Satellite positioning apparatus

• US 3,906,204 A
• Filed: 04/20/1973
• Issued: 09/16/1975
• Est. Priority Date: 04/20/1973
• Status: Expired due to Term

• Current Assignee: James W. Rigdon, Leroy D. Graber, Saburo Ifune
• Original Assignee: James W. Rigdon, Leroy D. Graber, Saburo Ifune
• Inventors: Rigdon, James W., Ifune, Saburo, Graber, LeRoy D.
• Primary Examiner(s): Ruggiero, Joseph F.
• Application Number:
  US05/352,953
• Time in Patent Office: 879 Days
• Field of Search: 235/150.27,150.271,150.26,150.2,150.24 343/1ST,1C,DIG.2 244/77SS 444/1 340/172.5
• US Class Current: 701/514
• CPC Class Codes: G01S 11/10 using Doppler effect

Abstract

A new and improved apparatus for determining the position of a vehicle or vessel on the earth'"'"''"'"'s surface by processing signals sent from a satellite, based on the doppler shift in frequency of the signals so sent, and the orbit description data encoded in the signals.

Claims

1. An apparatus for processing data, sent from a satellite in the form of a fixed frequency signal containing phase modulated pulse doublets or orbit definition data, to determine a position of a vehicle on the earth, comprising:

a. receiver means for receiving the signal from the satellite, said receiver means comprising;

1. intermediate frequency means for domodulating the fixed frequency signal for processing;

2. phase detector means for determining the phase of the demodulated signal from said intermediate frequency means;

3. phase lock loop means receiving an output of said phase detector means for regulating the frequency of said intermediate frequency means;

4. doppler demodulator means responsive to an output of said phase lock loop means for determining the doppler shift in frequency of the signal sent from the satellite;

5. local oscillator means for forming a reference frequency signal;

6. synthesizer means for forming demodulating frequency signals for said intermediate frequency means, said phase detector means, and said doppler demodulator means from said reference frequency signal;

7. bit phase detector means for determining the phase of the orbit definition data phase doublets;

8. bit rate phase lock loop means for contrOlling the phase of the orbit definition data pulse doublets; and

9. data decoder means for decoding the orbit definition data from the phase modulated pulse doublets;

b. computer means for processing the doppler shift and orbit definition data to determine the location of the vehicle;

c. interface circuit means for providing the doppler shift and orbit definition data to said computer means, said interface circuit means including doppler counter means for counting the doppler shift; and

d. display means for indicating the location of the vehicle determined by said computer means.

2. phase detector means for determining the phase of the demodulated signal from said intermediate frequency means;

3. The structure of claim 1, further including:

tape reader means for reading an operation controlling program into said computer means.

4. doppler demodulator means responsive to an output of said phase lock loop means for determining the doppler shift in frequency of the signal sent from the satellite;

5. The structure of claim 1, wherein said interface circuit means further includes:

data multiplexer means for multiplexing the decoded orbit description data and the doppler count from said doppler counter means for processing by said computer means.

6. synthesizer means for forming demodulating frequency signals for said intermediate frequency means, said phase detector means, and said doppler demodulator means from said reference frequency signal;

7. The structure of claim 6, wherein said interface circuit means comprises:

message reject means for suppressing output signals from said data decoder means in response to a message reject signal from said computer means.

8. bit rate phase lock loop means for contrOlling the phase of the orbit definition data pulse doublets;

and

9. The structure of claim 8, wherein said receiver means includes:

counter means for counting a predetermined number of valid data before transmitting such data to said computer means.

10. The structure of claim 1, further including:

means for entry of data and requests therefor into said computer means.