Use of PZT's for adaptive control of Fabry-Perot etalon plate figure

A Fabry Perot etalon, consisting of two spaced and reflective glass flats, provides the mechanism by which high resolution spectroscopy may be performed over narrow spectral regions. Space based applications include direct measurements of Doppler shifts of airglow absorption and emission features and the Doppler broadening of spectral lines. The technique requires a high degree of parallelism between the two flats to be maintained through harsh launch conditions. Monitoring and adjusting the plate figure by illuminating the Fabry Perot interferometer with a suitable monochromatic source may be performed on orbit to actively control of the parallelism of the flats. This report describes the use of such a technique in a laboratory environment applied to a piezo-electric stack attached to the center of a Fabry Perot etalon

Brightness of the O2 atmospheric bands in the daytime thermosphere

The Fabry-Perot interferometer on Dynamics Explorer 2 was used as a low sensitivity photometer to study the O2 Atmospheric A band during the daytime. A study of the brightness of the emission showed that the assumed source of O2(b1[Sigma]g+) in the thermosphere, O(1D), can account for the observed intensity up to about 250 km but with a significantly different scale height. This combined with an enhanced brightness above this altitude suggests an additional source for this emission.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25793/1/0000355.pd

Optical effects of spacecraft-environment interaction Spectrometric observations by the DE-B satellite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76162/1/AIAA-1983-2657-139.pd

High Resolution Doppler Imager observations of ozone in the mesosphere and lower thermosphere

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95237/1/jgrd9497.pd

Optical effects of spacecraft-environment interaction Spectrometric observations of the DE-2 satellite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76678/1/AIAA-25728-876.pd

Intercalibration of HRDI and WINDII wind measurements

The High Resolution Doppler Imager (HRDI) and the Wind Imaging Interferometer (WINDII) instruments, which are both on the Upper Atmosphere Research Satellite, measure winds by sensing the Doppler shift in atmospheric emission features. Because the two observation sets are frequently nearly coincident in space and time, each provides a very effective validation test of the other. Discrepancies due to geophysical differences should be much smaller than for comparisons with other techniques (radars, rockets, etc.), and the very large sizes of the coincident data sets provide excellent statistics for the study. Issues that have been examined include relative systematic offsets and the wind magnitudes obtained with the two systems. A significant zero wind position difference of ∼6 m s −1 is identified for the zonal component, and it appears that this arises from an absolute perturbation in WINDII winds of -4 m s −1 and in HRDI of +2 m s −1 . Altitude offsets appear to be relatively small, and do not exceed 1 km. In addition, no evidence is found for the existence of a systematic wind speed bias between HRDI and WINDII. However, considerable day-to-day variability is found in the quality of the agreement, and RMS differences are surprisingly large, typically in the range of 20-30 m s −1 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47857/1/585_1997_Article_70151089.pd

The dayglow of the O2 atmospheric band system

The dayglow of the O2 atmospheric band system has been simulated by taking into account the three main production mechanisms of the O2(1[Sigma]) state: resonance fluorescence, a photochemical term due to quenching of O(1D), and a pure chemical process. Values of the g factor, which are involved in the resonant scattering of the O2 atmospheric bands (A, B and [gamma]), have been obtained as a function of altitude (0-120 km) and solar zenith angle using a line-by-line calculation. The values of the g factor, along with updated rate coefficients, have been used in the calculation of the production rate of O2(1[Sigma]) and the volume emission rate of the (O21[Sigma], [nu]' = 0)-(O23[Sigma], [nu]" = 0) transition. The results of these calculations are compared to observational measurements and are found to be in excellent agreement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26002/1/0000068.pd

Atmospheric wind measurements with the high-resolution Doppler imager

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76745/1/AIAA-26590-119.pd

The High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76425/1/AIAA-1993-123-305.pd

Tidal influences on O 2 atmospheric band dayglow: HRDI observations vs. model simulations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95496/1/grl13062.pd