Overview
In the modern world, the aircraft is a common way of transportation. With thousands of flights every day, of course, the need for tracking planes, monitoring their position and health status arises.
At the moment, most airplanes are only tracked in densely populated areas. The main goal of the experiment is to show, which advantages an aircraft-based ADS-B surveillance system could have, using a stratospheric balloon for demonstration and evaluation.
One experiment goal is not to resort to using pre-built electronics, but instead develop, verify and produce the different parts of the experiment ourselves.

ADS-B (Automatic Dependent Surveillance Broadcast) is an automatic communication system used by many airplanes. Those planes transmit information, such as flight number, type of airplane, altitude, speed, direction and position about once per second
The receiver will listen to these transmissions, decoding position reports and log them on-board as well as downlink them to the ground station. There the data will be plotted by user interface software for a quick look analysis and be saved for careful interpretation afterwards.

Concept
The main objective of our experiment is to develop an embedded system, suitable for the
given task of receiving ADS-B signals. In addition to building a working system, the focus will be on testing, validation and comparison with existing devices for that purpose. The development process includes tests and parametrisation of an ADS-B receiver, making improvements on an existing design where possible. We will also estimate the possible distance of planes to be monitored using this technology and the corresponding data rate for such a large radio horizon.

The payload will consist of an antenna connected to a RF receiver and demodulator, an FPGA decoder and an ARM SoC running Linux. The received and demodulated (ADS-B downlink at 1.1 Mbit/s) are processed by an FPGA, decoding the data in real time and are then transmitted to the main processor to be logged and transferred to ground support.