MGEX
Galileo

This page provides an overview of the Satellites in the Galileo Constellation. Technical parameters of the indivdual satellites and related conventions applied within the MGEX project are summarized in the Spacecraft Characteristics section. Furthermore, a list of Events of interest for the Galileo data processing is given. Information on the GIOVE satellites is given on a separate page.

Satellites

Common Name
SVN
Int. Sat. ID
NORAD ID
PRN
Notes
IOV-1, Galileo PFM E101 2011-060A 37846 E11 Slot B05
IOV-2, Galileo FM2 E102 2011-060B 37847 E12 Slot B06
IOV-3, Galileo FM3 E103 2012-055A 38857 E19 Slot C04
IOV-4, Galileo FM4 E104 2012-055B 38858 E20 Slot C05
FOC-1 E201 2014-050A 40128 E18 Orbit injection failure (i=49.7° e=0.23)
FOC-2 E202 2014-050B 40129 E14 Orbit injection failure (i=49.7° e=0.23)
FOC-3 E203 2015-017A 40544 E26 Slot B08
FOC-4 E204 2015-017B 40545 E22 Slot B03
FOC-5 E205 2015-045A 40889 E24 Slot A08
FOC-6 E206 2015-045B 40890 E30 Slot A05
FOC-8 E208 2015-079B 41174 E08 Slot C07
FOC-9 E209 2015-079A 41175 E09 Slot C02
FOC-10 E210 2016-030B 41550 E01 Slot A02
FOC-11 E211 2016-030A 41549 E02 Slot A06
FOC-7 E207 2016-069A 41859 E07 Slot C06
FOC-12 E212 2016-069B 41860 E03 Slot C08
FOC-13 E213 2016-069C 41861 E04 Slot C03
FOC-14 E214 2016-069D 41862 E05 Slot C01
Spacecraft Characteristics

Metadata for Galileo IOV and FOC satellites including attitude law, mass, center of mass, satellite antenna PCOs and PCVs, geometry and optical properties, as well as satellite group delays are provided by the European GNSS Service Center. Additional information on the FOC satellites is given in the OHB Galileo Space Segment Brochure.

Parameter
IOV
FOC
Launch mass 700 kg 733 kg
Dry mass n/a n/a
Body size 2.61 m x 1.15 m x 1.15 m 2.53 m x 1.20 m x 1.10 m
Solar array size 2 x 2 x 2.5 m x 1.1 m 2 x 2 x 2.5 m x 1.1 m
Span width 14.5 m 14.7 m
Cross section n/a n/a
SRP acceleration 113 nm/s2 107 nm/s2 (FOC-1/2)
114 nm/s2 (others)

The Galileo-IOV/FOC spacecraft are equipped with broadband GNSS antennas for the E1, E5ab and E6 frequency bands and with a laser retroreflector array (LRA) for satellite laser ranging.

IOV
FOC

Fig. 1 Spacecraft reference system and sensor location for the Galileo IOV (left), and Galileo FOC (right) satellites. Blue arrows and labels indicate the reference system adopted by the IGS, while the manufacturer-specific systems are illustrated in red. During nominal yaw-steering, the Sun is always confined to the +xIGS-hemisphere. Reproduced from DOI 10.1016/j.asr.2015.06.019 with permission of Elsevier; satellite images courtesy ESA.

Phase center coordinates of the GNSS antenna and the LRA of the Galileo-IOV/FOC satellites as recommended for use within the MGEX project are provided in the following table. A machine-readable version of the phase center offset information for each satellite is provided as part of the IGS14 ANTEX product. All values refer to the IGS-specific spacecraft coordinate system illustrated in blue in Fig. 1. The spacecraft coordinate system is aligned with the main body axes and originates near the anti-Earth panel. By convention of the IGS
  • the +zIGS-axis is oriented along the boresight direction of the antenna,
  • the yIGS-axis is parallel to the rotation axis of the solar panels and the positive yIGS-direction is defined through the adopted +xIGS-direction,
  • the +xIGS-axis completes a right handed system and is chosen such that the Sun is always located in the +xIGS hemisphere during nominal yaw-steering.
The detailed orientation of the +xIGS and +yIGS-axes for individual satellites is defined as shown in the drawings.

