goGPS status update @FOSS4G 2013 Osaka - November 2013

1. International collaboration on open source
scientific software: latest developments in
goGPS positioning engine
Eugenio Realini
Daisuke Yoshida
Hirofumi Hayashi
Venkatesh Raghavan
RISH, Kyoto University
GSCC, Osaka City University
Applied Technology Co.,Ltd
GSCC, Osaka City University
FOSS4G 2013 Osaka
7 November 2013

2. GPS “raw data”(observations, orbits, …)
If we have:
- satellite positions
- satellite-receiver distances
- precise time
1
11
10
H e ig h t [ k m ]
32
24
28
8
we can estimate:
- receiver position/velocity
- atmospheric parameters
-…
19
20
8
6
7
4
2
0
12
and we can do research:
- positioning accuracy improvement
- deformation monitoring
- atmospheric water vapor retrieval
-…
10
10
8
6
N o rth [k m ]
5
4
2
0
0
E a s t [k m ]

3. From GPS to GNSS
GPS is not the only positioning system available
Other countries apart from US are building global (or regional)
satellite systems
GNSS Global Navigation Satellite System
GLONASS
BeiDou
Russia
China
Global
Galileo
Europe
QZSS
Japan
IRNSS
India
Regional

4. GNSS “raw data”(observations, orbits, …)
Standard consumer grade (low-cost) receiver:
- GNSS observations are processed within the receiver
- User can access only the processing result (e.g. coordinates)
GNSS observations
Coordinates
and ancillary data
Only visualization!

5. GNSS “raw data”(observations, orbits, …)
By accessing raw data, we can perform advanced analyses, e.g.
- improving the positioning accuracy by relative positioning
- study and monitor the atmosphere
- …
Raw
data

6. Receivers providing “raw data”
GNSS receivers generally provide raw data formatted according to
proprietary binary protocols.
Often these protocols are available to customers (or even public).
Almost all geodetic
(survey grade) receivers
(dual-frequency or
single-frequency)
~ $3,000 – $30,000
A few low-cost
(consumer grade) receivers
(single-frequency)
~ $100 – $500

7. Low-cost raw data logger prototype
ENVLoggerRPi
-
developed at Osaka City University
u-blox LEA-6T module (GPS raw data)
environmental sensors (T, P, RH, CO2)
logging data on microSD card
Raspberry Pi (credit card-sized Linux computer)
Power-over-Ethernet
Configurable (text file on SD card)
open source firmware

8. GNSS processing software
Commercial
Academic
GAMIT/GLOBK
TGO/TTC (Trimble)
LGO (Leica)
Bernese
RTNet
Topcon Tools (Topcon) (GPS Solutions)
Justin (JAVAD)
Bold = source code provided
GIPSY/OASIS II
Java
goGPS
MATLAB
RTKLIB/GpsTools
gLAB
Free and Open Source Software
(FOSS)

9. goGPS MATLAB
- Real-time and post-processing
- developed in MATLAB 7.6+
- works on both Windows and UNIX
- GUIs available
- single-frequency (L1) positioning

10. goGPS MATLAB downloads
(Apr 2009 – Oct 2013)

11. Collaborative environment
http://www.gogps-project.org/
MATLAB
Java
http://sourceforge.net/projects/gogps/
Version control systems:
SVN
http://code.google.com/p/gogps/
Mercurial

12. goGPS international network
(2012)
Cryms
http://www.cryms.com
Note: institution/company names are only
indicative of goGPS contributors’ affiliations,
NOT official endorsements of the project
Universidad de Jaén
http://www.ujaen.es
goGPS
Polytechnic of Milan
http://www.apptec.co.jp
OSGEO JP
http://www.polimi.it
http://www.osgeo.jp
GReD
Osaka City University
http://www.g-red.eu/
Galileian Plus
Applied Technology
http://www.galileianplus.it
http://www.osaka-cu.ac.jp
Volunteers
(open source)
Kyoto University (RISH)
http://www.rish.kyoto-u.ac.jp

13. Latest developments (during 2013)
• EGNOS (SBAS) support
code contributed by:
Giuliano Sironi, Politecnico di Milano, Italy
Antonio Herrera Olmo, Universidad de Jaén, Spain
• Integer phase ambiguity resolution by LAMBDA method
code contributed by:
Hendy F. Suhandri, Universität Stuttgart, Germany
Andrea Nardo, Curtin University, Australia
• Multi-GNSS support (also by using low-cost receivers by NVS)
GPS, GLONASS, Galileo, BeiDou, QZSS
code contributed by:
(myself), Kyoto University, Japan (with knowledge support from Andrea Nardo)
Daisuke Yoshida, Osaka City University, Japan

14. EGNOS (SBAS) support
Accuracy improved to < 1 m in
stand-alone mode (i.e. without a
base station)
SBAS: Satellite-Based
Augmentation System
(geostationary systems)

15. Integer ambiguity resolution by
LAMBDA method
Static test results:
•u-blox AEK-4T receiver (low-cost)
•geodetic base station (~60 m baseline)
Accuracy:
< 1 cm
Example application: deformation monitoring with multiple low-cost receivers

16. Multi-GNSS support
increased number of available
satellites
improved positioning capabilities,
esp. in urban environments
source: goGPS plot
source: http://www.multignss.asia/campaign.html

17. http://www.gogps-project.org