Hyperspectral measurements of the solar hot spot using the HyperSpecTIR imaging spectrometer

The scan mechanism of the HyperSpecTIR hyperspectral instrument has been modified to allow BRDF measurements from an airborne platform. The HyperSpecTIR is a flexible, airborne hyperspectral imager capable of on-the-fly programmability. Such measurements afford the opportunity to study geometric and spectral properties of natural scenes such as fields and canopies, as well as man-made substances such as composite materials and paints. As a proof of concept study for the BRDF measurement method, data was collected during flight operations near Phoenix Arizona. The measurements were performed in the principle plane and included the solar hot-spot. Detailed descriptions of the instrument and data collection methods are presented. The collected data is analyzed and compared to BRDF models of the solar hot-spot.