IOV
 
Coordinates (w.r.t. origin)
Coordinates (w.r.t. CoM)
Reference
xIGS yIGS zIGS xIGS yIGS zIGS
GNSS Antenna (since week 1915)
all
E1       -170.0 mm +30.0 mm +950.0 mm [4]
E5a/b/ab       -170.0 mm +30.0 mm +950.0 mm [4]
E6       -170.0 mm +30.0 mm +950.0 mm [4]
GNSS Antenna (before week 1915) all E1       -200.0 mm 0.0 mm +600.0 mm
E5a/b/ab       -200.0 mm 0.0 mm +600.0 mm
E6       -200.0 mm 0.0 mm +600.0 mm
LRA IOV-1 -2298.0 mm -595.0 mm +1174.0 mm -1092.2 mm +34.0 mm +620.6 mm [2],[3]
IOV-2 -2298.0 mm -595.0 mm +1174.0 mm -1092.7 mm +33.8 mm +622.6 mm [2],[3]
IOV-3 -2298.0 mm -595.0 mm +1174.0 mm -1092.7 mm +34.6 mm +621.2 mm [2],[3]
IOV-4 -2298.0 mm -595.0 mm +1174.0 mm -1092.7 mm +34.0 mm +622.5 mm [2],[3]
CoM (Nov. 2014) IOV-1 -1205.8 mm -629.0 mm +553.4 mm       [3]
IOV-2 -1205.3 mm -628.8 mm +551.4 mm       [3]
IOV-3 -1205.3 mm -629.6 mm +552.8 mm       [3]
IOV-4 -1205.3 mm -629.0 mm +551.5 mm       [3]

FOC
  Coordinates (w.r.t. origin) Coordinates (w.r.t. CoM) Reference
xIGS yIGS zIGS xIGS yIGS zIGS
GNSS Antenna (since week 1915)
FOC-1,2
E1       +160.0 mm -10.0 mm +1050.0 mm [4]
E5a/b/ab       +160.0 mm -10.0 mm +1050.0 mm [4]
E6       +160.0 mm -10.0 mm +1050.0 mm [4]
others E1       +120.0 mm -10.0 mm +1100.0 mm [4]
E5a/b/ab       +120.0 mm -10.0 mm +1100.0 mm [4]
E6       +120.0 mm -10.0 mm +1100.0 mm [4]
GNSS Antenna (before week 1915) FOC-1,2 E1       +150.0 mm 0.0 mm +1000.0 mm
E5a/b/ab       +150.0 mm 0.0 mm +1000.0 mm
E6       +150.0 mm 0.0 mm +1000.0 mm
others E1       +150.0 mm 0.0 mm +1000.0 mm
E5a/b/ab       +150.0 mm 0.0 mm +1000.0 mm
E6       +150.0 mm 0.0 mm +1000.0 mm
LRA FOC-1 +703.0 mm +27.5 mm +1120.5 mm +1034.7 mm +14.0 mm +558.6 mm [1],[2]
FOC-2 +703.0 mm +27.5 mm +1120.5 mm +1017.0 mm +14.9 mm +558.1 mm [1],[2]
FOC-3 +703.0 mm +27.5 mm +1120.5 mm +962.1 mm +18.3 mm +559.3 mm [1],[2]
FOC-4 +703.0 mm +27.5 mm +1120.5 mm +963.6 mm +18.2 mm +559.3 mm [1],[2]
CoM (Feb 2016) FOC-1 -316.9 mm +13.5 mm +561.9 mm       [2]
FOC-2 -311.6 mm +12.6 mm +562.3 mm       [2]
FOC-3 -259.5 mm +9.2 mm +561.1 mm       [2]
FOC-4 -261.1 mm +9.2 mm +561.1 mm       [2]
FOC-5 -258.6 mm +9.9 mm +565.5 mm       [2]
FOC-6 -259.2 mm +9.5 mm +565.3 mm       [3]
FOC-8 -261.1 mm +10.4 mm +565.3 mm       [2]
FOC-9 -261.5 mm +9.6 mm +565.0 mm       [2]

Due to an initial lack of publicly available measured antenna phase center offsets conventional values of (x,y,z)IGS=(-0.2 m, 0.0 m, +0.6 m) and (x,y,z)IGS=(+0.15 m, 0.0 m, +1.0 m) were recommended for orbit and clock determination of the Galileo-IOV and -FOC satellites, respectively, until GPS week 1914. These values provided a first estimate of the actual phase center relative to the center of mass based on the images and models or coarse phase center estimates.

In 2016, GFZ and DLR estimated PCOs for the Galileo IOV and FOC satellites based on the ionosphere-free linear combination of E1 and E5a [4]. These values are included in igs08.atx since GPS week 1915 [5]. The switch dates of the individual ACs are given in the following table:

Analysis center com gbm grm tum wum
Switch date 262/2016 269/2016 262/2016 268/2016 n/a

For the modelling of satellite laser ranging measurements nominal coordinates of the effective LRA reflection point have been specified by ESA as part of the ILRS mission support request.

