Abstract
This lab was conducted using a tutorial developed by ESRI. Throughout the tutorial I was tasked with being able to understand the effects of using the correct coordinate systems as well as datum planes and how these effect GIS mapping. Through the usage of many different task such as that of labeling key cities in African countries I was able to see first hand how no matter what coordinate system is used projections will never be perfect and you will always have to compromise with deviations caused as a result of the chosen coordinate system.
Methods
Using one of ESRIs training tutorial along with the program of ARC-GIS I completed this lab. All data for this lab was provided from the ESRI tutorial so no further data gathering was required. At the end of each activity in the tutorial I completed required quizzes to be able to test my knowledge of the work I had completed. As a result of my successful completion of the lab I earned the Certificate of Completion of the introductory course related to projections and coordinate systems.
Figure 1: Certificate of Completion
Discussion
Being able to choose the right type of projection for your map is extremely important to how your map itself will visually turn out and how it will display your data. Furthermore when deciding what type of projection you want to choose remember to think about what properties of the map you are going to want to preserve such as the properties of area and direction.
Not all Coordinate systems are the same which means that you will be able to see an offset between different layers that are using different coordinate systems. When looking at Figure 1 you can see the offset between the different coordinate systems where assigned to different layers of the projection.
Figure 2: In this image I was measuring the offset created between the Clarke 1866 layer which is in purple and the WGS 1984 layers which is in orange.
In one of the excersizes in this lab I needed to be able to display specific cities in specific countries throughout Africa. This proved to be a challenge because part of the lab was to figure out why some data was not appearing properly. What I learned however through the completion of this is how it is important to make sure that all your projections are using the same coordinate system as the default coordinate system that ARC-GIS assigns to the data may not necessarily be the same coordinate system that you need for you projections causing your data to appear improperly.
Figure 3: This is how some of the coordinates where displayed which is obviously incorrect because none of these locations are in the middle of the ocean.
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