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Fix A, Quatrevalet M, Amediek A, Wirth M. Energy calibration of integrated path differential absorption lidars. APPLIED OPTICS 2018; 57:7501-7514. [PMID: 30461816 DOI: 10.1364/ao.57.007501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/07/2018] [Indexed: 06/09/2023]
Abstract
The stringent requirements for energy reference measurement represent a challenging task for integrated path differential absorption lidars to measure greenhouse gas columns from satellite or aircraft. The coherence of the lidar transmitter gives rise to speckle effects that have to be considered for accurate monitoring of the energy ratio of outgoing on- and off-line pulses. Detailed investigations have been performed on various measurement concepts potentially suited for deployment within future satellite missions.
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2
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Pal A, Clark CD, Sigman M, Killinger DK. Differential absorption lidar CO2 laser system for remote sensing of TATP related gases. APPLIED OPTICS 2009; 48:B145-B150. [PMID: 19183572 DOI: 10.1364/ao.48.00b145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A CW tunable 10.6 microm CO(2) laser differential absorption lidar (DIAL) system has been developed, for the first time to our knowledge, for the remote sensing of triacetone triperoxide (TATP) gas vapors, which have strong absorption lines at several wavelengths, including 3.3, 8.3, and 10.6 microm. The DIAL laser beam was transmitted through an enclosed absorption cell containing TATP or SF(6), and backscattered returns were measured from a retroreflector array target at ranges of 5-100 m. DIAL sensitivity for the detection of TATP was about 0.5 ng/microl [52 parts in 10(6)(ppm)] for a 0.3 m path.
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Affiliation(s)
- Avishekh Pal
- University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, USA
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3
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Schilling BW, Barr DN, Templeton GC, Mizerka LJ, Trussell CW. Multiple-return laser radar for three-dimensional imaging through obscurations. APPLIED OPTICS 2002; 41:2791-2799. [PMID: 12027165 DOI: 10.1364/ao.41.002791] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A compact imaging laser radar was constructed and tested to investigate phenomenological issues in targeting, especially cases involving imaging through obscurations such as foliage and camouflage netting. The laser radar employs a Nd:YAG microchip laser that operates at a wavelength of 1.06 microm and produces pulses of 1.2-ns duration at a 3-kHz rate. The detector is a commercial indium gallium arsenide avalanche photodiode. A single computer controls the scanning mirrors and performs the digitization of the returning signal at 2 giga samples/s. A detailed description of the laser radar is presented as well as results from field experiments that examined its range accuracy capability and its ability to image a target through camouflage. Results of data collected from deciduous tree lines are also discussed to characterize the presence and quantity of multiple returns.
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Affiliation(s)
- Bradley W Schilling
- US Army Communications and Electronics Command Research, Development and Engineering Center, Night Vision and Electronic Sensors Directorate, Fort Belvoir, Virginia 22060, USA.
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4
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Nelson DH, Walters DL, Mackerrow EP, Schmitt MJ, Quick CR, Porch WM, Petrin RR. Wave optics simulation of atmospheric turbulence and reflective speckle effects in CO2 lidar. APPLIED OPTICS 2000; 39:1857-1871. [PMID: 18345082 DOI: 10.1364/ao.39.001857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Laser speckle can influence lidar measurements from a diffuse hard target. Atmospheric optical turbulence will also affect the lidar return signal. We present a numerical simulation that models the propagation of a lidar beam and accounts for both reflective speckle and atmospheric turbulence effects. Our simulation is based on implementing a Huygens-Fresnel approximation to laser propagation. A series of phase screens, with the appropriate atmospheric statistical characteristics, are used to simulate the effect of atmospheric turbulence. A single random phase screen is used to simulate scattering of the entire beam from a rough surface. We compare the output of our numerical model with separate CO(2) lidar measurements of atmospheric turbulence and reflective speckle. We also compare the output of our model with separate analytical predictions for atmospheric turbulence and reflective speckle. Good agreement was found between the model and the experimental data. Good agreement was also found with analytical predictions. Finally, we present results of a simulation of the combined effects on a finite-aperture lidar system that are qualitatively consistent with previous experimental observations of increasing rms noise with increasing turbulence level.
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Affiliation(s)
- D H Nelson
- Los Alamos National Laboratory, CST-1/MS E543, PO Box 1663, Los Alamos, New Mexico 87545, USA.
