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otography.
orectified
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The results from the orthophoto satisfy the
NATO A rating planimetric accuracy
(CMAS=25m) for the 1:50 000 maps,
equivalent to standard deviation of differences
of £8.3m.
Although no extensive tests were performed at
these stage, the overlay between vector data and
the digital orthophotography demonstrated a
good fit between the two types of data. The
visual identification of changes was much easier
than the one from the satellite image and was
supported very well with the image processing
capabilities of the CARIS system.
5.0 CONCLUDING REMARKS
As a result of the map revision pilot project,
CCM's in-house expertise in vector data
generalization, raster image processing, and
raster and vector data integration has increased.
Having completed the derivation of the pilot
area through the generalization of a 1:50 000
data set, the requirements for data generalization
to produce 1:250 000 data are very clear. In
order to pursue this methodology, sixteen
1:50 000 digital data sets covering the
1:250 000 map are required. Although the pilot
site was revised using Landsat TM imagery and
the accuracy requirements are met, the team has
some reservations concerning the sole use of
Landsat TM imagery for 1:250 000 map
revision. These reservations are based on the
uncertainty in identifying and collecting certain
features. Ancillary information will be required
to improve the feature identification process
(aerial photography, existing maps, field
checks, etc.), as well as the use in the future of
image segmentation techniques. The
combination of the Helava system for the
production of digital orthophotographs with the
CARIS system offering real vector/raster data
integration for the revision of existing digital
spatial databases proved to be quite successful.
It can be effectively implemented to a full
production and quality assurance system. The
production of image maps is also possible. A
more thorough evaluation of this system
integration and application for map revision
from digital orthophotographs is in progress
Vm the revision of an entire 1:50 000 map
sheet.
ACKNOWLEDGMENTS
The contributions of the team members Gilles
Auger, Art Dow, Rolland Dussault, Benoit
Frappier, Héléne Lachance and Jeffrey Young
are gratefully acknowledged.
REFERENCES
Bouloucos T., R. Kunarak, K. Tempfli (1992)
"Low-cost feature extraction from aerial
photographs for database revision", Inter.
Archives of Photogrammetry and Remote
Sensing, Vol. XXIX, Part B4, Com. IV, pp.
493-498.
Colvocoresses A.P. (1986) "Image mapping
with the Thematic mapper", Photogrammetric
Engineering and Remote Sensing, Vol. 52, No.
9, pp. 1499-1505.
Derenyi E.E. (1991) "Design and development
of a heterogeneous GIS", CISM Journal
ACSGC, Vol. 45, No. 4, pp. 561-567.
Derenyi, E.E, T.Y. Shih (1991) "Digital map
revision in a vector/raster environment”, internal
paper, University of New Brunswick.
Halim M., E. Derenyi, R. Pollock, T.Y. Shih,
C.K. Xian (1992) "Design and implementation
of a GIS based digital image processing
system", Inter. Archives of Photogrammetry
and Remote Sensing, Vol. XXIX, Part B4,
Com. IV, pp. 776-780.
Mackaness W.A. (1991) "Integration and
evaluation of map generalization", in Map
Generalization edited by B.P. Buttenfield and
R.B. McMaster, pp. 217-226.
Turner. A.M., .D.R.... Stafford... (19087)
"Operational revision of national topographic
maps in Canada using Landsat images", ITC
Journal 1987-2, pp. 123-128.
USL (1992) "Guide to using image data in
CARIS", Universal Systems Ltd.
Welch R., T.R. Jordan, M. Ehlers (1985)
"Comparative evaluation of geodetic accuracy
and cartographic potential of Landsat-4 and
Landsat-5 Thematic mapper image data",
Photogrammetric Engineering and Remote
Sensing, Vol. 51, No. 11, pp. 1799-1812.
Welch R. (1989) "Desktop mapping with
personal computers”, Photogrammetric
Engineering and Remote Sensing, Vol. 55, No.
11, pp. 1651-1662.
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