The TROPOMI instrument aboard the SENTINEL-5P space craft is a nadir-viewing, imaging spectrometer covering wavelength bands between the ultraviolet and the shortwave infra-red. TROPOMI's purpose is to measure atmospheric properties and constituents such as NO2₂. It is contributing to monitoring air quality and providing critical information to services and decision makers.

The instrument uses passive remote sensing techniques by measuring the Top Of Atmosphere (TOA) solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum, allowing operational retrieval of a number of trace gas constituents.

Local equator crossing time of the ascending node is 13:30. Daily NO₂ observations are used for assimilation into the POLYPHEMUS/DLR air quality model.

POLYPHEMUS/DLR is a state-of-the-art air quality model taking into consideration

• meteorological conditions,
• photochemistry,
• anthropogenic and natural (biogenic) emissions,
• TROPOMI NO₂ observations for data assimilation.

These Level 4 air quality products (surface NO₂ at 15:00 UTC) which are based on innovative algorithms, processors and data assimilation are operationally processed and disseminated in the framework of the INPULS project.

Sensor: TROPOMI/Sentinel-5P
Processor: POLYPHEMUS/DLR Air Quality Model
Period: January 2023 - ongoing
Horizontal resolution: 0.09 degrees x 0.06 degrees

Attribution: These products are an outcome of the INPULS project (Innovative Produktenwicklung zur Analyse der Atmosphaerenzusammensetzung), funded by DLR Programmatik Raumfahrtforschung und -technologie. Data is generated and distributed by DLR under the CC-BY-NC 4.0 license. Products contain processed and modified Copernicus Sentinel data (2023-ongoing).