TRF (Timed Risk Framework) evaluates and tracks the periods of time during which a specific region-of-interest is at risk of impact during a satellite re-entry. Whilst re-entry epochs, and therefore impact locations, carry significant uncertainty, the periods of time at which a particular country or region is at-risk, are constrained by the satellite's orbital properties. For an area the size of the UK these local risk windows are typically less than one hour in duration. They are also relatively stable during the final days of orbit decay, and are naturally filtered as the size of the overall re-entry uncertainty falls.

This information helps civil planning by giving advance warning of periods at which the populace is potentially at risk of injury.

TRF makes use of satellite TLE observations to identify at-risk windows for one or more regions. It then applies data assimilation techniques to incorporate additional observations to the data population, updating the predicted windows.

  • Integrated - TRF maintains a database of satellite observations uses it to evaluate the ballistic coefficient of an re-entering satellite. It assimilates new observation data, updating its assessment of the ballistic coefficient, nominal impact time and at-risk windows as an integrated process.
  • Configurable - All aspects of TRF can be configured using JavaScript.
  • High performance - Integration of new observations and window updates take a matter of minutes.
  • Portable - Written in a combination of Java and JavaScript, TRF is fully supported on Windows, Unix / Linux and OS X.