There wasn't a protocol good enough for us, so we made our own.
The PilotAware protocol (P3i) has now become a highly recognised frequency in general aviation due to its highly efficient and modern modulation technique, high bandwidth and low power consumption. The frequency PilotAware has adopted is 869.525Mhz, this is recognised by the European Telecommunications Standards Institute meaning that it can be in all European countries and other ETSI member states.
Currently, the P3i eco-system is integrated into airborne, and ground-based transceivers (ATOM Stations) creating a bespoke network capable of satisfying the requirements for future airspace.
PilotAware -> PilotAware
All PilotAware equipped aircraft, transmit and receive on the P3i protocol. Currently, the data transmitted from a PilotAware unit is.
- GPS Location: Knowing the GPS position of an aircraft allows navigation applications and displays to accurately plot 3D aircraft positions, and provide audible alerts to the pilot.
- GPS Altitude (Calibrated to 1013.25mbar). Because all PilotAware devices use the same altitude algorithm, the relative altitudes of local PilotAware equipped aircraft are displayed through the use of moving maps and voice alerts.
- Aircraft identification though the ICAO 24 bit aircraft address. PilotAware can be configured to transmit the aircraft identification code or Hex-ID and is designed to be easily changeable through profiles.
- Group-ID: Created for clubs and schools, Group-ID highlights the aircraft of fellow group members. The registration of group member will be prefixed and suffixed with a #. I.e. #G-ERTI#
It's key to understand that additions to the protocol are made through software updates, and not by hardware upgrades.
ATOM Station -> PilotAware
The purpose of the ATOM station is to uplink further traffic information to PilotAware equipped aircraft. The stations are equipped with a P3i radio and are designed to give a line of sight range of 50km per station.
The data uplinked to PilotAware units consist of:
- FLARM Locations: The FLARM protocol based around the 868.6 MHz frequency, this limits the broadcasting power to 25mW and duty cycle to 1%. FLARM also encrypts the protocol, making it a proprietary system. PilotAware has overcome these obstacles with the ATOM station. Each Station is equipped with a receiver tuned to 868.6MHz, this receiver is capable of detecting FLARM equipped aircraft ~100km away. The received FLARM packets, are decrypted by ATOM's onboard processor using the OGN's decryption algorithm and is converted into a P3i packet. This P3i packet is then broadcast from the ATOM station to PilotAware equipped aircraft. This entire re-broadcasting process only takes 25 milliseconds and is replicated every 1.5 seconds, ensuring that aircraft positions are regular and accurate.
- Mode-S/3D is a tehnique unique to PilotAware that reboradcasts the location of Mode-S traffic using multilateration of its position. Using the multilateration technique, the locations of Mode-S equipped aircraft can be calculated through precise timing methods. Once the Mode-S locations are calculated, they are sent to the ATOM stations where they are then broadcast up to PilotAware equipped aircraft.
- METARS: This data is collected by NOAA National Oceanic and Atmospheric Administration. It records the weather at major airports and updates every 5 minutes. This data is broadcast up to PilotAware equipped aircraft, where it can then be processed by GDL90 compatible navigation applications. It will also be made available on the PilotAware Radar Screen after the upcoming software update. Learn More
But PilotAware is just getting started
Additions and changes to the P3i protocol are being made every day to ensure the quality, integrity and security of the data.