Autonomous field spectroradiometers

In field spectroscopy applications the autonomous field spectroradiometer is configured to measure the down-welling irradiance and up-welling radiance, from this it is possible to calculate the reflectance properties of the surface or canopy and how it may change over time and with illumination geometry. This paper reviews the merits and limitations of autonomous systems with “bi-conical” and hemispherical-conical geometries, single and multi-spectrometer configurations and the options for improving the measurement uncertainty in future autonomous systems.