This dataset contains NO2 differential slant column densities (dSCD), acquired at BAQUNIN-APL supersite in an urban environment.
The acquisition followed a fixed hourly pattern with one zenith spectrum (80° elevation) and six sequential low-elevation (typically 7°) measurements at azimuths 015°, 050°, 085°, 115°, 155°, and 340°, repeating every hour.
The methods for retrieving the dSCDs from Level-0 measurements are described in https://doi.org/10.5194/amt-18-6021-2025
The dataset contains one NetCDF file per month, per main azimuth and per elevation, gathering all the corresponding Level-2 NO2 retrievals.
Each file's dimensions are:
date_hour for the day and hour of the measurement (only one acquisition per day and hour, due to the data acquisition plan)row and col identifying the camera's pixels, spatially downsampled with a factor 5x5 to limit data volume, i.e. a horizontal and vertical sampling of ~0.22°.
The data variables available at pixel level are the NO2 differential slant column density (dSCD), its uncertainty, scene radiance, viewing elevation and azimuth angles, and a QC mask for the dSCD (no2_qc_passed).
The other data variables depend only on the measurement time: solar zenith and azimuth angles and several time coordinates.
