Compiled By: Rauf Tabassum
•Issues to Consider:
–extent of area to map: city, state,
country, world?
–location: polar, mid-latitude,
equatorial?
–predominant extent of area to map: E-W,
N-S, oblique?
•Rules of thumb
–Choose a standard for your organization
and keep all data that way.
–Also retain lat/long coords in
the GIS database if possible
–for small areas, projection is less
critical and datum is more critical; reverse for large areas
–check contract; does it specify a
required projection? State Plane or UTM
often specified for US gov. work.
–use equal-area projections for thematic
or distribution maps, and as a general choice for GIS work
–use conformal projections in
presentations
–for navigational applications, need
true distance or direction.
–Even though modern GIS systems are
sophisticated in their handling of projections, you ignore them at your
peril
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