Gianluca Marucco

Performance analysis of MBOC, AltBOC and BOC modulations in terms of multipath effects on the carrier tracking loop within GNSS receivers

The objective of the work is the evaluation of the impact of new modulation strategies foreseen for the galileo signal in space (SIS) on the carrier tracking operation within the global navigation satellite systems (GNSS) receiver (namely frequency locked loop (FLL)/phase locked loop (PLL)) in presence of multipath. Although multipath has more relevant effects in term of measurement errors on the code tracking, its consequences on the carrier tracking can not be neglected in high accuracy applications that rely on the carrier phase measurement such as, for example, real time kinematics (RTK) survey. Particular attention is addressed to the multiplexed binary offset carrier (MBOC) signals and the alternate BOC (AltBOC) signals. The investigation is conducted considering a two ray model with the aim of producing an error diagram showing the multipath effect in the carrier tracking: the delay locked loop (DLL) PLL interaction is considered in a static - low dynamic environment. Closed loop simulations are conducted by means of specific software tools based on the GNSS fully software receiver developed by the NavSAS group. Performance verification is done for a noisy environment. Results show loops performance in a multipath affected environment and the effects of noise in the carrier tracking operations. The PLL performance evaluation under multipath conditions, considering as input MBOC and AltBOC modulated signals, is important to understand the behavior of the new modulations especially in case of carrier tracking based applications that are the more demanding in terms of final positioning performance (i.e. geodetic applications).

Statistical analysis of different low cost GPS receivers for indoor and outdoor positioning

The greater part of modern low-cost GNSS receivers are able to guarantee a fair positioning performance almost everywhere: difficult environments as indoor and urban canyons are also considered. The aim of this work is to investigate the effective potentialities of this kind of receivers, in particular in static and kinematic positioning using post-processing techniques. The high number of GPS permanent stations and the continuous increase of the number of GNSS multi-constellation permanent stations, will give a good opportunity to improve accuracy and precision levels.

Loose and Tight GNSS/INS Integrations: Comparison of Performance Assessed in Real Urban Scenarios

Global Navigation Satellite Systems (GNSSs) remain the principal mean of positioning in many applications and systems, but in several types of environment, the performance of standalone receivers is degraded. Although many works show the benefits of the integration between GNSS and Inertial Navigation Systems (INSs), tightly-coupled architectures are mainly implemented in professional devices and are based on high-grade Inertial Measurement Units (IMUs). This paper investigates the performance improvements enabled by the tight integration, using low-cost sensors and a mass-market GNSS receiver. Performance is assessed through a series of tests carried out in real urban scenarios and is compared against commercial modules, operating in standalone mode or featuring loosely-coupled integrations. The paper describes the developed tight-integration algorithms with a terse mathematical model and assesses their efficacy from a practical perspective.

An innovative augmentation middleware for professional applications

The present paper describes an innovative system providing augmentation services following the cloud computing paradigm. Thanks to its flexibility it enables a large number of users to access to enhanced WADGPS functionalities in the navigation domain. Such platform, called augmentation module, relying on EGNOS and EDAS, has been originally conceived to make available integrity services to existent systems through an easy integration that avoid complete redesign of existing services. Such system for the remote Protection Levels computation has been successfully adapted and exploited in two projects funded by European Commission (GOLDEN-ICE and SAFE-PORT). Example of tests and results achieved by means of Augmentation Module will be reported at the end of the paper.

The SafePort project: Concepts and results of trials

The paper presents the SafePort project. The aim of the project is the realization of a system close to the market able to provide a safe and efficient control of the transit of all vessels in a port from the port entrance to their berths and out again using the European Geostationary Navigation Overlay Service (EGNOS) Safety of Life (SoL) information. After the description of the basic concepts the system wants to leverage on, an overview of all the modules is provided. The paper is focused on the implementation and tests of the Portable Pilot Unit called SafePilot which exploits EGNOS SoL feature in order to provide to the whole system a reliable information about vessel positioning. Test results for the validation of the SafePilot concept are shown.