Cost-effective precise positioning for geospatial applications

Transcription

1 Cost-effective precise positioning for geospatial applications Octavian Andrei Department of Survey Engineering, Chulalongkorn University, Thailand IPNTJ Summaer School 2014 Jul 28 Aug 02, Total Value of GNSS Precise Positioning Technology Seven billion GNSS devices by 2022 almost one for every person on the planet. 2

2 Who benefits of precision GNSS? Geodetic survey Earthquake & tsunami alert systems Machine Control Mobile Mapping Precision Agriculture 3 GNSS meteorology ITS (Intelligent Transportation System) Centimeter-level positioning Relative positioning using differential principles Carrier phase based techniques A pair of receivers Simultaneous tracking Baseline constraint RTK Single-baseline Limited area 10-20km Measurements Reference Yokyo, Japan 4 Baseline Rover

3 Traditional way Base Rover Radio antenna Controller 5 External baterry Disadvantages! High-operational costs for current positioning technology! Expensive geodetic-grade receivers! Expensive post-processing software! Infrastructure is required ! Limited applications due to cost issues 6

4 How to reduce de cost? Hardware Can we eliminate one receiver? Can we use other type of receivers? Software Can we use other positioning technique to obtain precise location information? Can we reduce the cost of the processing software? 7 Q1: Can we eliminate one receiver? 8

5 NetworkRTK: pro and cons Benefits No need to set up a base station Cost, labor, mobility, efficiency Homogeneous and consistent accuracy over larger areas The same area can be covered with fewer RS Reliability, availability, continuity (365/24/7) Drawbacks The cost to subscribe to an RTN and to receive NRTK corrections Limited wireless data access Interpolation (or extrapolation) 9 Different NRTK realizations Area Correction Parameters (FKP) Flächen-Korrektur Parameter Geo++ in the mid 1990s Virtual Reference Station (VRS) Terrasat in the late 1990 s Pseudo Reference Station (PRS) Master Auxiliary Concept (MAC) proposed by Leica and Geo++ in 2001 individualized-max 10

6 Test methodology DoY$ Session$ morning$ a.ernoon$ 251$ VRS$ VRS$ 258$ $ Nearest$ 259$ Nearest$ $ 265$ Post3Processing$ Two observation sessions Two NRTK modes Nearest Station (single-base) VRS Five time intervals 10, 60, 180, 300, 480 sec 10 occupations at each interval Average 11 Accuracy test Horizontal Precision vs. Accuracy 2 cm Rx spec 95% RTK VRS Mean OPUS center of precision North (m) center of accuracy OPUS PP Error East (m) 12

7 Q2: Can we use other type of receivers? Geodetic-grade Consumergrade Surveygrade 13 Cost-effective hardware Original Equipment Manufacturer boards Canadian Marconi Company (1997, 1998) itrax03 (2005) GPS/GNSS modules Garmin 12XL (2000) Garmin etrex Vista (2003) Garmin GPS25 (2010) Navigation-grade receivers ublox (2009) LEA 6T, UBX-RXM-RAW: carrier phase with half cycle ambiguity resolved, code and Doppler obs. 14

8 Baseline processing FGI0 TIIL KAIV OTA9 London, Tokyo, Japan UK Jul Nov Aug 1 Dec 02, European Navigation 2011 Conference octavian.andrei@aalto.fi SMOK Low-cost baseline post-processing statistical indicators & error ellipses London, Tokyo, Japan UK Jul Nov Aug 1 Dec 02, European Navigation 2011 Conference octavian.andrei@aalto.fi

9 Geodetic vs. low-cost baselines Andrei, C-O. Cost-effective precise positioning using carrier phase navigation-grade receiver. Localization and GNSS (ICL-GNSS) 2012, IEEE Conference Publications, IEEE Xplore, June 25-27, 2012, Starnberg, Germany, ISBN: , E-ISBN: , doi: /icl- GNSS Q3: Can we use other positioning technique to obtain precise location information? Dual-frequency data from a single GNSS receiver Precise orbits and SVs clocks Iono-free data combinations (P3, L3) Static positioning 1.0 cm (horizontal) and 5.0 cm (vertical) Convergence period Post-processing OS: OPUS, magicgnss, RTS-IGS, etc CS: CenterPoint RTX, Veripos APEX, Nexteq i-ppp Source: Andrei (2010)

10 Test methodology Test A (Pulmankivene) Cart mapping Test B (Tahtelä) Snow-mobile mapping Test C (Ivalojoki) Boat navigation FGI-ROAMER MMS Kukko et al. (2007) Photo: Harri Kaartinen Kukko, A., Andrei, C-O., Salminen, V.M., Kaartinen, H., Chen, Y., Rönnholm, P., Hyyppä, H., Hyyppä, J., Chen, R., Haggren, H., Kosonen, I., Capek, K. (2007). Road environment mapping system of the Finnish Geodetic Institute - FGI ROAMER. International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXVI, Part 3/W52, pp , ISSN Boat-mounted mobile mapping system Multipath Complete loss-of-lock Statistics North (m) East (m) Up (m) 2D (m) Mean -0,035-0,067 0,293 0,151 RMS 0,194 0,167 0,837 0,256 Photo: Erkka Taivainen 20

11 Bridge Boat-mounted (cont ) Start / Stop Accuracy Epochs Percentage > 50 cm 815 8, cm 419 4, cm 783 8, cm ,95 < 10 cm ,30 TOTAL Forest For 60% of the recorded epochs, 2D positioning multipath errors are less than 10 cm. Andrei, C-O., Kaartinen, H., Kukko, A., Satirapod, C. Precise carrier phase-based point 21 positioning of boat-mounted terrestrial remote sensing platform. Localization and GNSS (ICL-GNSS) 2014, IEEE Conference Publications, IEEE Xplore, Results June 24-26, and Discussions 2014, Helsinki, Finland, ISBN: Q4: Can we reduce the cost of processing software? other open source or freely available 22

12 23 Summary Nr.crt Question Answer 1 Can we eliminate one receiver? NetworkRTK 2 Can we use other type of receivers? Navigation-grade phase-enabled receiver 3 Can we use other positioning technique to obtain precise location information? Precise Point Positioning 4 Can we reduce the cost of the processing software? Open-source 24

13 Acknowledgement This participation is partially funded by the Institute of Positioning Navigation and Timing of Japan. This research is partially funded by the Ratchadaphisek Somphot Endowment Grant GDNS Helsinki, Finland Jun 24-26, Thank you for Your attention! Chulalongkorn University Phayathai Road, Pathumwan, Bangkok 10330, Thailand 26