Airborne interferometer for atmospheric emission and solar absorption

The interferometer for emission and solar absorption (INTESA) is an infrare d spectrometer designed to study radiative transfer in the troposphere and lower stratosphere from a NASA ER-2 aircraft. The Fourier-transform spectro meter (FTS) operates from 0.7 to 50 mum with a resolution of 0.7 cm(-1). Th e FTS observes atmospheric thermal emission from multiple angles above and below the aircraft. A heliostat permits measurement of solar absorption spe ctra. INTESA's calibration system includes three blackbodies to permit in-f light assessment of radiometric error. Results suggest that the in-flight r adiometric accuracy is similar to0.5 K in the mid-infrared. (C) 2001 Optica l Society of America.