CIRCUITRY FOR REMOTELY DISPLAYING RADAR IMAGERY USING A SINGLE DATA CHANNEL

• US 3,713,146 A
• Filed: 01/29/1971
• Issued: 01/23/1973
• Est. Priority Date: 01/29/1971
• Status: Expired due to Term

• Current Assignee: Calvin A. Hughey, Charles W. May, John J. Carroll
• Original Assignee: Calvin A. Hughey, Charles W. May, John J. Carroll
• Inventors: Carroll, John J., Hughey, Calvin A., May, Charles W.
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US05/110,984
• Time in Patent Office: 725 Days
• Field of Search: 343/6A
• US Class Current: 342/58
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations

Abstract

A circuit for remotely displaying radar imagery from the radar circuits at a radar receiving station to a remote point by a single telemetry channel, the circuit having mixers to mix desired video signals on the pedestal level to form the composite video consisting of the blanking level, the pedestal level, and the saturation level, which desired video signals are demodulated and separated at the remote station and applied to a sampler circuit of an azimuth scan generator or phase lock loop and a sweep generator coupled to the remote display tube to display the desired video signals.

Claims

1. A circuit for remotely displaying radar imagery using a single data channel comprising:

a radar receiver having a radar video channel;

mixers in said radar video channel to mix center of scan cursor, range cursor, video symbols, and sync triggers producing composite video information in said channel;

a remote radar receiver station;

a data link coupled to transmit said composite video information to said remote radar receiver;

a demodulator and a video separator in said remote radar receiver for separating said composite video information into separate video, center of scan cursor, range cursor, and sync triggers;

a radar scope coupled to receive said video and said range cursor on a brightness control thereof;

an azimuth scan generator having a phase lock loop with a sampler network in a feedback loop to which is coupled said center of scan cursor to compare with the phase of said azimuth scan generator to produce error signals on the output of said sampler network operative to synchronize the horizontal voltage sweeps with said center of scan cursor, and a vertical sweep generator coupled to receive said sync triggers to produce range sweep voltages coupled to the vertical deflection inputs of said radar scope whereby video target range information is displayed on said remote radar scope in real time over a single data channel.

2. A circuit for remotely displaying radar imagery as set forth in claim 1 wherein said vertical sweep generator receives said sync triggers through a threshold sensitive detector to eliminate spurious noise signals from the sync trigger signals.

3. A circuit for remotely displaying radar imagery as set forth in claim 2 wherein said video channel of said radar receiver includes an amplifier preceding said mixers and an amplifying driver succeeding said mixers to ably drive said composite video signals over said data link.

4. A circuit for remotely displaying radar imagery as set forth in claim 3 wherein said azimuth scan generator includes a switched array of feedback network filters, a switched array of voltage controlled oscillators, and a switched array of waveform shaping filters in that coupled order between said sampler network and said output to said scope horizontal deflection circuits whereby different horizontal drive frequencies can be selectively switched to provide different scope range scales.

5. A circuit for remotely displaying radar imagery as set forth in claim 4 wherein said video separator includes two channels isolated by a emitter follower transistor, each channel having a differential amplifier with a bias input to establish a threshold level, the threshold bias input for one channel being fixed to develop said sync triggers and the threshold bias input for the other channel being adjustable to develop center of scan cursor pulses of adjusted amplitude.