Raymarine RAYSTAR 120, Owner'S Handbook Manual, Page: 7 / 26

Chapter 1: Introduction 1-1
Chapter 1: Introduction
1.1 Satellite Differential System
The Raystar 120 Satellite Differential GPS Receiver utilizes a new
satellite differential system to improve the accuracy, integrity and
availability of the basic GPS signals, resulting in satellite differential
corrections and enhanced positional accuracy over standard GPS
receivers. Three separate compatible systems currently exist or are
being developed:
1. Wide Area Augmentation System (WAAS). Developed by the
Federal Aviation Administration (FAA).
2. European Geostationary Navigation Overlay System
(EGNOS). This system is being developed by a European con-
sortium.
3. The MTSAT Satellite-Based Augmentation System (MSAS).
This is being developed by the Japan Civil Aviation Bureau
(JCAB) for civil aviation use.
The area coverage of the WAAS system is the furthest advanced so
far and includes the entire United States of America but also covers
large areas outside of this as shown in Figure 1-1 .
Figure 1-1: WAAS Coverage Map
D4910-1
0˚
5˚N
0˚N
5˚N
0˚N
5˚N
5˚S
0˚ 15˚W 30˚W 45˚W 60˚W 90˚W 75˚W 105˚W 120˚W 135˚W 150˚W 165˚W 15˚E 135˚E 150˚E 165˚E 180˚
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