First observation of tropospheric nitrogen dioxide from the Environmental Trace Gases Monitoring Instrument onboard the GaoFen-5 satellite

摘要

Remote sensing: Tuned-up satellite identifies pollutant hot spots Improvements to a high-resolution spectrometer onboard China's recently-launched GaoFen-5 (GF-5) satellite can give researchers a new tool to assess atmospheric trace gases. Cheng Liu from the University of Science and Technology of China and his colleagues reported the first successful retrieval of nitrogen dioxide from the GF-5 orbiter thanks to crucial adjustments to calibration algorithms. The satellite's payload Environmental Trace Gases Monitoring Instrument (EMI) uses visible spectroscopic measurements to detect nitrogen dioxide in the atmosphere, which can be used to identify the spatial distribution of pollution emissions on the Earth. To overcome on-orbit issues including detector saturation, the team has optimized the spectral retrieval settings by spectral precalibration, fitting wavelength adjustment, reference spectrum selection, etc. Comparisons to other satellite and ground measurements revealed the optimization effort yielded reliable results for monitoring pollution levels.