space surveillance what i really meant thanks to the people who have answered here and in email to my question about which countries engage in space surveillance unfortunately i apparently didn t make the meaning of the message clear since most replies have addressed satellite reconnaissance rather than space surveillance what i meant was not which countries use satellites to look at the earth satellite reconnaissance but was which countries have programs to detect and track i e determine the orbital elements of satellites as they pass overhead space surveillance the us uses missile defense radars supplemented by a fascinating quasi radar operated by the navy to do this for satellites in leo and electrooptical systems for objects at altitudes above km or so the fee i understand does much the same thing amateur satellite observers use eyeballs binoculars stopwatches and pcs for objects out to around km enabling them to keep track of satellites for which ah official element sets aren t available see the fascinating books by desmond king hele for details as well as the files in the molczan directory on kilroy jpl nasa gov the material posted in my previous message suggests that japan engages in optical and radar space surveillance to a modest degree and it may be that other countries do also which was the question i meant to ask who are they how do they do it and why do they do it allen thomson saic mclean va oh yes i don t speak for saic
