Error correction of messages by a passive radar system
AssigneeMegadata Corporation
InventorsJames A. Cole, Robert Damis, Bruce A. Leidahl, John R. Keller
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Abstract
Receiving a message including bits corresponding to an identifier, the identifier including a unique address for a aircraft transponder, extracting the unique address from the identifier, comparing the unique address to a set of predetermined addresses, changing selected ones of the identifier bits when the unique address is not one of the set of predetermined addresses, wherein the changing of the identifier bits changes a value of the unique address in the identifier, read-comparing the updated unique address to the set of predetermined addresses and processing the message when the unique address matches one of the set of predetermined addresses.
Claims19
A method, comprising the steps of:
- receiving a message including bits corresponding to an identifier, the identifier including a unique address;
- extracting the unique address from the identifier;
- comparing the unique address to a set of predetermined addresses;
- changing selected ones of the identifier bits when the unique address is not one of the set of predetermined addresses, wherein the changing of the identifier bits changes a value of the unique address in the identifier;
- re-comparing the updated unique address to the set of predetermined addresses;
- and
- processing the message when the unique address matches one of the set of predetermined addresses.
A method, comprising the steps of:
- receiving an in-the-clear message from an aircraft transponder at a passive ground station, the message including an identifier, the identifier including a unique address for the aircraft transponder;
- extracting the address from the identifier;
- determining whether the address has been previously stored in a set of addresses corresponding to aircraft in a range of the passive ground station;
- storing the address in the set of addresses when the address has not been previously stored;
- receiving an interrogation from an active ground station at the passive ground station, the interrogation including the unique address for the aircraft transponder;
- and
- error correcting the interrogation with the set of addresses.
A system, comprising:
- a passive radar receiving a message including bits corresponding to an identifier, the identifier including a unique address;
- a database including a set of predetermined addresses;
- and
- a processor comparing the unique address to the set of predetermined addresses and changes selected ones of the identifier bits when the unique address is not one of the set of predetermined addresses, wherein the changing of the identifier bits changes a value of the unique address in the identifier.
Dependencies are inferred from the claim text.