New Directions in Development of Canopy Reflectance Sensors.

Optical reflectance technology is being used to remotely gather plant canopy reflectance information. Reflectance information can be related to plant phenotype for use in plant breeding and may be used to infer nutrient status, water status or other states that may be used in managing plant performance. This presentation will provide an introduction to reflectance sensor principals and will address passive vs. active sensors, Image vs. single element sensors, a discussion of reflectance variability in field plots, the impact of spatial scale and field of view, and cross calibration of sensors. The issues associated with measurements (reflectivity vs. raw count), wavelength and the limitations of the current semiconductor technology will be discussed. A brief examination of future directions for sensor technology will be made.