Galileo Receivers

GALILEO
Title	Galileo Receivers
Author(s)	GMV
Level	Basic
Year of Publication	2011

The Galileo System will be an independent, global, European-controlled, satellite-based navigation system and will provide a number of guaranteed services to users equipped with Galileo-compatible receivers.

Basic elements of a generic GNSS Receiver are an antenna with pre-amplification, an L-band radio frequency section, a microprocessor, an intermediate-precision oscillator, a feeding source, some memory for data storage, and an interface with the user. The calculated position is referred to the antenna phase centre.

Galileo receivers

The Galileo global navigation satellite system will employ many new methods and technologies to offer superior performance and reliability. Development of the advanced receivers required to make use of the system is continuing..

Three receiver development activities have been initiated within the Galileo programme, addressing the different needs of the system development process and covering the range of signals and services that will be offered.

Activities in receiver development are in the following areas:

• test user segment;
• receivers for the signals transmitted by the first, experimental satellites;
• receivers for the Galileo receiver chain.

Test user segment

The test user segment is being used for system validation and signal experimentation. Two parallel developments have been performed, with the aim of securing equipment availability and achieving the highest confidence in the results. The test user segment consists of: a test user receiver for the open, commercial and safety-of-life services a test user receiver for the public, regulated service search and rescue test beacon equipment test support tools, such as a simulator for the satellite constellation The receivers are based on a highly flexible software-defined concept implementing 14 different receiver configurations. They are able to emulate different receiver classes and provide a variety of internal measurements when combined with an analysis sub-system running on an attached laptop computer.

Experimental satellite receivers

These receivers are being used to receive the signals that are transmitted by the first, experimental satellite. They serve both as reference receivers for Galileo sensor stations and as experimental receivers for field tests.

Galileo receiver chain

Galileo sensor stations will be equipped with high-performance, ultra-reliable receivers. The stations provide measurement data to the Galileo system central processing facilities for establishing system integrity and performing satellite orbit determination and time synchronisation.

First achievements

The objectives of the initial part of the design phase for the test user segment have been fully achieved. A prototype receiver has been constructed, which is capable of receiving all Galileo signal components on all carriers defined in the current specification. The feasibility of acquiring and tracking the new Galileo signals has been proven.

Prototype receivers have also been used for verification of the payloads on the experimental satellites, GIOVE-A and GIOVE-B. They are also being used for validation of the satellite constellation simulator, which emulates the signals as generated by the satellites and modified by environmental effects (due to atmospheric effects, multi-path reception and interference), resulting in a signal that a user receiver would see on the ground.

The Interface Control Document (ICD) for Galileo is available on the European Commission website, so receiver manufacturers can already work to prepare the acquisition of real Galileo data.