uAvionix has unveiled its latest offering, truSky™ ADS-B “spoofing” detection, which is being integrated into its SkyLine Uncrewed Aircraft System (UAS) Beyond Visual Line of Sight (BVLOS) services. This breakthrough feature assures both pilots and controllers that the ADS-B signal they receive from a particular aircraft is authentic and not falsified or spoofed.

ADS-B Spoofing & Validation

ADS-B spoofing is the act of deliberately altering ADS-B signals to disseminate misleading data on an aircraft’s location, speed, and identity. This disrupts the functionality of Detect and Avoid (DAA) and Air Traffic Control (ATC) systems, undermines situational awareness, and poses safety and security hazards. While ADS-B technology is a valuable DAA tool, it can be risky to depend on unverified ADS-B data. Numerous articles and reports have highlighted the dangers of ADS-B spoofing and warned pilots to exercise caution when relying on unvalidated ADS-B information for critical application.

ADS-B validation involves verifying and validating the accuracy and reliability of the data transmitted by an aircraft. This involves cross-referencing the information with other sources of air traffic data and detecting any irregularities or inconsistencies in the signals. The primary aim of ADS-B validation is to ensure the credibility of the transmitted information, allowing UAS operators and ATC to make informed decisions and ensure safe separation between aircraft.

uAvionix truSky™ Solution

uAvionix’s truSky™ validation process is an innovative solution that employs a network of low-cost, low-profile dual-frequency (1090MHz and 978MHz) ADS-B ground receivers to assess each signal transmitted by the aircraft. The system then quickly cross-references the received signals to confirm that they originated from the aircraft’s actual position. When multiple sensors are available, truSky utilizes various methods such as Doppler information, multilateral timing, and aircraft kinetics to retroactively calculate the aircraft’s position and compare it with the position data in the ADS-B transmission. This calculation produces a validation score for each aircraft, which provides the necessary confidence and safety margin for Beyond Visual Line of Sight (BVLOS) operations. This process requires a secure and tightly integrated network of receivers with precise timing capabilities, such as those provided by the uAvionix SkyLine platform.

When used within the uAvionix SkyLine platform, each aircraft track point is color-coded based on its confidence score.   In the example below, an aircraft departs Denver airport with only visibility to a single receiver (red), but quickly gets picked up by a second (yellow), then a third (green) receiver. When used with the SkyLine API, the validation score is transmitted along with the position updates of the aircraft.

Image depicting an aircraft where the flight path confidence increases with the addition of sensors able to track the aircraft
Image Credit- uAvionix

An FAA whitepaper published in 2017 titled: “White Paper: FAA position on use of ADS-B for Alerting and Guidance” concludes with the following:

“For DAA systems, the implications of this policy are as follows:  DAA Warning guidance may only be generated on ADS-B tracks that have been validated […].  DAA guidance to regain well-clear may only be generated on tracks that have been validated.  DAA Caution suggestive guidance may be generated by unvalidated ADS-B tracks.  If the DAA system is being integrated with the UAS flight control system to automate maneuvers, the guidance system may only maneuver automatically against ADS-B tracks that have been validated.”

Until truSky, validated ADS-B signals came at immense cost, requiring high-cost MLAT sensors, primary radar, or onboard Traffic Collision Avoidance Systems (TCAS) to correlate aircraft positions.

truSky is being piloted in numerous locations in the United States, and is available as a component of uAvionix’s SkyLine UAS BVLOS service or as an API for integration into UAS GCS, UTM, or ATM platforms. (Press Release)

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