Multispectral Analysis

This week we delved into multispectral analysis primarily focused on using ERDAS Imagine.  We looked at histograms of both greyscale and multispectral images and then used a breakpoint feature to isolate pixels in certain ranges to help identify what features we were looking at.  For the final exercise we were to determine three different features using the skills we learned and then create maps for each feature.  These maps are below along with a description of what I was trying to highlight. 

Feature 1: Water in general.  By adjusting the breakpoints on the greyscale layers, I was able to isolate the target peak on the histogram and verify that it matched up to a single feature.  Map is displayed in TM False Color IR.

Feature 2:  This feature are the snowy areas on the mountain peak.  Again, by adjusting the breakpoints on the greyscale layers, it was easy to see that the snow was the target.  This was especially true for layers 1-4.  However layers 5-6 also included the water features along with the snow.  So therefore, the snow has to be the feature as it was the only one that was visible on all 6 layers.  I displayed the map for this feature in TM False Natural Color as it distinguished between water (dark blues/blacks) and the snow (light/pale blue)

Feature 3: For this I chose the river mouth that feeds into the bay area.  Again I used breakpoints on greyscale.  For layers 1-3, and even 4, the river discharge is distinctly different than that of the water in the bay.  For layers 5-6, you cannot see any different between the discharge and the body of water.  For this map I used an inverted TM False Natural Color.  R:3, G:4, B:5.  This made a distinct looking map and highlighted the discharge in red as it entered the dark blue body of water.