Minimize Orbit Characteristics

The SENTINEL-3 orbit is almost the same orbit as ENVISAT, allowing continuation of the ERS/ENVISAT and CRYOSAT time series.

The main parameters for the reference orbit are:

  • type: near-polar frozen sun-synchronous
  • inclination: 98.65°
  • mean local solar time at descending node: 10:00 h
  • repeat cycle: 27 days (14 + 7 / 27 orbits per day) 
  • reference altitude: 814.5 km
  • cycle length: 385 orbits
  • ground track separation at the Equator: 104 km with SENTINEL-3A, and 52 km with SENTINEL-3A and SENTINEL-3B.

Figure 1: Example of SENTINEL-3 Single Orbit Ground Track (Credit: isardSAT)

The mean local solar time at descending node at 10:00h still provides complementary local time coverage while optimising the viewing conditions for the imager and allowing continuity with the existing ERS and ENVISAT climate products.

Having a high inclination provides important extra information about sea level variations in high latitudes not properly sampled before by a high precision altimeter.