Model and observation of the impact of JTIDS/MIDS on GNSS $C/N_{0}$ degradation

Global Navigation Satellite System (GNSS) L5/E5a interference environment is dominated by DME/TACAN and JTIDS/MIDS pulses causing a degradation of the effective Carrier to Noise (C/N0) observed by the receiver. This causes delay for the receiver satellite acquisition and impacts the tracking capability. As a mitigation technique, a time-domain blanker is implemented to mitigate their impact. RTCA DO-292 proposes a model to compute the (C/N0) degradation of the received useful signal by the increase of the noise power spectral density (PSD). This paper developed by ENAC and The MITRE Corporation as part of their cooperative efforts to support RTCA analyses, focus on the impact of Joint Tactical Information Distribution System/Multifunctional Information Distribution System (JTIDS/MIDS) Radio Frequency Interference (RFI) signals. Three relevant interfering scenarios are presented as well as a method to generate time-domain equivalent JTIDS/MIDS signals for interference analysis purposes. Simulated results as well as predicted results are presented for the interfering scenarios. The predicted results are calculated from an updated (C/N0) degradation formula with respect to RTCA DO-292 proposed formula. The impact of GNSS receiver Radio Frequency Front End (RFFE) filter bandwidth and blanker threshold are evaluated.