G-Nut software library and its applications within context of
EPOSJ. Douša, P. Václavovic, G. Györi [[email protected]]
Geodetic Observatory Pecný of the Research Institute of Geodesy,
Topography and Cartography, Czech Republic
EGU General Assembly 2013 — Vienna, Austria, April 7-12,
2013
AbstractWe present the G-Nut software library aimed for the
development of targeted end-user GNSS
applications in various geoscientific fields - geodesy,
seismology, meteorology, climatology end
others in future. It has been developed since 2011 at the
Geodetic Observatory Pecný
(http://www.pecny.cz/).
The library is written in C++ applying the object oriented
approach aiming for a flexible source
code implementation, easy maintenance and future extension.
Currently, the library supports the
Precise Point Positioning technique, which is a highly efficient
and autonomous method suitable for
various accuracy-demanding tasks in GNSS online or offline
processing. Specific user applications
were developed - 1) the tool for GNSS data converting,
cutting/splicing, editing and quantity
and quality checking, 2) the application for troposphere
monitoring (real-time or post-processing)
and 3) the application for the precise positioning in a static
or kinematic mode. The latest
results are demonstrated including the capability and relevance
for applications in inter-disciplinary
domains. Although the G-Nut library is still in a testing stage,
selected lite programs (beta
versions) were already released (http://www.pecny.cz - GNSS -
software). We expect that these
could significantly contribute to a broad scientific community
to be consolidated in the EPOS
project, in particular to facilitate GNSS data collecting,
monitoring and processing.
G-Nut software libraryThe G-Nut project was initiated in 2011 at
the Geodetic Observatory Pecný, RIGTC for implementing core
software library to support
developments of various end-user applications. The library is
written in C++ taking advantages of object-oriented design and
supporting
multi-thread processing. It is designed for Linux OS and
providing command-line applications which are usually used for
operational tasks.
The G-Nut exploits the Boost’s library for a platform
independent threading implementation (this dependence is likely to
be revised in
future). For matrix representation and factorization methods,
the G-Nut utilizes the New-Mat library developed by Davis (2009)
and, for
parsing XML configurations, the Pugixml light-weight C++ library
by Kapoulkine (2012). The XML mark-up language was selected for
user application settings due to its high flexibility and
support by various other editing and viewing user-tools. Main
characteristics are
summarized as follows:
• C++ object-oriented design for multi-thread applications
• adaptable data containers for real-time and off-line batch
processing
• multi-GNSS data handling and processing support,
• unique IO operations for various protocols (files,
streams),
• inherited encoders/decoders for file/stream data formats,
• different adjustment models (LSQ, Kalman, Kalman/srcf,
back-smoothing),
• dual-layer XML configurations (for library classes and for
user applications),
• command-line, GUI to be implemented for prominent
applications.
Geb - positioning toolTwo top figures below display real-time
positioning in a kinematic (left) and static
(right) mode in a routine solution, April 9, 2013 (site GOPE).
Kalman filter with a
square root covariance modification was used. Two middle figures
show post-processing
daily solutions (30s) with a) a forward filter applied only
characterized by an initialization
period (left), b) additional back-smoothing algorithm applied
(right) providing similar
results (without initialization) like a least-square batch
processing. Finally, two figures at
bottom demonstrate a capability to track position displacements
during the earthquake
Tohoku-Oki, Japan, 11th March, 2010 (5:46:23 UTC, Mg9.0). Two
stations were
processed offline with a high-rate data sampling and in
different distances from the
epicentre - MIZU (140 km) and USUD (430 km). While the first
site was shifted at
a meter level (after showing strong initial earthquake shock
waves), the second didn’t
show significant displacement, but only small waves with a delay
after earthquake.
-0.60
-0.45
-0.30
-0.15
0.00
0.15
0.30
0.45
0.60
00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00
20:00 22:00 00:00 2.10
2.12
2.14
2.16
2.18
2.20
2.22
2.24
2.26
N, E
, U [m
]
ztd
[m]
09-APR-2013
GOPE0 N E U ztd
-0.60
-0.45
-0.30
-0.15
0.00
0.15
0.30
0.45
0.60
00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00
20:00 22:00 00:00 2.10
2.12
2.14
2.16
2.18
2.20
2.22
2.24
2.26
N, E
, U [m
]
ztd
[m]
09-APR-2013
GOPE0 N E U ztd
-0.80
-0.60
-0.40
-0.20
0.00
0.20
0.40
0.60
0.80
00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00
20:00 22:00 00:00
2.10
2.12
2.14
2.16
2.18
2.20
2.22
2.24
N, E
, U [m
]
ztd
[m]
26-DEC-2010
WTZR
(c) GOP/RIGTC, 13-04-10 16:08
NorthEast
UpZTD
-0.80
-0.60
-0.40
-0.20
0.00
0.20
0.40
0.60
0.80
00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00
20:00 22:00 00:00
2.10
2.12
2.14
2.16
2.18
2.20
2.22
2.24
N, E
, U [m
]
ztd
[m]
26-DEC-2010
WTZR
(c) GOP/RIGTC, 13-04-10 16:07
NorthEast
UpZTD
-300
-200
-100
0
100
200
300
45 46 47 48 49 50 51 52 53 54 55
Dis
plac
emen
ts [c
m]
2011-Mar-11, UTC time from 5am [min], Earthquake Time: 05:46:23
UTC
MIZU
(c)
GO
P/J
D -
May
20,
201
1
NorthEastUp
-300
-200
-100
0
100
200
300
45 46 47 48 49 50 51 52 53 54 55
Dis
plac
emen
ts [c
m]
2011-Mar-11, UTC time from 5am [min], Earthquake Time: 05:46:23
UTC
USUD
(c)
GO
P/J
D -
May
20,
201
1
NorthEast
Up
Tefnut - troposphere monitoring toolTwo figures below display
the Zenith Total Delays (ZTD) from a routine real-time anal-
ysis based on PPP technique supported by IGS real-time products.
