Radar system

• US 4,142,189 A
• Filed: 01/07/1965
• Issued: 02/27/1979
• Est. Priority Date: 01/07/1965
• Status: Expired due to Term

• Current Assignee: Mesc Electronic Systems, Inc.
• Original Assignee: Magnavox (Koninklijke Philips N.V.)
• Inventors: Gleason, Joseph P.
• Primary Examiner(s): Tubbesing, T.H.
• Application Number:
  US04/424,464
• Time in Patent Office: 5,164 Days
• Field of Search: 340/347, 340/348, 332/10, 332/14, 332/16, 235/152, 235/92 SH, 235/92 NG, 343/100.7, 343/13, 343/17.1, 343/17.1 R, 343/9, 343/17.2 R, 343/17.2 PC, 333/1.1, 333/31 A, 328/37, 307/221 R
• US Class Current: 342/109
• CPC Class Codes: G01S 13/30 using more than one pulse per radar period

Abstract

1. A radar system for determining the range to and velocity of a target comprising the combination of:

Transmitting means for radiating energy at a first particular frequency toward the target,

Encoding means for generating a series of binary encoding pulses having a repetitive pseudo-random pattern, said series including a plurality of groups each of which include the same number of pulses wherein the plurality constitutes an odd number,

Means for operatively interconnecting said encoding means with said transmitting means for modulating the transmitted energy in response to said binary encoding pulses to thereby provide a modulation pattern on said energy,

Gating means operatively interconnected with said transmitting means for periodically gating said transmitting means "ON" and "OFF" at a particular time in successive groups of the binary encoding pulses,

Means operatively interconnected with said gating means to count said binary encoding pulses for actuating said gating means at the particular time in the successive groups so that said gating means will cause said transmitting means to radiate pulses of energy that have their modulation patterns repeat in accordance with the repetition rate of said series of encoding pulses,

Receiving means operative during the intervals between the radiation of said pulses for receiving the energy reflected from the target to provide reflected energy having frequencies that differ from the frequency of the transmitted energy in accordance with the velocity of the target relative to the transmitting means and having modulation patterns substantially identical to but delayed from the transmission pattern in accordance with the range to the target,

Means operatively interconnected with said first encoding means for producing a second series of binary encoding pulses according to said predetermined code and having said pseudo-random pattern,

Means operatively interconnecting said last means with said receiving means for supplying said second series of binary encoding pulses to said receiving means with a time delay substantially equal to the time required for the radiated energy to return from the target, and

Means for comparing said delayed series with the modulation pattern on the reflected signals from the target to provide an output signal having a frequency corresponding to the difference between the frequency of the transmitted energy and the frequency of the energy received from the target.

Claims

1. A radar system for determining the range to and velocity of a target comprising the combination of:

transmitting means for radiating energy at a first particular frequency toward the target,

encoding means for generating a series of binary encoding pulses having a repetitive pseudo-random pattern, said series including a plurality of groups each of which include the same number of pulses wherein the plurality constitutes an odd number,

means for operatively interconnecting said encoding means with said transmitting means for modulating the transmitted energy in response to said binary encoding pulses to thereby provide a modulation pattern on said energy,

gating means operatively interconnected with said transmitting means for periodically gating said transmitting means "ON" and "OFF" at a particular time in successive groups of the binary encoding pulses,

means operatively interconnected with said gating means to count said binary encoding pulses for actuating said gating means at the particular time in the successive groups so that said gating means will cause said transmitting means to radiate pulses of energy that have their modulation patterns repeat in accordance with the repetition rate of said series of encoding pulses,

receiving means operative during the intervals between the radiation of said pulses for receiving the energy reflected from the target to provide reflected energy having frequencies that differ from the frequency of the transmitted energy in accordance with the velocity of the target relative to the transmitting means and having modulation patterns substantially identical to but delayed from the transmission pattern in accordance with the range to the target,

means operatively interconnected with said first encoding means for producing a second series of binary encoding pulses according to said predetermined code and having said pseudo-random pattern,

means operatively interconnecting said last means with said receiving means for supplying said second series of binary encoding pulses to said receiving means with a time delay substantially equal to the time required for the radiated energy to return from the target, and

means for comparing said delayed series with the modulation pattern on the reflected signals from the target to provide an output signal having a frequency corresponding to the difference between the frequency of the transmitted energy and the frequency of the energy received from the target.

