Spectral reference data of molecules relevant to Earth's atmosphere: impact of European metrology research on atmospheric remote sensing

European metrology research has seen a tremendous change of focus concerning research impacting specific fields of applications. The European Metrology Research Programme (EMRP)1 in its different calls on environmental and energy subjects has revealed many new metrology projects devoted to problems, applications, and stakeholder needs in atmospheric sensing, pollution management, air quality assessments, and new energy technologies. We present the current status of development of a European infrastructure for traceable spectral reference data to be used, e.g., in remote sensing or for new developments of field-employable spectrometric transfer standards. This is demonstrated by means of standardized measurement approaches we are developing and by new measurement results regarding H2O, CO2, and N2O molecular line parameters, in this paper pressure broadening coefficients. Molecular line data are required to process raw spectra in order to extract column concentrations or local emission rates of specific analytes. Without molecular line data, all instruments were to be calibrated frequently by means of certified reference gas mixtures which were to keep available onboard throughout the instrument’s life time. At present, many instruments use line data from managed line collections like HITRAN and GEISA. These comprise paramount information on many thousands of lines for many different molecular species, but, modern remote sensing applications, like CO2 emission monitoring by satellites, tend to significantly tighten data quality objectives and thus require improved data quality that go quite frequently beyond that of the present database entries. In this presentation, we will show how metrology attempts to benefit this aim.