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Quagliano JR, Stoutland PO, Petrin RR, Sander RK, Romero RJ, Whitehead MC, Quick CR, Tiee JJ, Jolin LJ. Quantitative chemical identification of four gases in remote infrared (9-11 mum) differential absorption lidar experiments. APPLIED OPTICS 1997; 36:1915-1927. [PMID: 18250883 DOI: 10.1364/ao.36.001915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A combined experimental and computational approach utilizing tunable CO(2) lasers and chemometric analysis was employed to detect chemicals and their concentrations in the field under controlled release conditions. We collected absorption spectra for four organic gases in the laboratory by lasing 40 lines of the laser in the 9.3-10.8-mum range. The ability to predict properly the chemicals and their respective concentrations depends on the nature of the target, the atmospheric conditions, and the round-trip distance. In 39 of the 45 field experiments, the identities of the released chemicals were identified correctly without predictions of false positives or false negatives.
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6
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Carlisle CB, van der Laan JE, Carr LW, Adam P, Chiaroni JP. CO(2) laser-based differential absorption lidar system for range-resolved and long-range detection of chemical vapor plumes. APPLIED OPTICS 1995; 34:6187-6200. [PMID: 21060462 DOI: 10.1364/ao.34.006187] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A dual CO(2) laser-based differential absorption lidar (DIAL) system has been constructed and demonstrated for range-resolved mapping of chemical vapor plumes. The system acquires high range resolution through the use of plasma-shutter pulse clippers that extinguish the nitrogen tail of the CO(2)-laser output. Aprogrammable servomotor-driven scanner allows full hemispherical coverage of the interrogated field. A high-speed direct-detection receiver subsystem is used to gather, process, and display vapor-concentration data in near real time. Data demonstrating range-resolved detection of low concentrations of chemical plumes from ranges of 1 to 2 km are presented. In the column-content detection mode, trace levels of secondary vapors from various organophosphate liquids were monitored. Detection of an SF(6) vapor plume released 16 km from the DIAL system is also adduced.
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7
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Rob MA. Absorption studies and minimum detectable concentration of ethylene by using a room-temperature HgCdTe detector. APPLIED OPTICS 1993; 32:3917-3920. [PMID: 20830025 DOI: 10.1364/ao.32.003917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The usefulness of a room-temperature HgCdTe detector in a simple air pollution detection system with a CO(2) laser has been investigated. The results show that the detector responsivity is flat in the frequency range 200-400 Hz and the minimum detectable concentration of ethylene is ~2 parts in 10(6)-meter (ppm-m). The estimated sensitivity is comparable with the values obtained by using liquid-nitrogencooled HgCdTe detectors.
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8
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Ben-David A, Emery SL, Gotoff SW, D'Amico FM. High pulse repetition frequency, multiple wavelength, pulsed CO(2) lidar system for atmospheric transmission and target reflectance measurements. APPLIED OPTICS 1992; 31:4224-4232. [PMID: 20725406 DOI: 10.1364/ao.31.004224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A multiple wavelength, pulsed CO(2) lidar system operating at a pulse repetition frequency of 200 Hz and permitting the random selection of CO(2) laser wavelengths for each laser pulse is presented. This system was employed to measure target reflectance and atmospheric transmission by using laser pulse bursts consisting of groups with as many as 16 different wavelengths at a repetition rate of 12 Hz. The wavelength tuning mechanism of the transversely excited atmospheric laser consists of a stationary grating and a flat mirror controlled by a galvanometer. Multiple wavelength, differential absorption lidar (DIAL) measurements reduce the effects of differential target reflectance and molecular absorption interference. Examples of multiwavelength DIAL detection for ammonia and water vapor show the dynamic interaction between these two trace gases. Target reflectance measurements for maple trees in winter and autumn are presented.
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9
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Cvijin PV, Ignjatijevic D, Mendas I, Sreckovic M, Pantani L, Pippi I. Reflectance spectra of terrestrial surface materials at CO2 laser wavelengths: effects on DIAL and geological remote sensing. APPLIED OPTICS 1987; 26:4323. [PMID: 20490230 DOI: 10.1364/ao.26.004323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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10
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Walter DP, Cooper DE, van der Laan JE, Murray ER. Carbon dioxide laser backscatter signatures from laboratory-generated dust. APPLIED OPTICS 1986; 25:2506. [PMID: 18231521 DOI: 10.1364/ao.25.002506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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11
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Grant WB. He-Ne and cw CO2 laser long-path systems for gas detection. APPLIED OPTICS 1986; 25:709-719. [PMID: 18231238 DOI: 10.1364/ao.25.000709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This paper describes the design and testing of a laboratory prototype dual He-Ne laser system for the detection of methane leaks from underground pipelines and solid-waste landfill sites using differential absorption of radiation backscattered from topographic targets. A laboratory-prototype dual cw carbon dioxide laser system also using topographic backscatter is discussed, and measurement results for methanol are given. With both systems, it was observed that the time-varying differential absorption signal was useful in indicating the presence of a gas coming from a nearby source. Limitations to measurement sensitivity, especially the role of speckle and atmospheric turbulence, are described. The speckle results for hard targets are contrasted with those from atmospheric aerosols. The Appendix gives appropriate laser lines and values of absorption coefficients for the hydrazine fuel gases.