GOP real-time
ZTDs (TEF:RT) are compared to GOP near real-time regional
(BSW:NRT) and global
(GLO:NRT) ZTD solutions. The yellow lines indicate ZTDs filtered
out according to ex-
ceeding formal accuracy (usually due to re-initialization etc).
The results demonstrate a
high quality of real-time ZTDs in support of severe weather
monitoring. Some systematic
errors still occur, which are due to some modeling
simplifications (not all precise models has
been already implemented), however, a priority interest is to
achieve stable ZTD standard
deviations based on real-time data and products. Two additional
figures (bottom) show
the statistics achieved in a preliminary benchmark of a
post-processing mode (IGS final
products) and simulated real-time mode (IGS RTS products).
2.380
2.400
2.420
2.440
2.460
2.480
2.500
2.520
2.540
05.Apr00:00
05.Apr12:00
06.Apr00:00
06.Apr12:00
07.Apr00:00
07.Apr12:00
08.Apr00:00
08.Apr12:00
09.Apr00:00
09.Apr12:00
10.Apr00:00
10.Apr12:00
11.Apr00:00
ZT
D [
me
ters
]
ZENITH TOTAL DELAY [ZTD]Apr 10, 2013 [14:06] @ GOP
PDEL MET_RT - TEF:RT MET_RT - GLO:NRT
2.140
2.160
2.180
2.200
2.220
2.240
2.260
2.280
2.300
05.Apr00:00
05.Apr12:00
06.Apr00:00
06.Apr12:00
07.Apr00:00
07.Apr12:00
08.Apr00:00
08.Apr12:00
09.Apr00:00
09.Apr12:00
10.Apr00:00
10.Apr12:00
11.Apr00:00
ZT
D [
me
ters
]
ZENITH TOTAL DELAY [ZTD]Apr 10, 2013 [14:06] @ GOP
GOPE MET_RT - TEF:RT MET_RT - BSW:NRT MET_RT - GLO:NRT
-5.0
0.0
5.0
10.0
15.0
20.0
BOGO
BOR1
BRST
GOPE
MAS1
NICO
ONSA
PDEL
POTS
WTZR
YEBE
Bia
s/S
tdD
ev [m
m]
ZTD comparison : gNut-Tef [PP/fix] x EUR-repro1
20
12
-12
-02
@ G
OP
an
aly
sis
ce
ntr
e /
JD
Bias Sdev
-5.0
0.0
5.0
10.0
15.0
20.0
BOGO
BOR1
BRST
GOPE
MAS1
NICO
ONSA
PDEL
POTS
WTZR
YEBE
Bia
s/S
tdD
ev [m
m]
ZTD comparison : gNut-Tef [RT/fix] x EUR-repro1
20
12
-12
-02
@ G
OP
an
aly
sis
ce
ntr
e /
JD
Bias Sdev
Anubis - data QC and editing toolTool for data and navigation
message editing, splicing/cutting,
quality monitoring (clock jumps, cycle slips, multipath,
SNR,
. . . ) and quantity monitoring (number of satellites,
systems,
obs-gaps/types/percentages, . . . ) has been developed along
with the PPP applications when utilizing common functions.
Currently, a post-processing mode is supported, but
real-time
could be derived easily too. Implementations of a multi-GNSS
capability in RINEX V3.01/V2.11 data formats were tested
using dataset from the IGS multi-signals tracking campaign
- MGEX. Although some capabilities are still under develop-
ment (e.g. RINEX encoder for support-
ing saving modified files), the tool is al-
ready tested for GNSS data and naviga-
tion message handling at the GOP data
center. (Note: the application hasn’t
yet been released since still defining an
optimal output in ASCII, XML or figs).
0
30
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210
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270
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330
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60
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Newest information about the library development is
maintained
at: http://www.pecny.cz/ (GNSS, software) with possibility
to
join G-Nut mailing list. Or contact us at [email protected].
A k n o w l e d g m e n t s :
The development was partly supported by the Czech Scientific
Founda-
tion (P209/12/2207) and by the Technology Agency of the Czech
Republic
(TB01CUZK006).
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https://www.researchgate.net/publication/258782861
