THE EFFICIENCY OF BEAMSPLITTERS IN THE FAR INFRA-RED MICHELSON INTERFEROMETER

1967 ◽  
Vol 28 (C2) ◽  
pp. C2-150-C2-152
Author(s):  
D. J. JAMES ◽  
J. RING
Keyword(s):  
Michelson Interferometer ◽  
Infra Red

scholarly journals Twenty Years of Speckle Interferometry

1992 ◽  
Vol 135 ◽  
pp. 459-468
Author(s):  
William I. Hartkopf
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Michelson Interferometer ◽  
Speckle Interferometry ◽  
New Technique ◽  
Orbital Elements ◽  
Interferometric Technique ◽  
Infra Red ◽  
Michelson Interferometry ◽  
Using Data

The purpose of my talk is to briefly review the results of two decades of astrometric research using the technique of speckle interferometry. Although speckle, invented by Labeyrie in 1970 (Gezari et al. 1972), is the most well–known and widely–used interferometric technique in the visible and near infra-red, it neither the only technique in use, nor was it the first. Karl Schwarzschild made the first interferometric measurements of binary stars in 1895, using the then–new technique of Michelson interferometry and following a suggestion by Michelson himself that his technique was amenable to binary star astrometry. From 1919 to 1921, Anderson (1920) and Merrill (1922) made a series of measurements of Capella and other bright stars, using a Michelson interferometer of 20-foot baseline, mounted on the Mount Wilson 100-inch. These early measurements have definitely stood the test of time. Figure 1 shows a recently calculated orbit of Capella (Bagnuolo & Hartkopf 1989), using data spanning some 250 full revolutions. Anderson and Merrill’s measurements agree beautifully with observations made 7 decades later. As a result, Capella has probably the most accurately known orbit of any visual binary. Orbital elements calculated in 1981 (McAlister 1981) and again 10 years later differ in period by about 14 seconds, or less than 2 parts per million!

A Fourier-transform spectrometer for infra-red cathodoluminescence in TEM

1983 ◽  
Vol 41 ◽  
pp. 128-129
Author(s):  
J.C.H. Spence ◽  
J. Isenman
Keyword(s):  
Electronic Structure ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Design Problem ◽  
Michelson Interferometer ◽  
Fourier Transform Spectrometer ◽  
Extended Defects ◽  
Infra Red ◽  
Mirror Movement ◽  
Defects In Semiconductors

The study of the electronic structure of deep states associated with isolated, well characterised extended defects in semiconductors requires the use of a cathodoluminescence apparatus for TEM in the wavelength range 1-50 microns (1.2 - 0.02 eV). This would also allow the study of the III-V alloys and their defects used for I.R. emitters and lasers. Preliminary results using a grating spectrometer have been obtained by Petroff, however experience from Astronomy indicates that the Fellgett + Jacquinot advantage obtainable using Fourier Transform Infrared Spectroscopy (F.T.I.R.S.) is important for weak sources and noisy detectors. (See Davidson who has compared both techniques in SEM).The crucial design problem in the 1-10 micron range is the mirror movement in the Michelson Interferometer, which must be reproduceably positioned with submicron accuracy over a one centimeter range.

The use of a michelson interferometer for continuous gas analysis in the far infra-red

1972 ◽  
Vol 12 (1) ◽  
pp. 35-44 ◽  
Author(s):  
G.W. Chantry ◽  
J.W. Fleming ◽  
D.W.E. Fuller ◽  
H.A. Gebbie ◽  
B.R. Steventon
Keyword(s):  
Michelson Interferometer ◽  
Gas Analysis ◽  
Infra Red

scholarly journals MIPAS detection of cloud and aerosol particle occurrence in the UTLS with comparison to HIRDLS and CALIOP

2012 ◽  
Vol 5 (1) ◽  
pp. 1795-1841 ◽  
Author(s):  
H. Sembhi ◽  
J. Remedios ◽  
T. Trent ◽  
D. P. Moore ◽  
R. Spang ◽  
...  
Keyword(s):  
Aerosol Particle ◽  
Detection System ◽  
Michelson Interferometer ◽  
Detection Limits ◽  
High Spectral Resolution ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Polar Regions ◽  
Particle Injection ◽  
Infra Red

Abstract. Satellite infra-red emission instruments require efficient systems that can separate and flag observations which are affected by clouds and aerosols. This paper investigates the identification of cloud and aerosols from infra-red, limb sounding spectra recorded by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), a high spectral resolution, Fourier transform spectrometer on ENVISAT. Specifically, the performance of an existing cloud and aerosol particle detection method is simulated, with a radiative transfer model, in order to establish for the first time limits to confident detection of particle effects in MIPAS data. The newly established thresholds improve confidence in the ability of MIPAS to detect particle injection events and plume transport in the UTLS as well as better characterised cloud distributions. The method also provides a fast front-end detection system for the MIPClouds processor, a processor designed for the retrieval of macro- and microphysical cloud properties from the MIPAS data. It is shown that across much of the stratosphere, the threshold for the standard cloud index in band A is 5 although values of greater than 6 occur in restricted regimes. Polar regions show a surprising degree of uncertainty at altitudes above 20 km due to potential high ClO formation and also poor signal-to-noise due to low atmosphere temperatures. The optimised thresholds of this study can be used for much of the time, but time/composition dependent thresholds are recommended for MIPAS data for the strongly perturbed polar stratosphere. In the UT, thresholds of 5 apply at 12 km and above but decrease rapidly at lower altitudes. The new thresholds are shown to allow much more sensitive detection of particle distributions in the upper troposphere and lower stratosphere (UTLS), with extinction detection limits above 13 km often better than 10−4 km−1, with values approaching 10−5 km−1 in some cases. Comparisons of the new MIPAS results with data from HIRDLS and CALIOP, outside of the poles, establishes good agreement in distributions (cloud occurrence frequencies and clouds and aerosol top heights) with an offset between MIPAS and the other instruments of 0.5 km between 12 and 20 km. We conclude that current infra-red limb sounders provide a very consistent picture of particles in the UTLS, allowing detection limits which are consistent with the lidar observations. Investigations of the MIPAS data for the Kasatochi volcanic eruption and the Black Saturday fires in Australia are used to exemplify the usefulness of MIPAS limb sounding data for monitoring aerosol injections into the UTLS, and into the stratosphere, in particular over monthly timescales. It is shown that the new thresholds allow such events to be much more effectively monitored from MIPAS with detection limits for these case studies of 1 × 10−5 km−1 at 12 μm.

scholarly journals The Use of a Michelson Interferometer to Obtain Infra-Red Spectra of Venus

1961 ◽  
Vol 123 (6) ◽  
pp. 497-500 ◽  
Author(s):  
H. A. Gebbie ◽  
L. Delbouille ◽  
G. Roland
Keyword(s):  
Michelson Interferometer ◽  
Infra Red

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

The infra-red spectra of B-chloro- and B-bromoborazoles

1962 ◽  
Vol 18 (4) ◽  
pp. 1487-1497 ◽  
Author(s):  
I BUTCHER ◽  
W GERRARD ◽  
E MOONEY ◽  
R ROTHENBURY ◽  
H WILLIS
Keyword(s):  
Infra Red
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