Progress Report

Project GEOIDE ENV#14

Research Team and Partners


Research Team

Dr. Rock Santerre, Scientific Supervisor, CRG (Centre for Research in Geomatics, Laval University)

Dr. Richard B. Langley, Scientific Supervisor, UNB (Department of Geodesy and Geomatics Engineering, University of New Brunswick)

Dr. Donghyun Kim, Post Doc., UNB

Annie Biron, M.Sc. Student, CRG

Dr. Mami Ueno, Research Associate, CRG

J. Sanscartier, Research Associate, part-time, CRG

Peter Stewart, Research Associate, part-time, UNB

Paul Collins, Research Associate (until September 1999), part-time, UNB



Viasat (Viasat Geo-Technologie inc.): Denis Parrot, Claude St-Pierre (Research Associate, part-time).

GSD (Geodetic Survey Division, Geomatics Canada): Pierre Tétreault

CCG (Canadian Coast Guard): Guy Marceau

CHS (Canadian Hydrographic Survey): Daniel Langelier


Research activities

OTF phase ambiguity resolution

Dr. Mami Ueno was involved in the analysis of the OTF results of the CHS’s hydrographic survey in the 1998 sounding season. She also worked on the integration of a priori information on water level (from the COWLIS tide gauges) to impose constraint on the resolution of phase ambiguities (Ueno and Santerre, 2000). Viasat also supplied to CRG intermediate results from the Bathykin software to facilitate the analysis of the data. Dr. Ueno also worked with the data collected during the OTF tests conducted by CHS and CCG, last September and October.

Dr. Donghyun Kim continued his work on an optimised least-squares ambiguity search technique and on the improvement of reliable and robust OTF solutions. Detection of outliers and cycle slips present in phase observations have also been addressed. Data sets from the CHS 1998 sounding season have been used for testing the potential of the new algorithms (Kim and Langley, 1999a; 1999b). Viasat has also supplied UNB with a copy of the Bathykin software for the comparison of the results.


Ionospheric modelling

C. St-Pierre has worked on the development of algorithms for the modeling of ionospheric errors in collaboration with the CRG. Research activities and results can be found in the following publications: (Santerre and St-Pierre, 1999) and (St-Pierre et al., 1999).

UNB has carried out ionospheric investigations as part of its Nav Canada-sponsored Wide Area Augmentation System work (Stewart and Langley, 1999). Results of this work will be applied as appropriate to the GEOIDE investigation.

GSD is going to provide expertise on regional ionospheric modeling. Most of their contribution will come in the following months.


GLONASS positioning

Annie Biron has started the development of software for combined data processing of the pseudoranges from GPS and GLONASS for absolute and relative positioning. First results have been obtained by the end of September. During the next months, she will start developing software for GLONASS, particularly for the resolution of GLONASS phase ambiguities.

UNB has acquired two GPS/GLONASS dual-system receivers. Funding for this equipment came primarily from non-GEOIDE sources. However, for one of the receivers, a state-of-the-art choke ring antenna was acquired using GEOIDE funds. One of the receivers will be installed as a permanent base station in Fredericton with its data made available in real time via the Web.

GSD will arrange access to the data collected with their dual frequency GPS+GLONASS receiver.


GPS antenna phase centre calibration and phase observation weighting

The UNB Electrical Engineering Department has calibrated, in their anechoic chamber, the phase centre variation of two of the CRG geodetic GPS antennas (a D-M chokering antenna and a geodetic Ashtech Z-XII antenna).

P. Collins and P. Stewart prepared a memorandum on the interpretation of S/N (signal to noise) ratio to properly weight GPS phase observations (Collins and Stewart, 1999).


GPS-OTF field tests

CHS and CCG planned and coordinated the OTF and ionospheric tests conducted on the St-Lawrence River from the 23th to the 28th of September, in the area of Trois-Rivières and from the 13th to the 20th of October, in the region of Quebec City.

The contribution of CHS was to give access to two of their survey ships Smith and Puffin and to the GPS data collected during the sounding seasons of 1998 and 1999. They have also provided data from the COWLIS (tide gauges) network. CCG provided GPS data from its OTF-RT stations located at Lauzon, Ste-Marthe and L’Acadie. The interpolation of water level from the COWLIS tide gauges (SINEM) has also been provided by CCG.

