Radar trilateralization position locators

Claim 2

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising digital gate means for generating and transmitting cyclically recurring digitally repetitive interrogation radar signals to said other units at a fixed station identifying pulse repetition rate, digital gate means in each of said other units for monitoring said interrogation radar signals to digitally detect the particular cyclic digital signals having the pulse repetition rate identifying the monitoring unit, digital means in the particular one of the other units which is identified by a detected pulse repetition rate for digitally re-transmitting a radar signal as a reply signal to said first unit, whereby said re-transmitted signals are also digital signals which have said cyclically recurring repetition rate, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected cyclically recurring pulse repetition rate and return to said first unit, means whereby said first unit transmits with an omnidirectional transmission antenna pattern, and means whereby each of said other units transmits with narrow overlapping beam antenna patterns.

Claim 3

The system of claim 1 wherein said other units are separated from each other and located at known spots, and means in said first unit for separately measuring the distances between the first unit and each of the other units while said first unit is in the overlapped areas of said narrow beam antenna pattern.

Claim 4

The system of claim 2 and means in said first unit for evaluating the reply signals as they are received, and means responsive to the evaluating means detection of an apparently invalid signal for precluding the acceptance of the signal as a valid one and to the evaluating means detection of an apparently valid signal for allowing the acceptance of it.

Claim 5

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising digital gate means for generating and transmitting cyclically recurring digitally repetitive interrogation radar signals to said other units at a fixed station identifying pulse repetition rate, digital gate means in each of said other units for monitoring said interrogation radar signals to digitally detect the particular cyclic digital signals having the pulse repetition rate identifying the monitoring unit, each of said other units comprising a decoder means coupled to said monitoring means for decoding signals to detect the rate identifying the associated other unit, a two input AND gate means having one input coupled to said decoder means and another input coupled to said monitoring means, digital means responsive to the output of said AND gate in the particular one of the other units which is identified by a detected pulse repetition rate for digitally re-transmitting a radar signal as a reply signal to said first unit, whereby said re-transmitted signals are also digital signals which have said cyclically recurring repetition rate, and means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected cyclically recurring pulse repetition rate and return to said first unit.

Claim 6

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising digital gate means for generating and transmitting cyclically recurring digitally repetitive interrogation radar signals to said other units at a fixed station identifying pulse repetition rate, digital gate means in each of said other units for monitoring said interrogation radar signals to digitally detect the particular cyclic digital signals having the pulse repetition rate identifying the monitoring unit, each of said other units comprising a decoder means coupled to said monitoring means for decoding signals to detect the rate identifying the associated other unit, a two input AND gate means having one input coupled to said decoder means and another input coupled to said monitoring means, digital means responsive to the output of said AND gate in the particular one of the other units which is identified by a detected pulse repetition rate for digitally re-transmitting a radar signal as a reply signal to said first unit, whereby said re-transmitted signals are also digital signals which have said cyclically recurring repetition rate, and means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected cyclically recurring pulse repetition rate and return to said first unit.

Claim 7

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising encoding means for transmitting an encoded interrogation radar signal to said other units, means in each of said other units for monitoring said interrogation radar signals to detect a particular one of said encoded signals identifying the monitoring unit, means in the particular one of the other units which is identified by a detected code for re-transmitting a radar signal as a reply signal to said first unit, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected code and return to said first unit, said encoding means comprising a function pulse repetition rate encoder including a source of cyclically recurring clock pulses, means for counting the recurring clock pulses, means for simultaneously generating one of said function pulses and starting the counting of said clock pulses from said source, means responsive to said counting means reaching a predetermined clock pulse count for generating another of said function pulses and restarting said clock pulse counting means, and means for selectively changing said predetermined count.

