SENTINEL 3A
Country: European Union
Live Position
Ground Track · Last 90 Minutes
Upcoming Passes · Over Your Location
About This Satellite
Sentinel-3A launched on February 16, 2016, to measure several aspects of the oceans and land surface. The mission combines colour, temperature, and surface-height observations. These are complementary quantities: an ocean region can change temperature without having the same pattern of change in colour or sea level.
Broad coverage rather than street-level mapping
The nominal near-polar, sun-synchronous orbit is about 814.5 km high. Wide instrument swaths support repeated large-scale environmental observations. A revisit figure depends on the instrument and on whether it describes one spacecraft or the paired constellation. It is not interchangeable with the orbital period displayed below.
One marker cannot represent every instrument footprint
The point beneath Sentinel-3A is a geometric reference. Its imaging instruments observe broad swaths, while altimetry samples a much narrower path. The same ground track therefore supports different coverage interpretations. For an actual measurement, consult the relevant product and acquisition geometry rather than treating the map line as a universal coverage boundary.
Mission reference: ESA: Sentinel-3 mission facts. Editorial review: .
Colour and temperature ask different questions
OLCI, the Ocean and Land Colour Instrument, measures 21 spectral bands. SLSTR, the Sea and Land Surface Temperature Radiometer, uses multiple channels and viewing directions to support temperature measurements and fire detection. OLCI imagery can support ocean-ecosystem studies; it should not be interpreted as a temperature map simply because colours are used to display it.
Reference: ESA: Sentinel-3 instrument roles.
Altimetry needs more than the satellite altitude
The SRAL radar altimeter measures the range toward the surface. A microwave radiometer supports correction for atmospheric effects. Sea-surface height products therefore depend on calibrated ranging and orbit knowledge, not merely the altitude of the spacecraft shown in this catalog. The sensor measurement and the predicted orbital height are different parts of the problem.
Reference: ESA: SRAL and microwave-radiometer corrections.
Reading this orbital snapshot
Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 802 km at perigee to 803 km at apogee, a difference of 1 km. The orbital period is about 100.9 minutes. Eccentricity 0.00010 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 98.63 degrees implies approximate geocentric ground-track limits of 81.4 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 41335 · GCAT: S41335 (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)