The International Scene: How Precise Positioning Will Underpin Critical GNSS Applications

Transcription

1 The International Scene: How Precise Positioning Will Underpin Critical GNSS Applications School of Civil & Environmental Engineering, UNSW, Sydney, Australia Chris Rizos Member of the IGS Governing Board ( ) President International Association of Geodesy ( )

2 Diversity of Precise Positioning applications... 1cm 2cm < dm 1dm Scientific geodesy Datum Deformation surveys Machine automation Surveying Engineering & construction Sensor georeferencing Precision agriculture LEO POD Advanced ITS Mapping & Hydrography Offshore engineering Disaster response

3 Diversity of Precise Positioning applications... 1cm 2cm < dm 1dm Scientific geodesy Datum Deformation surveys Machine automation Sensor georeferencing Precision agriculture Although there is a wide range of Surveying user equipment, services & Engineering & operational construction procedures, most use the relative positioning method... Advanced ITS LEO POD Mapping & Hydrography Offshore engineering Disaster response

4 Relative Positioning (Differential GPS)... GPS satellites Local base station(s) DGNSS corrs or raw data Real-time or postmission GPS user

5 Comments to Precise Positioning differential has been dominant PP mode since 1980s... mitigates impact or orbit, satellite clock & atmospheric errors... base or reference station(s) needed... increasingly evolving to CORS infrastructure... raw data or corrections increasingly from Service Providers... real-time or post-survey mode... short baselines commercial/typical implementation... long baselines scientific/datum applications

6 Global/Regional/National GNSS Networks

7 Global/Regional/National GNSS Networks

8 Commercial operations Short baselines, high productivity Base stn data Surveying, mapping, precise navigation, etc Science applications Long baselines/network precise positioning Base stn data, precise orbits Geodesy, geoscience, etc

9 Commercial operations Support... Precise Positioning users National or project datum Science applications Support... Geodesy, geoscience, etc International Services data & products Global or project datum

10 GLOBAL, LONG-TERM REFERENCE FRAME Commercial operations Short baselines, high productivity Precise Positioning users National or project datum In Science applications International Services data, products & infrastructure Long baselines/network, precise positioning Geodesy, geoscience, etc Global or project datum Connection to datum

11 International Services & Infrastructure underpin Precise Positioning... Global Geodetic Reference Frame: International Earth Rotation & Reference Systems Service (IERS) Integrated outputs of multiple space geodetic techniques Definition & maintenance of International Terrestrial Reference Frame (ITRF) ITRF recognised as the highest fidelity global datum Global GNSS data & products: International GNSS Service (IGS) Global GNSS tracking (base stn) network Raw base stn data & derived high quality orbit & clock products freely available to all users The gold standard GNSS services & expertise

12 ? 1.1 Without a geodetic framework...???

13 1.2 The ITRF: the modern GGRF... What links isolated GNSS (& other surveys) is a Reference Frame defined at national or international level All modern national datums directly (or indirectly) aligned with ITRF; recognised the best GGRF All points, objects, geodetic control marks, GNSS CORS on the surface of the Earth move (4-D coordinates): Crustal motion Origin, Scale & Orientation Local deformation Ground subsidence or inflation etc It is now easy to link to the ITRF using GNSS techniques

14 2.2 International GNSS Service... IGS is an IAG service established in 1994 IGS is a voluntary federation more than 200 worldwide agencies in more than 90 countries that pool resources and permanent GNSS station data to generate precise IGS products IGS operates on a best efforts basis though with considerable redundancy IGS products are combinations of independent results from several ACs Improvements in signals, receivers and computations have led to continuous improvements in product quality Geospatial applications & earth science missions rely upon IGS products IGS launched in 2011 a Multi-GNSS Experiment IGS launched in 2013 a Real-Time Service

