We have been learning a lot about about projections and coordinate systems. Based on what was taught, students were tasked to create a map of Miami using Albers and UTM datasets. As taught, there are many ways that you can project data. Therefore when dealing with different data sets that have different projections, it is vital that one knows how to change these projections to their desired outcome. This is important because in most analytical functions used, multiple data sets are to be in the same condition coordinate system. Therefore, in this activity, we learnt how to re-project data sets. Firstly, students utilized one of several tools found in ArcToolbox. A tool named Project tool was used change the coordinate system to UTM instead of Albers and having both in separate data frames. Upon viewing these data frames separately, a slight change was observed only. In addition to changing coordinate systems, students learnt how to add new fields in the attribute table and also add data into the new field. Therefore, a field labeled "Area" was added and thus, the value for area being displayed was added to that field by using the calculate geometry function. This was done for both data frames( Alber and UTM). Although the change between the two projections was slight, a difference was clear when the area of both data sets were calculated since the areas was different for both. At the end of the exercise, a map showing the two different projections was made. It also displayed the area of the two projections for four counties: Alachua, Escambia, Polk and Miamia-Dade. The map was finished by adding basic map features such as the scale bar and scale text, legend, title, north arrow, and author name and date.
This blog is dedicated to the University of Belize's course: NRMP3401- GIS for Natural Resource Managers.
Friday, 6 November 2015
We have been learning a lot about about projections and coordinate systems. Based on what was taught, students were tasked to create a map of Miami using Albers and UTM datasets. As taught, there are many ways that you can project data. Therefore when dealing with different data sets that have different projections, it is vital that one knows how to change these projections to their desired outcome. This is important because in most analytical functions used, multiple data sets are to be in the same condition coordinate system. Therefore, in this activity, we learnt how to re-project data sets. Firstly, students utilized one of several tools found in ArcToolbox. A tool named Project tool was used change the coordinate system to UTM instead of Albers and having both in separate data frames. Upon viewing these data frames separately, a slight change was observed only. In addition to changing coordinate systems, students learnt how to add new fields in the attribute table and also add data into the new field. Therefore, a field labeled "Area" was added and thus, the value for area being displayed was added to that field by using the calculate geometry function. This was done for both data frames( Alber and UTM). Although the change between the two projections was slight, a difference was clear when the area of both data sets were calculated since the areas was different for both. At the end of the exercise, a map showing the two different projections was made. It also displayed the area of the two projections for four counties: Alachua, Escambia, Polk and Miamia-Dade. The map was finished by adding basic map features such as the scale bar and scale text, legend, title, north arrow, and author name and date.
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