Spectral Radiance of Sky and Terrain at Wavelengths between 1 and 20 Microns I Instrumentation*

A description is given of a mobile laboratory equipped with two spectrographs for radiance measurements of the sky and terrain between 1 and 20 μ. The laboratory has its own ac power supply and means for controlling its temperature. Procedures are described for calibrating the instrumentation and transforming the data into spectral radiance (in microwatts cm−2 steradian−1 micron−1) as a function of wavelength.