Measurement of the atmospheric absorption of radio waves in the range 1.36?3.0 mm

Dryagin, Yu. A.; Kislyakov, A. G.; Kukin, L. M.; Naumov, A. P.; Fedoseev, L. I.

doi:10.1007/bf01038560

Cited by 7 publications

(3 citation statements)

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“…In the lower frequency range from 0.1 -0.3 THz there have been several examples of long path THz propagation in the context of measuring attenuation due to water vapor absorption. Using backward wave oscillator (BWO) sources field measurements of atmospheric THz attenuation were performed by Dryagin et al [2] and Ryadov et al [3]. In the case of Ref [3], output power as high as 300 mW was used.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, laboratory measurements of the dry air continuum have been reported using the cavity ring down method [11]. An important goal of the measurements in references [1][2][3][4][5][6][7][8][9][10][11] is towards developing and refining theoretical models that predict atmospheric transmission in the millimeter-wave and submillimeter/THz regions [12][13][14]. Finally, numerous atmospheric studies have been made at high altitudes using aircraft and balloon platforms.…”

Section: Introductionmentioning

confidence: 99%

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THz detection of small molecule vapors in the atmospheric transmission windows

et al. 2012

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Using a low power beam of ultrashort THz pulses that propagate in the ambient laboratory environment we have measured the rotational signatures of small molecule vapors at frequencies within the atmospheric transmission windows. We investigate two types of apparatus. In the first type the THz beam propagates along a 6.7 meter round trip path that is external to the spectrometer, and which contains a long sample tube (5.4 meter round trip path) that holds the analyte vapor. The environment of the tube is controlled to simulate dry or humid conditions. In the second apparatus the THz beam propagates over a much longer 170 meter round trip path with analyte vapor contained in a relatively short 1.2 meter round trip path sample chamber. We describe the rotational signatures for each apparatus in the presence of the strong interference from water vapor absorption. For the shorter path long-tube apparatus we find that the peak detection sensitivity is sufficient to resolve a 1% absorption feature. For the more challenging 170 meter path apparatus we find that the peak detection sensitivity is sufficient to resolve a 3-5% absorption feature. The experiments presented here represent a first step towards using ultrashort THz pulses for coherent broad band detection of small molecule gases and vapors under ambient conditions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

THz detection of small molecule vapors in the atmospheric transmission windows

et al. 2012

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“…This ensures high reliability of the obtained values of the molecule constants. Precision measurements of the line broadening of an oxy- Rusk [7], point 2, to Dryagin et al [8], point 3, to Frenkel and Woods [9], point 4, to Hemmi and Straiton [10], point 5, to Ryadov and Furashov [11], point 6, to Bauer et al [12], point 7, to Bauer et al [13], point 8, to Goyette and De Lucia [14], point 9, to Pumphrey and Buehler (MLS) [1], and point 10, to Pumphrey and Buehler (MAS) [1]. For obtaining points 11 and 12, we used the cavity spectrometer and the RAD spectrometer, respectively [15,16].…”

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confidence: 99%

Obtaining precise constants of atmospheric lines in the millimeter and submillimeter wavelength ranges

Tretyakov

Golubiatnikov

Паршин

et al. 2008

Radiophys Quantum El

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An important physical problem of supplying the Earth's atmosphere satellite monitoring with precise laboratory measurements of the line constants of atmospheric gases has been resolved. We developed a complex of spectrometers and techniques which improves the accuracy of lineconstant measurements by about an order of magnitude. Systematic errors of measurements do not exceed the statistical ones. Agreement of the results obtained by two different spectrometers improves reliability of the measured constants. Examples of measurements of collisional constants (broadening, shift, and collisional coupling) for the most important diagnostic atmospheric lines of water and oxygen molecules are presented. A number of collisional constants of the molecules are obtained for the first time and some errors of the previous researchers are corrected. The measured parameters have been used for the international projects. Prospects for supplying planned satellite terahertz projects with precise laboratory data are pointed out.1. Global monitoring of the Earth's atmosphere, data acquisition for weather forecast, and prediction of climate variations are fulfilled, in the long run, by microwave radiometric measurements from satellites. Measurement of altitude distributions of the atmospheric temperature and humidity is based on observation of spectral lines of atmospheric gases, primarily water and oxygen molecules. The interpretation of complex profiles of atmospheric lines observed from a satellite requires laboratory measurements of collisional-interaction constants of the corresponding molecule transitions, including broadening, shift, and collisional coupling (interference) of spectral lines. The accuracy of knowledge of the mentioned constants determines the accuracy of retrieved information.Until very recent time, the required accuracy of laboratory measurements of these parameters has not been reached, especially in the millimeter and submillimeter wavelength ranges. For the most important diagnostic line of a water molecule at 183 GHz, the spread of values of the broadening constants measured in different laboratories reached 30%, and the shift constant was not measured in a laboratory at all [1]. The errors of determining the line broadening constants of an oxygen molecule reached up to 25% [2,3]. In this case, if the error of assigning the broadening constant exceeds 5%, it becomes the main in the total error of determining the atmospheric parameters [4]. Improvement of the accuracy of laboratory studies of the atmospheric-line constants is a topical problem in experimental physics, which is of great applied value.2. We developed a complex of spectrometers of the millimeter and submillimeter wavelength ranges with measurement and calibration techniques. As a result, the accuracy was increased by more than one order of magnitude amd the reliability of measurement of all mentioned molecule constants, such as broadening, shift, and collisional coupling of spectral lines, was improved.The complex comprises two types of spect...

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