Thermal Imagery

The feature I identified for this lab was a large tract of bare soil located at the southern tip of the city, surrounded predominantly by urban area and some vegetation directly to the south of it. I was looking over the stretched symbology (Band 6) of the image in ArcMap when I saw a bright spot in that area, surrounded by grey (urban area) and a darker spot just below it (which looks like vegetation in the natural color image). Further analysis and comparison between the two images (natural color and thermal) determined this was bare soil. I chose to use the band combination Red- 6, Green- 3, Blue- 2. This band combination is used to distinguish between different soils and soil moisture content. The 6, 3, 2 band combination made soils appear in light to dark reds, starkly contrasting it with surrounding colors.

Scythian Landscapes - Analyze Week

In this lab, Elevation, Slope, and Aspect are taken into consideration and reclassified in ArcMap to aid in the interpretation and analysis of the Tuekta Mounds study area. They were each simplified for further analysis by condensing their data into smaller groupings, as reflected in their legends. Contour lines in meters of elevation were made for the Tuekta area as well. Also, a shapefile was made including point locations of up to 50 mound sites in the georeferenced Tuekta Mounds image.

Image Preprocessing 2: Spectral Enhancement and Band Indices

In this lab, we used ERDAS Imagine to perform various image processing tools. Tools and topics covered were the histogram, the Inquire tool, the help menu, and interpreting features digital data. The deliverable for this assignment was to locate 3 features based on pixel variations using the directions provided in the lab. The features I located are water, ice, and water body variations. Below are my map outputs.

Scythian Landscapes - Data Prepare Week

This week, we explored USGS Earth Explorer for ASTER DEM data for our target study area. Because imagery in this region is difficult to come by, we also georeferenced an image of a known Scythian burial mound site in Tuekta to our DEM dataset. We further narrowed our study area by clipping the mosaic raster to a smaller polygon boundary. The goal of the study is to determine if the Scythians had a placement pattern of the mounds themselves.

Image Enhancement

This lab required an attempt to remove the striping effect from a Landsat 7 image with a sensor malfunction called the Scan Line Corrector failure. In the original image, black stripes mark diagonally throughout the whole image. My final image output greatly reduced the visibility of the stripes, but slightly distorted and blurred it in some areas. I used ERDAS Imagine to enhance the image, using the Convolution, Focal Analysis, and Fourier Analysis tools. The Convolution tool, using a 3x3 sharpen kernel, lightened the stripes to white. The Focal Analysis tool was ran 6 times over the image to further lighten the stripes to a light grey. The Fourier Analysis tool was the greatest benefactor in reducing the visibility of the stripes, but as mentioned it reduced the image quality slightly.

Predictive Modeling

In this lab, predictive modeling was used to determine potential site locations in the Tangle Lakes Archaeological District in Alaska. Predictive modeling is a useful tool for estimating the amount of time and money needed to devote to any given area, as well as the amount of field survey effort. It is used to suggest broad trends in settlement patterns and resource utilization. However, it should be used as a supplementary tool for guiding and informing field surveys. It can not justify the development, avoidance, or destruction of an area without conducting field survey beforehand. Being only one tool, it generates only one possible interpretation and should not be taken as a definitive explanation.

The weighted overlay model I created, though a simplistic version, is significant in that it provides a model for determining archaeological site locations in a site dense area. The Tangle Lakes Archaeological District contains the densest known concentration of archaeological sites in the American subarctic, with over 600 sites identified. A model like this could help identify potential site locations as well as help park officials designate visitor friendly trails to prevent disruption and negative impact of sites. My model is seen below: