FASSEN NEE EEE
Ambient Temp. -16 C
70 — 1 1e
Layer 3
60 — -14 C
SWE = 5.3 cm
40 — Layer 2
-6.5 C
SWE = 6.2 cm
| Solid Crus
203 4 Layer 1
SWE = 7 cm
-2C |
Figure 2. Snow pit profile (Target G3).
received diverging and sometimes contradicting advice
from experts concerning our experimental design. Finally
we adapted a simple linear regression design for the
establishment of relationships between SAR and SWE
data. As we collected a very large amount of ground data
on snow parameters and of SAR data (two incidence
angles, two SAR bands, four different polarizations), the
data analysis consumed a lot of time. In addition, we had
to write our own computer programs for the data display,
dumping, and analysis. We also encountered numerous
technical difficulties, most of them out of our control, which
made the data analysis a very difficult task.
Our overall conclusion based on partial data analysis is that
the single C-band VV polarization provided about the same
estimate of SWE as the HH polarization. The 3 by 3
averaging filter does not improve the precision of SWE
estimation but actually decreases it when only the
maximum snow cover SAR C band data are used.
Although our data analysis has not been completed and the
results are not fully conclusive, we learned a great deal
concerning the pitfalls of data collection and analysis.
We can also conclude that the field data collection and the
SAR data acquisition requires extreme precision. We are
now in a position to conduct further experiments which
would yield more conclusive results. We are planning to
use the Canadian RADARSAT and the Japanese JERS
satellite data to refine our procedure of SWE estimation.
ACKNOWLEDGMENTS
We would like to thank the Canada Centre for Remote
Sensing (CCRS) for providing the SAR data acquisition
under very adverse conditions. We acknowledge all the
help we received from various scientists of CCRS,
especially Dr. T. Lukowski for working out the absolute
calibration procedure. Thanks are also extended to Mr. W.
Smith, Site Service Manager Churchill Falls (L) Company
for the logistic support and to the members of the Water
Resources Management Section of the same company for
their help in the field data collection. The Faculty of
Engineering and Applied Science of the Memorial University
of Newfoundland (MUN), the Canadian Forest Service
(CFS, Newfoundland and Labrador Region) and the Water
Resources Division of the Newfoundland Department of the
Environment materially aided our research efforts. The
image analysis programs were written by Mr. A. Galloway
of MUN which we gratefully acknowledge.
REFERENCES
Bajzák, D. 1990. Newfoundland RADAR development
project. Memorial University of Newfoundland.
Project establishment report. St. Johns,
Newfoundland, Canada. 16 p. plus Appendices.
Bernier, M and J.P. Fortin. 1998. The potential of times
series of C-Band SAR data to monitor dry and
shallow snow cover. IEEE Trans. On Geosc. And
Rem. Sens. Vol.36, No.1. pp. 226-243.
Bernier, M and J.P. Fortin. 1991. Evaluation of the
potential of C- and X-band SAR data to monitor
dry and wet snow cover. Proceedings of
IGARSS'91. Espoo. Finland, June 3-6. Pp. 2315-
2318.
Caines, J.R. 1991. Snow Hydrology by remote sensing.
Status and preliminary analysis report. Seabright
Co. Ltd. Memorial University of Newfoundland.
St. John's, Newfoundland. St. John's,
Newfoundland, Canada. 33 p plus Appendices.
Donald, J.R., F.R. Seglenicks, E.D. Soulis, N. Kowen, and
S.W. Mullins. 1993. Mapping partial snow cover
during the melt season using C-band SAR
imagery. Can. Jour. of Rem. Sens. Vol. 19, No.
1. Pp. 68-76.
Grangerg, H.B., A.S. Judge, K. Fadaie and R. Simard.
1994. C-band SAR backscatter from northern
terrain with discontinuous permafrost: The
Schefferville digital transect. Can. Jour. of Rem.
Sens. Vol. 20, No. 3. pp. 245-256.
National Aeronautic and Space Administration. 1981.
Remote sensing of snow parameters from space-
synthetic aperture RADAR earth observation
666 International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998
Ran
Rang
Shi,
Shi, .