Similar to the GPS satellites, the attitude of the Galileo satellites is actively controlled to orient the +zIGS axis towards the Earth. At the same time the spacecraft is continuously rotated about this axis to maintain the yIGS-axis perpendicular to the plane made up by the Sun, Earth, and satellite. The +xIGS-panel is always sunlit, while the -xIGS-panel is oriented towards "deep space". Details of the IOV attitude control during noon- and midnight turns in periods when the Sun is close to the orbital plane are described in [3] although differing from the information published on the GSA webpage.

References

[1] Galileo-101 and -102 ILRS SLR Mission Support Request Form (2011/06)
[2] ILRS Galileo IOV Center of Mass Information
[3] Konrad A., Fischer H.-D., Müller C., Oesterlin W.; "Attitude & orbit control system for Galileo IOV"; 17th IFAC Symposium on Automatic Control in Aerospace (2007). DOI 10.3182/20070625-5-FR-2916.00006
[4] Steigenberger P., Fritsche M., Dach R., Schmid R., Montenbruck O., Uhlemann M., Prange L.; "Estimation of satellite antenna phase center offsets for Galileo"; Journal of Geodesy 90(8):773-785. DOI 10.1007/s00190-016-0909-6
[5] Schmid R. "igs08_1915.atx: Updated phase center offsets for Galileo satellites", IGSMAIL-7356

Events

List of events before 2017.

Date
UTC
Satellite
PRN
Description
Notes
2017/03/01 Afternoon FOC-4 E24 Start of transmission outage CONGO/MGEX monitoring, NAGU 2017006
2017/03/02 10:40 FOC-7 E07 Start of E1 and E5 signal transmission CONGO/MGEX monitoring
2017/03/03 09:44 FOC-14 E05 Start of E1 and E5 signal transmission CONGO/MGEX monitoring
2017/03/05 Morning FOC-4 E24 End of transmission outage CONGO/MGEX monitoring, NAGU 2017007
2017/03/06 Morning FOC-7 E07 End of signal transmission CONGO/MGEX monitoring
2017/03/06 Noon FOC-14 E05 End of signal transmission CONGO/MGEX monitoring
2017/03/11 Morning FOC-7 E07 Restart of signal transmission CONGO/MGEX monitoring
2017/03/12 Morning FOC-14 E05 Restart of signal transmission CONGO/MGEX monitoring
2017/03/19 Morning FOC-14 E05 Few hours transmission outage CONGO/MGEX monitoring
2017/03/21 Morning FOC-7 E07 Few hours transmission outage CONGO/MGEX monitoring
2017/03/28 08:40 FOC-7 E07 Start of broacast message transmission CONGO/MGEX monitoring
2017/04/05 05:50 FOC-14 E05 Start of broacast message transmission CONGO/MGEX monitoring
2017/04/22 Morning FOC-12 E03 Start of E1 and E5 signal transmission CONGO/MGEX monitoring
2017/04/22 Evening FOC-13 E04 Start of E1 and E5 signal transmission CONGO/MGEX monitoring
2017/04/24 Evening FOC-12 E03 End of signal transmission CONGO/MGEX monitoring
2017/04/25 Afternoon FOC-13 E04 End of signal transmission CONGO/MGEX monitoring
2017/04/29 Morning FOC-13 E04 Restart of signal transmission CONGO/MGEX monitoring
2017/04/29 Morning FOC-13 E04 Short transmission outage CONGO/MGEX monitoring
2017/05/01 Morning FOC-12 E03 Restart of signal transmission CONGO/MGEX monitoring
2017/05/01 Morning FOC-12 E03 Short transmission outage CONGO/MGEX monitoring
2017/05/01 Evening FOC-13 E04 Start of transmission outage CONGO/MGEX monitoring
2017/05/02 Morning FOC-13 E04 End of transmission outage CONGO/MGEX monitoring
2017/05/03 Evening FOC-12 E03 Start of transmission outage CONGO/MGEX monitoring
2017/05/04 Morning FOC-12 E03 End of transmission outage CONGO/MGEX monitoring
2017/05/14 15:50 ALL ALL Navigation messages not refreshed for all satellites NAGU 2017015
2017/05/16 12:44 ALL ALL Navigation messages refreshed for all satellites NAGU 2017016
2017/05/29 18:23 FOC-7 E07 Satellite declared usable NAGU 2017018
2017/05/30 13:15 FOC-14 E05 Satellite declared usable NAGU 2017017
2017/06/16 Noon FOC-6 E30 Short transmission outage CONGO/MGEX monitoring, NAGU 2017023


Notes:

Last Updated: 2017/11/22 10:14:51
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