J. Sanscartier from CRG participated to the field tests. During these tests, CRG also provided a dual-frequency receiver. Viasat also collected GPS data at its office in Montreal during these tests.


GEOIDE ENV#14 Internet site

A new Internet site has been developed by J. Sanscartier at the CRG which included most of the activities performed within the Project GEOIDE ENV#14 ( see Section: Research).



With respect to the planned milestone for the first year (see below), the only aspect which we have not dealt with is the use of precise real-time orbits. This will be addressed during the second year of our project. The other planned research activities have been initiated as described above.

Milestone Year-1: Ionospheric modeling; Integration of the GLONASS observations; Use of precise real-time orbits.

Milestone Year-2: Ionospheric modeling; Integration of the GLONASS observations and the use of multiple reference stations; Use of precise real-time orbits.

Milestone Year-3: Network solution from multiple reference stations; Radio communication management.


Exchange of personnel

Exchange of personnel between CRG and UNB has been discussed. Possibility also exists for Viasat to invite researchers to work with their Research and Development staff in Montreal. GSD would like to come to the CRG to work on GLONASS and ionospheric modeling. These exchanges will be realised during the next year.


Links with the GEOIDE Network

Richard Langley is participating in two other GEOIDE projects (ENV#17, RES#47).

Denis Parrot is a member of the GEOIDE Board of Directors.

Dr. Mami Ueno had previously worked with Martin Lee-Gosselin’s team (Dr Lee-Gosselin is the Scientific Leader of the Project SOC#8).

Seven other researchers of the CRG (R. Santerre’s colleagues) and three other professors from UNB (R. Langley’s colleagues) are participating at 16 of the 20 GEOIDE projects.

The research activities within the Project GEOIDE ENV#14 are quite closely related to the scope of Special Study Groups sponsored by the International Association of Geodesy. Drs. Santerre and Kim are members of the Special Study Group SSG1.179 – Wide Area Modelling for Precise Satellite Positioning and Dr. Langley is member of the Ad Hoc Working Group – Refractive Indices of Light, Infrared, and Radio Waves in the Atmosphere.

R. Langley and D. Kim held discussions with international researchers on OTF ambiguity resolution at the International Symposium on GPS-Application to Earth Sciences and Interaction with Other Space Geodetic Techniques, in Tsukuba, Japan, in October. During a subsequent visit to South Korea, Dr. Kim visited 8 universities, 9 government research institutes and agencies, and more than 10 private companies to discuss GPS research activities and to foster collaboration between S. Korea and Canada in GPS-related research.


Project GEOIDE ENV#14 Meetings and other participation in the GEOIDE Meetings

Meeting of R. Santerre and M. Ueno with the Canadian Hydrographic Service (Quebec Region) at the Maurice-Lamontagne Institute concerning their participation in the Project GEOIDE ENV#14. 13 April 1999, Mont-Joli, Quebec.

Attendance at the GEOIDE Regional Workshop, Ste-Foy, 29 April 1999 (R. Santerre, M. Ueno, A. Biron, G. Marceau, D. Langelier).

Attendance at the GEOIDE Regional Workshop, Fredericton, April 1999 (R.B. Langley and D. Kim).

Presentation by R. Santerre of the GEOIDE Network and Project ENV#14 at the Canadian Coast Guard in Quebec City, 3 May 1999.

First Meeting of Project ENV#14, U. Laval, 28 May 1999. (Attendance: R. Santerre, M. Ueno, A. Biron, R.B. Langley, D. Kim, D. Parrot, C. St-Pierre, L. Lamoureux, P. Tétreault, G. Marceau, D. Langelier), see for the Summary of the Meeting. Followed by UNB and CRG Technical Presentations on May 29th.

GEOIDE First Annual Workshops, Château Bonne-Entente, Ste-Foy, 9-10 September 1999 (Attendance: R. Santerre, M. Ueno, A. Biron, D. Kim, D. Parrot, C. St-Pierre, P. Tétreault).

R. Santerre made a presentation of Project ENV#14 and was Member of the Discussion Panel: Data Acquisition Workshop, during the First GEOIDE General Assembly, Ste-Foy, 9 September 1999.

Second Meeting of the Project ENV#14, Château Bonne-Entente, 9 September 1999. (Attendance: R. Santerre, M. Ueno, A. Biron, D. Kim, D. Parrot, C. St-Pierre, P. Tétreault), see for the Summary of the Meeting.


Publications and Presentations (in reverse chronological order)

Santerre, R., R.B. Langley, M. Ueno, A. Biron, D. Kim, D. Parrot, C. St-Pierre, P. Tétreault, G. Marceau et D. Langelier (2000). "Amélioration du positionnement cinématique GPS-OTF sur de longues distances: Applications aux levés bathymétriques." Résumé soumis pour la Conférence Hydrographique du Canada 2000, Montréal, Québec, 15-19 mai.

Ueno, M. and R. Santerre (2000). "Improvement of GPS ambiguity resolution using height constraint for bathymetric surveys." Abstract accepted for the Geomatics 2000 Conference, GEOIDE Session: Data Acquisition, Montreal, Quebec, 8-10 March.

St-Pierre, C., D. Parrot and R. Santerre (2000). "Reference Station Network: A solution for precise GPS positioning over long distances." Abstract submitted for the Geomatics 2000 Conference, Montreal, Quebec, 8-10 March.

Santerre, R. et R.B. Langley (1999). " Amélioration du positionnement cinématique GPS en temps réel sur de longues distances: Application aux levés bathymétriques." Présentation dans le cadre des Séminaires du Centre de Recherche en Géomatique, Université Laval, 3 décembre (see

St-Pierre, C., R. Santerre and D. Parrot (1999). "Improvement of OTF-kinematic GPS positioning over long distances using ionospheric regional modelling." Geomatica, Journal of the Canadian Institute of Geomatics, 53(4), pp. 291-299. (Invited Paper, Special Issue on Geomatics 2000 Conference and on the GEOIDE Network).

Kim, D. and R.B. Langley (1999a). A search space optimization technique for improving ambiguity resolution performance and computational efficiency. Proceedings of the International Symposium on GPS-Application to Earth Sciences and Interaction with Other Space Geodetic Techniques, 18-22 October, Tsukuba, Ibaraki, Japan, Presentation Session Number: 10-11.

Kim, D. and R.B. Langley (1999b). "An optimized least-squares technique for improving ambiguity resolution and computational efficiency." Proceedings of the U.S. Institute of Navigation ION GPS’99 Conference (CD-ROM), Nashville, U.S.A., 14-17 September, 9 pp. (in press).

Collins, P. and P. Stewart (1999). "GPS SNR Observations." Internal Memorandum for the Project GEOIDE ENV#14, Department of Geodesy and Geomatics Engineering, UNB, July, 8 pp.

Santerre, R. and C. St-Pierre (1999). "Improvement of precise and reliable kinematic GPS positioning in real-time over long distances." Presented at the International Union of Geodesy and Geophysics XXII General Assembly, Birmingham, U.K., 18-30 July.

Langley, R.B. and P.J. Stewart (1999). "Mitigating the Effects of Space Weather on the Canadian WAAS." Presented in Session JSG28, "Probing the Atmosphere by GPS", IUGG99, 22nd General Assembly of the International Union of Geodesy and Geophysics, Birmingham, England, 19-30 July.

Santerre, R. (1999). "Travaux de recherche sur l’amélioration de la solution GPS-OTF (projet GEOIDE)." Conférencier invité dans le cadre des Séminaires de l'Institut Maurice-Lamontagne, organisé par le Service Hydrographique du Canada, Mont-Joli, 4 février.


Other comments

Our research team is relatively small (two universities involved) but we humbly believe that it is efficient. A small team is easier to manage. So, instead of spending a lot of time for management and co-ordinating works we spend more time on our research activities. UNB and CRG shared half and half the research budget which leaves a substantial amount of money to establish two viable research groups (with good relationships between them) composed of post-doctoral fellows, graduate students and research assistants in each of our two universities.


Équipe GPS ] Étudiants gradués ] Travaux de recherche en géodésie à l'Université Laval (1995-1999) ] Points géodésiques de la forêt Montmorency ] Projets de recherche ] Informations GPS ] Brevets ]