87 
Figure 7 - Composite "snap-shot" of GEOSAT-derived 
l°-degree zonal averaged surface current variability. 
Space/time variability is estimated with respect to a 2-year 
long mean [After Christou (1990)]. 
satellite altimetry data. Given the complexity of using such 
data for monitoring global change in Canada, the most 
important aspect of satellite altimetry data collection is to 
built on past data sets (e.g. GEOS-3, SEASAT and 
GEOSAT) and continue archiving data and data products 
from the future missions (e.g. with data from TOPEX, 
ERS-1, etc.). In the long term, these data will be combined 
with information of ocean density and applied to theories of 
ocean dynamics to produce for the first time accurate 
models of how regional and global ocean circulation (from 
the surface to the sea floor) changes over time. 
SUMMARY 
within relevant government agencies supporting a 
national global change program for the coordination, 
acquisition, processing, archiving and distribution of 
current and future altimetry data sets; 
• ensuring the adequacy of existing capabilities and the 
continuation of current efforts to apply the information 
derived from the GEOSAT Exact Repeat Mission; 
• providing the means to develop prototype processing 
facilities, product preparation and data utilization 
schemes for future operational space platforms with 
altimetry instruments (e.g. ERS-1, TOPEX, Eos/GLRS, 
etc.); 
• preparing for the conduct of altimetric operations of 
the ERS-1 polar mission over the Canadian ice-covered 
regions and Arctic ice-sheets; and finally 
• bringing this technology into an operational environment 
where it will be used for global climate studies. 
ACKNOWLEDGEMENTS 
The second author wishes to thank his supervisor Dr. R.B. 
Langley, Department of Surveying Engineering, University 
of New Brunswick for his expert advice and guidance 
during the course of his disseration work. Also the 
continual financial support the author received through 
NSERC operating grants held by R.B. Langley is gratefully 
acknowledged. Henry S.H. Li, Department of Surveying 
Engineering, University of Calgary and Dave Fielder, 
Department of Mathematics and Computer Science, 
Waterloo University while on Co-Op Student Assignments 
at the Geodetic Survey Division, Canada Centre for 
Surveying have provided valuable computational support 
and developed various data management and graphics 
modules for the analysis of GEOSAT data. 
REFERENCES 
Chaney, R.E., B.C. Douglas, R.W. Agreen, L. Miller, D.L. 
Porter and N.S. Doyle (1987) - "GEOSAT Altimeter 
Geophysical Data Record User Handbook", NOAA 
Tech. Mem. NOS NGS-46, Nat. Ocean Service, 
Rockville, Md., July. 
That satellite altimetry techniques would be a remarkable 
means of monitoring ocean circulation and its role in 
shaping world climate was never in doubt. The recent three 
years of successful GEOSAT observations have 
demonstrated that this is the most efficient way for the 
global study of the oceans from space. However, 
expansion of this observing system to provide a global sea 
level measurement reference base, to produce a multi 
parameter oceanic database for diagnosis and prediction, 
and to provide assessment of the potential rise in sea level 
and its likely impact on climate change requires a much 
more significant, and well-focused government 
commitment. For Canada specific priorities include: • 
Christou, N. (1990) - "On the Space-Time Ocean Current 
Variability and its Effect on the Length-of-day", Ph.D. 
Dissertation, School of Graduate Studies and Research, 
University of New Brunswick, May. 
Haines, B.J., G. H. Bom, G.W. Rosborough, J.G. Marsh 
and R.G. Williamson (1990) - "Precise Orbit 
Computation for the GEOSAT Exact Repeat Mission", 
J. Geop. Res. Vol. 95, No. C3, March, pp. 2871-2885. 
Keating, M. (1989) - "Toward a Common Future: A Report 
on Sustainable Development and its Implications for 
Canada", Dept. Supply and Services Canada Report No. 
En 21-83/1989E. 
• a needed clear definition of primary responsibilities