Filter wedge spectrometer for field use.

Two spectrometers, utilizing interference filter wedges, have been constructed for measurements under field conditions. One, operating from 1.6 micro. to 5.4 micro, has been flown unpressurized in an airplane to 12.2 km; the other, operating from 7.4 micro to 14.6 micro has been flown in a balloon to 33.3 km. Both instruments performed well, proving the interference filter wedge as avaluable tool for spectral measurements, especially in hostile environments.