ECLSS Trace Gas Monitoring: Breadboarding of an FTIR Michelson Interferometer

1994 ◽  
Author(s):  
Hermann Bittner ◽  
Markus Erhard ◽  
Tonje Midtgaard ◽  
Katja David ◽  
Gijsbert Tan
Keyword(s):  
Michelson Interferometer ◽  
Trace Gas ◽  
Gas Monitoring

scholarly journals Validation of MIPAS IMK/IAA methane profiles

2015 ◽  
Vol 8 (12) ◽  
pp. 5251-5261 ◽  
Author(s):  
A. Laeng ◽  
J. Plieninger ◽  
T. von Clarmann ◽  
U. Grabowski ◽  
G. Stiller ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
European Space Agency ◽  
Trace Gas ◽  
Mixing Ratios ◽  
Air Sampler ◽  
Solar Occultation ◽  
Space Agency ◽  
Scanning Imaging ◽  
Satellite Instruments

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is an infrared (IR) limb emission spectrometer on the Envisat platform. It measures trace gas distributions during day and night, pole-to-pole, over an altitude range from 6 to 70 km in nominal mode and up to 170 km in special modes, depending on the measurement mode, producing more than 1000 profiles day−1. We present the results of a validation study of methane, version V5R_CH4_222, retrieved with the IMK/IAA (Institut für Meteorologie und Klimaforschung, Karlsruhe/Instituto de Astrofisica de Andalucia, Grenada) MIPAS scientific level 2 processor. The level 1 spectra are provided by the ESA (European Space Agency) and version 5 was used. The time period covered is 2005–2012, which corresponds to the period when MIPAS measured trace gas distributions at a reduced spectral resolution of 0.0625 cm−1. The comparison with satellite instruments includes the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), the HALogen Occultation Experiment (HALOE), the Solar Occultation For Ice Experiment (SOFIE) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). Furthermore, comparisons with MkIV balloon-borne solar occultation measurements and with air sampling measurements performed by the University of Frankfurt are presented. The validation activities include bias determination, assessment of stability, precision validation, analysis of histograms and comparison of corresponding climatologies. Above 50 km altitude, MIPAS methane mixing ratios agree within 3 % with ACE-FTS and SOFIE. Between 30 and 40 km an agreement within 3 % with SCIAMACHY has been found. In the middle stratosphere, there is no clear indication of a MIPAS bias since comparisons with various instruments contradict each other. In the lower stratosphere (below 25 km) MIPAS CH4 is biased high with respect to satellite instruments, and the most likely estimate of this bias is 14 %. However, in the comparison with CH4 data obtained from cryogenic whole-air sampler (cryosampler) measurements, there is no evidence of a high bias in MIPAS between 20 and 25 km altitude. Precision validation is performed on collocated MIPAS–MIPAS pairs and suggests a slight underestimation of its uncertainties by a factor of 1.2. No significant evidence of an instrumental drift has been found.

scholarly journals The horizontal resolution of MIPAS

2008 ◽  
Vol 1 (1) ◽  
pp. 103-125 ◽  
Author(s):  
T. von Clarmann ◽  
C. De Clercq ◽  
M. Ridolfi ◽  
M. Höpfner ◽  
J.-C. Lambert
Keyword(s):  
Michelson Interferometer ◽  
Elevation Angle ◽  
Emission Spectra ◽  
Horizontal Resolution ◽  
Atmospheric Composition ◽  
Trace Gas ◽  
Atmospheric Conditions ◽  
Tangent Point ◽  
High Vertical Resolution ◽  
Along Track

