Hi Per, its likely there is no way to answer your question generally. All I can state is that Wolfram gets its TLE data from USSTRATCOM (US Department of Defense) via www.space-track.org that has its own radar tracking stations. Where those are located and where LeoLabs have theirs is not something I am privy to. In both cases, they try to fit orbital elements to a set of observation positions obtained by the tracking stations. Those orbital elements are essentially a best fit to data points. How they factor in things like atmospheric refraction, etc. which can heavily distort observed positions of this above the atmosphere. I'm assuming refraction would be one source of error. In both cases, the claimed separation distance was a computation resulting from the relative TLEs used from different fitted data. Neither one, as far as I know, had observing stations in Antarctica that actually directly measured the separation distance between these two and in fact, the fact that they didn't know if they collided until actual observations of one of the satellites sometime later supports the fact that no direct observation was done. The only thing known for sure is that the collision didn't happen.

I also followed the incident, both on Twitter at LeoLabs and using the above calculations. According to the above code, the satellites passed within 7.6km, while LeoLab claims that the near collision was within a few meters.

I don't know the company, other than from this event, but it seems that they have several radar trackers in multiple places on the Earth.

So, my question is who is correct, as the two methods are seperated by three orders of magnitude.

Best, Per

I'm now hearing that 10 minutes after the possible collision, one of the satellites was detected as a single object so its sounding like the collision did not happen

-- you have earned Featured Contributor Badge

Your exceptional post has been selected for our editorial column Staff Picks http://wolfr.am/StaffPicks and Your Profile is now distinguished by a Featured Contributor Badge and is displayed on the Featured Contributor Board. Thank you!