Measurement of stratospheric chromatic scintillation with the AMON-RA balloonborne spectrometer

The balloonborne instrument AMON (which is a French acronym for Absorption par les Minoritaires Ozone et NO,,) has been modified to record chromatic s cintillation during stellar occultation by the Earth's atmosphere. A 14-cha nnel spectrophotometer with a sampling rate of 10 Hz was added, and the mod ified instrument, AMON-RA, performed successful measurements of the setting star Alnilam during the third European Stratospheric Experiment on Ozone ( THESEO) project. Unambiguous records of the chromatic scintillation were ob tained, to our knowledge for the first time from above the atmosphere, and some of its basic properties are reported. The properties of atmospheric st ructures that are responsible for this chromatic scintillation were found t o be consistent with those of previous monochromatic measurements performed from space. A maximum chromatic delay of 2.5 s was observed for widely dif ferent wavelengths. (C) 2001 Optical Society of America.