Lab 8: Thermal Infrared Images

The objectives of lab 8 is to interpret thermal infrared images using the Stefan Boltzmann constant and create thermal images by adjusting symbology and band combinations. The images that were used were from Ecuador and Pensacola.   

Once I went through the exercises, the last assignment was to identify features applying what I learned and enhance the image.  From the exercises in lab, I noticed there was a visible difference between farm land and natural vegetation when I adjusted the bands to R-6, G-4. B-7.  However, that difference was not as noticeable when I looked at the image with layer 6.  The two different feature types look very similar.  Band 6 shows how the vegetation emits less energy than the urban areas.

Thermal and Multispectral Image of Ecuador

Lab 7: Multispectral Image

The objectives of lab 7 were to look at the histograms of an image and use tools to look at data.  By looking at the histogram, an objective was to interpret the data. Within ERDAS, also use the Inquire Cursor tool to look at pixel data and find tools from the Help Tab.  After going through all the exercises, applied skills to identify features.

By looking at the metadata histograms, I was able to see if the features I was looking for were dark or light.  The size of the spike also told me if the feature was large or small.  Once I had an idea of the brightness and size, I used the inquire cursor to see pixel count.  I was then able to see the pixel count for each layer and see if it matched the clues.  I then adjusted the color to spectrum to help highlight the features I needed to find.

Deep Water - TM False Natural Color

Snow - True Color

Shallow Water - Near Infrared Color

Lab 6: Image Enhancement

Enhanced Image

This week's lab objectives were to download satellite images from USGS.  Once the data was downloaded, perform spatial enhancement in ArcMap and ERDAS.  The enhancements included high and low pass filters and Fourier Analysis.

To enhance the striped image, I used the Fourier Analysis tool to fill in the striped areas.  By using the Wedge tool and Low Pass button.  Once this was done, I sharpened the image with kernel size 3x3.  After sharpening the image, I used the convolution tool to apply a 3x3 low pass filter.  Once that filter was applied, I moved the image to ArcMap where I adjusted the histogram.

I enjoyed this lab because it was interesting to see how images can be improved and by various tools.  However, it was challenging to figure out how to continue to improve the image.  I did play around with various filters and tools.  It is clear a lot of experience and practice is needed to develop image enhancement skills.