Institut für Erdmessung
g
Determination of Phase Biases
with
p
zero-baseline common clock setups
Steffen Schön, Tobias Kersten
Institut für Erdmessung
Experimental set up
Temperature
p
+/- 0.5 K
Zero-Baseline Common Clock
Forming
differences
F
i single
i l diff
Here: results from RINEX2.11 signals
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
2
Analysis Concept
 Forming between station single differences
Initial receiver clock difference
common for all satellites
constant if no assymetry in the
experiment
p
Phase bias
Phase ambiguity
g y
integer multiple
constant per arc
if no cycle slips
 Quantities are not separable
 3 step approach:
1) determine „ambiguity“ by rounding
=> diff clock and bias
2) forming differences between frequencies
=> elimination of a „common clock“
3) studying the remaining „biases“
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
3
Results for RINEX2.11 observations
common scale: 2cm
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
4
Results for RINEX2.11 observations
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
5
Short baseline common clock setup
p for GDV:
Uncorrected
single differences
corrected
single differences
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
6
Experimentelle Bestimmung
g von GDV
A
B
ideal
tatsächliches Pattern
dSDAi , B  SDAi , B  tk 1   SDAi , B  tk 
 GDVAi  tk 1   GDVAi  tk   d  Ai , B
Kersten T.,
Kersten,
T Schön,
Schön S.,
S Weinbach,
Weinbach U
U. (2012): On the Impact of Group Delay Variations on GNSS Time and Frequency Transfer,
Transfer In: Proceedings of the 26th European
Frequency and Time Forum (EFTF), Gothenburg, Sweden, April 24.-26. 2012
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
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C/A Group Delay
y Variationen
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
8
P1 Group Delay Variationen
GDV smaller 1.5 ns
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
9
impact on GDV on kinematic positioning and
ambiguity resolution
8 cm
1m
Kersten, T., Schön, (2013): IAG Potsdam
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
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Conclusions
 Common clock set-up are useful to assess phase and
code biases independently from global networks
o Temperature sensitivity to small changes (<1K) in room
temperature
p
((~ computing
p
g load of receiver?))
o Whole equipment delay has an impact (antenna, cable, splitters,
receiver,…)
o Sometimes
S
ti
d
deviations
i ti
and
dd
drifts
ift ((some mm)) iin ti
time series
i
(Still asymmetry in the set up?,
common equipment (splitter, ..) not sufficient stable (ps level) ?)
o Sometimes single satellites are not following the mean
 Current
C
analyses
l
ffocus on RINEX3
RINEX3-conform
f
signals
i
l
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
11
Literature








Kersten T., Schön S. (2015): An alternative method for determining GPS receiver biases, Poster, EGU
General Assembly 2015, Vienna, Geophysical Research Abstracts, Vol. 17, EGU2015-12042, 2015
Kersten T. (2014): Bestimmung von Codephasen
Codephasen-Variationen
Variationen bei GNSS
GNSS-Empfangsantennen
Empfangsantennen und deren
Einfluss auf die Positionierung, Navigation und Zeitübertragung, Deutsche Geodätische Kommission bei
der Bayerischen Akademie der Wissenschaften, Reihe C, Nr. 740 (identical with Wissenschaftliche Arbeiten
der Fachrichtung Geodäsie und Geoinformatik der Leibniz Universität Hannover, Nr. 315)
) Antenna Code Phase Variations ((GDVs)) and the Impact
p
on Ambiguity
g y
Kersten T.,, Schön S. ((2014):
Resolution, In: IGS Analysis Workshop, June 23.-27., Pasadena, California, USA
Kersten T., Schön S. (2013): Analysis of IfE-Robot based Group Delay Variations for the Positioning and
Navigation of Mobile Platforms, In: Proceedings of the European Navigation Conference (ENC) 2013,
Vienna, Austria
Kersten T., Schön S. (2013): The Impact of Group Delay Variations on Wide- and Narrowlane Linear
Combinations, Proceedings of IAG Scientific Assembly 2013, 150 years International Association of
Geodesy (IAG), September 01.-06., GfZ - Potsdam, Brandenburg, Germany
) Impact
p
of individual Receiver Antenna Code Phase Variations on the
Kersten T.,, Schön S. ((2013):
Ambiguity Resolution, Abstract #G53b-0920, AGU Fall Meeting, December 09.-13., San Francisco,
California
Kersten T., Schön S. (2012): Antenna specific IfE-Robot based Code Phase Delays and its Impact on
Positioning and Navigation, 6th ESA Workshop on Satellite Navigation Technologies & European Workshop
on GNSS Signals and Signal Processing, ESA ESTEC, Noordwijk, The Netherlands Link
DOI: 10.1109/NAVITEC.2012.6423088
Kersten, T., Schön, S., Weinbach, U. (2012): On the Impact of Group Delay Variations on GNSS Time
and Frequency Transfer, In: Proceedings of the 26th European Frequency and Time Forum (EFTF),
Gothenburg, Sweden, April 24.-26. 2012, pp 514 - 521 Link
DOI: 10.1109/EFTF.2012.6502435
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
12
Literature

Parts of the work were realized during research projects
S. Schön – IGS Bias Workshop Bern 5.11-6.11.2015
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