Data Providers: Satellite: SEET Magnetic Conjugacy

Computes the time intervals when the vehicle is magnetically conjugate with a target object. The user must specify the target object and the maximum separation angle between their respective field lines that will indicate conjugacy. The smaller the separation is made, the closer the field lines containing the vehicle and the target object must be. Valid for vehicles whose central body is earth.

Name	Dimension	Type	Description
Time	DateFormat	Real Number	Time.
Separation Angle	AngleUnit	Real Number	The centric angle between the north footprint of the field line containing the vehicle's location and the north footprint of the field line containing the target's location. The north footprint is the point of intersection of the field line with the earth's surface north of the magnetic equator. If either north footprint is not defined, then the south footprint is used. This value serves as a measure of the closeness of the vehicle's and the target's field lines - as the angle approaches zero, the field lines between the objects become equal and the objects are located on the same field line (i.e., they are magnetically conjugated).
Longitude Separation Angle	AngleUnit	Real Number	The longitudinal angle between the north footprint of the field line containing the vehicle's location and the north footprint of the field line containing the target's location. If either north footprint is not defined, then the south footprint is used. The longitudinal angle is measured in geomagnetic coordinates as the angle about the magnetic north pole.
Footprint Type	Unitless	Text	The hemisphere of the magnetic footprint: either "N" or "S".
Dipole L-shell parameter	Unitless	Real Number	The L value for the field line passing through the vehicle's location computed using the dipole approximation to the magnetic field. For a dipole field line, the L value corresponds to the distance, measured in earth mean radii, at the point on the field line at the magnetic equator. (For a dipole field, this point is also the furthest extent of the field line from the earth.)
McIlwain L-shell parameter	Unitless	Real Number or Text	A measure that indicates a particle's drift shell in the magnetic field at the vehicle's location, as defined by Carl McIlwain (J. Geophys. Res. 1961). The value is computed as a function of several magnetic invariants along a field line and thus its computation requires field line tracing. It is not strictly a constant over the entire field line. In cases where the field line is close to the dipole field line (i.e., the field line traced using only the dipole component of the magnetic field model), the value will be close to the dipole L-shell parameter.
McIlwain Abs(L-shell) parameter	Unitless	Real Number or Text	The absolute value of the McIlwain L-shell parameter
B/Beq	Unitless	Real Number or Text	The ratio of the magnetic intensity at the vehicle's location to the minimum magnetic intensity along the field line through the vehicle's location.
Beq	MagneticFieldUnit	Real Number or Text	The minimum magnetic intensity along the field line through the vehicle's location. The minimum value occurs at the magnetic equator, at the furthest extent of the field line from the earth.
Target Dipole L-shell parameter	Unitless	Real Number	The L value for the field line passing through the target's location computed using the dipole approximation to the magnetic field.
Target McIlwain L-shell parameter	Unitless	Real Number or Text	The L value for the field line passing through the target's location computed using McIlwain's definition.
Target McIlwain Abs(L-shell) parameter	Unitless	Real Number or Text	The absolute value of the McIlwain L-shell parameter of the target object.
Target B/Beq	Unitless	Real Number or Text	The ratio of the magnetic intensity at the target's location to the minimum magnetic intensity along the field line through the target's location.
Target Beq	MagneticFieldUnit	Real Number or Text	The minimum magnetic intensity along the field line through the target's location.

Name

Dimension

Type

Description

Time

DateFormat

Real Number

Time.

Separation Angle

AngleUnit

Real Number

The centric angle between the north footprint of the field line containing the vehicle's location and the north footprint of the field line containing the target's location. The north footprint is the point of intersection of the field line with the earth's surface north of the magnetic equator. If either north footprint is not defined, then the south footprint is used. This value serves as a measure of the closeness of the vehicle's and the target's field lines - as the angle approaches zero, the field lines between the objects become equal and the objects are located on the same field line (i.e., they are magnetically conjugated).

Longitude Separation Angle

AngleUnit

Real Number

The longitudinal angle between the north footprint of the field line containing the vehicle's location and the north footprint of the field line containing the target's location. If either north footprint is not defined, then the south footprint is used. The longitudinal angle is measured in geomagnetic coordinates as the angle about the magnetic north pole.

Footprint Type

Unitless

Text

The hemisphere of the magnetic footprint: either "N" or "S".

Dipole L-shell parameter

Unitless

Real Number

The L value for the field line passing through the vehicle's location computed using the dipole approximation to the magnetic field. For a dipole field line, the L value corresponds to the distance, measured in earth mean radii, at the point on the field line at the magnetic equator. (For a dipole field, this point is also the furthest extent of the field line from the earth.)

McIlwain L-shell parameter

Unitless

Real Number or Text

A measure that indicates a particle's drift shell in the magnetic field at the vehicle's location, as defined by Carl McIlwain (J. Geophys. Res. 1961). The value is computed as a function of several magnetic invariants along a field line and thus its computation requires field line tracing. It is not strictly a constant over the entire field line. In cases where the field line is close to the dipole field line (i.e., the field line traced using only the dipole component of the magnetic field model), the value will be close to the dipole L-shell parameter.

McIlwain Abs(L-shell) parameter

Unitless

Real Number or Text

The absolute value of the McIlwain L-shell parameter

B/Beq

Unitless

Real Number or Text

The ratio of the magnetic intensity at the vehicle's location to the minimum magnetic intensity along the field line through the vehicle's location.

Beq

MagneticFieldUnit

Real Number or Text

The minimum magnetic intensity along the field line through the vehicle's location. The minimum value occurs at the magnetic equator, at the furthest extent of the field line from the earth.

Target Dipole L-shell parameter

Unitless

Real Number

The L value for the field line passing through the target's location computed using the dipole approximation to the magnetic field.

Target McIlwain L-shell parameter

Unitless

Real Number or Text

The L value for the field line passing through the target's location computed using McIlwain's definition.

Target McIlwain Abs(L-shell) parameter

Unitless

Real Number or Text

The absolute value of the McIlwain L-shell parameter of the target object.

Target B/Beq

Unitless

Real Number or Text

The ratio of the magnetic intensity at the target's location to the minimum magnetic intensity along the field line through the target's location.

Target Beq

MagneticFieldUnit

Real Number or Text

The minimum magnetic intensity along the field line through the target's location.