The relative ephemeris of the assigned
object with respect to the primary object, expressed in curvilinear
coordinates, as a function of time. It produces three coordinates
and their rates (Crossrange, Downrange, and Crosstrack) that are
defined relative to the osculating orbit of the reference
satellite.
| Name |
Dimension |
Type |
Description |
| Time |
DateFormat |
Real Number |
Time. |
| Crossrange |
DistanceUnit |
Real Number |
Cross range is in the orbit plane along the outward
normal to the osculating orbital ellipse. |
| Downrange |
DistanceUnit |
Real Number |
Down range is along the curved orbit in the
direction of flight. |
| Crosstrack |
DistanceUnit |
Real Number |
Cross track is orthogonal to the osculating orbital
plane completing the right-handed triad. |
| Crossrange Rate |
Rate |
Real Number |
Rate of change of the cross range coordinate. |
| Downrange Rate |
Rate |
Real Number |
Rate of change of the down range coordinate. |
| Crosstrack Rate |
Rate |
Real Number |
Rate of change of the cross track coordinate. |
| Position Combined Cov Sigma |
Unitless |
Real Number |
Position difference measured in terms of the
combined position covariance of primary and target satellites.
Reports N where the current relative position vector lies on an N
sigma ellipsoid, where the ellipsoid is obtained from the sum of
the covariances matrices of the two objects. This can only be
computed if position covariance is available. |
| Position Cov
Sigma |
Unitless |
Real Number |
Position difference measured in terms of the
position covariance. Reports N where the current relative position
vector lies on a N sigma ellipsoid, where the ellipsoid if obtained
from the position covariance of the primary satellite. This can
only be computed if position covariance is available. |