Sentinel-5P continues a series of spectrometers that were or are currently measuring atmospheric properties since 1995 until today:

• the Global Ozone Monitoring Experiment (GOME) on ESA's ERS-2 satellite which operated between 1995 and 2011.
• GOME-2 on EUMETSAT's Met-OP-A satellite, launched in 2006, still in service. A second GOME-2 is operating since 2012 on MetOp-B satellite.
• SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) on ESA's ENVISAT mission which operated between 2002 and 2012.
• Ozone Monitoring Instrument (OMI) since 2004 on NASA's AURA spacecraft, still in service.

Sentinel-5P will extend the data records of these missions and will be followed by the Sentinel-5 missions, planned for launch in 2021 onwards.

The mission forms the link between the current missions and the future Sentinel-4 and Sentinel-5 missions.

GOME(-2), SCIAMACHY, OMI and TROPOMI are passive sun backscatter spectrometers. SCIAMACHY and GOME(-2) use a scanning concept and linear detector arrays whereas OMI uses a staring push-broom concept with two-dimension detector arrays. The staring push-broom concept measures all ground pixels in the swath simultaneously and allows improved spatial resolution. SCIAMACHY measurements cover almost the entire solar irradiance spectrum from UV to SWIR (240 to 2 400 nm) whereas GOME(-2) and OMI are scaled down in terms of wavelength range covering respectively the UV-VIS-NIR range (270 – 790 nm) and the UV-VIS range (270-500 nm). The main characteristics of these four heritage instruments are summarised in the table.

TROPOMI employs the best of its predecessors by combining:

• large wavelength range of SCIAMACHY (albeit with some gaps) where the SWIR band allows for detection of molecules like CH₄ and CO.
• OMI's staring concept to provide the combination of daily global coverage with high spatial resolution and good signal-to-noise ratio.

When compared to these heritage instruments, the 7×7 km² spatial resolution at nadir and the improved signal-to-noise ratio of the TROPOMI instrument allows detection of small-scale sources, and increases the fraction of cloud-free observations. This represents a significant step forward in meeting the challenging requirements for Sentinel-5.