Orbit
From its launch on February 2013 to July 2016, Saral/AltiKa has a repetitive orbit, on the same ground-track as Envisat (during its repetitive orbit, before 2010/10) with a 501-pass, 35-day exact repeat cycle on a sun-synchronous orbit (see below these paramters). It is complentary to Jason-2 ground tracks. Due to technical issues on the reaction wheels from March 2015, CNES and ISRO have decided to pursue this mission with a new phase named “SARAL-DP” for SARAL-Drifting Orbit". From July 2016, and during this drifting phase, the repetitive ground track are no more maintained and with the natural decay of the orbit, the ground track will drift.
The mean classical orbit elements duriong the repetitive phase (2013-2016) are given in the table below:
Pass locator
Referenced orbit Saral
Orbit parameters (repetitive phase 2013/02 - 2016/07)
Main characteristics | |
---|---|
Semi-major axis | 7159.496 km |
Eccentricity | 0.000165 |
Argument of perigee | 90.0° |
Inclination (sun-synchronous) | 98.55° |
Auxiliary data | |
Mean altitude | 800 km |
Nodal period | 100.59 min |
Repeat cycle | 35 days |
Number of revolution per cycle | 501 |
Ground track separation at Equator | 75 km |
Orbital velocity | 7.47 km/s |