Data Providers: AdvCAT: Time Events: TCA

Data reported at the time of close approach for each close approach event. The actual time interval considered is determined through the range filter and may be a larger interval encompassing the close approach interval itself.

Name	Dimension	Type	Description
Primary Roll	AngleUnit	Real Number	The roll angle for the primary object's ellipsoid at the given time. The roll angle locates the minor axis of the ellipsoid as a rotation about the major axis, with zero being aligned with the cross-track direction.
Approach Angle	AngleUnit	Real Number	The angle between the inertial velocity of the primary object and the inertial velocity of the secondary object at the given time
Ellipsoid Norm wrt Primary	Unitless	Real Number or Text	A measure of the "distance" between the primary and secondary object, using the primary object's ellipsoid size as a norm, at the given time. If the primary ellipsoid size were to be scaled uniformly by this value, then the ellipsoid would just touch the secondary. The value is set to "Undefined" if an error occurs computing the norm.
Ellipsoid Norm wrt Secondary	Unitless	Real Number or Text	A measure of the "distance" between the primary and secondary object, using the secondary object's ellipsoid size as a norm, at the given time. If the secondary ellipsoid size were to be scaled uniformly by this value, then the ellipsoid would just touch the primary. The value is set to "Undefined" if an error occurs computing the norm.
Event Defn	Unitless	Text	The method of determining the event: Local Minimum, EndPoint Minimum, or Below Threshold.
Event	Unitless	Text	Type of event (i.e., the name of the folder).
Separation	DistanceUnit	Real Number or Text	The separation distance between the primary and secondary threat volumes at the given time. If the ellipsoids intersect, then the value will be "Intersect".
EventTime	DateFormat	Real Number	The time at which the event occurs.
Primary Alt	DistanceUnit	Real Number	The primary object's detic altitude at the given time.
Primary Yaw	AngleUnit	Real Number	The yaw angle for the primary object's ellipsoid at the given time. The yaw angle locates from the tangential direction the projection of the major axis of the ellipsoid onto the plane whose normal is the cross-track direction.
Primary Ellipsoid - CrossTrack	DistanceUnit	Real Number	The length of the primary object's ellipsoid at the given time in the cross-track direction. The cross-track direction lies along the object's orbit normal.
Primary Ellipsoid - Max	DistanceUnit	Real Number	The length of the longest symmetry axis of the primary object's ellipsoid at the given time.
Primary Ellipsoid - Middle	DistanceUnit	Real Number	The length of the intermediate symmetry axis of the primary object's ellipsoid at the given time.
Primary Ellipsoid - Min	DistanceUnit	Real Number	The length of the shortest symmetry axis of the primary object's ellipsoid at the given time.
Primary Ellipsoid - Normal	DistanceUnit	Real Number	The length of the primary object's ellipsoid at the given time in the normal direction. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.
Primary Ellipsoid - Tangential	DistanceUnit	Real Number	The length of the primary object's ellipsoid at the given time in the tangential direction. The tangential direction lies along the object's inertial velocity.
Primary Lat	LatitudeUnit	Real Number	The primary object's detic latitude at the given time.
Primary Lon	LongitudeUnit	Real Number	The primary object's detic longitude at the given time.
Primary Name	Unitless	Text	The name of the primary object in the close approach event.
Primary NumberID	Unitless	Text	The number identifier of the primary object involved in the close approach event. If the object has no number identifier, then the value will be "Not Avail".
Primary Pitch	AngleUnit	Real Number	The pitch angle for the primary object's ellipsoid at the given time. The pitch angle locates the major axis of the ellipsoid from the plane whose normal is the cross-track direction.
Primary Radius	DistanceUnit	Real Number	The magnitude of the position vector of the primary object.
Primary Rev	Unitless	Integer	The rev (pass) number for the primary object.
Primary SourceID	Unitless	Text	The identifier of the primary as used by the ephemeris source for the object. For example, the identifier for objects that use a GPS sem or yuma file is PRN-##.
Primary Speed	Rate	Real Number	The magnitude of the inertial velocity vector of the primary object.
Primary SSC	Unitless	Integer	The SSC number of the primary object involved in the close approach event.
Velocity wrt Primary - CrossTrack	Rate	Real Number	The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.
Primary StringID	Unitless	Text	The string identifier of the primary object involved in the close approach event. If the object has no string identifier, then the value will be "Not Avail".
Primary vx	Rate	Real Number	The X component of the inertial velocity vector of the primary object at the given time.
Velocity wrt Primary - Tangential	Rate	Real Number	The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.
Velocity wrt Primary - Normal	Rate	Real Number	The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.
Primary vy	Rate	Real Number	The Y component of the inertial velocity vector of the primary object at the given time.
Velocity wrt Primary - Radial	Rate	Real Number	The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's radial direction at the given time.
Velocity wrt Primary - InTrack	Rate	Real Number	The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.
Primary vz	Rate	Real Number	The Z component of the inertial velocity vector of the primary object at the given time.
Primary x	DistanceUnit	Real Number	The X component of the inertial position vector of the primary object at the given time.
Velocity wrt Secondary - CrossTrack	Rate	Real Number	The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.
Primary y	DistanceUnit	Real Number	The Y component of the inertial position vector of the primary object at the given time.
Primary z	DistanceUnit	Real Number	The Z component of the inertial position vector of the primary object at the given time.
Velocity wrt Secondary - Tangential	Rate	Real Number	The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.
Velocity wrt Secondary - Normal	Rate	Real Number	The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.
