Multichannel Heterodyne Spectroradiometer for Atmospheric Greenhouse Gas Measurements

2021 ◽  
Author(s):  
Sergei Zenevich ◽  
Iskander Gazizov ◽  
Dmitry Churbanov ◽  
Maxim Spiridonov ◽  
Alexander Rodin
Keyword(s):  
Spectral Resolution ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Basic Research ◽  
High Spectral Resolution ◽  
Vertical Profiles ◽  
Atmospheric Measurements ◽  
Stratospheric Wind ◽  
Signal Evaluation ◽  
Channel Configuration

<p>We present a portable, multichannel laser heterodyne spectroradiometer (MLHS) with a spectral resolution of 0.0013 cm-1 for precision column measurements and vertical profiling of atmospheric greenhouse gases (GHG). Sample spectra of CO<sub>2</sub> and CH<sub>4</sub> absorption lines obtained by direct Sun observations have allowed us to measure GHG column abundance with a precision of 0.5% for CO<sub>2</sub> and 10% for CH<sub>4</sub>, as well as to retrieve their vertical profiles and to get a vertical profile of the stratospheric wind Rodin et al. (2020). The fundamentals and specifics of the multichannel configuration implementation of heterodyne receivers are presented in Zenevich et al. (2020). This work presents the first data of atmospheric CO<sub>2</sub> and CH<sub>4</sub> measurements, which were taken in a 4-channel configuration of the heterodyne receiver. Such configuration has allowed us to get atmospheric spectra with the SNR 300-500 within 2 minutes period of signal integration and keep the high spectral resolution. The results of retrieving CO<sub>2</sub> and CH<sub>4</sub> vertical concentration profiles and vertical profiles of the stratospheric wind are also presented.</p><p> </p><p><strong>Acknowledgments</strong></p><p>This work has been supported by the Russian Foundation for Basic Research grants # 19-29-06104  (A.V. Rodin, M. V. Spiridonov, I.Sh. Gazizov) and # 19-32-90276 (S. G. Zenevich).</p><p> </p><p><strong>References:</strong></p><p>Zenevich S. et al.: The improvement of dark signal evaluation and signal-to-noise ratio of multichannel receivers in NIR heterodyne spectroscopy application for simultaneous CO2 and CH4 atmospheric measurements, OSA Continuum, 3, 7, 1801-1810, doi:10.1364/OSAC.395094, 2020.</p><p>Rodin, A. et al.: Vertical wind profiling from the troposphere to the lower mesosphere based on high-resolution heterodyne near-infrared spectroradiometry, Atmos. Meas. Tech., 13, 2299–2308, doi:10.5194/amt-13-2299-2020, 2020.</p>

scholarly journals A Concept of 2U Spaceborne Multichannel Heterodyne Spectroradiometer for Greenhouse Gases Remote Sensing

2021 ◽  
Vol 13 (12) ◽  
pp. 2235
Author(s):  
Sergei Zenevich ◽  
Iskander Gazizov ◽  
Dmitry Churbanov ◽  
Yegor Plyashkov ◽  
Maxim Spiridonov ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Low Earth Orbit ◽  
High Spectral Resolution ◽  
Solar Occultation ◽  
Vertical Profiling ◽  
Multichannel Laser ◽  
Laser Heterodyne ◽  
One Year

We present the project of a 2U CubeSat format spaceborne multichannel laser heterodyne spectroradiometer (MLHS) for studies of the Earth’s atmosphere upper layers in the near-infrared (NIR) spectral range (1258, 1528, and 1640 nm). A spaceborne MLHS operating in the solar occultation mode onboard CubeSat platform, is capable of simultaneous vertical profiling of CO2, H2O, CH4, and O2, as well as Doppler wind measurements, in the tangent heights range of 5–50 km. We considered the low Earth orbit for the MLHS deployment and analyzed the expected surface coverage and spatial resolution during one year of operations. A ground-based prototype of the MLHS for CO2 and CH4 molecular absorption measurements with an ultra-high spectral resolution of 0.0013 cm−1 is presented along with the detailed description of its analytical characteristics and capabilities. Implementation of a multichannel configuration of the heterodyne receiver (four receivers per one spectral channel) provides a significant improvement of the signal-to-noise ratio with the reasonable exposure time typical for observations in the solar occultation mode. Finally, the capability of building up a tomographic picture of sounded gas concentration distributions provided by high spectral resolution is discussed.

