Emily's GIS Blog

  In this week's assignment, we were familiarized with ERDAS Imagine and using digital data within it. I created this map layout with Imagine and ArcGIS Pro. It is a subset of a digital image from the Pacific Northwest in the US. Below is my process summary.  First, I opened the file tm_class.img to the viewer within ERDAS Imagine. I then created a new field in the attribute table that contained the area, in acres, of each class. In order to view a subset of the original image, I selected the Create Subset Image tool in the Raster tab. I then selected the area I wanted, designated my output file, and selected ok to create the subset. I then opened the subset file in ArcGis Pro to create my map layout. I changed the symbology of the image to unique values in order to symbolize the layer according to the classes. I included all map elements and the area of each class in the legend. I did this by editing the name of each class in the symbology tab.

  In this assignment, we were required to assess the land use and cover of an area in Pascagoula, MS. We used polygons to distinguish the various land use and cover codes, of which we used levels I and II. All of my polygons were within a single feature class. I used the snapping tool to align my polygons with each other. After I finished creating all of my polygons, I used the symbology tool to change the color of each code.  We were also asked to place 30 random points to conduct determine ground-truthing accuracy. To determine this, I created a new feature class with a single polygon over the entire subject area. Then I used the Create random points tool to create 30 random points within the project area. I used Google maps to determine whether or not the code for each point was accurate. Each point was marked as accurate or inaccurate. The codes on my map were 97% accurate.