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data. The digitizing process is done by pointing the
measuring marks on the analytical plotter at features and
recording feature coordinates in a format suitable to
directly input into the data base. Coordinates can be in
"real world" coordinates and they do fit "on the ground".
The host computer in the analytical stereoplotter system
provides the converting methodology that is required.
Edit - Data digitized either from maps or aerial imagery
must be checked prior to final placement into a permanent
file in the GIS. This edit process from maps or imagery
can be accomplished in much the same way. Use of an
interactive CRT can be made to display digitized data as
it is being gathered. Many of these systems can enlarge
the data to check that lines properly join, etc. The
operator can interact with the CRT to join lines, delete
data, etc. Data should be edited layer by layer and with
all layers shown to assure that, for instance, drainages
and contours cross with proper relationships. After edit
of data, it is placed in permanent files, as appropriate,
for a particular GIS.
DATA ACQUISITION COSTS
Costs displayed in this section are those incurred by use of an analy
tical plotter, specifically the US-2. Costs are related to a MICRO GIS
need that is equal to a map at a scale of 1:4800 with a contour inter
val of 10 feet and spot elevation accuracies of 2 feet.
Cost of operation of the analytical stereoplotter:
Cost of US-2 ~ $125,000
Hourly Cost Amortization
Amortization over a 5-year period
or 5 years X 1,800 hr. yr. = 9,000 hrs.
or $125,000
9,000 hrs. = $13.89 hr.
Total Cost per Hour to Operate Analytical Plotter
Amortization US-2
$13.
.89
Operator
10,
.00
Related Personnel Cost
1.
.80
Material Cost
2.
.75
Overhead
8.
.50
Total Hourly Cost $36.94