PROBLEM: Where are the UTM zone boundaries?
Add two layers from the T:\12.114_Fall2011 folder, UTMZones.shp and worldCountries.shp. The UTM
layer is transparent so you can see the countries below the UTM Zones (but make sure that the zones
are “above” the countries in the map table of contents). You will need to change the display parameters
of the UTM zones layer, making each adjacent zone a different color, eliminating the border lines, and
labeling the zones. We will walk through this in class.
Find the UTM projection for two north-south trending countries
You will be looking at how well UTM zones match political and physical realities.
Find the optimal UTM zone for Portugal and Chile. Do you need to modify the UTM zone? Does either of
these countries span more than 6 degrees in east-west extent? You will need to use the Arcmap
measuring tool to measure distances (and you can measure in degrees).
For the following two problems, you will need to use the modify projection tool.
Problem: make a conic projection for Montana
You will be seeing how the 1/6 rule is employed, or not, in practice (in the State Plane Coordinate
System).
In a new Arcmap window, add the Montana.shp layer from the T:\12.114_Fall2011 folder. Be sure that
your map is in geographic coordinates.
Use the one sixth rule to determine the appropriate standard parallels for Montana. Also find the best
central meridian. Apply this by changing the map projection using the form found under the View menu
under Data Frame Properties and click on the coordinate tab. This is easiest done by choosing any conic
projection, such as the USA Contiguous Albers Equal Area Conic projection under the Predefined>Projected Coordinate Systems->Continental->North America path and then modifying the parameters.
For this exercise you can disregard the false easting and northing as well as the latitude of origin. Check
how the parameters that you choose compare with the Montana State Plane projection.
The Montana solution keeps most of the state (except the extreme SW corner) within the standard
parallels. This limits distortions to areas and distances to being slightly under its actual size.
Problem:
Compare Vermont’s State Plane projection with the UTM zones. You will need to add the Vermont.Shp,
the UTMZones.shp, and the StatePlane.shp layers. Does Vermont fit into a single UTM Zone? Check for
which UTM zone Vermont is in. Also check for the code for the State Plane projection for Vermont.
Once you know the State Plane Project, find out how it is defined. The easiest way to find this is by
changing the map’s projection. Do this by clicking of View then Data Frame Properties. Change to the
Coordinate System tab. Follow this path: Predefined->Projected Coordinate Systems->State Plane>NAD 83 and select NAD 1983 StatePlane Vermont FIPS 4400 (which should match what you found in
the database.
Change the stock NAD 83 UTM Zone 18 to accommodate Vermont’s geographic extent using the Map
View’s Data Frame Properties.
This example shows you were the local system is a slightly altered UTM zone, which limits the distortion
to less than 0.1%.