For the crossover point between the interleaved track
085 and the nominal track 222 (P085/222o with “o” for
“old”, i.e. nominal), the configuration is exactly the same
as for the point B in Fig. 1, with the crossover point
between the nominal tracks 222 and 085 standing for point
A. Mean profiles along the nominal tracks 222 and 085
must be used. The crossover point between the interleaved
track 222 and the nominal track 085 (P222/085o) is in the
same configuration as point A. Although it is situated on
the other side of the Sardinia Island, it is an interesting case
to see whether the bias estimates are still homogeneous at
this distance from the calibration site and, a priori, in different
oceanic conditions. For the crossover point between
the interleaved tracks 222 and 085, two different ways are
possible. The first solution is to start from the track 085
and follow the track 222 (P085/222) up to P222/085o.
The other path starts from the track 222 and follows the
track 085 (P222/085) up to the crossover point with the
nominal track 222 (P085/222o). Finally, the way that was
chosen to transfer the SSH from the crossover point
between the interleaved track 222 and the nominal track
009 (P222/009o) includes the crossover points between
the nominal tracks 009 and 222 and then between the nominal
tracks 222 and 085. Other possibilities were still available
but the simplest paths were chosen in order to avoid
the multiplication of steps before reaching the Senetosa calibration
site, as it would increase the error budget of the
bias as explained in Section 2.