SENTINEL 5P

About This Satellite

Sentinel-5 Precursor, usually written Sentinel-5P, launched on October 13, 2017. Its TROPOMI instrument measures atmospheric composition, including trace gases and aerosols. This is an atmosphere-monitoring mission: its maps are derived measurements rather than ordinary photographs of pollution above individual streets.

A broad view of atmospheric composition

A 2600 km swath supports global daily mapping. That coverage is useful for studying broad pollution patterns and volcanic emissions, but does not mean every place receives a valid, equally precise measurement every day. The appropriate data product and its quality screening remain important.

A coloured gas map needs a quantity and units

Before comparing two maps, check what quantity is plotted, the acquisition period, and the quality criteria. Column measurements and conditions at ground level are different quantities. A marker passing overhead does not itself measure local air quality, and this orbital catalog does not supply a pollution alert.

Mission reference: ESA ESOC: Sentinel-5 Precursor mission. Editorial review: 2026-09-12.

Level-1B and Level-2 answer different questions

ESA describes Level-1B as geolocated, radiometrically corrected radiances and solar irradiances. Level-2 contains retrieved atmospheric parameters. Processing therefore stands between the detected light and the displayed gas amount. Treating raw radiance as a direct concentration reading skips that essential inference step.

Reference: ESA: Sentinel-5P product levels.

Nitrogen dioxide is often reported as a column

The TROPOMI nitrogen-dioxide product documentation defines its tropospheric column as the amount between the surface and the top of the troposphere. It is not the concentration a person would measure at breathing height. Product-specific interpretation is needed before comparing satellite values with a ground monitoring station.

Reference: Copernicus/KNMI: TROPOMI NO2 product definition.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 826 km at perigee to 828 km at apogee, a difference of 2 km. The orbital period is about 101.4 minutes. Eccentricity 0.00012 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.00 times apogee speed. These are mean-element estimates, not instantaneous measurements. Distance per orbit uses an ellipse approximation.

Saved build snapshot. If a valid TLE is retrieved, this explanation and the orbit panel update together. Otherwise this dated snapshot is retained.

Ground track is not sensor coverage

An inclination of 98.80 degrees implies approximate geocentric ground-track limits of 81.2 degrees north and south. This is a retrograde orbit, moving against the direction of Earth rotation. The plotted line marks the point beneath the object. It does not represent camera coverage, radio reception, or a guaranteed visible pass.

Accuracy and missing information

The introductory record describes the build snapshot. The orbital snapshot explanation and orbit panel share any successfully retrieved TLE; check the displayed epoch. Reentered objects retain historical data only. Mission history is not rewritten by TLE updates. TLE/SGP4 positions are predictions and can change after maneuvers or updated observations. The 14-day stale-data cutoff is a display safeguard, not an accuracy guarantee. Local passes are geometric predictions, not a visibility forecast. No verified operator or mission status means unknown, not active. Do not use this catalog for collision avoidance or operational flight decisions.

Catalog sources: CelesTrak SATCAT: NORAD 42969 · GCAT: S42969 (source update 2026 Sep 4 2345:57). Supplementary metadata: SatNOGS DB, retrieved 2026-09-05T12:57:25.375Z. Page assembled 2026-09-15. GCAT phase codes describe trajectory phases, not mission health.

Learn more: TLE data · Perigee and apogee · Ground tracks · JOT (Jewawud Live Orbital Map)

Satellite Details