Method for satellite tracking and extracting the signal by correlation

• US 6,404,801 B1
• Filed: 10/19/1998
• Issued: 06/11/2002
• Est. Priority Date: 12/28/1995
• Status: Expired due to Fees

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Lennen, Gary R.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Bayard, Emmanuel
• Application Number:
  US09/175,602
• Time in Patent Office: 1,331 Days
• Field of Search: 375/134, 375/137, 375/142, 375/145, 375/149, 375/259, 375/326, 375/343, 701/13, 701/213, 701/215, 342/352, 342/356, 342/357, 342/450, 370/316, 455/13.2, 455/427, 455/12.1, 455/98
• US Class Current: 375/134
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2

Abstract

The apparatus and method of the present invention is designed to receive SATPS satellites encoded information using a high gain antenna and pre-process the encoded information. The apparatus includes a High Gain Antenna (HGA), an extracting receiver, and a transmitter circuit configured to transmit the unknown code modulated on a transmission frequency for further processing in the delayed correlation receiver.

Claims

1. A method for observing the satellite signals coded with unknown code, said method utilizing a satellite receiving station equipped with a High Gain Antenna (HGA), said method comprising the steps of:

receiving the satellite signal coded with unknown code using said HGA;

extracting said unknown code; and

transmitting said unknown code for further processing.

2. The method of claim 1, wherein said step of receiving the satellite signal coded with unknown code using said HGA further comprises the step of receiving the GPS satellite signals coded with unknown Y code.

3. The method of claim 1, wherein said step of receiving the GPS satellite signals coded with unknown Y code further comprises the steps of:

tracking C/A L1 signal using said HGA antenna;

acquiring said tracked C/A L1 signal; and

synchronizing locally generated P code with said acquired C/A L1 signal.

4. The method of claim 1, wherein said step of receiving the GPS satellite signals coded with unknown Y code further comprises the steps of:

tracking C/A L1 and C/A L2 signals using said HGA antenna;

acquiring said tracked C/A L1 and C/A L2 signals; and

synchronizing locally generated P code with said acquired C/A L1 and C/A L2 signals.

5. The method of claim 3, wherein said step of tracking said C/A L1 signal using said HGA antenna further includes the steps of:

selecting a GPS satellite-vehicle (SV) to be observed; and

observing said selected SV GPS by steering said HGA to azimuth and elevation of said SV.

6. The method of claim 2, wherein said step of extracting said unknown Y code further includes the steps of:

removing P code from said incoming Y code, wherein said Y code is equal to the summation of said P code and an unknown W code; and

resynchronizing said W code with a transmission frequency F, wherein said transmission frequency F is greater than or equal to the W code frequency.

7. The method of claim 2, wherein said step of transmitting said unknown W code for further processing further includes the steps of:

modulating said W code on carrier; and

transmitting said modulated on carrier W code using a regular antenna to a processing station.

8. The method of claim 2, wherein said step of transmitting said unknown W code for further processing further includes the step of:

transmitting said W code using a land line to a processing station.

9. An apparatus for observing the satellite signals coded with unknown code, said apparatus including:

a High Gain Antenna (HGA) configured to receive the satellite signal coded with unknown code;

an extracting receiver configured to extract said unknown code from the received satellite signal; and

a transmitter circuit configured to transmit said unknown code modulated on a transmission frequency.