Week 6: Visibility Analysis

Finish Line Camera Coverage Map (symbology described in text)

This weeks lab involved using Visibility analyses on topographic data.  Specifically, we utilized Line of Sight, Visibility, and Viewshed tools (among others) in the 3D Analyst toolbox.  We worked with DEMs to determine what regions were visible from both point and line features and compared the outputs of these tools.

We also used veiwshed analysis to make an informed decisions about surveillance camera placement around the finish line of the Boston Marathon.  We were restricted to a 90 degree field of view for our cameras, and there were several buildings which obstructed possible placement.  I first analyzed aerial imagery to determine building locations, as I wanted to place the cameras on top of a tall structure.  I then used a DEM which included building height to determine how high these cameras would be placed.  The viewshed tool produced a raster with cell values from 0 - 3, where the value represented the number of cameras that captured that particular cell.  Cells with a value of 3 were colored red, 2 were yellow, and 1 were green (zeros were omitted).  Above is my output using this symbology.  [The cameras are magenta triangles and the finish line a blue dot].  All three of the cameras had an unobstructed view of the finish line as well as much of the surrounding area.