Rf link control of satellite clocks
CA 2190273 C · Owner: Cummiskey, Peter · Inventors: Cummiskey, Peter; Epstein, Marvin A.; Doyle, Lawrence J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system and method for maintaining a precise time standard among a system of orbiting satellites is disclosed. In an illustrative embodiment (the figure), atomic clock data is circulated among the satellites (2 4, 6) via RF crosslinks (10). Each satellite uses the received data as input to a Kalman process which acts to minimize the means squared error among the satellite clocks to form a set of "ensemble clocks". The resulting ensemble clock values are then transmitted (12) to an earth station (8) where an offset between the ensemble clocks and Universal Time is computed. The offset is transmitted (14) from the earth station to the satellites where it is used by the satellites to lock …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 1, 1995 and granted August 12, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 1, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 1, 2017.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.