15 2.1 The IGS tracking network... ~450 stations ~150 real-time ~100 multi-gnss

16 2.3 The IGS Products... Primary products global raw IGS receiver tracking data GPS and GLONASS orbits station coords, contribute to: definition & densification of ITRF Related products clock corrections for satellites and IGS stations earth rotation parameters global ionosphere maps IGS station troposphere parameters standards & formats (site guidelines, RINEX, SINEX, IONEX, RTCM...) GNSS system monitoring (constellation status, DCB, )

17 Precise Positioning... some crystal ball gazing... non-differential PP techniques emerge... adoption of ITRF-based datums... transition from GPS-only to multi-constellation GNSS... real-time operations the norm, including for science... PP applications set for rapid growth... commercial PPP services, & other PP services... open standards & data formats... wider variety of PP hardware options, including non-gnss solutions... an increased role for international services such as IERS & IGS

18 From GPS to multi-gnss + GNSS: GPS (30) (32) GLONASS (24) (30) Galileo (4) (30) BeiDou (14) (35) RNSS: QZSS (1) (5-7) IRNSS (2) (7) SBAS: WAAS MSAS EGNOS GAGAN SDCM Number of satellites: (Current) (Planned)

19 Some benefits of PP GNSS in Australia 2008 study found productivity gains with potential cumulative benefit $73B to $134B over period of 20 years in agriculture, construction and mining alone Additional cumulative economic benefit $32B to $58B from a coordinated rollout of NPI Also, significant environmental benefits, such as reduced carbon footprint through improved fuel efficiency Market uptake in A-C-M still comparatively low, with new apps looming Economic benefits of high resolution positioning services, Allens Consulting Group, for CRC-SI & Vic. DSE, Nov 2008, download:

20 Advanced ITS PP applications... Positioning in vehicles is going from Passive to Active... from simple navigation to information about traffic to warnings about hazards to actively avoiding hazards... current local GNSS solutions inadequate...

21 Precise Point Positioning (PPP) GNSS constellation(s) CORS network GNSS user Infrastructureless? Or less CORS infrastructure? What has happened to the datum? Precise GNSS satellite orbit & clock corrections Real-time or post-processed? Commercial or free services? PPP or PPP-RTK?

22 Augmented PPP: PPP-RTK? GNSS constellation(s) CORS network Less infrastructure Local CORS network GNSS user Precise GNSS satellite orbit & clock corrections What has happened to the datum? Measurement biases

23 Commercial PPP services...

24 Free PPP via RT-IGS...

25 RTS IGS01/IGC01 products

26 RTS IGS01/IGC01 products

27 RTS IGS01... PPP Results Frankfurt a.m. SIS-UERE at decimetre-level

28 RTS IGS03... PPP results Frankfurt a.m. SIS-UERE at decimetre-level

29 A sign of things to come... RT-PPP enabled by geodetic services & OEM components GPS OEM + Open Source RTKLIB + Internet + RT-IGS = Low-cost RT-PPP

30 A sign of things to come... mass market PPP enabled by smartphone-type receivers, taking advantage of geodetic services

31 IGS in the future... High quality GPS/GLONASS network and products High quality multi-gnss network and products MGEX Build-up and share multi-gnss know-how Build-up network and provide access to multi-gnss data Develop prototype multi-gnss products Develop recommendations and standards Engage with receiver manufacturers and system providers RTS GPS PP Transition Merge legacy and multi- GNSS networks Achieve interoperability of legacy and multi-gnss products and services RTS GPS+ GLONASS Multi-GNSS Pilot Service Incorporate BeiDou, Galileo, and QZSS into standard IGS processing Issue combined and quality controlled multi-gnss IGS orbit, clock and iono products Regular multi-gnss intersystem, interfrequency and intersignal bias estimation Link GNSS system times with IGS system time Embed new GNSSs into IGS/IAG reference frames RTS for multi-gnss

32 Final remarks... Trends in the international scene impacting on PP use of ITRF-based national datums... increasing number of GNSS satellites & signals... increasing use of PPP-based techniques, hence global datum... global & regional services to support PP, commercial & free... increasing range of IGS products to support PP... mass market PP applications... global standards & formats, user requirements & solutions... increasing recognition of importance of Precise Positioning