ADS-B transponder system and method
An ADS-B transponder system is associated with a vehicle including a transponder. The system includes a universal access transceiver (UAT) subsystem configured for detecting and responding to an interrogation signal by broadcasting a signal representing a vehicle parameter. The interrogation signal can be detected by monitoring current fluctuations in a power bus on the vehicle. The UAT subsystem is connected to a smart antenna configured for transmitting and receiving ADS-B signals. In an aircraft (A/C) application the vehicle parameter can comprise squawk code, altitude, heading vector, airspeed and other flight data.
1. An Automatic Dependent Surveillance-Broadcast (ADS-B) system for a vehicle including a transponder transmitting on a first radio frequency (RF1), which system comprises:
a universal access transceiver (UAT) subsystem associated with the vehicle and including a programmable device configured for transmitting an output corresponding to a vehicle parameter on a second radio frequency (RF2);
an antenna associated with the vehicle and connected to said UAT subsystem;
said antenna comprising a smart antenna configured for transmitting said vehicle parameter and receiving signals from another vehicle equipped with ADS-B and from an air traffic control (ATC) station;
said ATC station transmits an interrogation code on a third frequency (RF3);
said transponder responds to said interrogation code with a squawk code assigned to said vehicle;
said UAT subsystem programmed for transmitting via said antenna on RF2 a vehicle parameter associated with an ADS-B requirement;
said vehicle includes a power source;
said UAT subsystem utilizes conducted emissions from said power source to detect interrogation code signals and activate said UAT subsystem in response;
an ADS-B Out component connected to said UAT and configured for transmitting said vehicle parameter; and
an ADS-B In component connected to said UAT and configured for receiving vehicle parameters transmitted from another vehicle.
2. The system according to claim 1 wherein said interrogation codes are transmitted by secondary surveillance radar equipment associated with a respective ATC station.
3. The system according to claim 1 , which includes:
a power bus connected to said power source and configured for distributing electrical power therefrom;
a monitor located in proximity to said power bus and configured for monitoring power fluctuations therein; and
said UAT subsystem activating in response to said power fluctuations.
4. The system according to claim 1 , which includes:
a coil associated with said smart antenna and said vehicle transponder; and
said coil configured for providing a current representative of a conducted emission in a power line connecting the smart antenna and the transponder.
5. The system according to claim 1 wherein said smart antenna includes first and second internal transformers and provides an output activating said UAT subsystem in response to current flow in said smart antenna transformers.
6. The system according claim 1 , which includes a fleet of multiple vehicles each including:
an ADS-B Out component transmitting a vehicle parameter; and
an ADS-B In component receiving vehicle parameters transmitted from another vehicle.