Aircraft tracking

BDARS Mt Cotton ADS-B Receiver station

On behalf of BDARS, David VK4ZF has kindly put together this receiving station for the Mt Cotton Facility.

About the station

Not long ago this required specialist expensive equipment and a lot of work to receive the data. Fortunately, today we can use an inexpensive software defined radio (SDR), a small single board computer and a simple home-made antenna. Once we have the processed data it is sent over the internet without any intervention on our behalf. It sounds easy but we must remember the RF side of this is at 1090 MHz

The heart of the station consists of a very low low cost RTL-SDR Dongle. This software defined radio is based on the popular RTL2832U integrated circuit wideband receiver, but has several additional features which improve performance and make it more ham friendly.

You will note that there are actually dual receivers, this is to supply the feed to two different networks.

What is ADS-B?

ADS-B is an acronym for Automatic Dependent Surveillance Broadcast. Its a beaconing system carried by most aircraft. The aircraft transmits its identity, position, altitude velocity etc at regular intervals, typically twice per second.

The frequency most often used is 1090MHz and the modulation method is pulse position modulation with error detection.

The data is encapsulated in ADS-B mode S encoding which uses a pulse sequence that consists of a control field followed by a 24 bit aircraft address, a 56 bit message and a parity block.

To see a real-time map of the aircraft being received by the BDARS ADS-B receiver station located at Mt Cotton please click here.

Most people will be familiar with Flight Radar 24. This website can be used on computers and portable hand-held devices. The display shows the position of all ADSB equipped aircraft in a selected location. This is not the only website that performs this function as there are several others and free programs that can be downloaded.