Lab 8

Goal

The main goal of this lab is for us to gain experience on the measurement and interpretation of spectral reflectance (signatures) of various Earth surface and near surface materials captured by satellite images. In this lab, we will learn how to collect spectral signatures from remotely sensed images, graph them, and perform analysis on them to verify whether they pass the spectral separability test discussed in lectures. This is a prerequisite for image classification which will be covered in the advanced version of this class. At the end of this lab, we will be able to collect and properly analyze spectral signature curves for various Earth surface and near surface features for an multispectral remotely sensed image. 

Methods

For lab eight, we weren't given a whole lot of instruction. It may have been the "shortest" lab yet. We were given 12 different materials and surfaces from the eau_claire_2000.img. The twelve surfaces were, standing water, moving water, vegetation, riparian vegetation, crops, urban grass, dry soil, moist soil, rock, asphalt highway, airport runway, concrete surface. We were given instructions for digitizing the first surface. Lake Wissota is a perfect place to digitize standing water. After digitizing, we were able to enter the digitized area into the signature editor. We were then told to digitize areas for the rest of the surfaces. Honestly it was pretty difficult to find some of the surfaces on the map that would have a large enough area to effectively digitize. Because of this, I felt like some of my plotted lines might not be as accurate as they should be. When the data was in the signature editor, we could then plot the line for the data in the signature mean plotter. That was the largest part of the lab. The rest of it was just analyzing the plots and comparing them to the other plots. 

Results

The following images are the individual plots and then a combined plot of all of the digitized surfaces taken in the lab. The final image is comparing dry and moist soil. 

Sources

All sources were provided to us through the geog 338 drive. The image  eau_claire_2000.img was included in the sources provided.