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EUREF LOCAL ANALYSIS CENTRE
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Agency acronym : RGA
Institution : Republic Geodetic Authority
Mail Address : bul. Vojvode Misica 39
: 11000 Beograd
: upto GPSWEEK 1751
: in cooperation with
: University of Belgrade
: Faculty of Civil Engineering
: bul. Kralja Aleksandra 73
: 11000 Beograd
Country : Serbia
Primary Contact
Contact Name : Sasa Lazic
Telephone : +381112651325
Fax : +381112651330
E-Mail : slazic@rgz.gov.rs
Secondary Contact
Contact Name : Zoran Veljkovic
Telephone : +381112651325
Fax : +381112651330
E-Mail : zoranveljkovic@rgz.gov.rs
Third Contact
Contact Name : Danko Ducic
Telephone : +381112651325
Fax : +381112651330
E-Mail : danko.ducic@rgz.gov.rs
Software Used : Bernese GPS Software Version 5.0 upto 1751
: Bernese GPS Software Version 5.2 since 1752
Stat. Included in Analysis : 4CHAR start - stop
ALBA 1632 - now
AUT1 1632 - now
BACA 1632 - now
BAIA 1632 - now
BBYS 1773 - now
BISK 1773 - now
BUCU 1632 - now
BUTE 1773 - now
BZRG 1632 - now
CACE 1632 - now
CAEN 1632 - now
CFRM 1632 - now
CLIB 1632 - now
CPAR 1632 - now
CREI 1632 - now
CTAB 1632 - now
DEVA 1632 - now
DRAG 1773 - now
DYNG 1763 - now
ELBA 1632 - now
GOPE 1773 - now
GRAZ 1632 - now
GSR1 1632 - now
HUEL 1632 - now
ISTA 1632 - now
IZAN 1632 - now
KATO 1632 - now
KRA1 1632 - now
KUNZ 1632 - now
LAGO 1632 - now
LAMP 1632 - now
LIL2 1632 - now
LPAL 1632 - now
MARJ 1773 - now
MATE 1632 - now
MOPI 1773 - now
ORID 1632 - now
OROS 1632 - now
PADO 1632 - now
PENC 1632 - now
PEN2 1745 - now
SALA 1632 - now
SMLA 1632 - now
SODA 1632 - now
SOFI 1632 - now
SONS 1632 - now
SRJV 1632 - now
TERC 1632 - now
TUBI 1773 - now
TUBO 1773 - now
VACO 1773 - now
VALE 1632 - now
VEN1 1632 - now
ZIMM 1632 - now
former IGS/EPN Stations: DUBR 1632 - 1711
OSJE 1632 - 1734
EUREF solutions generated : RGAwwww7.SNX Weekly coordinate solution in
SINEX format
RGAwwwwn.SNX Daily SINEX file
RGAwwww7.SUM Weekly processing summary file
RGAwwwwn.TRO Daily troposphere results in
tropospheric SINEX format, for
weekdays "n" (0-6)
EUREF solutions sent to : BKG
Report generated : 05/04/2011
Report updated : 20/05/2011
: 09/06/2011
: 26/04/2013
: 03/09/2013
: 29/01/2014
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MEASUREMENT MODELS
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Preprocessing : Phase preprocessing in a baseline by baseline mode
using triple-differences. In most cases cycle slips
are fixed looking simultaneously at different linear
combinations of L1 and L2. If a cycle slip cannot be
fixed reliably, bad data points are removed or new
ambiguities are set up.
3 deg cut off in pre-processing
Basic Observable : Carrier phase, code only used for receiver clock
synchronization, elevation cut-off angle of 3 degrees,
sampling rate of 30 and 180 seconds, respectively.
Modelled : Double differences, ionosphere-free linear combination.
observable
Ground antenna : Absolute antenna phace center variations (APCV)
phase center according to epn_08.atx (regularly updated with I08.atx from CODE)
calibrations are applied, partly including individual APCV.
: Since GPS week 1773: according to epn_08_FULLSN.atx
Troposphere : upto week 1751: Saastamoinen apriori model mapped with
DRY NIELL mapping function and ZPD
parameters estimated using WET NIELL
mapping function.