Primary: Time Since Epoch	TimeUnit	Real Number	The difference between the given time and the primary object's epoch.
Velocity wrt Secondary - Radial	Rate	Real Number	The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's radial direction at the given time.
Velocity wrt Secondary - InTrack	Rate	Real Number	The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.
Range Sigma	Unitless	Real Number	The value of the range between the objects measured at TCA, expressed in terms of sigma (i.e., the scale factor by which the combined covariance ellipsoid would need to be scaled to just touch the range vector).
Range Uncertainty	DistanceUnit	Real Number	The uncertainty in the range at the given time. The uncertainty is computed by treating the ellipsoid size and orientation as a measure of the position covariance for each object. The relative position covariance is then computed and projected onto the line of sight direction between the two objects to compute the value.
Secondary Alt	DistanceUnit	Real Number	The secondary object's detic altitude at the given time.
Range wrt Primary - CrossTrack	DistanceUnit	Real Number	The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.
Range wrt Primary - InTrack	DistanceUnit	Real Number	The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.
Range wrt Primary - Normal	DistanceUnit	Real Number	The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.
Range wrt Primary - Radial	DistanceUnit	Real Number	The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's radial direction at the given time.
Secondary Lat	LatitudeUnit	Real Number	The secondary object's detic latitude at the given time.
Range wrt Primary - Tangential	DistanceUnit	Real Number	The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.
Secondary Lon	LongitudeUnit	Real Number	The secondary object's detic longitude at the given time.
Range wrt Secondary - CrossTrack	DistanceUnit	Real Number	The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.
Secondary Radius	DistanceUnit	Real Number	The magnitude of the position vector of the secondary object.
Secondary Ellipsoid - CrossTrack	DistanceUnit	Real Number	The length of the secondary object's ellipsoid at the given time in the cross-track direction. The cross-track direction lies along the object's orbit normal.
Range wrt Secondary - InTrack	DistanceUnit	Real Number	The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.
Range wrt Secondary - Normal	DistanceUnit	Real Number	The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.
Secondary Ellipsoid - Max	DistanceUnit	Real Number	The length of the longest symmetry axis of the secondary object's ellipsoid at the given time.
Secondary Ellipsoid - Tangential	DistanceUnit	Real Number	The length of the secondary object's ellipsoid at the given time in the tangential direction. The tangential direction lies along the object's inertial velocity.
Range wrt Secondary - Radial	DistanceUnit	Real Number	The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's radial direction at the given time.
Secondary x	DistanceUnit	Real Number	The X component of the inertial position vector of the secondary object at the given time.
Secondary Ellipsoid - Normal	DistanceUnit	Real Number	The length of the secondary object's ellipsoid at the given time in the normal direction. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.
Secondary y	DistanceUnit	Real Number	The Y component of the inertial position vector of the secondary object at the given time.
Secondary: Time Since Epoch	TimeUnit	Real Number	The difference between the given time time and the secondary object's epoch.
Secondary Ellipsoid - Middle	DistanceUnit	Real Number	The length of the intermediate symmetry axis of the secondary object's ellipsoid at the given time.
Range wrt Secondary - Tangential	DistanceUnit	Real Number	The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.
Secondary z	DistanceUnit	Real Number	The Z component of the inertial position vector of the secondary object at the given time.
Secondary Ellipsoid - Min	DistanceUnit	Real Number	The length of the shortest symmetry axis of the secondary object's ellipsoid at the given time.
Secondary vx	Rate	Real Number	The X component of the inertial velocity vector of the secondary object at the given time.
Secondary Speed	Rate	Real Number	The magnitude of the inertial velocity vector of the secondary object.
Secondary vy	Rate	Real Number	The Y component of the inertial velocity vector of the secondary object at the given time.
Range	DistanceUnit	Real Number	The range (i.e., distance between the primary and secondary object) at the given time.
Secondary vz	Rate	Real Number	The Z component of the inertial velocity vector of the secondary object at the given time.
Relative Velocity	Rate	Real Number	The magnitude of the difference in the inertial velocities of the primary and secondary objects at the given time.
Secondary Name	Unitless	Text	The name of the secondary object in the close approach event.
Secondary NumberID	Unitless	Text	The number identifier of the secondary object involved in the close approach event. If the object has no number identifier, then the value will be "Not Avail".
Secondary Pitch	AngleUnit	Real Number	The pitch angle for the secondary object's ellipsoid at the given time. The pitch angle locates the major axis of the ellipsoid from the plane whose normal is the cross-track direction.
Secondary Rev	Unitless	Integer	The rev (pass) number for the secondary object.
Secondary Roll	AngleUnit	Real Number	The roll angle for the secondary object's ellipsoid at the given time. The roll angle locates the minor axis of the ellipsoid as a rotation about the major axis, with zero being aligned with the cross-track direction.
Secondary SourceID	Unitless	Text	The identifier of the secondary as used by the ephemeris source for the object. For example, the identifier for objects that use a GPS sem or yuma file is PRN-##.
Secondary SSC	Unitless	Integer	The SSC number of the secondary object involved in the close approach event.
Secondary Yaw	AngleUnit	Real Number	The yaw angle for the secondary object's ellipsoid at the given time. The yaw angle locates from the tangential direction the projection of the major axis of the ellipsoid onto the plane whose normal is the cross-track direction.
Secondary StringID	Unitless	Text	The string identifier of the secondary object involved in the close approach event. If the object has no string identifier, then the value will be "Not Avail".

