4.2.1.2. ERS-2 orbit

To carry out its mission ERS-2's orbit must enable its instruments to scan along predetermined paths designed to give optimum coverage for a set number of orbits. To achieve this, ERS-2 is a three-axis-stabilised, Earth-pointing satellite in yaw steering mode (YSM). The elliptical orbit is sun-synchronous, near-polar, with a mean altitude of 785 km, an inclination of 98.5° and a local solar time at the descending node of 10:30 a.m.

ERS-2 orbit
Heavens Above

Orbit parameters

35-day orbit

Main characteristics
Semi-major axis	7159.5 km
Eccentricity	0.0001042
Argument of perigee	92.4836°
Inclination (sun-synchronous)	98.55°
Auxiliary data
Reference altitude (equatorial)	799.8 km
Nodal period	50 min 25.5 s
Repeat cycle	35 days
Number of passes per cycle	1002
Ground track separation at Equator	80 km
Acute angle at Equator crossings
Longitude at Equator of pass 1
Orbital velocity	7.45 km/s
Ground scanning velocity

Further information on ERS (ESA website)