadius, double mu)

Parameters

llaPosition GeodeticElements

[-] Position in latitude/longitude/altitude coordinates

j20002Pfix Matrix3

[-] Planet rotation matrix

planetRadius double

[m] Planetary radius, assumed to be constant (i.e., spherical)

mu double

[kg m^2 s^3] The gravitational constant for the body orbiting

Returns

VectorElements

[m]/[m/s] Final position and velocity in the planet-centered, planet-fixed frame.

GetRotationVelocity(GeodeticElements, Matrix3, Matrix3, double)

Returns the rotation velocity of a particular location on a body based on the geodetic coordinates and the rotation speed of the body at the current point in time. This assumes a PCI frame velocity.

public static Vector3 GetRotationVelocity(GeodeticElements llaPosition, Matrix3 j2000, Matrix3 j2000Dot, double planetRadius)

Parameters

llaPosition GeodeticElements

[deg] The geodetic coordinates to get the rotation at

j2000 Matrix3

[-] The J2000 rotation frame of the body at the current time

j2000Dot Matrix3

[-] The J2000 rotation velocity of the body at the current time

planetRadius double

[m] The radius of the body that the location exists on

Returns

Vector3

[m/s] A PCI frame velocity at the current location

HCS2PCPF(Matrix3, double, double, double)

Converts a HCS (horizontal coordinate system) rotation frame to a PCPF (planet centered planet fixed) rotation frame with a rotation about the azimuth angle (clockwise from the primary direction) and elevation angles in degrees into a new rotation frame.

public static Matrix3 HCS2PCPF(Matrix3 hcs, double yaw, double pitch, double roll = 0)

Parameters

hcs Matrix3

[-] The HCS frame at the current position

yaw double

[deg] The angle to rotate clockwise about the HCS direction

pitch double

[deg] The angle to rotate about the horizon plane

roll double

[deg] The angle to roll about the final axis

Returns

Matrix3

[-] A rotated HCS rotation in the PCPF frame

LLA2ENU(double, double)

Converts a latitude and longitude position to an ENU (east north up) rotation frame.

public static Matrix3 LLA2ENU(double latitude, double longitude)

Parameters

latitude double

[deg] The latitude of the position

longitude double

[deg] The longitude of the position

Returns

Matrix3

The ENU rotation frame

LLA2NED(double, double)

Converts a latitude and longitude position to an NED (north east down) rotation frame.

public static Matrix3 LLA2NED(double latitude, double longitude)

Parameters

latitude double

[deg] The latitude of the position

longitude double

[deg] The longitude of the position

Returns

Matrix3

The NED rotation frame

LLA2PCI(GeodeticElements, Matrix3, double)

Converts from a planet-centered inertial coordinates to latitutde/longitude/altitude (LLA) coordinates given a planet radius and rotation matrix.

public static Vector3 LLA2PCI(GeodeticElements llaPosition, Matrix3 J20002Pfix, double planetRadius)

Parameters

llaPosition GeodeticElements

[-] Position in latitude/longitude/altitude coordinates

J20002Pfix Matrix3

[-] Rotation matrix between inertial and PCPF frames

planetRadius double

[m] Planetary radius, assumed to be constant (i.e., spherical)

Returns

Vector3

[m] Position in inertial coordinates.

LLA2PCPF(GeodeticElements, double)

Converts from a Lat/Long/Altitude coordinates to planet-centered, planet-fixed coordinates given a planet radius.

public static Vector3 LLA2PCPF(GeodeticElements llaPosition, double planetRadius)

Parameters

llaPosition GeodeticElements

[-] Position in latitude/longitude/altitude coordinates

planetRadius double

[m] Planetary radius, assumed to be constant (i.e., spherical)

Returns

Vector3

[m] Final position in the planet-centered, planet-fixed frame.

