The HGR receiver and its antispoofing technology is an economic solution that integrates various sources of information ensuring accuracy, sturdiness and precision that currently no other receiver can provide. The key driver for HGR application class is the ability to detect spoofing and meaconing, therefore determining the authenticity of the location-related data. The system exploits the use of three sources of information, as follows:
- The GNSS, for continuous, accurate and worldwide available timing and positioning services;
- The ADS-B, as source of a priori unknown messages in terms of content, signal characteristics (e.g. the actual bits of the message) and emission time. By design, in fact, ADS-B messages are transmitted by each airplane at random times, in order to avoid message conflicts in accessing the shared ALOHA channel at 1090 MHz (ADS-B is based on a pure ALOHA access);
- A secure synchronisation mechanism based on a communication network, to provide alternative timing through a secure channel.
The unique combination of the three elements above, or part of them when not all contemporary available, provides capabilities to detect the most likely spoofing attacks, i.e. those based on “signal retransmission” (meaconing) and even those based on “signal simulation”.