Our conventional configuration has 3 inclinometers, one on the TMU platform,
one each on the A-frames. They are oriented
with their X-axes pointing to the right of the JCMT building, measuring
ROLL, and the Y-axes pointing forwards, measuring PITCH. Each inclinometer
also has a temperature probe, thus giving 3 output data channels. The
notation for these channels and their arrangement within
the datafiles are TX, TY, TT, LX, LY, LT, RX, RY, RT in Channels 1-9,
respectively. Measurements are usually made in the azimuth range 20
to
440
, with the overlap region being used to remove linear drifts. (The
overlap differences are also the subject of a discussion below). Samples of
inclinometry data are shown in Fig.2, which shows the similarities of all the
measurements of ROLL, viz TX, LX & RX, and in Fig.3 which shows the
similarities between TY (PITCH) & RY. LY & RY are also similar to themselves
and each other after a change in sign and a change of phase of 180
.