Special Topics In GIS (GIS5935): Lab 1

In this week's lab, we learned how to calculate metrics for spatial data quality. The first image shows the precision and accuracy of the GPS Unit's results. The number of waypoints that were analyzed were 50. The data had to be projected from GCS WGS 1984 to UTM N17 NAD 1983. This allows us to be able to measure these points using metrics instead of degrees. We had to find out the accuracy and precision of the data. The result of the horizontal accuracy is 3.2 meters. The horizontal precision is 4.5 meters. The both of the results are 0.7 meters off from each other. The vertical accuracy is 5.96 meters and the vertical precision is 0.9 meters. The difference between the two vertical results is substantial. The measured difference between the two is 5.06 meters.  The second image is a CDF scatterplot chart of the error of x and y coordinates from 200 points. 

The horizontal accuracy was measured by measuring the reference point and the average location point. The Measure tool was used to measure the distance between the point which give the resulted number of what the horizontal accuracy is. The precision was found by sorting the distance field in the attribute table of the spatial joined data sets and assuming that the first number that was listed was 2% and count all the way to 68%.