Kabushiki Kaisha Toshiba

Yoshinori Kuji

Yoshirou Aoki

Hisashi Ootomo

Takafumi Yamada

Takafumi Takeda

A transmittertransmits interrogations to aircraft airborne in a coverage, a receiverreceives signals transmitted from aircraft airborne in the coverage, reply analyzersandanalyze a reply responding to an interrogation transmitted from the transmitter, as the reply is detected from signals received by the receiver, and a squitter analyzeranalyzes an extended squitter, as the extended squitter is detected from the signals received by the receiver.

Secondary surveillance radar

It is related to a mode S secondary surveillance radar system for carrying out a target (aircraft) surveillance with a high reliability, where a surveillance processorproduces a detection report of a acquisition surveillance by a scan of an antenna thereafter by adopting the mode A code information with coinciding code data among mode A code information acquired by scans of a plurality of times. In this way, the efficient utilization of RF channels during the roll-call period can be maintained while improving the reliability of a target detection report.

Mode S secondary surveillance radar system

A secondary surveillance radar system comprising a including a ground system which observes an observation area where an aircraft equipped with a mode S transponder and an aircraft equipped with an ATCRBS transponder possibly coexist, wherein the ground system comprises includes a transmit processor which transmits to the observation area an all-call interrogation signal specific for mode S including an identification code of the ground system, a receive processor which receives a reply signal to the interrogation signal transmitted by the transmit processor, and a recognition processor which recognizes the reply signal as a processing target when identification information included in the reply signal received by the receive processor coincides with the identification code of the ground system, and wherein the recognition processor recognizes the reply signal as the processing target also when the identification information included in the reply signal received by the receive processor coincides with null information.

Secondary surveillance radar system, and ground system for use therein

There are provided a differential processing unit which performs differential processing for a Mode S transponder transmission signal, an auto correlation arithmetic operation unit which performs an arithmetic operation of a degree of auto correlation between an increasing change rate and decreasing change rate of a power level in the signal which has been subjected to the differential processing, a pulse regeneration unit which regenerates a pulse based on the degree of auto correlation, which has been obtained by the auto correlation arithmetic operation processing, a pulse phase locked loop unit which performs gate processing and phase locked processing for the regenerated pulse, and a pulse decoding unit which decodes the Mode S transponder transmission signal based on the pulse which has been subjected to the gate processing and the phase locked processing.

Mode S transponder transmission signal decoder and mode S transponder transmission signal decoding method

An interrogation transmission method of a secondary surveillance radar compares prediction angle ranges for transmitting interrogations with a beam-width of an antenna, and transmits the interrogations at every roll-call period if the prediction angle ranges for transmitting interrogations are narrower than the beam-width of the antenna. In contrast, if the prediction angle ranges for transmitting the interrogations are wider than the beam-width of the antenna, the radar respectively sets a period to transmit the interrogations and a period not to transmit the interrogations until responses can be received, and transmits interrogations at every roll-call period after the responses can be received (even if a receiving error or downlink occurs).

Secondary surveillance radar and its interrogation transmission method

Mode S transponder transmission signal decoder and Mode S transponder transmission signal decoding method

A secondary surveillance radar system for use in surveillance of an airspace, which reliably achieves surveillance of the airspace even when an aircraft including a mode S transponder and an aircraft including an ATCRBS transponder are both located in the airspace, wherein both of a time interval between time when transmission of an all-call interrogation signal specific for mode S is completed and time when the transmission of an all-call interrogation signal specific for mode A is started and a time interval between time when transmission of the all-call interrogation signal specific for mode S is completed and time when transmission of an all-call interrogation signal specific for mode C is started is varied in units of one all-call time period.

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Yokohama, Japan

Yoshinori Kuji