For this lab we looked at the spectral signatures that objects produce, which aids in analysis. Each object reflects light in a different manner, some absorb certain wavelengths and refelect others, creating a unique signature that can be used to idenify objects. Using a landsat image of Eau Claire, we collected spectral signatures with the signature editor tool in Erdas Imagine. Tweleve signatures were collected: Standing water, moving water, vegetation, riparian vegetation, crops, urban grass, uncultivated moist soil, dry soil, rock, parking lot, asphalt highway, and airport runway.
Most plant signatures are moderate in the blue and green bands but then increases significantly in the red and near infrared bands, this allows them to absorb green light energy and reflect harmful red and near infrared light, which can cause cell damage. Water signatures are higher in the blue band but then decrease significantly in the near infrared band as it absorbs the infrared light. Rock surfaces tend to absorb red and near infrared light, but reflect blue green and red light.
Overall this was a very interesting lab because it shows how remote sensing analysis can be used for image classification and analysis.
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