Satellite Based Augmentation System (Sbas); Quartz Lock Loop; File System - Topcon B111 Hardware Integration Manual

Satellite Based Augmentation System (SBAS)

SBAS is designed to improve the accuracy and availability of, as well as ensure the integrity of, information
broadcast from GPS satellites. It works by providing a net of ground stations that receive GPS signals,
generating correction messages and uploading them to geostationary satellites. These correction messages are
then broadcast to a GPS receiver using the GPS L1 frequency. The receiver applies these messages to correct
for various errors that affect the measurements. In addition, the geostationary satellites can be used for
positioning as ordinary GPS satellites, improving system availability.
The B111 supports the following SBAS services:
•
The Wide Area Augmentation System (WAAS) – developed and operated by the Federal Aviation
Administration (FAA) in the United States. WAAS uses two geostationary satellites, Galaxy 15 (PRN 135) and
Anik F1R (PRN 138) to broadcast correction messages over the majority of the continental U.S. and large parts
of Canada, Alaska, and Mexico. The system is fully operational and delivers submeter position accuracy
provided all WAAS corrections for at least four GPS satellites are available.
•
The European Geostationary Navigation Overlay Service (EGNOS) – developed and operated by the European
Space Agency (ESA), the European Commission (EC), Eurocontrol, and the European Organization for the
Safety of Air Navigation. EGNOS uses three geostationary satellites—AOR-E (PRN 120), ARTEMIS (PRN 124),
and IOR-W (PRN 126)—to broadcast correction messages. Starting with 2 March 2011, EGNOS is fully
operational and delivers submeter position accuracy using Open and Safety-of-Life services.
•
The Multi-functional Satellite Augmentation System (MSAS) – developed and operated by the Japan Civil
Aviation Bureau (JCAB) for civil Aviation and Meteorological Agency. MSAS uses two geostationary satellites,
MTSAT-1R (PRN 129) and MTSAT-2 (PRN 137), to broadcast correction messages.
Further Reading:
•
Official information on WAAS at the GPS.gov website (www.gps.gov).
•
Official information on EGNOS at the ESA website
(http://www.esa.int/Our_Activities/Navigation/The_present_-_EGNOS/What_is_EGNOS).
•
Official information on MSAS at the Japan Meteorological Agency website 
(http://www.jma.go.jp/jma/jma-eng/satellite/index.html).
•
Details on how to configure the B111 for SBAS using GRIL commands in the

Quartz Lock Loop

GNSS receivers are often deployed in high-vibration environment such as machine control and construction
equipment. In these severe environmental conditions, shock and vibration can cause significant frequency shifts
in the receiver's quartz crystal. Such large frequency excursions degrade the receiver performance, leading to
difficulties in maintaining continuous tracking of the satellite signals.
Topcon's Quartz Lock Loop (QLL) technology minimizes the vibration-induced impact through permanent
monitoring, detection, and isolation of the frequency deviations thus improving survivability and performance
of the B111 in dynamic applications.
Further Reading:
Details on how to enable QLL in the

File System

The B111 board records TPS data to a storage medium with a file system in which files and folders are organized
in a hierarchical structure for storage and retrieval. As a storage medium, the B111 supports
A storage medium must be formatted to a Topcon file system. The capacity of a storage medium is limited to 
32 GB. You can record TPS data to up to a maximum of 2 simultaneous files at the rates shown in Table 16.
Table 16. Recording Rates vs Number of
Simultaneous Files
Recording Rate, Hz
Simultaneous Files
Firmware Features
GRIL Reference Manual.
20 10
1 ≤2
P/N: 1018409-01
GRIL Reference Manual.
SD/SDHC cards.
17