Method for reducing transmit power for traffic alert and collision avoidance systems and airborne collision avoidance systems
US6483453B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2001 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Aug 29, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/933
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a method for efficient use of the transmit power of a Traffic Alert Collision Avoidance System (TCAS) that allows enhanced surveillance range and limits radio frequency (RF) interference in crowded airspace. The method reduces power density in crowded airspace by modifying Mode S, Mode A and Mode C interrogations. During Mode S broadcasts, tracking interrogation power is reduced as a function of range. Further transmit power reduction is achieved by broadcasting a variable power density whisper-shout interrogation technique for Mode A/C aircraft when garbling is detected. If garbling is observed during a medium whisper-shout interrogation sequence, the method of the present invention attempts to clear the garbling by using focused high-density whisper-shout steps but only in the ranges where garbling was detected. Formation members can account for other formation members that are TCAS equipped using a special E-TCAS Broadcast Interrogation. The presence of other E-TCAS will be used in the RF interference limiting calculations. Aircraft flying in formation further minimize broadcast power by sharing information between the formation leader and formatio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.