International Association of Geodesy   COMMISSION 4: Positioning & Applications Sub-commission 4.5: Next Generation RTK

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Terms of Reference

Current carrier phase-based Real-Time Kinematic (RTK) positioning at the centimetre accuracy level requires the combination of observations from two GPS receivers, with one serving as the base station with known coordinates and another as the mobile/user station. One significant drawback for this approach, however, is the practical constraints imposed by the requirement that simultaneous observations be made at the user and reference stations, and that the user station be within the vicinity of the reference station typically up to 20 kilometres. Development of methods and algorithms to eliminate such constraints for increased flexibility and accessibility using RTK therefore presents a current trend. This Sub-Commission will identify, encourage investigation into the important research issues and problems for the development of next generation RTK technologies, report on such developments, and will promote international collaborations among researchers and organisations from academia, government and private sectors. The latter will be done through linkages with sister scientific and professional organisations, and especially with the IAG's International GPS Service (IGS).

Steering Committee

Yang Gao (Univ. of Calgary, Canada) - Chair
Lambert Wanninger (IngenieurbŸro Wanninger, Germany) - Vice-Chair
Wu Chen (The Hong Kong Polytechnic Univ., Hong Kong) - Secretary
Mark Caissy (Natural Resources Canada, Canada) - Member at Large
John Raquet (Air Force Institute of Technology, USA) - Member at Large
Sunil Bisnath (York University, Canada) - Member at Large

Objectives

The objective of the Sub-Commission are to promote collective research efforts on the development of new methods and technologies for next generation RTK and to stimulate strong research collaborations among international organisations, including the industry. The main objectives of SC4.5 will be:

• To identify and investigate important technical issues in next generation RTK system development.

• To investigate and develop data standards and operational procedures for next generation RTK, including the communication protocols and message formats.

• To establish collaborative relationship with other organisations, and especially with the IGS.

• To develop strong links with the industry sector.

• To participate and organise international conferences, workshops and meetings.

Working Groups

WG4.5.1 Network RTK

Chair: Lambert Wanninger (IngenieurbŸro Wanninger, Germany)
Co-Chair: Ola Ovstedal (Agricultural University of Norway, Norway)
Terms of Reference: To study the various technical aspects of network RTK positioning and to stimulate further research work in this field. To report progress on the development of GNSS reference station networks for RTK positioning.

WG4.5.2 Carrier Phase Based Precise Point Positioning

Chair: Sunil Bisnath (York University, Canada)
Co-Chair: Maxim Kechine (Tech. Univ. of Delft, The Netherlands)
Terms of Reference: To address and investigate issues and problems related to the development of a new RTK positioning technology based on the processing of un-differenced carrier phase (and pseudo-range) observations without the need of a reference station.

WG4.5.3 High Precision Positioning on Buoys and Moving Platforms

Chair: Wu Chen (The Hong Kong Polytechnic Univ., Hong Kong)
Co-Chairs: Mark Dumville (Nottingham Univ., UK), Oscar Colombo (NASA, USA)
Terms of Reference: To study precise positioning in marine environment including precise positioning algorithms on moving platforms, multipath effects off water surfaces, and data fusion of GNSS and other ocean environment sensors. To promote the collaboration of researchers from different research areas, including geodesy, navigation, oceanography, and meteorology.

WG4.5.4 Multiple Carrier Phase Ambiguity Methods & Applications

Chair: Yanming Feng (Queensland University of Technology, Australia)
Co-Chair: Hiro Ishiki (Institute of Mathematical Analysis, Japan)
Terms of Reference: The next generation GNSS, such as modernized GPS and Galileo systems, offer three and more carriers for civilian use. With respect to the current GPS two-frequency signals, additional frequencies can bring significant benefits to GNSS applications. Dormant features include the ability to provide aviation and other transportation users with continuous, accurate three-dimensional position information, especially precision-approach navigation worldwide and redundancy in the event of electromagnetic interference or jamming. The full potential of the three and more frequencies for professional positioning and scientific communities, however, has yet to be fully explored. The Working GroupÕs work will focus on the development of the efficient approaches to carrier phase ambiguity resolution with three and multiple GNSS signals, so-called Three Carrier Ambiguity Resolution (TCAR) or generally Multiple Carrier Ambiguity Resolution (MCAR). The effort will improve real time kinematic positioning (RTK) performance over long ranges in particular, but extend TCAR/MCAR to other precise applications on local, regional and global scales.