Passive terrain navigation
CA 2477681 C · Owner: Saab Ab · Inventors: Neregard, Fredrik
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to terrain navigation wherein an earth-reflected satellite signal is received from at least one reference signal source whose position is known (120) for example a navigation satellite. Based on information contained in the received signal a measured estimate of a shortest reflection distance (d1(t b)) to the satellite (120) is derived. A relative spatial movement (.DELTA.x .DELTA.y, .DELTA.h) of a relevant craft (110) since a previous positioning instance (t a) is registered onboard the craft (110). Moreover stored surface information is retrieved pertaining to an elevation (h1b) of the earth surface (130) in relation to the mean sea level (z0) at at least one …
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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 August 16, 2004 and granted December 17, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 16, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 16, 2026.
- 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.