LLA2SEZ(double, double)

Converts a latitude and longitude position to an SEZ (south east zenith) rotation frame.

public static Matrix3 LLA2SEZ(double latitude, double longitude)

Parameters

latitude double

[deg] The latitude of the position

longitude double

[deg] The longitude of the position

Returns

Matrix3

The SEZ rotation frame

LLA2WGS(GeodeticElements)

Converts a latitude longitude altitude (LLA) to a WGS-84 (Earth centered Earth fixed) terrestrial reference system

public static Vector3 LLA2WGS(GeodeticElements lla)

Parameters

lla GeodeticElements

[deg] The LLA value for the position

Returns

Vector3

[m] The final PCPF frame in the WGS-84 standard

PCI2LLA(Vector3, Matrix3, double)

Converts from a planet-centered inertial coordinates to latitutde/longitude/altitude (LLA) coordinates given a planet radius and rotation matrix.

public static GeodeticElements PCI2LLA(Vector3 pciPosition, Matrix3 J20002Pfix, double planetRadius)

Parameters

pciPosition Vector3

[m] Position vector in PCI coordinates

J20002Pfix Matrix3

[-] 3x3 rotation matrix representing the rotation between PCPF and ECI frames

planetRadius double

[m] Planetary radius, assumed to be constant (i.e., spherical)

Returns

GeodeticElements

Final position in latitude/longitude/altitude coordinates [0] : [deg] latitude above planetary equator [1] : [deg] longitude across planetary meridian [2] : [m] altitude above planet radius

PCI2PCPF(Vector3, Matrix3)

Converts from a planet-centered inertial position (i.e., J2000 ECI) to a planet-centered, planet-fixed position given a rotation matrix.

public static Vector3 PCI2PCPF(Vector3 pciPosition, Matrix3 J20002Pfix)

Parameters

pciPosition Vector3

[m] Position vector in PCI coordinates

J20002Pfix Matrix3

[-] 3x3 rotation matrix representing the rotation between PCPF and ECI frames

Returns

Vector3

[m] Position vector in PCPF coordinates

PCPF2LLA(Vector3, double)

Converts from a planet-centered, planet-fixed coordinates to latitutde/longitude/altitude (LLA) coordinates given a planet radius.

public static GeodeticElements PCPF2LLA(Vector3 pcpfPosition, double planetRadius)

Parameters

pcpfPosition Vector3

[m] Position vector in PCPF coordinates

planetRadius double

[m] Planetary radius, assumed to be constant (i.e., spherical)

Returns

GeodeticElements

Final position in latitude/longitude/altitude coordinates [0] : [rad] latitude above planetary equator [1] : [rad] longitude across planetary meridian [2] : [m] altitude above planet radius

PCPF2PCI(Vector3, Matrix3)

Converts from a planet-centered, planet-fixed to a planet-centered inertial position (i.e., J2000 ECI) position given a rotation matrix.

public static Vector3 PCPF2PCI(Vector3 pcpfPosition, Matrix3 J20002Pfix)

Parameters

pcpfPosition Vector3

[m] Position vector in planet centered, planet fixed coordinates

J20002Pfix Matrix3

[-] Rotation between inertial and pcf coordinates.

Returns

Vector3

[m] Final position in the planet-centered inertial frame.

PCPF2PCIDCM(Matrix3, Matrix3)

Converts a PCPF (planet-centered planet-fixed) rotation matrix to a PCI (planet-centered inertial) frame, with the combination of the planet rotation matrix and the raw DCM (direction cosine matrix) rotation matrix.

public static Matrix3 PCPF2PCIDCM(Matrix3 pcpf, Matrix3 j2000)

Parameters

pcpf Matrix3

[-] The PCPF DCM rotation matrix

j2000 Matrix3

[-] The SPICE J2000 rotation frame

Returns

Matrix3

[-] The PCI DCM rotation matrix

WGS2LLA(Vector3)

Converts a standard WGS-84 (Earth Centered, Earth Fixed) terrestrial reference system for Earth to an appropriate latitude longitude altitude (LLA) value.

public static GeodeticElements WGS2LLA(Vector3 position)

Parameters

position Vector3

[m] The PCPF frame relative to the center of the Earth

Returns

GeodeticElements

[deg] The LLA value for the position