Method and apparatus for positioning a satellite antenna from a remote well logging location

• US 4,707,699 A
• Filed: 02/14/1985
• Issued: 11/17/1987
• Est. Priority Date: 02/14/1985
• Status: Expired due to Fees

• Current Assignee: Halliburton Company
• Original Assignee: Halliburton Company
• Inventors: Toellner, Robert L., Copland, George V.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Hayes, Jr., Donald E.
• Application Number:
  US06/701,721
• Time in Patent Office: 1,006 Days
• Field of Search: 343/352, 343/359, 343/356, 343/7.4
• US Class Current: 342/352
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• CPC Class Codes: H01Q 1/1257 using the received signal strength
• CPC Class Codes: H01Q 3/005 using remotely controlled antenna positioning or scanning

Abstract

A system and method for automatically pointing a microwave antenna at a desired satellite in geosynchronous earth orbit from a remote location, such as encountered in a well logging, is disclosed. The system uses a truck borne, gimbal mounted antenna and a computer arranged to automatically control and drive servo motors connected to the gimbal mounts of the antenna. Accurate pointing with minimal human intervention is achieved.

Claims

1. An automatic system for positioning a Ku band microwave antenna accurately to within approximately 0.1 degrees to point at a particular satellite located among others having as close as 2 degree angular spacing in geosynchronous earth orbit from a remote location for establishing a Ku band microwave communication link from the remote location via the satellite, comprising:

a Ku band microwave antenna having a gimbal mount adapted to move in at least azimuth and elevation;

means for driving said gimbal amount in azimuth and means for driving said gimbal mount in elevation;

means for sensing a satellite signal detected by said antenna and for producing an output signal representative of the strength of said satellite signal and a separate output signal indicative of a satellite code or signature;

inclinometer means for measuring the actual elevation angle of said elevation gimbal with respect to vertical and for generating an output signal representative thereof;

means for measuring the azimuth angle of said azimuth gimbal relative to a fixed reference and for generating an output signal representative thereof;

computer means capable of receiving input data comprising the earth latitude and longitude of a remote location and a satellite position and capable of receiving as inputs said strength representative signal, said satellite code or signature indicative signal, said elevation representative signal and said azimuth representative signal and further being capable of generating output command signals to said driving means to drive said azimuth and elevation gimbals to commanded positions the initial commanded position of said azimuth gimbal being one of its stops;

means, included in said computer means, for pointing said elevation gimbal to a fixed direction and for scanning said azimuth gimbal to a computed direction based on said earth latitude and longitude and said satellite position signals and then for varying the pointing of said gimbals in response to said signal strength signal in such a manner as to optimize said strength signal; and

wherein said computer means further includes means capable of receiving said input signal indicative of a satellite code or signature and means for comparing said code or signature input signal with a predetermined reference code or signature signal in the memory of said computer means to verify the pointing of said antenna at the correct satellite and means responsive to such comparison for moving said gimbal mount in azimuth away from its initial stop position if said comparison fails to match.

2. The system of claim 1 wherein said step of varying the pointing in response to said signal strength is repeated at selected periodic intervals to maintain accurate pointing throughout a data transmission via the satellite.

3. A method for automatically positioning a microwave antenna accurately to point at a satellite in geosynchronous earth orbit from a remote location for establishing a communications link from the remote location via the satellite, comprising the steps of:

positioning a microwave antenna having a gimbal mount adapted to move at least in azimuth and in elevation in an approximately level position in a remote earth location, said gimbal mounts being adapted to be automatically driven in azimuth with respect to a reference and in elevation with respect to vertical and being equipped with sensors to detect their actual azimuth with respect to a reference and elevation with respect to vertical and to generate signals representative thereof;

inputting to a control computer the earth latitude and longitude of the remote location of said antenna and the location of a geosynchronous satellite to which it is desired to point said antenna;

automatically computing in said control computer the elevation angle of the satellite at the remote locations and automatically driving the elevation gimbal to this angle and stopping said gimbal;

initially driving the azimuthal gimbal to one of its stops and then driving said azimuthal gimbal from this stop to an azimuth computed by said control computer for said satellite and stopping said gimbal;

sampling a received signal from said satellite and testing said signal for signal strength and generating an output signal to said control computer representative thereof and generating a second output signal to said computer representative of a satellite code or signature;

varying said elevation gimbal and said azimuthal gimbal in relatively small increments in response to said signal strength signal to optimize said signal strength signal; and

comparing said received signal representative of a satellite code or signature from said satellite with a predetermined code or signature signal to validify that the correct satellite is being received.

4. The method of claim 3 wherein the varying step is repetitively performed during the communications interval to assure continued accurate pointing of said antenna toward the satellite.