Date post: | 12-Jun-2015 |
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Improving goGPS:Java implementation,
web applications and add-ons
FOSS4G 2011 Osaka
GPS receivers for navigation(i.e. kinematic positioning)
15-30 cm 3-5 m 2-3 cm RTK
(L1+L2) DGPS / RTK (L1)
stand-alone
US $ 10000 - 30000 US $ 1000 - 2000 US $ 50 - 200
Double frequency geodetic receivers
Single frequency professional receivers
Single frequency low-cost (consumer-level) receivers
40 cm - 80 cm
goGPS single-frequency RTK
raw data!
Relative positioning (double differences)
GPS error budget:
- orbit error (ephemeris): negligible- satellite and receiver clock errors: negligible- ionosphere and troposphere effects: negligible if D<10 km
- signal degradation- hardware quality
DMaster receiver (known position)
Rover receiver
goGPS MATLAB
- developed in MATLAB 7.6+
- GUIs available
- Real-time and post-processing
- works on both Windows and UNIX
goGPS Java
- client/server architecture
- GUI not yet available
- Real-time and post-processing
- platform independent
- faster than goGPS MATLAB
goGPS Java first official release (two days ago!)
http://www.gogps-project.org
Collaborative environment
http://sourceforge.net/projects/gogps/ http://code.google.com/p/gogps/
MATLAB Java
SVN Mercurial
goGPS international network (as of November 2011)
Polytechnic of Milan http://www.polimi.it
Osaka City University http://www.osaka-cu.ac.jp
OSGEO JP http://www.osgeo.jp
Cryms http://www.cryms.com
goGPS Applied Technology
http://www.apptec.co.jp
Galileian Plus http://www.galileianplus.it
FISIhttp://www.fisi.org
SBBhttp://www.sbb.ch
Tezukayama Gakuin University http://www.tezuka-gu.ac.jp/
gRED
Volunteers (open source)
Universidad de Jaén http://www.ujaen.es
(GNSS positioning services)
Post-processing
Real-time processing
Position known with few centimeters of error (RMS < 2 cm)
goGPS positioning using single frequency raw data:
- with TOPCON receivers → RMS 20 ~ 40 cm - with u-blox receiver → RMS 40 ~ 80 cm
TOPCON double frequency receivers
u-blox receiver
Accuracy tests with receivers mounted on a car driven at different speeds with good sky visibility condition.
Accuracy test (December 2010)
Kinematic positioning
Receiver: u-blox AEK-4T
goGPS solution - RTK (VRS) - Dynamical model (const vel.) - Observations weighted on SNR
u-blox solution - Stand-alone - Pedestrian dynamical model
2D translation: ~2m
Static positioning
u-blox+goGPS solution compared with static positioning by double frequency receiver:
~ 30 cm
Low-cost receivers supported by goGPS(as of November 2011)
u-blox 4T / 5T / 6T SkyTraq S1315F-RAWFastrax IT03
goGPS
Multi-receiver logging (since version 0.2.0beta)
RINEX 1
RINEX 2
RINEX 3
REC. 1
REC. 2
REC. 3
Multi-receiver test
Variable dynamic model (since version 0.2.0beta)
goGPS Kalman filter � dynamic model
static
constant velocity
constant acceleration
BEFORE v0.2.0beta � same dynamic model for each processing session
SINCE v0.2.0beta � the user can switch between different dynamic models during the survey
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Variable dynamic model
goGPS as a web service
goGPS can provide GPS data processing as a web processing service (WPS) to obtain accurate positioning from raw GPS observations
Server providing goGPS as WPS (ZOO WPS engine)
Raw data loggers raw observations (e.g. RINEX files)
accurate positioning (e.g. KML file)
http://localhost/cgi-bin/zoo_loader.cgi?metapath=&ServiceProvider=zgoGPS&Service=WPS&Request=Execute&Version=1.0.0&Identifier=goGPS&DataInputs=Obs=rover.11o; Nav=rover.11n;mObs=master.11o
goGPS processing by grid computing (Oracle GridEngine)
Scalability test for goGPS Java server-side processing with concurrent requests (Yoshida, 2011)
goGPS for road mapping
Accurate path maps with low-cost GPS receivers, integrating the output into a web-GIS
goGPS tracks can be used for OpenStreetMap
Polyline simplification(goGPS MATLAB tool)
goGPS for surveying
Archeological surveying with a required accuracy of the order of ~50 cm
goGPS + + VRS (or closest station)RTK – L1 only
Swiss Federal Railways SMART project
raw data collector client-side
goGPS Java processing server-side
Swisstopo VRS
measuring geographic areas by means of low-cost RTK positioning
Server-side processing environment (courtesy of CRYMS Sagl)
eZe2 deviceBoard M2M/custom Cinterion TC65i uBlox 5T
Display Keyboard
Server unix based Tomcat 6.0 Eriadne Server goGPS service
Swisstopo
Master VRS
uBlox
Navigation Ephemeris
Swiss Federal Railways
SAP
Swiss Federal Railways SMART project
only logging raw data!
Swiss Federal Railways SMART project
Server-side monitor & control interface (courtesy of CRYMS Sagl)
Swiss Federal Railways SMART project
Precision test (courtesy of CRYMS Sagl)
Swiss Federal Railways SMART projectmeasuring geographic areas by means of low-cost RTK positioning
Testing the system performance �
(photos courtesy of CRYMS Sagl and Politecnico di Milano, Geomatics Laboratory)
Future developments
1) Improvement of positioning algorithms, focusing on post-processing; additional receiver support; other satellite systems(QZSS, Compass, GLONASS, Galileo, EGNOS, MSAS)
2) Motion sensors integration (accelerometers, gyros, odometer, �) → hardware prototype
3) goGPS Java made available as an application (command line / GUI)
4) goGPS processing made publicly available as a web service