Interrogator-responsor system for different interrogator codes

Claim 2

In an interrogation-answer system for secondary radar with time dependently changed codes which are transmitted successively in time by an interrogation apparatus and at least one answering apparatus having means for receiving aN interrogation code and means producing and storing therein the time-dependent program of the interrogation codes to be expected from the interrogation apparatus and providing time-dependent answering codes which are related in such a predetermined manner to the interrogation codes that for each one of the interrogation codes one predetermined answer code is transmitted to the interrogation apparatus, the interrogation apparatus and the answering apparatus each having a clock connected thereto and operable to provide the same time standard for controlling the code sequence, the answering apparatus comprising means storing codes representing past, present and future time as respective past, present and future interrogation codes, means connected to said storage means for comparing the received interrogation code with the past, present and future codes to determine lead or lag of the answering apparatus time standard with respect to that of the interrogation apparatus, and means connected to said comparing means and to said clock of said answering apparatus for correcting the production of the time dependently changed codes in the answering apparatus.

Claim 3

Interrogation-answer apparatus comprising: clock means operable to provide a time standard; code means connected to said clock means and operative in response to said time standard to produce a program of first codes representing past, present and future time of interrogation codes to be received from the interrogation apparatus; first storage means connected to said code means including a plurality of first storage sections for storing respective first interrogation codes to be received; an input for receiving an interrogation code; a plurality of coincidence circuits connected to said input and to respective first storage sections and one of said coincidence circuits individually operable in response to coincidence between any one of the first codes and an interrogation code received at said input to indicate synchronism, lead or lag of the first codes relative to the received interrogation code; and correction means connected to at least some of said coincidence circuits, to said clock means and to said code means and operable to adjust the production of said first codes in response to the operation of a coincidence circuit to correct for lead or lag between a first code and the received interrogation code.

Claim 4

Interrogation-answer apparatus comprising: clock means operable to provide a time standard; code means connected to said clock means and operative in response to said time standard to produce a program of first codes representing past, present and future time of interrogation codes to be received from the interrogation apparatus; first storage means connected to said code means including a plurality of first storage sections for storing respective first interrogation codes to be received; an input for receiving an interrogation code; a plurality of coincidence circuits connected to said input and to respective first storage sections and one of said coincidence circuits individually operable in response to coincidence between any one of the first codes and an interrogation code received at said input to indicate synchronism, lead or lag of the first codes relative to the received interrogation code; and correction means connected to at least some of said coincidence circuits, to said clock means and to said code means and operable to adjust the production of said first codes in response to the operation of a coincidence circuit to correct for lead or lag between a first code and the received interrogation code.

Claim 5

Apparatus according to claim 2, wherein said code means is also operable to produce a program of second codes which bear a predetermined relationship to said first codes, and comprising second storage means connected to said code means including a plurality of second storage sections for storing said second codes; an answer output; and gating means interposed between said second storage sections and said answer output and connected to and controlled by the operation of said coincidence circuits to gate a second code to said answer output.

Claim 6

Apparatus according to claim 2, comprising an alarm apparatus controlled by a coincidence circuit which represents a large time deviation from the present time and operable to indicate such large deviation.

Claim 7

An interrogation-answer system comprising: interrogation apparatus including interrogation means for producing and transmitting interrogation codes and a first clock for driving said interrogation means; answer apparatus comprising a second clock; code means driven by said second clock to produce a program of first codes representing past, present and future time; means for receiving said interrogation codes; means for comparing the first codes with received interrogation codes to determine lead or lag of said second clock relative said first clock; and means for correcting the production of said first codes in response to the determination of a lead or lag condition.

Claim 8

An interrogation-answer system comprising: interrogation apparatus including interrogation means for producing and transmitting interrogation codes and a first clock for driving said interrogation means; answer apparatus comprising a second clock; code means driven by said second clock to produce a program of first codes representing past, present and future time; means for receiving said interrogation codes; means for comparing the first codes with received interrogation codes to determine lead or lag of said second clock relative said first clock; and means for correcting the production of said first codes in response to the determination of a lead or lag condition.

Claim 9

A system according to claim 5, wherein said comparing means comprises first storage means for storing said first codes, an interrogation input and coincidence means connected to said input and said First storage means for determining coincidence of a first code and an interrogation code.

Claim 10

A system according to claim 6, wherein said answer apparatus comprises second storage means and said code means is operable to store a plurality of second codes therein related to and corresponding as answer codes to said first codes; an answer output; and gating means interposed between said second storage means and said answer output and connected to and operated by said coincidence means for gating a second code to said answer output.

Claim 13

A method according to claim 8, further comprising the steps of producing a program of answering codes which are related in a predetermined manner with the interrogation codes, storing the answer codes, and transmitting that answer code which corresponds to that stored interrogation code which is in coincidence with the interrogation code actually received.

Claim 14

A method according to claim 8, wherein the interrogation and answer codes produced in the answer apparatus have their time sequences provided in accordance with the operating of a clock, and wherein the step of adjusting is further defined as changing the frequency of the clock.

Claim 15

Interrogation-answer apparatus comprising: clock means operable to provide a time standard; code means connected to said clock means and operative in response to said time standard to produce a program of first codes representing past, present and future time of interrogation codes to be received from the interrogation apparatus; first storage means connected to said code means including a plurality of first storage sections for storing respective first interrogation codes to be received; an input for receiving an interrogation code; a plurality of coincidence circuits connected to said input and to respective first storage sections and one of said coincidence circuits individually operable in response to coincidence between any one of the first codes and an interrogation code received at said input to indicate synchronism, lead or lag of the first codes relative to the received interrogation code; and correction means connected to at least some of said coincidence circuits, to said clock means and to said code means and operable to adjust the production of said first codes in response to the operation of a coincidence circuit to correct for lead or lag between a first code and the received interrogation code, said code means being operable to produce a program of second codes which bear a predetermined relationship to said first codes, and comprising second storage means connected to said code means including a plurality of second storage sections for storing said second code; an answer output; and gating means interposed between said second storage sections and said answer output and connected to and controlled by the operation of said coincidence circuits to gate a second code to said answer output, said first storage sections further including a storage section for each of the second past, first past, first future and second future interrogation codes expected to be received for comparison with received interrogAtion codes.

Claim 16

Interrogation-answer apparatus comprising: clock means operable to provide a time standard; code means connected to said clock means and operative in response to said time standard to produce a program of first codes representing past, present and future time of interrogation codes to be received from the interrogation apparatus; first storage means connected to said code means including a plurality of first storage sections for storing respective first interrogation codes to be received; an input for receiving an interrogation code; a plurality of coincidence circuits connected to said input and to respective first storage sections and one of said coincidence circuits individually operable in response to coincidence between any one of the first codes and an interrogation code received at said input to indicate synchronism, lead or lag of the first codes relative to the received interrogation code; and correction means connected to at least some of said coincidence circuits, to said clock means and to said code means and operable to adjust the production of said first codes in response to the operation of a coincidence circuit to correct for lead or lag between a first code and the received interrogation code, said code means being operable to produce a program of second codes which bear a predetermined relationship to said first codes, and comprising second storage means connected to said code means including a plurality of second storage sections for storing said second code; an answer output; and gating means interposed between said second storage sections and said answer output and connected to and controlled by the operation of said coincidence circuits to gate a second code to said answer output, said first storage sections further including a storage section for each of the second past, first past, first future and second future interrogation codes expected to be received for comparison with received interrogAtion codes.

Claim 17

Apparatus according to claim 11, wherein said second storage sections include a storage section for those second codes which are related as answer codes to said first past and first future interrogation codes expected to be received.