After the successful launch of Galileo satellites GSAT0226 (SVID 23) and GSAT0232 (SVID 16) carried out on September 17, 2024, the Galileo Satellite Metadata information has been updated for this new comers to the Galileo constellation.
The Galileo Satellite Metadata section, contains information on satellite properties. This information is necessary to properly implement advanced processing algorithms for precise orbit determination or Precise Point Positioning (PPP). This includes physical characteristics, the attitude law and antenna parameters, which are essential for refining satellite orbit calculations and minimizing positioning errors.
Satellite metadata plays a crucial role in high-precision GNSS applications by accounting for factors such as mass, centre of mass, antenna reference points and phase centre offsets (PCOs). These parameters help correct biases introduced by the satellite's attitude (orientation in space) and antenna phase centre variations, ensuring accuracy in signal transmission and reception. Without this information, GNSS receivers would struggle to achieve centimeters-level precision, which is critical for applications like geodesy, autonomous navigation and scientific research. Regular updates to satellite metadata, including adjustments to ANTEX files containing Phase Centre Variations (PCV), ensure that GNSS users always have access to the most accurate and up-to-date data for their positioning and navigation solutions.
The following Galileo satellite metadata information has been added for GSAT0226 and GSAT0232:
- Mass and Centre of Mass (COM);
| GSAT | Mass [Kg] | Centre of Mass | ||
| 0226 | 711.103 | 256.8 | -9.21 | 565.22 |
| 0232 | 706.384 | 261.07 | 10.35 | 565.3 |
- Antenna Reference Point (ARP);
| GSAT | ARP in Mechanical RF [mm] | ARP in ANTEX RF [mm] | ||||
| X | Y | Z | X | Y | Z | |
| 0226 | 140.00 | 0.00 | 1215.00 | 116.8 | -9.21 | 649.78 |
| 0232 | 140.00 | 0.00 | 1215.00 | 121.07 | -10.35 | 649.70 |
- Phase Centre Offsets (PCO) for E1, E5a, E6, E5b and E5 signals;
| GSAT | Signal | PCO in Mechanical RF [mm] | PCO in ANTEX RF [mm] | ||||
| X | Y | Z | X | Y | Z | ||
| 0226 | E1 | -0.8 | -2.18 | 63.39 | 0.8 | 2.18 | 63.39 |
| E5a |
-0.22 |
-1.33 | -20.42 | 0.22 | 1.33 | -20.42 | |
| E6 | -0.25 | -0.32 | 43.98 | 0.25 | 0.32 | 43.98 | |
| E5b | -0.95 | -0.27 | 22.52 | 0.95 | 0.27 | 22.52 | |
| E5 | -0.6 | -0.79 | 1 | 0.6 | 0.79 | 1 | |
| 0232 | E1 | 6.82 | -5.55 | 76.2 | -6.38 | 5.55 | 76.2 |
| E5a | 1.02 | 0.24 | -44.41 | -1.02 | -0.24 | -44.41 | |
| E6 | 0.45 | 1.11 | 30.56 | -0.45 | -1.11 | 30.56 | |
| E5b | 0.38 | 0.76 | 8.91 | -0.38 | -0.76 | 8.91 | |
| E5 | 0.69 | 0.5 | -17.78 | -0.69 | -0.5 | -17.78 | |
- Laser Retro Reflector Location.
| GSAT | LRR in Mechanical RF [mm] | LRR in ANTEX RF [mm] | ||||
| X | Y | Z | X | Y | Z | |
| 0226 | -703.00 | -27.50 | 1120.45 | 959.80 | 18.29 | 555.23 |
| 0232 | -703.00 | -27.50 | 1120.45 | 964.07 | 17.15 | 555.15 |
In addition, the ANTEX file has been updated to include Phase Centre Variation (PCV) figures for the GSAT0226 and GSAT0232 satellites. The process to generate the new ANTEX file takes several months since it requires performing complex measurements, as well as thorough post-processing and validation of the obtained data. The updated ANTEX file can be found here.
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