The Sentinel-2 mission orbit is sun-synchronous. Sun-synchronous orbits are used to ensure the angle of sunlight upon the Earth's surface is consistently maintained. Apart from small seasonal variations, anchoring of the satellites orbit to the angle of the sun minimises the potential impact of shadows and levels of illumination on the ground. This ensures consistency over time and is critical in assessing time-series data.
Sentinel-2A and Sentinel-2B occupy the same orbit, but separated by 180 degrees.The mean orbital altitude is 786 km. The orbit inclination is 98.62° and the Mean Local Solar Time (MLST) at the descending node is 10:30 (am). This value of MLST was chosen as a compromise between a suitable level of solar illumination and the minimisation of potential cloud cover. The MLST value is close to the local overpass time of Landsat and almost identical to that of SPOT-5, permitting the integration of Sentinel-2 data with existing and historical missions, and contributing to long-term time series data collection.
The following table contains a summary of useful orbital information for Sentinel-2A and –2B:
|Altitude||Inclination||Period||Cycle||Ground-track deviation||Local Time at Descending Node|
|786 km||98.62 deg||100.6 min||10 days||+- 2 km||10:30 hours|
The KML data file informing on the position of the Sentinel-2A and Sentinel-2B Relative Orbits for a full Cycle (143 Orbits) with a time step of 10 seconds is available: