Integrating Absolute Gravimetry into the Canadian Spatial Reference System: Current Efforts and Priorities

Joseph A. Henton, Jason Silliker, Jacques O. Liard, Mario Berube, Michael R. Craymer, Robert Duval, Carey Gagnon

Abstract:	The Canadian Spatial Reference System (CSRS) is the national terrestrial reference system in Canada, incorporating orthometric heights and the Canadian Gravity Standarizatrion Net (CGSN) that provides datum control for gravity observations across Canada. A modernization effort is currently underway in which precise absolute gravity (AG) will be employed to define and subsequently maintain control of Canada's national gravity datum. A Canada-wide array of approximately 60 absolute gravity (AG) sites is in the process of being surveyed. This modernization will also consolidate the AG sites with key Global Positioning System (GPS) points across Canada further integrating different aspects of the CSRS. Driven by glacial isostatic adjustment (GIA), the on-going viscous response of the solid-Earth due to past changes in ice sheets and sea levels, vertical motion is the major component of deformation exhibited for most of the Canadian landmass. Absolute gravimetry is a fundamental geodetic technique that is sensitive to radial changes in distance to the Earth's center-of-mass. Therefore AG can make an important contribution to better understand the time-evolution of the vertical component of the geometric reference frame within the Canadian Spatial Reference System (CSRS). The Canada-wide AG array will be multi-purpose and will support geophysical studies. FOr example, satellite gravimetry now offers images of mass changes which both inform and benefit from complementary terrestrial measurements. In this report we discuss the survey efforts to date for the Canadian AG array and outline our priority objectives associated with the national gravimetry effort.
Published in:	Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008) September 16 - 19, 2008 Savannah International Convention Center Savannah, GA
Pages:	3048 - 3056
Cite this article:	Henton, Joseph A., Silliker, Jason, Liard, Jacques O., Berube, Mario, Craymer, Michael R., Duval, Robert, Gagnon, Carey, "Integrating Absolute Gravimetry into the Canadian Spatial Reference System: Current Efforts and Priorities," Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008), Savannah, GA, September 2008, pp. 3048-3056.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In