Claim 8

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising encoding means for transmitting an encoded interrogation radar signal to said other units, means in each of said other units for monitoring said interrogation radar signals to detect a particular one of said encoded signals identifying the monitoring unit, means in the particular one of the other units which is identified by a detected code for re-transmitting a radar signal as a reply signal to said first unit, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected code and return to said first unit, said encoding means comprising a function pulse repetition rate encoder including a source of cyclically recurring clock pulses, means for counting the recurring clock pulses, means for simultaneously generating one of said function pulses and starting the counting of said clock pulses from said source, means responsive to said counting means reaching a predetermined clock pulse count for generating another of said function pulses and restarting said clock pulse counting means, and means for selectively changing said predetermined count.

Claim 9

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising means for transmitting an encoded interrogation radar signal to said other units, means in each of said other units for monitoring said interrogation radar signals to detect a particular onE of said encoded signals identifying the monitoring unit, code detecting means in the particular one of the other units which is identified by a detected code for re-transmitting a radar signal as a reply signal to said first unit, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected code and return to said first unit, said code detecting means comprising a function pulse repetition decoding means including a source of cyclically recurring clock pulses, means for counting said recurring clock pulses, means responsive to the reception of a function pulse for applying a signal to a two input AND gate and simultaneously starting the counting of said recurring clock pulses, and means responsive to the clock pulse count reaching a predetermined value for applying a signal to the other input of said AND gate, whereby said AND gate gives an output signal if one of said function pulses coincides with said predetermined clock pulse.

Claim 10

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising means for transmitting an encoded interrogation radar signal to said other units, means in each of said other units for monitoring said interrogation radar signals to detect a particular onE of said encoded signals identifying the monitoring unit, code detecting means in the particular one of the other units which is identified by a detected code for re-transmitting a radar signal as a reply signal to said first unit, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected code and return to said first unit, said code detecting means comprising a function pulse repetition decoding means including a source of cyclically recurring clock pulses, means for counting said recurring clock pulses, means responsive to the reception of a function pulse for applying a signal to a two input AND gate and simultaneously starting the counting of said recurring clock pulses, and means responsive to the clock pulse count reaching a predetermined value for applying a signal to the other input of said AND gate, whereby said AND gate gives an output signal if one of said function pulses coincides with said predetermined clock pulse.

Claim 11

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising means for transmitting cyclically recurring interrogation radar signals to said other units at a fixed station identifying pulse repetition rate, means in each of said other units for monitoring said interrogation radar signals to detect the particular cyclic signals having the pulse repetition rate identifying the monitoring unit, means in the particular one of the other units which is identified by a detected pulse repetition rate for re-transmitting a radar signal as a reply signal to said first unit, whereby said re-transmitted signals also have said cyclically recurring repetition rate, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected cyclically recurring pulse repetition rate and return to said first unit, and means for validating said reply signals comprising means for repeatedly storing data derived from said receipt of said reply signal, data accumulation means, means for transferring said stored data to said data accumulator means, means in said accumulator for accepting the transferred data which is consistent with said previsouly accumulated data and for rejecting non-consistent data, and means responsive to the accumulation of a predetermined amount of said accepted data for giving a read out of the average of said accumulated data.

Claim 12

A radar trilateralization position locator system including a first unit and at least two other units, said first unit comprising means for transmitting cyclically recurring interrogation radar signals to said other units at a fixed station identifying pulse repetition rate, means in each of said other units for monitoring said interrogation radar signals to detect the particular cyclic signals having the pulse repetition rate identifying the monitoring unit, means in the particular one of the other units which is identified by a detected pulse repetition rate for re-transmitting a radar signal as a reply signal to said first unit, whereby said re-transmitted signals also have said cyclically recurring repetition rate, means in said first unit operated responsive to the receipt of said reply signal for indicating the time required for said signal to make a round trip from said first unit to the other unit identified by said detected cyclically recurring pulse repetition rate and return to said first unit, and means for validating said reply signals comprising means for repeatedly storing data derived from said receipt of said reply signal, data accumulation means, means for transferring said stored data to said data accumulator means, means in said accumulator for accepting the transferred data which is consistent with said previsouly accumulated data and for rejecting non-consistent data, and means responsive to the accumulation of a predetermined amount of said accepted data for giving a read out of the average of said accumulated data.

