GIS 4035 - Module 4 - Ground Truthing

This weeks exercise was based off from the LULC shapefile created for Module 3.

Process Summary Details

For this exercise, in addition to documenting your technical procedures, make note of your thought process in deciding if your initial classification is correct. Your ground truthing of the photograph is much more important than documenting which tools you use to check the accuracy. That said, (1) your technical steps are still important, and (2) you do not need to record your processes for each and every point you check. Try taking notes on at least half of your points, as well as on features that are especially note-worthy or difficult to identify.

NOTES:

To begin the exercise, I created a new shapefile and called it Truthing. I dispersed the points myself, and attempted to create a 5x6 point grid. I did my best to keep the points marked in a systematic pattern. I clicked properties on the shapefile, and created two new columns in the attribute table as directed. Afterwards, I went over every feature point and tracked its location on google maps in order to verify its classification. Because the majority of the map on the left hand side falls onto a large body of water, many of the points fell onto a single classification.

Accuracy of truthing: 23/30=77%

At the very end, I went into the properties for the truthing shapefile. Under the symbology tab, I selected ‘caterogies’ and chose to add all values based on the True_Y/N value field. I chose a red symbol for the negative values and a green symbol for the positive.