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Analytics Products

Every conjunction event carries a set of analysis plots, for tracking how risk metrics evolve across CDMs, testing how those metrics respond to input assumptions, and inspecting close approach geometry.

Selecting Plots​

One plot shows at a time, or two together with Horizontal split or Vertical split. Trend plots highlight the latest data point and its delta from the previous CDM.

Plots are grouped by what they answer: Risk trend, Miss distance trend, Encounter geometry, Data sensitivity, and Primary vs Secondary Range.

Risk trend​

Time-series plots across the CDM history of the event:

  • Probability of collision - Pc from the primary method
  • Pc method comparison - Pc from every available method on one axis, for checking method agreement
  • Mahalanobis distance
  • Delta TCA - time shift between CDM reports

Plots are interactive and display uncertainty bands where applicable.

Miss distance trend​

Miss distance in RIC components, plotted across the CDM history:

  • Total (RSS) - root sum square of the RIC components
  • Radial
  • In-track
  • Cross-track
  • ∆ Miss sigma - change in each RIC component between the current and previous CDM, scaled by uncertainty

1σ uncertainty fills are shown as translucent regions for each component plot.

Encounter geometry​

Both plots in this group show the close approach at TCA in the encounter frame.

B-Plane​

Shows the plane normal to the relative velocity vector, with the combined uncertainty ellipse plotted relative to the secondary's position.

  • Combined uncertainty ellipses at 1σ, 2σ, and 3σ
  • Combined HBR boundary shown
  • Pre-maneuver and post-maneuver overlays available if plans exist

Encounter plane​

Displays both RSOs and their combined uncertainty ellipses at TCA in encounter-frame coordinates.

Used for assessing conjunction geometry, especially in low-relative-velocity or skewed-dispersion scenarios.

Data sensitivity​

These plots hold the conjunction fixed and vary one input, showing how far the risk estimate moves when an assumption changes.

Pc [FOSTER-1992] dilution​

Plots Pc as a function of log-scaled covariance, with Maximum Pc marked. Nominal Pc left of the Max Pc peak is a reliable estimate; to the right, the conjunction sits in the dilution region and nominal Pc understates the risk. See Pc Dilution.

HBR sensitivity​

Plots Pc against combined Hard-Body Radius (HBR). Useful for evaluating assumptions when third-party CDMs use generic or inferred object sizes.

Hard-Body Radius

HBR is optional in a CDM. When it is absent, Satcat uses the value from the RSO's parameters, which can be reviewed and updated in RSO Parameters.

Space weather sensitivity​

A contour of Pc across scaled drag coefficients for both objects, plotted as log10 primary Cd scale factor against log10 secondary Cd scale factor. The plot is labelled with the space weather classification in effect, and shows how much of the risk estimate rests on atmospheric density assumptions.

Collision consequence​

A contour of the estimated debris count produced by a collision, plotted as relative velocity against secondary object mass. Answers what the conjunction would cost if it happened, separately from how likely it is.

Primary vs Secondary Range​

Relative separation between the two RSOs over time, and its projections:

  • Range, Magnitude - scalar separation
  • Range, RIC - separation resolved into radial, in-track, and cross-track components
  • Cross-track <> In-track
  • Radial <> Cross-track
  • Radial <> In-track

The last three plot the relative path through a plane rather than against time.

3D Orbit Viewer​

Shows the RSOs' motion over time:

  • View in 3D inertial or 2D ground track
  • TCA-centric playback with scrub controls
  • Covariance ellipses shown at 1σ
  • Maneuver overlays when available

Supports better understanding of dynamic evolution and risk posture of the conjunction.

For supporting documentation: