International collaboration on open source scientific software: latest developments in goGPS positioning engine

FOSS4G 2013 Osaka7 November 2013

Eugenio Realini RISH, Kyoto UniversityDaisuke Yoshida GSCC, Osaka City UniversityHirofumi Hayashi Applied Technology Co.,LtdVenkatesh Raghavan GSCC, Osaka City University

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GPS “raw data”(observations, orbits, …)

If we have:- satellite positions- satellite-receiver distances- precise time

we can estimate:- receiver position/velocity- atmospheric parameters- …

and we can do research:- positioning accuracy improvement- deformation monitoring- atmospheric water vapor retrieval- …

From GPS to GNSS

GNSS Global Navigation Satellite System

GPS is not the only positioning system available

Other countries apart from US are building global (or regional) satellite systems

Russia China Europe Japan IndiaGLONASS BeiDou Galileo QZSS IRNSS

Global Regional

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 Coordinatesand ancillary data Only visualization!

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 - …

Rawdata

GNSS “raw data”(observations, orbits, …)

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 orsingle-frequency)

A few low-cost(consumer grade) receivers

(single-frequency)

~ $3,000 – $30,000

~ $100 – $500

Low-cost raw data logger prototypeLow-cost raw data logger prototypeENVLoggerRPi

- 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

GNSS processing softwareCommercial Academic

Free and Open Source Software(FOSS)

GAMIT/GLOBK

GIPSY/OASIS II

RTKLIB/GpsTools

goGPS

BerneseTGO/TTC (Trimble)

LGO (Leica)

RTNet(GPS Solutions)

Justin (JAVAD)

Topcon Tools (Topcon)

Bold = source code provided

gLAB

MATLABJava

- developed in MATLAB 7.6+

- GUIs available

- Real-time and post-processing

- works on both Windows and UNIX

- single-frequency (L1) positioning

goGPS MATLAB

goGPS MATLAB downloads (Apr 2009 – Oct 2013)

Collaborative environmentCollaborative environmenthttp://www.gogps-project.org/

http://sourceforge.net/projects/gogps/ http://code.google.com/p/gogps/

MATLAB Java

Version control systems: SVN Mercurial

goGPS international networkgoGPS international network(2012) (2012)

Polytechnic of MilanPolytechnic of Milanhttp://www.polimi.ithttp://www.polimi.it

Osaka City UniversityOsaka City Universityhttp://www.osaka-cu.ac.jphttp://www.osaka-cu.ac.jp

OSGEO JPOSGEO JPhttp://www.osgeo.jphttp://www.osgeo.jp

CrymsCrymshttp://www.cryms.comhttp://www.cryms.com

goGPSApplied TechnologyApplied Technology

http://www.apptec.co.jphttp://www.apptec.co.jp

Galileian PlusGalileian Plushttp://www.galileianplus.ithttp://www.galileianplus.it Kyoto University (RISH)Kyoto University (RISH)

http://www.rish.kyoto-u.ac.jphttp://www.rish.kyoto-u.ac.jp

GReDGReDhttp://www.g-red.eu/http://www.g-red.eu/

Volunteers(open source)

Universidad de JaénUniversidad de Jaénhttp://www.ujaen.eshttp://www.ujaen.es

Note: institution/company names are only indicative of goGPS contributors’ affiliations, NOT official endorsements of the project

Latest developments Latest developments (during 2013)(during 2013)

• EGNOS (SBAS) support

code contributed by:Giuliano Sironi, Politecnico di Milano, ItalyAntonio Herrera Olmo, Universidad de Jaén, Spain

• Integer phase ambiguity resolution by LAMBDA method

code contributed by:Hendy F. Suhandri, Universität Stuttgart, GermanyAndrea 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

EGNOS (SBAS) supportEGNOS (SBAS) support

Accuracy improved to < 1 m in stand-alone mode (i.e. without a base station)

SBAS: Satellite-Based Augmentation System

(geostationary systems)

Integer ambiguity resolution by Integer ambiguity resolution by LAMBDA methodLAMBDA 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

increased number of availablesatellites

improved positioning capabilities,esp. in urban environments

source: http://www.multignss.asia/campaign.html

source: goGPS plot

Multi-GNSS supportMulti-GNSS support

http://www.gogps-project.org