Matt Considine asked: > I came across this site > https://quadrature.co/work/classified-orbits/ > along with a companion page > https://quadrature.co/work/unknown/ > each of which reference unknown/classified objects in orbit, as tracked > by amateurs. > > I'm wondering if anyone knows the source of the data used? One > reference is to a dataset of 450 items, > but the McCants file has less than 200 if I read everything correctly. Based on the following investigation, I believe that the data source was Mike McCants's classfd.tle file. https://quadrature.co/work/unknown/ states: "Until today a devoted group of amateur astronomers runs an alternative catalogue, containing about 450 datasets missing in the officially published lists. Most of these classified objects are still defined though and their true nature is known. But for currently 52 objects no specifications are available. Only their locations can be calculated." The Wayback Machine first archived that page on 2018 Feb 03. The Wayback Machine archived Mike's classfd.zip file on 2018 Aug 26: https://web.archive.org/web/20180826082640/https://www.prismnet.com/~mmccants/tles/classfd.zip That file lists 444 TLEs, close to the 450 described by quadrature.co. For unknown objects, Mike used catalogue numbers beginning at 90000, There are 52 of them in the above file, which matches the number described by quadrature.co. In late 2018, the USAF began to declassify many of the secret TLEs, which is why Mike's file contains far fewer objects today than it did in mid-2018. Ted Molczan _______________________________________________ Seesat-l mailing list https://lists.seesatmail.org/mailman/listinfo/seesat-lReceived on Sun Jun 02 2024 - 06:16:36 UTC
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