MULTI-LAYER/BAND PROPAGATION MODELS FOR GNSS EVOLUTIONS EXPRO PLUS - RE-ISSUE

To develop a consistent set of propagation models for multi-layer/multi-frequency GNSS that will allow to carry out user performance assessments related to RF signal propagation.Description:In the recent years, there has been an increasing interest on investigating new technologies that can be used to backup or complement existing GNSS for increased reliability and performance. Among others, these initiatives include the use of satellites in other orbits (beyond traditionally used MEO) and new bands below and above current Radio Navigation Satellite Service (RNSS) allocations. The benefits for the user segment are promising (e.g. indoor penetration with longer wavelengths, higher decorrelation due to faster satellite dynamics...) but require preliminary analysis for correct system design. Among other aspects, the modelling of the signal propagation conditions is an essential part of the final user ranging error.The definition of such a model is particularly challenging due to the different range of frequencies, different dynamics andforeseen GNSS signal evolution bandwidths. In addition, the use of new frequency bands for navigation, which were traditionally dedicated to other types of services, requires an update on the characterization of propagation effects, focusing on synchronization aspects. A clear example of this is the use of millimeter wave signals which could potentially bring several benefits to Position, Navigation and Timing (PNT) users (terminal size, synergies with other systems...) but also impose some challenges such as higher propagation losses and sensitivity to obstacles. A better understanding of these new bands is essential for future system designs. While individual models for classical PNT bands and users exist with a high level of maturity, a framework to combine them in a consistent manner is missing, which limits the reliability on the estimated benefits of a multi-layer/frequency GNSS system. The activityencompasses the following tasks: - Providing a consistent software framework for the assessment of propagation effects in future GNSS including new frequency bands, beyond the current RNSS allocations and multiple types of orbit (from VLEO to GEO) in support of Signal in Space Performance assessments for PNT users.- Covering atmospheric losses using consolidated and standardised models- Covering multipath propagation and its impact on Time of Arrival estimation using a combined physicalstatistical approach for a more realistic characterisation of the local environment.- Providing interfaces to advanced hardware simulators for injection of channelrealizations for hardware receiver testing.- Submission of models to ITU-R for standardization.Procurement Policy: C(2) = A relevant participation (in terms of quality and quantity) of non-primes (incl. SMEs) is required. For additional information please go to:http://www.esa.int/About_Us/Business_with_ESA/Small_and_Medium_Sized_Enterprises/Opportunities_for_SMEs/Procurement_policy_on_fair_access_for_SMEs_-_the_C1-C4_Clauses