Claim 13

A mobile radar station comprising digital gating means for selectively transmitting interrogation radar pulses as predetermined cyclically recurring digital pulses at a pulse repetition rate selected to identify a particular receiving station, digital gating means responsive to the receipt of said cyclically recurring digital reply pulses at the same selected pulse repetition rate for identifying the receiving station, means for storing signals indicating the elapsed time between the transmission of the interrogation pulse and the reception of a responsive reply pulse, hold-off means for delaying the effect of said reply signal for a period of time equal to the time required for the equipment transmitting said reply signal to respond to said interrogation signal, means for thereafter measuring an interval of time corresponding to the actual transmission time elapsing between the transmission of said interrogation pulse and the receipt of said reply pulse, less the delay of said hold-off means, and means responsive to said measuring means for indicating the lengths of two sides of a triangle, the length of the other side being known, whereby location is known by trilateralization.

Claim 14

A mobile radar station comprising digital gating means for selectively transmitting interrogation radar pulses as predetermined cyclically recurring digital pulses at a pulse repetition rate selected to identify a particular receiving station, digital gating means responsive to the receipt of said cyclically recurring digital reply pulses at the same selected pulse repetition rate for identifying the receiving station, means for storing signals indicating the elapsed time between the transmission of the interrogation pulse and the reception of a responsive reply pulse, hold-off means for delaying the effect of said reply signal for a period of time equal to the time required for the equipment transmitting said reply signal to respond to said interrogation signal, means for thereafter measuring an interval of time corresponding to the actual transmission time elapsing between the transmission of said interrogation pulse and the receipt of said reply pulse, less the delay of said hold-off means, and means responsive to said measuring means for indicating the lengths of two sides of a triangle, the length of the other side being known, whereby location is known by trilateralization.

Claim 15

A function pulse repetition rate encoder for a radar transmitting station to identify a receiving system comprising a source of cyclically recurring clock pulses, means for counting the recurring clock pulses, means for simultaneously generating one pulse of radar energy and starting the counting of said clock pulses from said source, means responsive to said counting means reaching a predetermined clock pulse count for generating another pulse of radar energy, and simultaneously restarting said clock pulse counting means, and means for selectively changing said predetermined count for changing said encoding, whereby the spacing between pulses of radar energy is varied as a function of the identity of a called receiving station.

Claim 16

A function pulse repetition rate encoder for a radar transmitting station to identify a receiving system comprising a source of cyclically recurring clock pulses, means for counting the recurring clock pulses, means for simultaneously generating one pulse of radar energy and starting the counting of said clock pulses from said source, means responsive to said counting means reaching a predetermined clock pulse count for generating another pulse of radar energy, and simultaneously restarting said clock pulse counting means, and means for selectively changing said predetermined count for changing said encoding, whereby the spacing between pulses of radar energy is varied as a function of the identity of a called receiving station.

Claim 17

A function pulse repetition decoding means for a radar receiving station to recognize a call to a particular station, comprising a source of cyclically recurring clock pulses, means for counting said recurring clock pulses, means responsive to the reception of a pulse of radar energy for applying a signal to a two input AND gate and simultaneously starting the counting of said recurring clock pulses, and means responsive to the clock pulse count reaching a predetermined value for applying a signal to the other input of said AND gate, whereby said AND gate gives an output signal if one of said pulses of radar energy coincides with said predetermined clock pulse.

Claim 18

A function pulse repetition decoding means for a radar receiving station to recognize a call to a particular station, comprising a source of cyclically recurring clock pulses, means for counting said recurring clock pulses, means responsive to the reception of a pulse of radar energy for applying a signal to a two input AND gate and simultaneously starting the counting of said recurring clock pulses, and means responsive to the clock pulse count reaching a predetermined value for applying a signal to the other input of said AND gate, whereby said AND gate gives an output signal if one of said pulses of radar energy coincides with said predetermined clock pulse.