Signal processor for diversity frequency radar

Claim 3

Radar apparatus for tracking an object with a minimum of target scintillation comprising: transmitting means which repetitively radiate a plurality of electromagnetic pulses that are different in frequency according to a predetermined sequence; receiving means which receive echoes of said pulses from said object; a positionable antenna which is connected to and which intermittently and alternately functions as part of said transmitting means and as part of said receiving means; servo drive means connected to said positionable antenna and which functions to mechanically point said antenna at said object and comparing and selecting means connected to said receiving means and to said servo drive means and functioning to determine which frequency pulses produced echoes stronger than a threshold level and to apply only said stronger echoes to energize said servo drive means whereby said object is tracked with a minimum of target scintillation.

Claim 4

Radar apparatus for tracking an object with a minimum of target scintillation comprising: transmitting means which repetitively radiate a plurality of electromagnetic pulses that are different in frequency according to a predetermined sequence; receiving means which receive echoes of said pulses from said object; a positionable antenna which is connected to and which intermittently and alternately functions as part of said transmitting means and as part of said receiving means; servo drive means connected to said positionable antenna and which functions to mechanically point said antenna at said object and comparing and selecting means connected to said receiving means and to said servo drive means and functioning to determine which frequency pulses produced echoes stronger than a threshold level and to apply only said stronger echoes to energize said servo drive means whereby said object is tracked with a minimum of target scintillation.

Claim 5

The radar apparatus of claim 2 wherein said comparing and selecting means includes threshold level signal producing means which function to produce a threshold level signal that is a predetermined function of the average of said received echoes.

Claim 6

Radar apparatus for tracking an object with a minimum of target scintillation comprising: transmitting means which repetitively produce and radiate a plurality of electromagnetic pulses that are different in frequency according to a predetermined sequence; receiving means which receive echoes of said pulses from said object and which produce first, second and third signals from each received echo; a positionable antenna which is connected to and which intermittently and alternately functions as part of said transmitting means and as part of said receiving means; servo drive means connected to said positionable antenNa and which functions to mechanically point said antenna at said object; gating means which intermittently connect said second and third receiver signals to energize said servo drive means and comparing and selecting means connected to receive said first receiver signal and functioning to determine which frequency pulse echo produces first signals that are stronger than a threshold level and functioning to control said gating means so that said servo drive means is energized only by said second and third receiver signals that result from the frequency pulse echoes that produce first signals that are stronger than said threshold level whereby said object is tracked with a minimum of target scintillation.

Claim 7

Radar apparatus for tracking an object with a minimum of target scintillation comprising: transmitting means which repetitively produce and radiate a plurality of electromagnetic pulses that are different in frequency according to a predetermined sequence; receiving means which receive echoes of said pulses from said object and which produce first, second and third signals from each received echo; a positionable antenna which is connected to and which intermittently and alternately functions as part of said transmitting means and as part of said receiving means; servo drive means connected to said positionable antenNa and which functions to mechanically point said antenna at said object; gating means which intermittently connect said second and third receiver signals to energize said servo drive means and comparing and selecting means connected to receive said first receiver signal and functioning to determine which frequency pulse echo produces first signals that are stronger than a threshold level and functioning to control said gating means so that said servo drive means is energized only by said second and third receiver signals that result from the frequency pulse echoes that produce first signals that are stronger than said threshold level whereby said object is tracked with a minimum of target scintillation.

Claim 8

The radar apparatus of claim 4 wherein said comparing and selecting means includes threshold level signal producing means which function to produce a threshold level signal that is a predetermined function of the average of said first signals.

Claim 9

The radar apparatus of claim 5 and further including: a delay line connected to receive said first signals in such a way that the output signal of said delay line is related to the strength of said first signal for the whole of said predetermined electromagnetic pulse frequency sequence and range tracking means connected to said delay line and functioning to produce control signals for said receiving means and for said comparing and selecting means.

Claim 10

The radar apparatus of claim 6 wherein said comparing and selecting means includes: connecting means connecting said threshold level signal producing means to said delay line output signal and comparator means connected to receive said first signals and said threshold level signal and functioning to produce gating signals which control said gating means to pass said second and third receiver signals only when said first signals are stronger than said threshold level signal.