EGNOS/ESTB monitor station at Budapest

About EGNOS/ESTB   |    Monitor station at Budapest    |    EGNOS/ESTB Performance    |    Program for SkyPlot drawing    |
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About EGNOS/ESTB

EGNOS provide the information needed to use navigational signals from GPS and GLONASS satellites for such safety critical applications. It will improve the accuracy of positions from about 20 m to 5 m, inform users of the errors in position measurements and warn of disruption to a satellite signal within six seconds.

EGNOS is being developed by the European Space Agency in co-operation with the European Union and Eurocontrol. The system provides additional signals to users of satellite navigation services, broadcast through geostationary satellites guaranteeing the integrity of GPS so that it can be used in support of safety-of-life services such as civil aviation.

For more details regarding how the system works, please visit for example the ESA's homepage.

Before EGNOS becomes fully operational in 2004, users equipped with an EGNOS receiver can tune in to a test signal broadcast by one of the EGNOS satellites. The EGNOS System Testbed (ESTB is a complete prototype of the EGNOS system. It implements the main functions (ranging, GPS differential corrections and integrity) with real time elements enabling different user experiments or tests. Of course, the ESTB functions complexity and performances are reduced to an order of magnitude from the EGNOS system, principally concerning the availability, the robustness and redundant facilities.

Monitor station at Budapest

For monitoring the EGNOS/ESTB performance, Eurocontrol established a standardised data collection network for 2002. Stations are mainly operated by Universities: Delft, Barcelona, Toulouse, Lisbon, Sofia.

In the frame of the Eastern and Southern European region Extension of the EGNOS/ESTB data collection and evaluation project within Eurocontrol's GNSS programme, a new station has been set up at Budapest University of Technology and Economics (BUTE). The station is operated by the Department of Geodesy and Surveying in cooperation with Integricom of the Netherlands. The Department has been operating a permanent GPS station since 2000 as a part of the Hungarian Permanent GPS Network.

The monitor station for the EGNOS/ESTB project consists of:

1. a dual frequency GPS receiver (NovAtel OEM3),

2. a dual frequency GPS antenna (GPS-600),

3. a computer for data logging and processing,

4. permanent station softwares (SLOG, Pegasus).

The antenna is located close to the Trimble permanent antenna at the roof on an unused chimney. Its precise position was determined in ETRS89 system by using standard GPS positioning methods from geodesy within a few centimetre accuracy. The position of the antenna phase center is:

A key part of the station is the SLOG software, which controls the receiver and stores the data locally . The data is further processed using PEGASUS software, a dedicated EGNOS/ESTB analysis tool that has been developed within Eurocontrol. The permanent data logging started in November 14, 2003. After the EGNOS system started to broadcast the EGNOS, not ESTB data have been collected. All data are postprocessed using Pegasus software.

EGNOS/ESTB Performance

Illustrating the ESTB performance the results of a 24 hour data sets (29th January, 2004) are presented below. Performance is characterised with accuracy, integrity (protection levels) and availability.

The following figures represent the position error of the navigation solution with respect to the precisely surveyed antenna location.

The following figures (called Standford plots) represent the availability information. The system is available when it is operating within its specifications for accuracy, integrity (protection levels) and continuity. The results here are presented in the horizontal (APV-II and CAT-I) and vertical (CAT-I) dimensions.

Program for SkyPlot drawing

This software aims to develop a user-friendly interface that will simplify the interaction of the user with the vast amount of GNSS data that is continuously received by the GPS/SBAS NovAtel and Septentrio receivers. The program reads the raw data files, and visualize signal strength values on a convenient skyplot diagramm.

For a comparison of some stations' performance in the Eurocontrol's network (or let's say for some examples), please click here. Please find here a more detailed description how to use the program. With comments and bugs please contact the author. Finally you might download executables.

Download

Here you can download the raw binary data recorded in hourly loop at the station. Please note that only data from the last 8 weeks are available, for older data please contact the station manager. Data are in NovAtel OEM3 binary format, for an ascii or RINEX conversion please visit NovAtel's support. Futhermore you might download the reports generated each day about the performance of EGNOS experienced at the station on the previous day. The reports are generated by Pegasus and are in pdf.

Please find below some information about the files recorded recently:

• here you might check the file from the previous hour: status of the last data file
• here you might check all files since 04/11/2006. "o" means that the file was automatically uploaded, "-" means that the file is missing (in case of a power failure for example), finally "m" means that file was manually uploaded (in case of a network problem): status of all data files

prepared by Bence Takács, last update: 2007.12.06.