Tilt data from 07/07/00, tracking NGC 6334.
The data is fit to a sine function of the form
SPO = average + amplitude*sin(2*pi(t + phase))
(note the sign on the phase, which may be opposite what you're used to).
The "arb-az" given is the location in arbitrary-az of the point (1-phase),
i.e. where sin = 0 and cos = 1.
In this case the data is partly photometric data and partly photometric
data obtained from polarimetry data. In the RA graph the rightmost three
points above the fit curve are from polarimetry data; it seems there may
be some offset that shouldn't really be there. This would only change the
average slightly, however.
A table of all SPOs can be found here.
Added by Tim on 07/18/00