: since week 1752: GMF as a priori model, mapped with
DRY VMF mapping function and ZPD
parameters estimated using WET VMF
mapping function and CHENHER gradient
estimation model.
Ionosphere : Not modeled (ionosphere eliminated by forming the
ionosphere-free linear combination of L1 and L2).
CODE global ionosphere models used to improve
ambiguity resolution.
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ESTIMATED PARAMETERS (APRIORI VALUES & SIGMAS)
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Adjustment : Least-squares adjustment, mathematical correlations within
network correctly modeled. The elevation-dependent
observation weighting model adopted assumes a zero-
difference observation sigma being proportional 1/cos(z),
where z denotes the satellite zenith distance angle.
Rejection Criter.: Daily RINEX observation files containing
less than 12 hours good observations are
ignored. The threshold value concerning
data screening is 4 mm, specifically for
a normalized, or L1 zero-difference zenith
residual. Baseline data exceeding the over-
all sigma level of 6 millimeters is excluded
as whole.
Station : Datum definition for weekly solutions:
coordinates A 3-translation condition with respect to realization of IGS08
is imposed. The list of stations defining the datum (minimum constrain)
currently includes the following EPN stations (automatic outlier detection
using Helmert transformation test and if necessary repeated ADDNEQ2 run
with reduced number of datum stations) minimum constrain:
1632-1635
MATE
ZIMM
1636-1711
BUCU
BZRG
DUBR
ISTA
LAGO
LAMP
LPAL
MATE
ORID
PADO
PENC
SOFI
VALE
ZIMM
1712-now
BUCU
BZRG
ISTA
LAGO
LAMP
LPAL
MATE
ORID
PADO
PENC
SOFI
VALE
ZIMM
Troposphere : Zenith path delay parameters are solved for at 1-hour
intervals for each station. At the end of each week, the 7
daily sets of troposphere estimates are re-computed on the
normal equation level by substituting the 7-day combined
station coordinate results.
Troposphere gradient parameters are also solved for.
Daily .TRP and .TRO files as products.
Ionospheric : Introduce ION model from CODE, used only for ambiguity resolution.
Ionosphere not modelled in final solution (ionosphere eliminated
by forming the ionosphere-free linear combination
of L1 and L2)
since 1752: second order ionospheric correction from CODE
used to improve AR
Ambiguity : upto week 1751: If possible, fixed to integer values, using QIF strategy
combination of L1 and L2 (10 degrees cut off).
since week 1752: Advanced ambiguity resolution (AR) scheme is included:
- Code-Based Widelane (WL) AR for baselines shorter
than 6000km, a Melbourne-Wuebbena wide-lane
and narrow-lane AR is performed.
- Phase-Based Widelane (L5) AR for baselines shorter
than 200km the code-based wide-lane AR is replaced
by a phase-only wide-lane with a subsequent
narrow-lane AR.
- Quasi-Ionosphere-Free (QIF)AR
The QIF-strategy is applied on the remaining real-valued
ambiguities for baselines shorter than 2000km.
- Direct L1/L2 AR
A direct L1/L2 AR is applied on baselines shorter than 20km
- AR Verification
Each baseline is processed with introducing the resolved
ambiguities with their integer values and checking the
residuals. If there is any problem accounted, the resolved
ambiguities are re-initialized.
- 10 degrees cut off
Satellite clock : Satellite clock biases are not estimated but eliminated by
bias forming double differences.
Receiver clock : Receiver clock biases are estimated as part of the pre-
bias processing step using code measurements.
Orbits and ERPs : upto week 1751: IGS combined final orbit and ERP information are adopted.
Use DE200 planetary ephemeris. The Earth geopotential
is modeled using JGM3.
since week 1752: CODE final orbit and ERP information are adopted.
Use DE405 planetary ephemeris. The Earth geopotential
is modeled using JGM3.
Tidal : Solid earth tidal displacements are modeled according to
displacements IERS Conventions 1996/2000. Ocean loading corrections are
computed based on Scherneck's amplitudes and phases.
since week 1752: according to IERS2010 Convevtions
Ocean loading model : FES2004.
upto week 1751: No atmospheric loading corrections are computed.
since week 1752: Atmospheric loading corrections are
calculated using atmospheric tidal model Ray and Ponte
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