# US 7,612,705 B2 · Mode S radar

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,612,705 B2
- Document ID: US7612705B2
- Status: Granted
- Kind: B2
- Application number: 12/354,924
- Filed: 2009-01-16
- Published: 2009-05-14
- Granted: 2009-11-03
- Earliest claimed: 2006-06-23
- Assignees: Kabushiki Kaisha Toshiba
- Inventors: Masami Ino
- Web page: https://patentgrep.com/patent/US7612705B2

## CPC

- G01S 13/781: {Secondary Surveillance Radar [SSR] in general}
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

## Abstract

Disclosed is a Mode S radar which specifies an aircraft by transmitting interrogations to an aircraft A equipped with a Mode S transponder, and by then receiving and decoding replies corresponding to these interrogations. In the Mode S radar, detection reports on the aircraft A are generated in a manner that: for a Mode A code necessary for generating detection reports, when identicalness between the Mode A codes obtained in a plurality of scans after the initial acquisition of the aircraft A has been found to exist, the Mode A code thus found identical is adopted without carrying out a Mode A code interrogation (UF=5) thereafter. Accordingly, the Mode S secondary surveillance capable of generating more highly reliable detection reports is achieved.

## Claims

### Claim 1

A Mode S radar which specifies an aircraft by transmitting interrogations to a Mode S transponder installed in an aircraft, by receiving replies to the interrogations, and by then decoding the contents of the received replies, the Mode S radar comprising:
acquisition means, which transmits a Mode S only all-call interrogation, and which thereby accomplishes an initial acquisition of an aircraft equipped with a Mode S transponder;
first obtainment means, which transmits UF=4 and UF=5 as Mode S selective interrogations to the Mode-S-transponder-equipped aircraft with the initial acquisition having been accomplished by the acquisition means, and which thereby obtains a Mode A code as a DF=5 reply from the Mode-S-transponder-equipped aircraft;
scan counting means, which counts the number of scans performed on the Mode-S-transponder-equipped aircraft after the initial acquisition;
second obtainment means, which transmits UF=4 and UF=5, as Mode S selective interrogations, to the Mode-S-transponder-equipped aircraft every time the number of scans counted by the scan counting means reaches a preset optimal number of scans after a Mode A code is obtained by the first obtainment means, and which thereby re-obtains a Mode A code as a new DF=5 reply from the Mode-S-transponder-equipped aircraft; and
generation means, which generates a detection report on the aircraft.

### Claim 2 (depends on 1)

The Mode S radar according to claim 1 further comprising optimal scan-number setting means, which sets, as the optimal number of scans, a value obtained by calculating the number of interrogations repeated for obtaining a Mode A code, the calculation being carried out after a roll-call period allocatable to Mode S data links is secured in accordance with a setup environment of the Mode S radar and in response to the traffic,
wherein the second obtainment means repeatedly re-obtains the Mode A code every time the preset optimal number of scans set by the optimal scan-number setting means is reached.