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).
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.
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.