초록 ▼

A simple active/passive proximity warning system for an Own station that uses differential time of arrival values, direct time of arrival values, and differential altitude values determined from 1030 MHz interrogations from ground-based SSRs and Own station and 1090 MHz transponder replies from Othe

A simple active/passive proximity warning system for an Own station that uses differential time of arrival values, direct time of arrival values, and differential altitude values determined from 1030 MHz interrogations from ground-based SSRs and Own station and 1090 MHz transponder replies from Other stations to identify threats is disclosed. The invention combines a passive detection system and an active detection system into an integrated system that overcomes the limitations present when either type of system is used by itself. Generally speaking, the passive system identifies threats and produces a threat alert when the differential altitude value and the largest time of arrival value associated with an Other station are below predetermined values. A preferred embodiment of the active system monitors the environment for SSR density, classifies the environment into a plurality of “cases”, and automatically selects in response thereto one of a plurality of control modes. The control mode selected determines in whole or in part whether interrogations will be produced by an interrogator in the active system, and the rate at which they are produced. In one embodiment, the active system has three control modes, the first of which continuously produces sets of interrogations at a relatively low transmission rate, the second of which selectively produces a set of interrogations upon detection of a potential threat, and the third of which produces no interrogations. The integrated system includes a number of features which improve the performance and reliability of the system, minimize interference with other ATC systems, and minimize false alarms.

대표청구항 ▼

A proximity warning system for an Own station, comprising: (a) means for selectively enabling the production and transmission of interrogation messages at Own station at least in part in response to the SSR environment sensed at Own station; (b) means for producing from received interrogation messag

A proximity warning system for an Own station, comprising: (a) means for selectively enabling the production and transmission of interrogation messages at Own station at least in part in response to the SSR environment sensed at Own station; (b) means for producing from received interrogation messages transmitted by SSRs within operational range of said Own station and received reply messages transmitted by transponder-equipped Other stations in response to said SSR interrogation messages during a predetermined period following reception of each said interrogation message at Own station, a differential time of arrival value for each of said Other stations with respect to each of said SSRs; (c) means for producing from received reply messages transmitted by said Other stations in response to said interrogation messages from Own station during a predetermined period following transmission of each said interrogation message from Own station, a direct time of arrival value for each of said Other stations with respect to Own station; (d) means for selecting from among the several most recent time of arrival values produced by means (b) if any and by means (c) if any, the largest time of arrival value associated with each of said Other stations that has been substantially duplicated a predetermined number of times; and (e) means for producing a threat alert output in response to any time of arrival value selected by means (d) that is below a predetermined value.