Study of different strategies to setting up and correcting in-situ thermal infrared measurements

2021 ◽  
Author(s):  
Jean Dumoulin ◽  
Thibaud Toullier ◽  
Laurent Mevel
Keyword(s):  
Thermal Infrared ◽  
Infrared Measurements

scholarly journals A Blackbody Design for SI-Traceable Radiometry for Earth Observation

2008 ◽  
Vol 25 (11) ◽  
pp. 2046-2054 ◽  
Author(s):  
P. Jonathan Gero ◽  
John A. Dykema ◽  
James G. Anderson
Keyword(s):  
Phase Transitions ◽  
Temperature Scale ◽  
International System ◽  
Thermal Infrared ◽  
Earth Observation ◽  
International Standards ◽  
Future Climate Change ◽  
Single Temperature ◽  
System Of Units ◽  
Infrared Measurements

Abstract Spaceborne measurements pinned to international standards are needed to monitor the earth’s climate, quantify human influence thereon, and test forecasts of future climate change. The International System of Units (SI, from the French for Système International d’Unités) provides ideal measurement standards for radiometry as they can be realized anywhere, at any time in the future. The challenge is to credibly prove on-orbit accuracy at a claimed level against these international standards. The most accurate measurements of thermal infrared spectra are achieved with blackbody-based calibration. Thus, SI-traceability is obtained through the kelvin scale, making thermometry the foundation for on-orbit SI-traceable spectral infrared measurements. Thermodynamic phase transitions are well established as reproducible temperature standards and form the basis of the international practical temperature scale (International Temperature Scale of 1990, ITS-90). Appropriate phase transitions are known in the temperature range relevant to thermal infrared earth observation (190–330 K) that can be packaged such that they are chemically stable over the lifetime of a space mission, providing robust and traceable temperature calibrations. A prototype blackbody is presented that is compact, highly emissive, thermally stable and homogeneous, and incorporates a small gallium melting point cell. Precision thermal control of the blackbody allows the phase transition to be identified to within 5 mK. Based on these results, the viability of end-to-end thermometric calibration of both single-temperature and variable-temperature blackbodies on orbit by employing multiple-phase-change cells was demonstrated.

scholarly journals A High-Accuracy Multiwavelength Radiometer for In Situ Measurements in the Thermal Infrared. Part II: Behavior in Field Experiments

2003 ◽  
Vol 20 (7) ◽  
pp. 1023-1033 ◽  
Author(s):  
Gérard Brogniez ◽  
Christophe Pietras ◽  
Michel Legrand ◽  
Philippe Dubuisson ◽  
Martial Haeffelin
Keyword(s):  
Field Experiments ◽  
Thermal Infrared ◽  
High Accuracy ◽  
In Situ Measurements

scholarly journals Methane profiles from GOSAT thermal infrared spectra

2018 ◽  
Vol 11 (6) ◽  
pp. 3815-3828 ◽  
Author(s):  
Arno de Lange ◽  
Jochen Landgraf
Keyword(s):  
Lower Troposphere ◽  
Principal Component ◽  
Thermal Infrared ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
Data Sets ◽  
Atmospheric Methane ◽  
Infrared Band ◽  
Correction Scheme ◽  
Infrared Measurements

Abstract. This paper discusses the retrieval of atmospheric methane profiles from the thermal infrared band of the Japanese Greenhouse Gases Observing Satellite (GOSAT) between 1210 and 1310 cm−1, using the RemoTeC analysis software. Approximately one degree of information on the vertical methane distribution is inferred from the measurements, with the main sensitivity at about 9 km altitude but little sensitivity to methane in the lower troposphere. For verification, we compare the GOSAT-TIR methane profile retrieval results with profiles from model fields provided by the Monitoring Atmospheric Composition and Climate (MACC) project, scaled to the total column measurements of the Total Carbon Column Observing Network (TCCON) at ground-based measurement sites. Without any radiometric corrections of GOSAT observations, differences between both data sets can be as large as 10 %. To mitigate these differences, we developed a correction scheme using a principal component analysis of spectral fit residuals and airborne observations of methane during the HIAPER pole-to-pole observations (HIPPO) campaign II and III. When the correction scheme is applied, the bias in the methane profile can be reduced to less than 2 % over the whole altitude range with respect to MACC model methane fields. Furthermore, we show that, with this correction, the retrievals result in smooth methane fields over land and ocean crossings and no differences can be discerned between daytime and nighttime measurements. Finally, a cloud filter is developed for the nighttime and ocean measurements. This filter is rooted in the GOSAT-TIR (thermal infrared) measurements and its performance, in terms of biases, is consistent with the cloud filter based on the GOSAT-SWIR (shortwave infrared) measurements. The TIR filter shows a higher acceptance rate of observations than the SWIR filter, at the cost of a higher uncertainty in the retrieved methane profiles.

scholarly journals Biocleaning to Remove Graffiti: A Real Possibility? Advances towards a Complete Protocol of Action

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 104 ◽  
Author(s):  
Patricia Sanmartín ◽  
Pilar Bosch-Roig
Keyword(s):  
Target Surface ◽  
Bacterial Strains ◽  
Simple Task ◽  
Anaerobic Microorganisms ◽  
Infrared Measurements ◽  
Complex Chemical Composition ◽  
Cleaning Procedures ◽  
Methodological Aspects ◽  
Reducing Bacteria

The first academic studies on the use of microorganisms in cleaning procedures appeared in the late 1980s/early 1990s. In the past thirty years, most of such studies have addressed the removal of nitrate and sulphate salts and organic matter from surfaces by using non-pathogenic anaerobic microorganisms, mainly sulphate-reducing bacteria. The successful use of microbes in the removal of graffiti paint remains, however, a work in progress. Biocleaning surfaces to remove graffiti is not a simple task, because of the complex chemical composition of graffiti paints. This study looks at ways of improving the bioremoval of graffiti and presents the latest findings regarding different methodological aspects of cleaning natural and man-made stone. Granite and concrete substrates were coated with silver and black graffiti spray paints for comparison of the efficacy of the biocleaning method on these different materials. Visual and microscopic examination along with colour and infrared measurements made after application of the bacterial strains tested (previously shown to be suitable candidates for bioremoval of graffiti) revealed remarkably successful results. The findings presented thus represent progress in the development of a biocleaning protocol applicable to the in-situ removal of graffiti. Important improvements have been made regarding the time of treatment, which has been reduced by up to 20 days, and the use of a culture medium enriched with powdered graffiti, which facilitates and accelerates the adaptation of the microorganisms to the target surface.

scholarly journals Multiscale thermal-infrared measurements of the Mauna Loa caldera, Hawaii

2001 ◽  
Author(s):  
Lee K. Balick ◽  
Alan R. Gillespie ◽  
Elsa Abbott ◽  
Donald Sabol ◽  
Anne B. Kahle ◽  
...  
Keyword(s):  
Thermal Infrared ◽  
Mauna Loa ◽  
Infrared Measurements
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