Off-axis responses were measured early in the PV phase on the bright
source W Hya, out to a distance of 2
. Later in the
mission, specific straylight checks were performed, prompted by
scientific needs for a better characterization of the influence of
straylight from Saturn on planetary satellites such as Titan and Europa.
One measurement of straylight rejection was performed during observations of
Titan on revolution 384. The spectral line due to C
H
at 13.7
m
was measured on Saturn and at a position Y
-
,
Z
-
, corresponding to a total displacement of
. By comparing the spectral line at these positions a rejection
factor of 10
was calculated (ref. Salama 1998, [32]).