2. A radar system for determining the range to and velocity of a target comprising the combination of:

transmitting means for radiating energy at a first particular frequency toward the target,

a clock for generating a series of clock pulses at a second particular frequency different from the first particular frequency,

encoding means operatively interconnected with said clock for generating a first series of binary encoding pulses at the same frequency as said clock pulses and in synchronism with said clock pulses, said encoding pulses having a repetitive pseudo-random pattern, said first series including a plurality of groups each of which include the same number of pulses,

means for operatively interconnecting said encoding means with said transmitting means for modulating the transmitted energy in response to said binary encoding pulses to thereby provide a modulation pattern on said energy,

gating means operatively interconnected with said transmitting means for gating said transmitting means "ON" and "OFF" at a particular period in the successive groups of binary encoding pulses,

means operatively interconnected with said gating means to count said binary encoding pulses for actuating said gating means at the particular period in the successive groups of binary encoding pulses,

receiving means operative during the intervals between the radiation of said pulses of energy for receiving the energy reflected from the target to provide reflected energy having frequencies that differ from the frequency of the transmitted energy in accordance with the velocity of the target relative to the transmitting means and having modulation patterns that are substantially identical to the transmitted modulation patterns but are delayed therefrom in accordance with the range to the target,

means operatively interconnected with said clock for producing a second series of binary pulses at the same frequency as said clock pulses, said second series of pulses having said pseudo-random pattern,

means operatively interconnected with said last means and with said receiving means for supplying said second series of binary pulses to said receiving means but delayed from the first series by a particular number of clock pulses corresponding to the amount of time required for radiated pulses to return from the target, and

means for comparing said delayed series with the modulation pattern on the received pulses to provide an output signal having a frequency corresponding to the difference between the frequency of the transmitted energy and the frequency of the received energy.

3. A radar system for determining the range and velocity of a target comprising the combination of:

transmitting means for radiating energy at a first particular frequency toward the target for reflection therefrom,

a clock for generating a series of clock pulses at a second particular frequency different from the first particular frequency,

encoding means operatively interconnected with said clock for generating a series of binary encoding pulses at the same frequency as said clock pulses, said encoding pulses having a repetitive pseudo-random pattern, said series including a plurality of groups each of which include the same number of pulses,

modulating means in said transmitting means and operatively interconnected with said encoding means and responsive to said encoding pulses for modulating the phase of the transmitted energy depending upon the occurrence or non-occurrence of an encoding pulse to provide a modulation pattern on said transmitted energy,

gating means operatively interconnected with said transmitting means for periodically gating said transmitting means "ON" and "OFF" at a third particular frequency between the first and second particular frequencies,

means operatively interconnected with said gating means to count said binary encoding pulses for periodically actuating said gating means "ON" and "OFF",

receiving means operative during the intervals between the radiation of said pulses of energy for receiving the energy from the target to provide energy having frequencies that differ from the frequency of the transmitted energy in accordance with the velocities of the target relative to the transmitting means and having phase inversions substantially identical to the phase inversions in said transmitted pulses but delayed therefrom in accordance with the range to the target,

means for producing a second series of binary pulses at the same frequency as said clock pulses, said second series of binary pulses having said pseudo-random pattern,

delay means operatively interconnecting said last means with said clock for supplying said clock pulses to said last means and for delaying the binary pulses in the second series in accordance with the delay between the transmitted and received pulses to provide an indication of the range in accordance with such delay, and

means for supplying said second series of binary signals to said receiving means and correlating said binary signals with the phase inversions on the received signals to provide output signals having a frequency representing the velocity of the target relative to the transmitting means.