Event Ephemeris
Reports ephemeris and other related information as a function of time for each close approach event.Available for these objects: AdvCAT
Type: Time-varying data.
Availability: Reports
Data Provider Elements
| Name | Dimension | Type | Description |
|---|---|---|---|
| Time | Date | Real Number or Text | Time. |
| Primary SSC | Unitless | Integer | The SSC number of the primary object involved in the close approach event. |
| 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 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 Concurrent Events | Unitless | Integer | The number of secondaries experiencing a close approach event with the primary at this time. |
| Secondary SSC | Unitless | Integer | The SSC number of the secondary object involved in the close approach event. |
| 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". |
| 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". |
| Separation | Distance | 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". |
| Range | Distance | Real Number | The range (i.e., distance between the primary and secondary object) at the given time. |
| Range Uncertainty | Distance | 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. |
| 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). |
| Relative Velocity | Rate | Real Number | The magnitude of the difference in the inertial velocities of the primary and secondary objects at the given time. |
| Approach Angle | Angle | Real Number or Text | The angle between the inertial velocity of the primary object and the inertial velocity of the secondary object at the given time. |
| Primary: Time Since Epoch | Time | Real Number | The difference between the given time and the primary object's epoch. |
| Primary x | Distance | Real Number | The X component of the inertial position vector of the primary object at the given time. |
| Primary y | Distance | Real Number | The Y component of the inertial position vector of the primary object at the given time. |
| Primary z | Distance | Real Number | The Z component of the inertial position vector of the primary object at the given time. |
| Primary Lat | Latitude | Real Number or Text | The primary object's detic latitude at the given time. |
| Primary Lon | Longitude | Real Number or Text | The primary object's detic longitude at the given time. |
| Primary Alt | Distance | Real Number | The primary object's detic altitude at the given time. |
| Primary vx | Rate | Real Number | The X component of the inertial velocity vector of the primary object at the given time. |
| Primary vy | Rate | Real Number | The Y component of the inertial velocity vector of the primary object at the given time. |
| Primary vz | Rate | Real Number | The Z component of the inertial velocity vector of the primary object at the given time. |
| Primary Ellipsoid - Tangential | Distance | Real Number | For a Covariance class threat volume, this is the tangential position-estimation-error standard deviation for the primary vehicle. For other threat ellipsoid types expressed in the TCN principal axes frame, this is the length of the tangential-aligned semi-axis. |
| Primary Ellipsoid - CrossTrack | Distance | Real Number | For a Covariance class threat volume, this is the crosstrack position-estimation-error standard deviation for the primary vehicle. For other threat ellipsoid types expressed in the TCN principal axes frame, this is the length of the crosstrack-aligned semi-axis. |
| Primary Ellipsoid - Normal | Distance | Real Number | For a Covariance class threat volume, this is the normal position-estimation-error standard deviation for the primary vehicle. For other threat ellipsoid types expressed in the TCN principal axes frame, this is the length of the normal-aligned semi-axis. |
| Primary Ellipsoid - CrossTrack-Tangential | Unitless | Real Number | For a Covariance class threat volume, this is the correlation coefficient between the crosstrack and tangential position estimation errors for the primary vehicle. |
| Primary Ellipsoid - Normal-Tangential | Unitless | Real Number | For a Covariance class threat volume, this is the correlation coefficient between the normal and tangential position estimation errors for the primary vehicle. |
| Primary Ellipsoid - Normal-CrossTrack | Unitless | Real Number | For a Covariance class threat volume, this is the correlation coefficient between the normal and crosstrack position estimation errors for the primary vehicle. |
| Primary Ellipsoid - Max | Distance | Real Number | The length of the longest symmetry axis of the primary object's ellipsoid at the given time. |
| Primary Ellipsoid - Middle | Distance | Real Number | The length of the intermediate symmetry axis of the primary object's ellipsoid at the given time. |
| Primary Ellipsoid - Min | Distance | Real Number | The length of the shortest symmetry axis of the primary object's ellipsoid at the given time. |
| Primary Ellipsoid - CovMtx XX | Area | Real Number | The (1,1) component of the position covariance matrix for the primary obtained by interpreting the primary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Primary Ellipsoid - CovMtx YX | Area | Real Number | The (2,1) component of the position covariance matrix for the primary obtained by interpreting the primary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Primary Ellipsoid - CovMtx YY | Area | Real Number | The (2,2) component of the position covariance matrix for the primary obtained by interpreting the primary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Primary Ellipsoid - CovMtx ZX | Area | Real Number | The (3,1) component of the position covariance matrix for the primary obtained by interpreting the primary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Primary Ellipsoid - CovMtx ZY | Area | Real Number | The (3,2) component of the position covariance matrix for the primary obtained by interpreting the primary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Primary Ellipsoid - CovMtx ZZ | Area | Real Number | The (3,3) component of the position covariance matrix for the primary obtained by interpreting the primary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Primary Yaw | Angle | Real Number or Text | 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 Pitch | Angle | Real Number or Text | 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 Roll | Angle | Real Number or Text | 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. |
