An anomaly in a thruster used for Sentinel-1 orbit positioning control has resulted in the “orbit tube” diameter increasing from 100 meters to 200 meters maximum. The effect of this action on interferometric baselines has been predicted:
“The preliminary conclusion, supported by InSAR experts, is that the perpendicular baseline, a key InSAR performance indicator, will remain within acceptable limits. Burst synchronization at data-take start is not expected to be impacted, and degradation within data-take and as well as reduction of spectral overlap due to crossing orbits are expected to be limited.”
Detailed information is available from ESA:
Sentinel-1A change in the orbit control strategy
Increase of Sentinel-1a Orbital Tube: Impact on Interferometry