Medium earth orbit satellite surveillance system and antenna configuration therefore

• US 6,859,169 B2
• Filed: 06/11/2003
• Issued: 02/22/2005
• Est. Priority Date: 04/20/2000
• Status: Expired due to Term

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Jones, David A., Knight, James M., Jensen, Paul A., McCord, Henry L., Jensen, Eric B.
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US10/458,866
• Publication Number:
  US 20040113835A1
• Time in Patent Office: 622 Days
• Field of Search: 342/160, 342/352, 342/354, 342/356, 455/12.1, 455/13.1, 455/13.2
• US Class Current: 342/352
• CPC Class Codes: G01S 13/449 Combined with MTI or Doppler processing circuits
• CPC Class Codes: G01S 13/52 Discriminating between fixed and moving objects or between objects moving at different speeds
• CPC Class Codes: G01S 13/68 for angle tracking only
• CPC Class Codes: G01S 3/023 Monitoring or calibrating
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 19/19 comprising one main concave reflecting surface associated with an auxiliary reflecting surface
• CPC Class Codes: H01Q 19/192 with dual offset reflectors
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00

Abstract

A radar surveillance system includes a plurality of satellites a plurality of medium earth orbit satellites to provide continuous, long dwell coverage of a region of interest. Each satellite has an antenna having a main reflector and a subreflector electromagnetically coupled to the main reflector. A phased array generates multiple electromagnetic beams positioned so the electromagnetic beams reflect from the subreflector onto said main reflector. The system may be used in determining slow moving targets using a combination of monopulse anomaly and target spectral width measurements. The system also performs synthetic aperture radar imagery and focussed area fast moving target detection using alternating slope linear frequency modulated pulses. The plurality of medium Earth orbit satellites include a self-contained communications system consisting of high bandwidth self-relay crosslinks, high bandwidth downlink, and direct broadcast downlinks for processed data.

Claims

1. A satellite comprising:

a satellite body;

a surveillance antenna coupled to said satellite body;

a bi-directional downlink/uplink antenna coupled to said satellite body;

a plurality of high bandwidth radio frequency or optical crosslinks coupled to said satellite body;

a high bandwidth downlink antenna coupled to said satellite body;

a medium bandwidth directed broadcast downlink antenna coupled to said satellite body; and

,

a low bandwidth uplink receiver coupled to said satellite body.