Name

Dimension

Type

Description

Primary Roll

AngleUnit

Real Number

The roll angle for the primary object's ellipsoid at the given time. The roll angle locates the minor axis of the ellipsoid as a rotation about the major axis, with zero being aligned with the cross-track direction.

Approach Angle

AngleUnit

Real Number

The angle between the inertial velocity of the primary object and the inertial velocity of the secondary object at the given time

Ellipsoid Norm wrt Primary

Unitless

Real Number or Text

A measure of the "distance" between the primary and secondary object, using the primary object's ellipsoid size as a norm, at the given time. If the primary ellipsoid size were to be scaled uniformly by this value, then the ellipsoid would just touch the secondary. The value is set to "Undefined" if an error occurs computing the norm.

Ellipsoid Norm wrt Secondary

Unitless

Real Number or Text

A measure of the "distance" between the primary and secondary object, using the secondary object's ellipsoid size as a norm, at the given time. If the secondary ellipsoid size were to be scaled uniformly by this value, then the ellipsoid would just touch the primary. The value is set to "Undefined" if an error occurs computing the norm.

Event Defn

Unitless

Text

The method of determining the event: Local Minimum, EndPoint Minimum, or Below Threshold.

Event

Unitless

Text

Type of event (i.e., the name of the folder).

Separation

DistanceUnit

Real Number or Text

The separation distance between the primary and secondary threat volumes at the given time. If the ellipsoids intersect, then the value will be "Intersect".

EventTime

DateFormat

Real Number

The time at which the event occurs.

Primary Alt

DistanceUnit

Real Number

The primary object's detic altitude at the given time.

Primary Yaw

AngleUnit

Real Number

The yaw angle for the primary object's ellipsoid at the given time. The yaw angle locates from the tangential direction the projection of the major axis of the ellipsoid onto the plane whose normal is the cross-track direction.

Primary Ellipsoid - CrossTrack

DistanceUnit

Real Number

The length of the primary object's ellipsoid at the given time in the cross-track direction. The cross-track direction lies along the object's orbit normal.

Primary Ellipsoid - Max

DistanceUnit

Real Number

The length of the longest symmetry axis of the primary object's ellipsoid at the given time.

Primary Ellipsoid - Middle

DistanceUnit

Real Number

The length of the intermediate symmetry axis of the primary object's ellipsoid at the given time.

Primary Ellipsoid - Min

DistanceUnit

Real Number

The length of the shortest symmetry axis of the primary object's ellipsoid at the given time.

