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Geomatics Principles and Thematic Resolution
Based on the mapping project, a user will need to select and plan for at
least the following:
- Datum
selection for the GIS project (preferably NAD 83)
- Projection
for the data collection (i.e. Lat./Long. or UTM) If another projection is needed,
such as state plane, additional duties and problems with thematic
compilation with surrounding analyses will occur. Consult your GIS team
for guidance before selecting these alternative projections.
- Resolution
of the product based on scale and collection of imagery, quadrangle compilation
source, orthophoto base, etc.
- Accuracy
NEEDED, not DESIRED to answer the project question or drive the solution parameters.
- Positioning environment;
moving object, fixed waypoints, forest canopy likely, topographic masking,
steep-sided canyons? What geometry relative to the sky will you encounter?
- Cost of acquisition
in field time, methods, and observations.
- Cost of equipment
and associated GPS accessories, power sources, cabling, and antennas.
- Cost of software
to download, compile, convert, or otherwise prepare GPS data for GIS use.
- The implied order
of these items assists in a logical determination of tool selection.
- Develop a TOOLBOX of suitable receivers
or methods to accomplish positioning tasks suitable for the thematic layer
in question. Match the resolution to the layer's inherent accuracy goal. All
data (i.e. elk winter range habitat) does not have to be 1 meter or sub-meter!
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