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This paper presents the features of the MONITOR project. This project initiated by ESA / ESTEC aims to increase the knowledge of the ionospheric effects and its impact on GNSS systems during active periods of solar activity. It includes the deployment of a set of GNSS-based ionospheric monitoring receivers worldwide distributed, the development of specific analysis software tools some of them integrated...
Advances in computation and signal processing technologies allow the implementation sophisticated non-linear synchronization techniques that can be integrated in the acquisition and tracking modules, estimating both Line Of Sight Signal (LOSS) and multipath (MP) echoes. Instead of using an ordinary DLL/PLL, advanced DLLs as the Multipath Estimating Delay Lock Loop (MEDLL), based on maximum likelihood...
A multipath model for the aeronautical channel, which was derived from a channel measurement campaign, has been implemented into hardware simulators. The way of implementation is described in detail and simulation results obtained with a GNSS receiver and showing the impact of multipath are presented.
One of the current limitations to evaluate the impact of a realistic multipath environment over a GNSS receiver is the high number of multipath rays that are needed to model the channel in a HW RF constellation simulator. That makes necessary the application of reduction techniques to decrease the number of channels per satellite to be simulated. The initial evaluation of two reduction techniques...
This publication explores the influence of a realistic multipath channel model to satellite navigation applications in urban environments. In this context we have discovered that there is a tradeoff between accuracy and robustness concerning the bandwidth. While narrow band signals such as GPS C/A, BOC (1,1) proved to be robust especially under shadowing situations the wideband signals lost lock very...
The further development of multipath mitigation methods for Global Navigation Satellite Systems (GNSS) depends on the knowledge of the wave propagation circumstances present in various scenarios. The modeling of the multipath propagation properties for land-mobile users play a vital role in modern GNSS receiver algorithm development. This paper proposes a model for the simulation of a vehicle traveling...
With increasing utilization of satellite mobile services capacity shortage in respectively common frequency bands (L band) is to be expected. To enhance understanding of propagation channel characteristics at higher frequency bands (Ku/Ka band) an experiment with a mobile receiver, using narrow- and wideband test signals has been carried out. An airborne test platform has allowed to consider real...
This document presents the activities related to ionospheric assessment obtained after several months of experimentation with the two Galileo experimental satellites: GIOVE-A and GIOVE-B. The performance analysis covers the majority of ionospheric aspects, from Slant Total Electron Content (TEC) and Inter-Frequency Bias (IFB) estimation up to Single Frequency Ionospheric Correction Algorithm performance,...
This paper addresses the problem of ionospheric scintillations at L and C bands. The results of a L band scintillation measurement campaign are presented. The receivers used during this campaign were located in the five regions of the globe allowing to exhibit latitudinal and longitudinal dependence. Comparison with modeling has been done concurrently. The results presented for C band scintillations...
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