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Affiliation(s)
- W B Grant
- California Institute of Technology, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109, USA
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12
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Force AP, Killinger DK, DeFeo WE, Menyuk N. Laser remote sensing of atmospheric ammonia using a CO2 lidar system. APPLIED OPTICS 1985; 24:2837-2841. [PMID: 18223964 DOI: 10.1364/ao.24.002837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A CO2 differential-absorption lidar system has been used for the remote sensing of ammonia in the atmosphere. For CO2 lidar returns backscattered from topographic targets at ranges up to 2.7 km, the path-averaged sensitivity of the DIAL system was 5 ppb of NH3 . Concentrations of atmospheric ammonia were found to vary during the day from undetectable levels (<5 ppb) to as high as 20 ppb, depending on temperature and humidity conditions.
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Affiliation(s)
- A P Force
- MIT Lincoln Laboratory, Lexington, Massachusetts 02173-0073, USA
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13
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Hardesty RM. Coherent DIAL measurement of range-resolved water vapor concentration. APPLIED OPTICS 1984; 23:2545. [PMID: 18213034 DOI: 10.1364/ao.23.002545] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Menyuk N, Killinger DK. Assessment of relative error sources in IR DIAL measurement accuracy. APPLIED OPTICS 1983; 22:2690. [PMID: 18200095 DOI: 10.1364/ao.22.002690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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15
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Killinger DK, Menyuk N, DeFeo WE. Experimental comparison of heterodyne and direct detection for pulsed differential absorption CO2 lidar. APPLIED OPTICS 1983; 22:682-689. [PMID: 18195856 DOI: 10.1364/ao.22.000682] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A pulsed dual-wavelength dual-CO2-laser differential-absorption lidar (DIAL) system has been developed which permits simultaneous heterodyne and direct detection of the same lidar returns. This system has been used to make an experimental comparison of the SNRs and statistical and temporal characteristics of the DIAL returns from several topographic targets. These results were found to be in general agreement with theory and were used to quantify the relative merits of the two detection techniques. The measured parameter values were applied to an analytical treatment to predict system trade-offs for the remote sensing of atmospheric species, with application to both path-averaged and range-resolved measurements.
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Affiliation(s)
- D K Killinger
- MIT Lincoln Laboratory, P.O. Box 73, Lexington, Massachusetts 02173, USA
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Persson U, Johansson J, Marthinsson B, Eng ST. Ethylene mass flow measurements with an automatic CO(2) laser long-path absorption system. APPLIED OPTICS 1982; 21:4417-4420. [PMID: 20401089 DOI: 10.1364/ao.21.004417] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A computer controlled CO(2) laser long-path absorption system has been used in a field experiment to measure the total emission of ethylene from a petrochemical factory. The ethylene concentration was measured along eight measurement paths at different elevations. Simultaneously meteorological data were collected. From these data we have calculated the mass flow from the factory. The result of the calculations agree well with the value estimated at the factory using conventional methods.
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Brewer RJ, Bruce CW, Mater JL. Optoacoustic spectroscopy of C2H4 at the 9- and 10-microm C12O216 laser wavelengths. APPLIED OPTICS 1982; 21:4092-4100. [PMID: 20401015 DOI: 10.1364/ao.21.004092] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Absorption coefficients have been measured for ethylene in the 9- and l0-microm range with a photoacoustic spectrophone. Pressure dependency in the 10P C(12)O(2)(16) range was studied for various concentrations of ethylene. Comparisons of the data with other measurements of both atmospheric and pressure-dependent absorption coefficients were also made, and a method for relating ethylene pressure-dependency data on absorption to molecular structure was examined. Typical discrepancies between up to six independent measurements of ethylene absorption were 38.1% at the 10-microm R(20) line, 4.4% at the 10-microm P(18) line, and 18.5% at the 10-microm P(26) laser line.
