BRUX: A New EPN and IGS Reference Station in Brussels C. Bruyninx , W. Aerts, P. Defraigne, J. Legrand Royal Observatory of Belgium, Av. Circulaire 3, Brussels, Belgium, [email protected] P. De Doncker, D. Lafourte National Geographic Institute, Abdij ter Kameren 5, Brussels, Belgium.
C. Bruyninx, W. Aerts, P. Defraigne, J. Legrand
Royal Observatory of Belgium, Av. Circulaire 3, Brussels, Belgium, [email protected]
P. De Doncker, D. Lafourte
National Geographic Institute, Abdij ter Kameren 5, Brussels, Belgium
Royal Observatory of Belgium
GNSS Research Group
July 23 – 27, 2012
Data Availability and Performance
On, Feb. 14, 2012, after more than almost 19 years, ROB stopped operating its EPN/IGS station BRUS (Brussels, Belgium) because the antenna monument had to be destroyed due to the need to remove asbestos in the building around the antenna.
IGS station since 01-03-2012 + M-GEX EPN station since 11-03-2012
Real-time: RTCMv3.1 (BRUX0) & SBF (raw format/BRUX1) streams (NTRIP)
Daily and hourly RINEX v2.11 and RINEX v3.01 (generated using Septentrio’s software)
Comparison with BRUS shows superior data quality for BRUX:
Comparison with other IGS stations shows that multipath mitigation at BRUX was successful:
Fig. 7: Comparison of classic TEQC metrics for BRUS and BRUX
(# complete obs., cycle slips, L1 and L2 multipath – only for GPS observations).
Fig. 1: Areal view of BRUS and BRUX
Compared to BRUS, BRUX has improved visibility and equipment.
SEPT POLARX4TR timing receiver able to track GPS/ GLONASS/Galileo on L1/L2/L5
Connected to an external CH1-75A MASER clock
JAVRINGANT_DM individually calibrated by the University of
Cycle slips X 1000/observations RMS MP1 (L1 multipath) RMS MP2 (L2 multipath)
Fig. 8: Comparison of classic TEQC metrics (45-day average) of BRUX wrt other IGS stations
Fig. 3: Skyplots fo BRUS (top) and BRUX (bot-tom) showing the improved visibility in BRUX.
Local Tie : BRUS- BRUX
Bonn for: GPS L1/L2/L5, GLONASS L1/L2 and Galileo L1, L5, L6, L7, L8
Fig. 2: Telescope dome with on top the BRUX antenna
Approach 1 : Triangulation
Oct. 2010: The tie BRUS-BRUX was measured using terrestrial measurements done by IGN Belgium in Oct. 2010 with a ‘Leica TCRA 1101plus’ total station and five local auxiliary points.
In March 2012, a second measurement was performed after the installation of the metal shield with RF absorbing material, to confirm that the position of BRUX was not changed. At that time BRUS was already removed.
Shield antenna from multipath caused by sliding doors of the dome below using a metal shield topped with Eccosorb ANW-77 RF absorbing material
Table 1: Geocentric eccentricities (GRS80) of the tie between BRUS and BRUX measured with terrestrial measurements. (stdev= 3mm in all components)
Fig. 4: Technical drawing of the entire antenna supporting structure
Prior to position jump in BRUS (period 1)
After position jump in BRUS (period 2)
With (1) distance Antenna-RF material and (2) size of shield, the entire support was designed by solving a geometry problem.
Solution is not ideal, many other surrounding sources of reflection are not (yet) blocked!
Fig. 9: North, East, Up eccentricities between BRUS and BRUX as measured by GPS L1 and L3; the vertical line indicates the unknown position jump at BRUS on 204/2011.
Table 2: Eccentricities between BRUS and BRUX computed by GPS. Top: before position jump in BRUS, bottom: after the jump.
Fig. 5: Geometry of the shield height determination problem
Table 3: Comparison of BRUS-BRUX local tie measured by triangulation and GPS L1 and L3 (before the BRUS position jump)
Fig. 6: The ANW-77 rearranged tiles and the sealing silicone paste