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Herath, L.

Publications and source records attributed to Herath, L..

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

High resolution, balloon-borne emission spectroscopy of trace species in the lower stratosphere - N2O5, HNO3

A liquid-nitrogen cooled Fourier transform spectrometer (SIRIS) measures thermal limb-emission of the stratosphere from a balloon platform at a nominal altitude of 40 km, under night and day conditions, with a 3 km vertical resolution. N2O5 and HNO3 mixing ratios inferred from emission spectra are compared with previous measurements and with the predictions from a one-dimensional photochemical model.

Brasunas, J.↗
NASA NTRS1981

Infrared observations of the Saturnian system from Voyager 1

Atmospheric chemistry analyses of Saturn based on Voyager 1 infrared spectral and radiometric data are presented, including characteristics of the planet's rings and of Titan and other satellites. Infrared spectra of Saturn indicate the presence of H2, CH4, NH3, PH3, C2H2, and C2H6, with the possibility of C3H4 and C3H8. The atmospheric thermal structure of the planet shows hemispheric asymmetries that are consistent with seasonally varying insolation response, with an extensive small-scale latitudinal structure. Atmospheric chemistries of Titan, and optical and thermal characteristics for the rings of Saturn, are also given.

Hanel, R.↗
NASA NTRS1980

Infrared spectrometer for Voyager

The Voyager IR investigation is described, which uses a Michelson interferometer in the 180-2500/cm range, and a single-channel radiometer for the visible and near-IR, sharing a 50-cm diameter telescope. Emphasis is placed on the differences between the Voyager and the previous designs, including reductions in the field of view and in the noise equivalent spectral radiance of the instrument. Attention is given to the optical layout, the electronics module, power supply placement, thermal control heaters and flash heaters, data reduction, and calibration. A sample spectrum of Jupiter is also discussed.

Hanel, R.↗
NASA NTRS1979

Infrared observations of the Jovian system from Voyager 2

As on Voyager 1, the infrared spectroscopy and radiometry instrument on Voyager 2 returned a large number of spectral and radiometric data on Jupiter and its satellites for varying conditions of latitude, longitude, local time, and phase and emission angles. The Voyager 2 average spectrum is slightly noisier than that from Voyager 1. The paper presents selected examples of results from the Voyager 2 infrared investigation, with particular reference to latitudinal variation of the abundance ratio of ethane to acetylene, atmospheric thermal structure, Jupiter's ring, and satellites.

Hanel, R.↗