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Affiliation(s)
- R J Brewer
- Anorganisch-Chemische Institut der Universitat Zurich, Zurich, Switzerland
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18
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Grant WB. Effect of differential spectral reflectance on DIAL measurements using topographic targets. APPLIED OPTICS 1982; 21:2390-2394. [PMID: 20396041 DOI: 10.1364/ao.21.002390] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Differential absorption lidar (DIAL) measurements of atmospheric gases and temperature made using topographic targets to provide the backscattered signal are subject to errors from the differential spectral reflectance of the target materials. The magnitude of this effect is estimated for a number of DIAL measurements reported in the literature. Calculations are presented for several topographic targets. In general the effect on a DIAL measurement increases directly with increasing wavelength and laser line separation, and inversely with differential absorption coefficient and distance to the target. The effect can be minimized by using tunable or isotope lasers to reduce the laser line separation or by using additional reference wavelengths to determine the surface differential spectral reflectance.
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Menyuk N, Killinger DK, Defeo WE. Laser remote sensing of hydrazine, MMH, and UDMH using a differential-absorption CO2 lidar. APPLIED OPTICS 1982; 21:2275-2286. [PMID: 20396016 DOI: 10.1364/ao.21.002275] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A dual mini-TEA CO(2) laser differential-absorption lidar system has been used to test the remote sensing of hydrazine, unsymmetrical dimethylhydrazine (UDMH), and monomethylhydrazine (MMH) in atmospheric conditions. Average concentrations of these compounds were measured using backscattered laser radiation from a target located at a range of 2.7 km. The experimental results indicate that average atmospheric concentration levels of the hydrazine compounds of the order of 40-100 ppb can be detected over ranges between 0.5 and 5 km. The level of concentration sensitivity over this interval was found to be limited primarily by atmospheric fluctuations. An investigation of the effect of these fluctuations on measurement uncertainties indicated that the fluctuations reduce the benefits of signal averaging over N pulses significantly below the expected square root of N improvement. It is also shown that uncertainties due to long-term atmospheric drifts can be effectively reduced through use of dual-laser lidar return ratios.
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Affiliation(s)
- N Menyuk
- MIT Lincoln Laboratory, Lexington, Massachusetts 02173, USA
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Lundqvist S, Fält CO, Persson U, Marthinsson B, Eng ST. Air pollution monitoring with a Q-switched CO(2)-laser lidar using heterodyne detection. APPLIED OPTICS 1981; 20:2534-2538. [PMID: 20332988 DOI: 10.1364/ao.20.002534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A differential absorption lidar (DIAL) using a Q-switched CO(2) laser and a heterodyne receiver has been developed. The DIAL system is highly automated with computer-controlled laser-line selection and signal processing. The transmitter operates at a pulse-repetition frequency of 20 kHz and has an average output power of 1.8 W. A wideband HgCdTe detector is used together with a high speed adding buffer to detect the return signals. The system has been used in a field experiment to monitor ethylene emission from a petrochemical factory.
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Menyuk N, Killinger DK. Temporal correlation measurements of pulsed dual CO(2) lidar returns. OPTICS LETTERS 1981; 6:301-303. [PMID: 19701411 DOI: 10.1364/ol.6.000301] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The temporal correlation and statistical properties of backscattered returns from specular and diffuse topographic targets have been measured by using a pulsed dual-laser direct-detection lidar system operating near 10.6 microm. Our results show that atmospheric-turbulence fluctuations can effectively be frozen for pulse separation times of the order of 1-3 msec or less. However, only incomplete correlation was achieved; the diffuse target returns yielded much lower correlation than that obtained with the specular targets. This is shown to be due to uncorrelated system noise effects and different statistics for the two types of target returns.
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Murray ER, Powell DD, van der Laan JE. Measurement of average atmospheric temperature using a CO(2) laser radar. APPLIED OPTICS 1980; 19:1794-1797. [PMID: 20221126 DOI: 10.1364/ao.19.001794] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A single-ended CO(2) lidar system has been used to measure the average temperature over a path between the lidar and the foothills located 5 km away. The CO(2) lidar was used to measure the ratio of transmission of the P(38) to the P(20) lines in the 10-microm band of CO(2). This ratio of transmission is directly related to temperature. Good correlation was obtained between the lidar-measured temperature and the thermometermeasured values.
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