Primary Ellipsoid - Normal

DistanceUnit

Real Number

The length of the primary object's ellipsoid at the given time in the normal direction. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.

Primary Ellipsoid - Tangential

DistanceUnit

Real Number

The length of the primary object's ellipsoid at the given time in the tangential direction. The tangential direction lies along the object's inertial velocity.

Primary Lat

LatitudeUnit

Real Number

The primary object's detic latitude at the given time.

Primary Lon

LongitudeUnit

Real Number

The primary object's detic longitude at the given time.

Primary Name

Unitless

Text

The name of the primary object in the close approach event.

Primary NumberID

Unitless

Text

The number identifier of the primary object involved in the close approach event. If the object has no number identifier, then the value will be "Not Avail".

Primary Pitch

AngleUnit

Real Number

The pitch angle for the primary object's ellipsoid at the given time. The pitch angle locates the major axis of the ellipsoid from the plane whose normal is the cross-track direction.

Primary Radius

DistanceUnit

Real Number

The magnitude of the position vector of the primary object.

Primary Rev

Unitless

Integer

The rev (pass) number for the primary object.

Primary SourceID

Unitless

Text

The identifier of the primary as used by the ephemeris source for the object. For example, the identifier for objects that use a GPS sem or yuma file is PRN-##.

Primary Speed

Rate

Real Number

The magnitude of the inertial velocity vector of the primary object.

Primary SSC

Unitless

Integer

The SSC number of the primary object involved in the close approach event.

Velocity wrt Primary - CrossTrack

Rate

Real Number

The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.

Primary StringID

Unitless

Text

The string identifier of the primary object involved in the close approach event. If the object has no string identifier, then the value will be "Not Avail".

Primary vx

Rate

Real Number

The X component of the inertial velocity vector of the primary object at the given time.

Velocity wrt Primary - Tangential

Rate

Real Number

The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.

Velocity wrt Primary - Normal

Rate

Real Number

The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.

Primary vy

Rate

Real Number

The Y component of the inertial velocity vector of the primary object at the given time.

Velocity wrt Primary - Radial

Rate

Real Number

The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's radial direction at the given time.

Velocity wrt Primary - InTrack

Rate

Real Number

The component of the relative inertial velocity vector (i.e., secondary inertial velocity vector minus primary inertial velocity vector) in the primary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.

Primary vz

Rate

Real Number

The Z component of the inertial velocity vector of the primary object at the given time.

Primary x

DistanceUnit

Real Number

The X component of the inertial position vector of the primary object at the given time.

Velocity wrt Secondary - CrossTrack

Rate

Real Number

The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.

Primary y

DistanceUnit

Real Number

The Y component of the inertial position vector of the primary object at the given time.

Primary z

DistanceUnit

Real Number

The Z component of the inertial position vector of the primary object at the given time.

Velocity wrt Secondary - Tangential

Rate

Real Number

The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.

Velocity wrt Secondary - Normal

Rate

Real Number

The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.

Primary: Time Since Epoch

TimeUnit

Real Number

The difference between the given time and the primary object's epoch.

Velocity wrt Secondary - Radial

Rate

Real Number

The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's radial direction at the given time.

Velocity wrt Secondary - InTrack

Rate

Real Number

The component of the relative inertial velocity vector (i.e., primary inertial velocity vector minus secondary inertial velocity vector) in the secondary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.

Range Sigma

Unitless

Real Number

The value of the range between the objects measured at TCA, expressed in terms of sigma (i.e., the scale factor by which the combined covariance ellipsoid would need to be scaled to just touch the range vector).

Range Uncertainty

DistanceUnit

Real Number

The uncertainty in the range at the given time. The uncertainty is computed by treating the ellipsoid size and orientation as a measure of the position covariance for each object. The relative position covariance is then computed and projected onto the line of sight direction between the two objects to compute the value.

Secondary Alt

DistanceUnit

Real Number

The secondary object's detic altitude at the given time.

Range wrt Primary - CrossTrack

DistanceUnit

Real Number

The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.

Range wrt Primary - InTrack

DistanceUnit

Real Number

The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.

Range wrt Primary - Normal

DistanceUnit

Real Number

The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.

Range wrt Primary - Radial

DistanceUnit

Real Number

The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's radial direction at the given time.

Secondary Lat

LatitudeUnit

Real Number

The secondary object's detic latitude at the given time.

Range wrt Primary - Tangential

DistanceUnit

Real Number

The component of the relative position vector (i.e., secondary position vector minus primary position vector) in the primary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.