| Secondary: Time Since Epoch | Time | Real Number | The difference between the given time time and the secondary object's epoch. |
| Secondary x | Distance | Real Number | The X component of the inertial position vector of the secondary object at the given time. |
| Secondary y | Distance | Real Number | The Y component of the inertial position vector of the secondary object at the given time. |
| Secondary z | Distance | Real Number | The Z component of the inertial position vector of the secondary object at the given time. |
| Secondary Lat | Latitude | Real Number or Text | The secondary object's detic latitude at the given time. |
| Secondary Lon | Longitude | Real Number or Text | The secondary object's detic longitude at the given time. |
| Secondary Alt | Distance | Real Number | The secondary object's detic altitude 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 vy | Rate | Real Number | The Y component of the inertial velocity vector of the 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. |
| Secondary Ellipsoid - Tangential | Distance | Real Number | For a Covariance class threat volume, this is the tangential position-estimation-error standard deviation for the secondary vehicle. For other threat ellipsoid types expressed in the TCN principal axes frame, this is the length of the tangential-aligned semi-axis. |
| Secondary Ellipsoid - CrossTrack | Distance | Real Number | For a Covariance class threat volume, this is the crosstrack position-estimation-error standard deviation for the secondary vehicle. For other threat ellipsoid types expressed in the TCN principal axes frame, this is the length of the crosstrack-aligned semi-axis. |
| Secondary Ellipsoid - Normal | Distance | Real Number | For a Covariance class threat volume, this is the normal position-estimation-error standard deviation for the secondary vehicle. For other threat ellipsoid types expressed in the TCN principal axes frame, this is the length of the normal-aligned semi-axis. |
| Secondary Ellipsoid - CrossTrack-Tangential | Unitless | Real Number | For a Covariance class threat volume, this is the correlation coefficient between the crosstrack and tangential position estimation errors for the secondary vehicle. |
| Secondary Ellipsoid - Normal-Tangential | Unitless | Real Number | For a Covariance class threat volume, this is the correlation coefficient between the normal and tangential position estimation errors for the secondary vehicle. |
| Secondary Ellipsoid - Normal-CrossTrack | Unitless | Real Number | For a Covariance class threat volume, this is the correlation coefficient between the normal and crosstrack position estimation errors for the secondary vehicle. |
| Secondary Ellipsoid - Max | Distance | Real Number | The length of the longest symmetry axis of the secondary object's ellipsoid at the given time. |
| Secondary Ellipsoid - Middle | Distance | Real Number | The length of the intermediate symmetry axis of the secondary object's ellipsoid at the given time. |
| Secondary Ellipsoid - Min | Distance | Real Number | The length of the shortest symmetry axis of the secondary object's ellipsoid at the given time. |
| Secondary Ellipsoid - CovMtx XX | Area | Real Number | The (1,1) component of the position covariance matrix for the secondary obtained by interpreting the secondary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Secondary Ellipsoid - CovMtx YX | Area | Real Number | The (2,1) component of the position covariance matrix for the secondary obtained by interpreting the secondary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Secondary Ellipsoid - CovMtx YY | Area | Real Number | The (2,2) component of the position covariance matrix for the secondary obtained by interpreting the secondary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Secondary Ellipsoid - CovMtx ZX | Area | Real Number | The (3,1) component of the position covariance matrix for the secondary obtained by interpreting the secondary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Secondary Ellipsoid - CovMtx ZY | Area | Real Number | The (3,2) component of the position covariance matrix for the secondary obtained by interpreting the secondary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Secondary Ellipsoid - CovMtx ZZ | Area | Real Number | The (3,3) component of the position covariance matrix for the secondary obtained by interpreting the secondary's ellipsoid size and orientation as that matrix's 1-sigma equal probability surface. |
| Secondary Yaw | Angle | Real Number or Text | 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 Pitch | Angle | Real Number or Text | 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 Roll | Angle | Real Number or Text | 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. |
| Range wrt Primary - Tangential | Distance | 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. |
| Range wrt Primary - CrossTrack | Distance | 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 - Normal | Distance | 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 | Distance | 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. |
| Range wrt Primary - InTrack | Distance | 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. |
| 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. |
| Range wrt Secondary - Tangential | Distance | 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. |
| Range wrt Secondary - CrossTrack | Distance | 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. |
| Range wrt Secondary - Normal | Distance | 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. |
| Range wrt Secondary - Radial | Distance | 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. |
| Range wrt Secondary - InTrack | Distance | 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. |
| 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. |
| 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 - 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. |
| 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. |
| 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. |
| 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 - 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. |
| 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. |
| 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. |