Published online by Cambridge University Press: 13 May 2016
Observations with the SORO/CDS NIS detector prior to the recovery of SOHO showed strong correlations between line shifts and local intensity gradients along the slit, probably caused by an elliptical, tilted point spread function. This must be taken into account when interpreting NIS observations with strong intensity gradients. An initial analysis of post-recovery data does not display the same pattern, indicating that this particular problem was eliminated by changes in the optics during SOHO's “vacation”.