Spectrum Filter Performance Analysis on Near-Infrared High-Spectral-Resolution Lidar

2016 ◽  
Vol 43 (4) ◽  
pp. 0414004
Author(s):  
张与鹏 Zhang Yupeng ◽  
刘东 Liu Dong ◽  
杨甬英 Yang Yongying ◽  
罗敬 Luo Jing ◽  
成中涛 Cheng Zhongtao ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Spectral Resolution ◽  
Near Infrared ◽  
High Spectral Resolution ◽  
Filter Performance ◽  
High Spectral Resolution Lidar

scholarly journals Global monitoring of terrestrial chlorophyll fluorescence from moderate spectral resolution near-infrared satellite measurements: methodology, simulations, and application to GOME-2

2013 ◽  
Vol 6 (2) ◽  
pp. 3883-3930 ◽  
Author(s):  
J. Joiner ◽  
L. Guanter ◽  
R. Lindstrot ◽  
M. Voigt ◽  
A. P. Vasilkov ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Spectral Resolution ◽  
Near Infrared ◽  
High Spectral Resolution ◽  
High Signal ◽  
Good Precision ◽  
Atmospheric Absorption ◽  
Red Fluorescence ◽  
Fluorescence Measurements ◽  
Global Mapping

Abstract. Globally mapped terrestrial chlorophyll fluorescence retrievals are of high interest because they can provide information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling and agricultural applications. In addition, fluorescence can contaminate photon path estimates from the O2 A-band that has become an integral part of missions to accurately measure greenhouse gas concentrations. Global mapping of far-red (~ 755–770 nm) terrestrial vegetation solar-induced fluorescence from space has been accomplished using the high spectral resolution (ν/Δ ν > 35 000) interferometer on the Japanese Greenhouse gases Observing SATellite (GOSAT). These satellite retrievals of fluorescence rely solely upon the filling-in of solar Fraunhofer lines that are not significantly affected by atmospheric absorption. Although these measurements provide near global coverage on a monthly basis, they suffer from relatively low precision and sparse spatial sampling. Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data to disentangle the spectral signatures of three basic components in and surrounding the O2 A-band: atmospheric absorption, surface reflectance, and fluorescence radiance. Through detailed simulations, we demonstrate the feasibility of the approach and show that moderate spectral resolution measurements with a relatively high signal-to-noise ratio within and outside the O2 A-band can be used to retrieve far-red fluorescence information with good precision and accuracy. The method is then applied to data from the Global Ozone Monitoring Instrument 2 (GOME-2). The GOME-2 fluorescence retrievals display similar spatial structure as compared with GOSAT. GOME-2 enables global mapping of far-red fluorescence with higher precision over smaller spatial and temporal scales than is possible with GOSAT. It should be noted that both GOME-2 and GOSAT were designed to make atmospheric trace gas measurements and were not optimized for fluorescence measurements. Our approach can be applied to other existing and future space-based instruments that provide moderate spectral resolution observations in the near-infrared region.

scholarly journals Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+

2021 ◽  
Vol 646 ◽  
pp. A150
Author(s):  
G. P. P. L. Otten ◽  
A. Vigan ◽  
E. Muslimov ◽  
M. N’Diaye ◽  
E. Choquet ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Extrasolar Planets ◽  
Signal To Noise Ratio ◽  
Detection Limits ◽  
Spectral Lines ◽  
High Spectral Resolution ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
The Impact

Studies of atmospheres of directly imaged extrasolar planets with high-resolution spectrographs have shown that their characterization is predominantly limited by noise on the stellar halo at the location of the studied exoplanet. An instrumental combination of high-contrast imaging and high spectral resolution that suppresses this noise and resolves the spectral lines can therefore yield higher quality spectra. We study the performance of the proposed HiRISE fiber coupling between the direct imager SPHERE and the spectrograph CRIRES+ at the Very Large Telescope for spectral characterization of directly imaged planets. Using end-to-end simulations of HiRISE we determine the signal-to-noise ratio (S/N) of the detection of molecular species for known extrasolar planets in H and K bands, and compare them to CRIRES+. We investigate the ultimate detection limits of HiRISE as a function of stellar magnitude, and we quantify the impact of different coronagraphs and of the system transmission. We find that HiRISE largely outperforms CRIRES+ for companions around bright hosts like β Pictoris or 51 Eridani. For an H = 3.5 host, we observe a gain of a factor of up to 16 in observing time with HiRISE to reach the same S/N on a companion at 200 mas. More generally, HiRISE provides better performance than CRIRES+ in 2 h integration times between 50 and 350 mas for hosts with H < 8.5 and between 50 and 700 mas for H < 7. For fainter hosts like PDS 70 and HIP 65426, no significant improvements are observed. We find that using no coronagraph yields the best S/N when characterizing known exoplanets due to higher transmission and fiber-based starlight suppression. We demonstrate that the overall transmission of the system is in fact the main driver of performance. Finally, we show that HiRISE outperforms the best detection limits of SPHERE for bright stars, opening major possibilities for the characterization of future planetary companions detected by other techniques.

