RESUMO
A wide-angle Michelson Doppler imaging interferometer (WAMDII) is described that is intended to measure upper atmospheric winds and temperatures from naturally occurring visible region emissions, using Spacelab as a platform. It is an achromatic field-widened instrument, with good thermal stability, that employs four quarterwave phase-stepped images to generate full images of velocity, temperature, and emission rate. For an apparent emission rate of 5 kR and binning into 85 x 105 pixels, the required exposure time is 1 sec. The concept and underlying principles are described, along with some fabrication details for the prototype instrument. The results of laboratory tests and field measurements using auroral emissions are described and discussed.
RESUMO
This paper considers the optical design of a wide-angle fixed-path Michelson interferometer consisting of two arm glasses and an air gap. It is shown that this configuration can be optimized to give (a) extra large fringes (over 50 degrees in diameter) over a range of wavelength, (b) a path difference nearly independent of wavelength, or (c) a path difference specified differently at two different wavelengths for observing a pair of doublets. Specific examples refer to the airglow wavelengths of 557.7, 630.0, 732.0 nm and others, and to a path difference of 4.5 cm. The properties of different glass combinations are discussed.
RESUMO
A series of far-ir Michelson interferometers utilizing the rapid-scanning technique have been designed and built for balloon-borne measurement of the emission spectrum of the stratosphere. Design criteria for such instrumentation are presented, and details of the evolution of these designs are discussed, including liquid helium-cooled bolometer detector systems, internal blackbody calibration, and atmospheric limb-scanning. Stratospheric emission spectra between 30 cm(-1) and 110 cm(-1) at a resolution of 0.07 cm(-2) are presented as examples of results taken at balloon altitudes, and the merits of this type of instrumentation for monitoring stratospheric trace gas constituent concentrations are discussed.