Field-averaging spectrograph camera for remote sensing applications and its characteristics.

A field-averaging spectrograph camera utilizing a continuous interference filter and a step tablet has been investigated and its characteristics measured. Using color patches, the values obtained with the camera are compared with those obtained by a spectroradiometer and a self-spectrophotometer. The results obtained with the photographic method show slightly higher values than those of the other methods in the measured wavelength region. In the measurement of spectral reflectances of two-color patches with different ratios of area within a field of view angle, the same reversal point of the relative reflectance curves is observed with this camera as the spectroradiometer. Therefore, the function of a field-averaging spectrograph camera is the same as a spectroradiometer, which is widely used for remote sensing applications at the present time. Moreover, it is more compact, portable, and lower priced than conventional instruments. The spectral reflectances of scenes were measured by photographic and spectroradiometer methods in field experiments. The spectral image of soil photographed by a beam split camera used with the field-averaging spectrograph camera is displayed in false color.