These maps of the study points were made with Landsat images taken from the ESRI Landsat Explorer.
The Landsat imagery is considered medium resolution and is designed to show a larger area. Most of the bands are 30 meter resolution. According to the ESRI website:
This band combination (4,3,2) approximates the spectral range of vision of the human eye, and has been pansharpened using the 15m panchromatic band. Here the 30m natural color imagery has been pansharpened using the 15m panchromatic band in order to achieve better imagery resolution. This Landsat band combination is well suited for broad-based analysis of both terrestrial and underwater features, and for urban studies. This true-color composite approximates the range of vision for the human eye, and hence these images appear to be close to what we would expect to see in a normal photograph. Natural color images tend to have low contrast and are somewhat hazy in appearance. This is because blue light is more susceptible than other bandwidths to scattering by the atmosphere, however, it penetrates clear water deeper than the other bands, and is well suited to analysis of underwater features, Healthy vegetation is green, recently cleared fields are very light, unhealthy vegetation is brown and yellow, roads are gray, and shorelines are white.
The above map shows the near infrared band. Here is the technical description:
This band combination (5,4,3) gives results similar to traditional false color infrared photography. This band combination gives results similar to traditional false color infrared photography, which adds a near infrared (NIR) band and drops the visible blue band. Vegetation in the NIR band is highly reflective due to chlorophyll, and a NIR composite vividly shows vegetation in various shades of red. Urban areas are cyan blue, and soils vary from dark to light browns. Ice, snow, and clouds are white or light cyan. Coniferous trees will appear darker red than hardwoods. Generally, deep red hues indicate broad leaf and/or healthier vegetation while lighter reds signify grasslands or sparsely vegetated areas. Water appears very dark, due to the absorption of energy in the visible red and near IR bands.
The last map is optimized for a view of agricultural resources.
This band combination (6,5,2) is good for agricultural studies. In this band combination, vigorous vegetation appears bright green, healthy vegetation appears as a darker green, while stressed vegetation appears dull green. Coniferous forests appear as a dark, rich green while deciduous forests appear as a bright green. Sparsely vegetated and bare areas appear brown and mauve.