86
ERDC TR-05-1
and scanning adds one additional dollar per acre over the cost of the CAMIS im-
agery (i.e., .00 per acre) gives a total cost to produce a true-color digital mo-
saic of approximately ,000. The false-color mosaic would double the price to
,000.
The one advantage that scanned hardcopy photos have over the CAMIS im-
agery is the potential to produce digital frames with very high spatial resolution.
Depending on the original scale of the photography, the pixel dimensions of the
scanned print can be very small (e.g., less than 0.25 m). CAMIS imagery can also
be acquired with extremely high spatial resolution by lowering the altitude of the
aircraft. A decrease in pixel size results in a decrease in the areal coverage of
each frame. The addition of frames needed to fully cover the site requires larger
digital file sizes. For example, to increase the spatial resolution from 1 to 0.5 m,
the total number of frames required to cover the same area increases by a factor
of four. To further increase the resolution to 0.25 m requires 16 frames for every
frame with 1-m pixels. The costs of post-processing and mosaicking these higher
resolution imagery increases at the same exponential rate, but would easily dou-
ble if pixel dimensions were decreased to 0.5 m and would more than double
with the decrease to 0.25-m pixels.
8.3
Invasive Species Mapping at Lake Okeechobee, Florida
The cost to acquire the December 2001 CAMIS frames was ,000. Image
post-processing and mosaicking costs were estimated at approximately ,000
(200 hours at /hour). Field data collection costs, including travel and labor,
are estimated at ,000. Image classification required another 00 (80 hours
at /hour). At a total cost of ,400, the completion of the CAMIS vegetation
classification required roughly /ha (.50/acre).
The IKONOS image acquisition costs were ,000. With no post-process-
ing steps necessary, image analysis was focused on developing the vegetation
class map. At total of 80 hours were used to develop the final map, for a total
cost of 00. The 4-m satellite image covers roughly 35,000 ha (85,500 acres)
of marshland. At a total cost of almost ,000, the IKONOS class map cost little
over
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per hectare (~
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.50/acre).The total costs for both of the vegetation class maps reflects an inadequate
amount of field data collection. The IKONOS data were processed without any
concurrent on-site observations. Based on the cost to visit the limited number
sample sites used to classify CAMIS mosaics, a more thorough field data cam-
paign would require at least three times the sample size. The number plots would
again increase to collect an adequate number of accuracy sample sites within the
CAMIS mosaic areas. The IKONOS image, covering seven times the area shown
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