Threat Model Design for new GNSS signals

Abstract : This paper proposes threat models (TM) for Galileo E1C, the pilot component of the E1 Open Service signal, (CBOC(6,1,111⁄) modulation) and Galileo E5a (BPSK(10) modulation) signals, as they are the Galileo signals that will be used by civil aviation airborne receivers for pseudorange computation. The advent of new GNSS signals requests new definitions for prospective signal distortions. Indeed, new signals and/or new tracking methods change the conception of hazardous signal distortion. The problem was already studied in [1] and [2] but the idea was more about replicating the GPS L1 C/A TM on new signals and on new correlation functions. The justification of using such models with the same Threat Space as GPS L1 C/A was not tackled. TMs provided in this report are based on the GPS L1 C/A TM established by ICAO (International Civil Aviation Organisation) [3]. The primary aim of such a TM is to look at the entire class of signal anomalies which could lead to important differential pseudo-range error (also called Evil Waveform (EWF)).