6. CONCLUDING REMARKS
This study, which has been conducted under the auspices of the
SPOT 5 HRS-SAP, has examined the accuracy of DSMs
created from SPOT 5 HRS imagery via an affine projective
sensor orientation model. The affine model has previously been
shown to produce highly successful geopositioning and DSM
results with other high-resolution satellite imaging systems.
The results obtained have shown that, at least for a 10km by
lOkm area in the centre of a pair of SPOT 5 HRS images,
DSMs with a vertical accuracy of 3-5m, or about 0.6-1 pixel,
can be obtained. No information on the sensor model or satellite
ephemeris is required to attain this accuracy, but a modest
number of well-measured GCPs are required to determine the
parameters of the affine model. In this case, configurations of
10 and 20 GCPs were considered. The results obtained indicate
very little accuracy distinction in the final DSMs for the cases
of 10 and 20 GCPs.
The scope of the work presented has been limited in that no
tests have thus far been carried out with full-scene images.
Future work will investigate the performance of the affine
model over full-scene HRS images, where the effective field of
view is substantially larger than the 17-2" range in which the
assumptions implicit in this linear model have been shown to
hold up well for all practical purposes.
7. ACKNOWLEDGEMENTS
This study was partially funded by a Discovery Grant from the
Australian Research Council. The authors wish to thank Ms.
Joanne Poon and Mr. Simon Cronk for their assistance with the
data processing.
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