scholarly journals Long-term validation of ESA operational retrieval (version 6.0) of MIPAS Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using balloon-borne observations and trajectory matching

2016 ◽  
Vol 9 (3) ◽  
pp. 1051-1062 ◽  
Author(s):  
Andreas Engel ◽  
Harald Bönisch ◽  
Tim Schwarzenberger ◽  
Hans-Peter Haase ◽  
Katja Grunow ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
European Space Agency ◽  
High Spectral Resolution ◽  
Vertical Profiles ◽  
Validation Data ◽  
Data Set ◽  
Mixing Ratios ◽  
Trajectory Matching ◽  
Wide Range ◽  
Resolution Data

Abstract. MIPAS-Envisat is a satellite-borne sensor which measured vertical profiles of a wide range of trace gases from 2002 to 2012 using IR emission spectroscopy. We present geophysical validation of the MIPAS-Envisat operational retrieval (version 6.0) of N2O, CH4, CFC-12, and CFC-11 by the European Space Agency (ESA). The geophysical validation data are derived from measurements of samples collected by a cryogenic whole air sampler flown to altitudes of up to 34 km by means of large scientific balloons. In order to increase the number of coincidences between the satellite and the balloon observations, we applied a trajectory matching technique. The results are presented for different time periods due to a change in the spectroscopic resolution of MIPAS in early 2005. Retrieval results for N2O, CH4, and CFC-12 show partly good agreement for some altitude regions, which differs for the periods with different spectroscopic resolution. The more recent low spectroscopic resolution data above 20 km altitude show agreement with the combined uncertainties, while there is a tendency of the earlier high spectral resolution data set to underestimate these species above 25 km. The earlier high spectral resolution data show a significant overestimation of the mixing ratios for N2O, CH4, and CFC-12 below 20 km. These differences need to be considered when using these data. The CFC-11 results from the operation retrieval version 6.0 cannot be recommended for scientific studies due to a systematic overestimation of the CFC-11 mixing ratios at all altitudes.

scholarly journals Development of a high spectral resolution surface albedo product for the ARM Southern Great Plains central facility

2011 ◽  
Vol 4 (3) ◽  
pp. 3097-3145
Author(s):  
S. A. McFarlane ◽  
K. L. Gaustad ◽  
E. J. Mlawer ◽  
C. N. Long ◽  
J. Delamere
Keyword(s):  
Great Plains ◽  
Spectral Resolution ◽  
Surface Albedo ◽  
Vegetation Index ◽  
Near Infrared ◽  
High Spectral Resolution ◽  
Surface Type ◽  
Southern Great Plains ◽  
Green Vegetation ◽  
Visible Wavelengths

Abstract. We present a method for identifying dominant surface type and estimating high spectral resolution surface albedo at the Atmospheric Radiation Measurement (ARM) facility at the Southern Great Plains (SGP) site in Oklahoma for use in radiative transfer calculations. Given a set of 6-channel narrowband visible and near-infrared irradiance measurements from upward and downward looking multi-filter radiometers (MFRs), four different surface types (snow-covered, green vegetation, partial vegetation, non-vegetated) can be identified. A normalized difference vegetation index (NDVI) is used to distinguish between vegetated and non-vegetated surfaces, and a scaled NDVI index is used to estimate the percentage of green vegetation in partially vegetated surfaces. Based on libraries of spectral albedo measurements, a piecewise continuous function is developed to estimate the high spectral resolution surface albedo for each surface type given the MFR albedo values as input. For partially vegetated surfaces, the albedo is estimated as a linear combination of the green vegetation and non-vegetated surface albedo values. The estimated albedo values are evaluated through comparison to high spectral resolution albedo measurements taken during several Intensive Observational Periods (IOPs) and through comparison of the integrated spectral albedo values to observed broadband albedo measurements. The estimated spectral albedo values agree well with observations for the visible wavelengths constrained by the MFR measurements, but have larger biases and variability at longer wavelengths. Additional MFR channels at 1100 nm and/or 1600 nm would help constrain the high resolution spectral albedo in the near infrared region.

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