Precision agriculture is increasingly used to create efficiencies in crop management and increasing crop yields. It is justified by its ability to address within-field spatial heterogeneity. Current remote monitoring requires a substantial investment by farmers, produces data at a low spatial resolution, and cannot be repeated as frequently as successful management requires. An Unmanned Aerial Systems (UAS) combines the best features of conventional monitoring techniques with generally increased resolution and lower cost. UAS technology can produce high quality images with excellent spatial resolution across a wide range of the electromagnetic spectrum, however, the correct interpretation of these images is severely hampered by the lack of adequate characterization of the spectral and radiometric response of the collected digital images and the lack of site-specific scientific data. In order to address this problem, we will evaluate an array of camera-based sensors and, for each of the sensors, compare the true spectral response to the advertised spectral response.