Secure position identity and time reporting system

• US 4,077,005 A
• Filed: 06/18/1971
• Issued: 02/28/1978
• Est. Priority Date: 06/18/1971
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Bishop, Walton B.
• Primary Examiner(s): Birmiel, Howard A.
• Application Number:
  US05/154,617
• Time in Patent Office: 2,447 Days
• Field of Search: 343/7.5, 343/100 ST, 325/32, 325/4, 325/6, 325/115
• US Class Current: 380/258
• CPC Class Codes: H04K 1/00 Secret communication

Abstract

A system for identifying ships and aircraft, both in position and time, uizing shipboard cryptographic equipment and satellites is described.

Claims

1. A cryptosecure identification system comprising:

a ship;

means aboard said ship for transmitting an enciphered identification code, position, and time of day signal;

an airborne relay station;

receiver means aboard said relay station;

clock means aboard said relay station for supplying the time of day of said received enciphered signal;

means aboard said relay station for retransmitting said enciphered signal and said satellite time of day signal;

ground receiving means including means for deciphering said retransmitted enciphered signal and comparing the two time of day signals; and

means for indicating said signal to be valid if the difference between said two time of day signals is less than a predetermined time.

2. An identification system as recited in claim 1 wherein said relay station is a geostationary satellite.

3. An identification system as recited in claim 1 wherein said relay station is a variable positioned satellite, and further including delay means aboard said satellite for storing said enciphered signal and the satellite time of day until said satellite retransmits to said ground receiving means.

4. An identification system as recited in claim 3 further including:

means for displaying and correlating said valid deciphered signal.

5. An identification system as recited in claim 4 wherein said ship is an airship and said time of day signals are produced by clocks.