GIS Survey Class

Assignment 7: Projections in GIS and Saving Your Work

Projections are a critical part of map making, each creates a different distortion of the face of the earth.  To give you an example of how important it is to understand them let me point-out that the "streets" currently in the Bellingham City gis database do not properly match the "roads" in the U.S. Census database for the city.  Imagine giving a presentation before a group where roads are cutting across someone's backyard (opps... better think of a new career).

Assignment Requirements:

Part 1: Activities

This is a straight forward and quite easy but interesting exercise

1. Choose a country(ies) and cities to test with projections (on the c: drive the data under c:\ESRI|ESRIDATA\ can be used -- more distant places show the variation more easily) and determine how they effect distances. Experiment with at least 5 projections for the same two cities.

2.  Move your data to a new file on the  u:\ drive or the "c:\temp\your-new-folder", perform your work by choosing different projections, measure a distance between two known points, and record your results below.  Make maps of at least 5 of your projections and export them as jpeg images.

3.  Save your project to the same "your-new-folder".  Be ready to display this work next class period if time permits.

Part 2: Write-up

1. TABLE: In a table format list the From and To location for your measurement, the projection, and the distance (you may copy and paste this into your MSWord document if you use MSExplorer).

From	To	Projection	Distance	Comments

2. DISCUSSION: Discuss your results. Address issues such as which do you feel is best and why? When would you use each of these projections and why?

3. MAPS: Make at least 3 maps of your results. Besides the usual information required on a map, also include the projection name and distance between the two locations on the map this could be a second line in the title, or separate text written on the map.  Export these maps as jpeg images and insert them directly into your write-up as pictures.  You may wish to include them as part of the discussion section above each comment.

4.  PROCLIB: Write a short proclib for the steps necessary to make a jpeg of your layout map and bring it into your MSWord document.