Abstract. Limb remote sensing from space provides atmospheric composition measurements at high vertical resolution while the information is smeared in the horizontal domain. The horizontal components of two-dimensional (altitude and along-track coordinate) averaging kernels of a limb retrieval constrained to horizontal homogeneity can be used to estimate the horizontal resolution of limb retrievals. This is useful for comparisons of measured data with modeled data, to construct horizontal observation operators in data assimilation applications or when measurements of different horizontal resolution are intercompared. We present these averaging kernels for retrievals of temperature, H2O, O3, CH4, N2O, HNO3 and NO2 from MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) high-resolution limb emission spectra. The horizontal smearing of a MIPAS retrieval in terms of full width at half maximum of the rows of the horizontal averaging kernel matrix varies typically between about 200 and 350 km for most species, altitudes and atmospheric conditions. The range where 95% of the information originates from varies from about 260 to 440 km for these cases. This information spread is smaller than the MIPAS horizontal sampling, i.e. MIPAS data are horizontally undersampled, and the effective horizontal resolution is driven by the sampling rather than the smearing. The point where the majority of the information originates from is displaced from the tangent point towards the satellite by typically less than 10 km for trace gas profiles and about 50 to 100 km for temperature, with a few exceptions for uppermost altitudes. The geolocation of a MIPAS profile is defined as the tangent point of the middle line of sight in a MIPAS limb scan. The majority of the information displacement with respect to this nominal geolocation of the measurement is caused by the satellite movement and the geometrical displacement of the actual tangent point as a function of the elevation angle. In none of the cases investigated, propagation of the horizontal smoothing on the vertical profile shape has been observed.

First Year On-Orbit Calibration of the Chinese Environmental Trace Gas Monitoring Instrument Onboard GaoFen-5

2020 ◽  
Vol 58 (12) ◽  
pp. 8531-8540
Author(s):  
MinJie Zhao ◽  
FuQi Si ◽  
Yu Wang ◽  
HaiJin Zhou ◽  
ShiMei Wang ◽  
...  
Keyword(s):  
Trace Gas ◽  
First Year ◽  
Gas Monitoring ◽  
Monitoring Instrument

scholarly journals Recent Advances in Aerosol and Trace Gas Monitoring by Employing the Scheimpflug Lidar Techniques

2020 ◽  
Vol 237 ◽  
pp. 07022
Author(s):  
Liang Mei ◽  
Zheng Kong ◽  
Teng Ma ◽  
Zhi Liu ◽  
Zhenfeng Gong ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Laser Diodes ◽  
Image Sensor ◽  
Trace Gas ◽  
Light Sources ◽  
Continuous Wave Laser ◽  
Gas Monitoring ◽  
Power Laser ◽  
Recent Advances ◽  
Atmospheric Remote Sensing

Lidar techniques, based on the time-of-flight principle, have been widely employed in atmospheric remote sensing since decades. The Scheimpflug lidar (SLidar) technique, which employing robust high-power laser diodes as light sources and highly integrated CCD/CMOS image sensor as detectors, has been recently developed for various atmospheric applications. Range-resolved atmospheric backscattering signal is obtained by capturing the backscattering imaging of transmitted continuous-wave laser beam based on the Scheimpflug principle. This paper reported recent advances in aerosol and trace gas monitoring by employing the SLidar techniques.

scholarly journals Use of a Maximum Entropy Method as a Regularization Technique during the Retrieval of Trace Gas Profiles from Limb Sounding Measurements

2006 ◽  
Vol 23 (12) ◽  
pp. 1657-1667 ◽  
Author(s):  
J. Steinwagner ◽  
G. Schwarz ◽  
S. Hilgers
Keyword(s):  
Maximum Entropy ◽  
Random Noise ◽  
A Priori ◽  
Michelson Interferometer ◽  
Simulated Data ◽  
Optimal Estimation ◽  
Initial Guess ◽  
Entropy Method ◽  
Trace Gas ◽  
Regularization Techniques

Abstract The retrieval of trace gas profiles from radiance measurements of limb sounding instruments represents an inverse problem: vertical profiles of mixing ratios have to be extracted from sequences of horizontally measured radiances recorded by a spectrometer. Typically, these retrievals are plagued by random noise and systematic errors, necessitating the use of regularization techniques during inversion calculations. In the following, the use of selected maximum entropy operators as a regularization tool is discussed and their performance with conventional optimal estimation and Tikhonov-type regularization techniques is compared. The main gain with the proposed maximum entropy operators is that no a priori knowledge is needed; a reasonable initial guess profile is fully sufficient. The approach is verified by using simulated data of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, an infrared Fourier transform spectrometer flown on the European Envisat mission.

New perspectives in ultrasensitive trace gas monitoring by cavity-enhanced laser absorption spectroscopy

1999 ◽  
Author(s):  
Alexander A. Kachanov ◽  
Daniele Romanini ◽  
Marc Chenevier ◽  
A. Garnache ◽  
Frederic Stoeckel
Keyword(s):  
Absorption Spectroscopy ◽  
Trace Gas ◽  
Laser Absorption Spectroscopy ◽  
Gas Monitoring ◽  
Laser Absorption
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