Advanced GIS Lab2

Part 1. Georeferencing image

Introduction

In this Lab, I conducted Georeferencing a past image and Digitizing land use polygons. 

First, I georeferenced the unreferenced 1953 St.Helena California image by overlaying the 2014 St.Helena California image in part 1. 

Also, I located the 1953 image in the 2014 image having spatial data (NAD 1983 UTM Zone 10N) and assigned the 1953 image a spatial reference. 

In part 2, I conducted georeferencing and digitizing of 1937 and 2018 Logan, UT images. To complete the task, I create a shapefile after georeferencing the 1937 image (NAD 1983 UTM Zone 12N). 

Part 2. Digitizing land use polygons

Methods

For conducting part 1 (georeferencing), I used the Georeference tool in the Imagery tab. I also used the Add Control Points button to locate it correctly. The results of  adding control points were showed in the Control Point Table. Thus, I could recover mistakes by identifying residual errors. 

In part 2, I used the Add Control Points button and the Control Point Table. I tried to reduce residual errors under 1.5 and applied 2nd Order Polynomial transformation type. the Create Feature Class tool to make shape file. I created a polygon feature edited to add fields like undeveloped area, road, and residential. Also, a measured grid tool was used in both images.

The calculation results of 1937_Logan