What the Voyager infrared investigators hope to learn about the Saturn system

The Voyager infrared investigation uses a Michelson interferometer (IRIS) covering the spectral range from 200 to 3000 cm/1 (3.3 to 50 micrometers) and a bore sighted radiometer covering the range from 5000 to 25000 cm/1 (0.4 to 2 micrometers). The spectral resolution of the interferometer is 4.3 cm/1 and the field of view is 0.25 deg. Scientific results anticipated from the investigation of the Saturnian system are discussed

Fourier spectroscopy on planetary missions including Voyager

In the last dozen years spaceborne Fourier transform spectrometers have obtained infrared emission spectra of Earth, Mars, Jupiter, Saturn and Titan as well as of the Galilean and other Saturnian satellites and Saturn's rings. Intercomparisons of the properties of planetary atmospheres and of the characteristics of solid surfaces are now feasible. The principles of remotely sensing the environment on a planetary body are dicussed. Special consideration is given to the most recent results obtained by the Voyager infrared investigation on the Saturn system

The infrared interferometer spectrometer experiment /iris/. volume ii- meteorological mission

IRIS - infrared interferometer spectrometer measurements of atmosphere vertical structure - humidity, temperature, and cloud heigh

Fourier spectroscopy and planetary research

The application of Fourier Transform Spectroscopy (FTS) to planetary research is reviewed. The survey includes FTS observations of the sun, all the planets except Uranus and Pluto, the Galilean satellites and Saturn's rings. Instrumentation and scientific results are considered and the prospects and limitations of FTS for planetary research in the forthcoming years are discussed

Special topics in infrared interferometry

Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented

On the robustness of q-expectation values and Renyi entropy

We study the robustness of functionals of probability distributions such as the R\'enyi and nonadditive S_q entropies, as well as the q-expectation values under small variations of the distributions. We focus on three important types of distribution functions, namely (i) continuous bounded (ii) discrete with finite number of states, and (iii) discrete with infinite number of states. The physical concept of robustness is contrasted with the mathematically stronger condition of stability and Lesche-stability for functionals. We explicitly demonstrate that, in the case of continuous distributions, once unbounded distributions and those leading to negative entropy are excluded, both Renyi and nonadditive S_q entropies as well as the q-expectation values are robust. For the discrete finite case, the Renyi and nonadditive S_q entropies and the q-expectation values are robust. For the infinite discrete case, where both Renyi entropy and q-expectations are known to violate Lesche-stability and stability respectively, we show that one can nevertheless state conditions which guarantee physical robustness.Comment: 6 pages, to appear in Euro Phys Let

The Dielectric Bolometer, A New Type of Thermal Radiation Detector

Thermal detectors for the infrared, such as thermocouples and bolometers, are limited in their ultimate sensitivity predominantly by Johnson noise rather than temperature noise. Low noise figures are hard to achieve since Johnson noise preponderates temperature noise, which is the only essential noise for thermal detectors. The dielectric constants of some materials are sufficiently temperature dependent to make a new type of bolometer feasible. The basic theory of a dielectric bolometer, as shown here, promises noise figures below 3 decibels even at chopper frequencies well above the 1/tau value of the detector. Ferroelectrics such as barium-strontium titanate and others seem to be well suited for radiation-cooled dielectric bolometers

A Low-Resolution Unchopped Radiometer for Satellites

The blackbody temperature and the albedo of a planet, and the variation of both parameters with latitude, longitude, and time, are of great value in understanding the climatic and meteorological conditions of the planet. An unchopped radiometer with a wide but restricted field of view is capable of such temperature and albedo measurements. Coated thermistors mounted in highly reflective cones serve as detectors. Their performance as sensor elements is analyzed in detail herein to prove the feasibility of the measurement. The simplicity of the instrumentation and the low information bandwidth required make the experiment equally attractive for earth satellites and space probes

High spectral resolution ground-based observations of Venus in the 450-1250 cm sup-1 region

The thermal emission of Venus was recorded during the winter of 1970-1971, and in 1973 using the 2.7m telescope at McDonald Observatory. The double beam Michelson interferometer installed at the Coude focus was used. The spectrum was recorded between 400/cm and 1,400/cm. For the 1970 observations, the spectral resolution was 0.25/cm and the linear spatial resolution was 3/4 of the disk of Venus. In 1973 the spectral resolution was 0.20/cm with a spatial resolution 1/3 of the planetary disk. In addition to Venus, the moon, the sky adjacent to each object, and the zenith sky were recorded to help eliminate the absorption and emission effects of the earth's atmosphere