Secondary Lon

LongitudeUnit

Real Number

The secondary object's detic longitude at the given time.

Range wrt Secondary - CrossTrack

DistanceUnit

Real Number

The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's cross-track direction at the given time. The cross-track direction lies along the object's orbit normal.

Secondary Radius

DistanceUnit

Real Number

The magnitude of the position vector of the secondary object.

Secondary Ellipsoid - CrossTrack

DistanceUnit

Real Number

The length of the secondary object's ellipsoid at the given time in the cross-track direction. The cross-track direction lies along the object's orbit normal.

Range wrt Secondary - InTrack

DistanceUnit

Real Number

The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's in-track direction at the given time. The in-track direction completes a triad involving the radial and cross-track directions.

Range wrt Secondary - Normal

DistanceUnit

Real Number

The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's normal direction at the given time. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.

Secondary Ellipsoid - Max

DistanceUnit

Real Number

The length of the longest symmetry axis of the secondary object's ellipsoid at the given time.

Secondary Ellipsoid - Tangential

DistanceUnit

Real Number

The length of the secondary object's ellipsoid at the given time in the tangential direction. The tangential direction lies along the object's inertial velocity.

Range wrt Secondary - Radial

DistanceUnit

Real Number

The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's radial direction at the given time.

Secondary x

DistanceUnit

Real Number

The X component of the inertial position vector of the secondary object at the given time.

Secondary Ellipsoid - Normal

DistanceUnit

Real Number

The length of the secondary object's ellipsoid at the given time in the normal direction. The normal direction completes a triad involving the tangential and cross-track directions and is akin to the radial direction.

Secondary y

DistanceUnit

Real Number

The Y component of the inertial position vector of the secondary object at the given time.

Secondary: Time Since Epoch

TimeUnit

Real Number

The difference between the given time time and the secondary object's epoch.

Secondary Ellipsoid - Middle

DistanceUnit

Real Number

The length of the intermediate symmetry axis of the secondary object's ellipsoid at the given time.

Range wrt Secondary - Tangential

DistanceUnit

Real Number

The component of the relative position vector (i.e., primary position vector minus secondary position vector) in the secondary object's tangential direction at the given time. The tangential direction lies along the object's inertial velocity.

Secondary z

DistanceUnit

Real Number

The Z component of the inertial position vector of the secondary object at the given time.

Secondary Ellipsoid - Min

DistanceUnit

Real Number

The length of the shortest symmetry axis of the secondary object's ellipsoid at the given time.

Secondary vx

Rate

Real Number

The X component of the inertial velocity vector of the secondary object at the given time.

Secondary Speed

Rate

Real Number

The magnitude of the inertial velocity vector of the secondary object.

Secondary vy

Rate

Real Number

The Y component of the inertial velocity vector of the secondary object at the given time.

Range

DistanceUnit

Real Number

The range (i.e., distance between the primary and secondary object) at the given time.

Secondary vz

Rate

Real Number

The Z component of the inertial velocity vector of the secondary object at the given time.

Relative Velocity

Rate

Real Number

The magnitude of the difference in the inertial velocities of the primary and secondary objects at the given time.

Secondary Name

Unitless

Text

The name of the secondary object in the close approach event.

Secondary NumberID

Unitless

Text

The number identifier of the secondary object involved in the close approach event. If the object has no number identifier, then the value will be "Not Avail".

Secondary Pitch

AngleUnit

Real Number

The pitch angle for the secondary object's ellipsoid at the given time. The pitch angle locates the major axis of the ellipsoid from the plane whose normal is the cross-track direction.

Secondary Rev

Unitless

Integer

The rev (pass) number for the secondary object.

Secondary Roll

AngleUnit

Real Number

The roll angle for the secondary object's ellipsoid at the given time. The roll angle locates the minor axis of the ellipsoid as a rotation about the major axis, with zero being aligned with the cross-track direction.

Secondary SourceID

Unitless

Text

The identifier of the secondary as used by the ephemeris source for the object. For example, the identifier for objects that use a GPS sem or yuma file is PRN-##.

Secondary SSC

Unitless

Integer

The SSC number of the secondary object involved in the close approach event.

Secondary Yaw

AngleUnit

Real Number

The yaw angle for the secondary object's ellipsoid at the given time. The yaw angle locates from the tangential direction the projection of the major axis of the ellipsoid onto the plane whose normal is the cross-track direction.

Secondary StringID

Unitless

Text

The string identifier of the secondary object involved in the close approach event. If the object has no string identifier, then the value will be "Not Avail".