It may be expected that a product of inclinometry would be the track profile.
However, the inclinometry measurements taken on the A-frames are a convolution
of the track profile with the geometry of the antenna wheel arrangement. We
intend moving the inclinometers to other locations on the antenna to avoid
structural flexure problems, but in such locations, eg atop the elevation axis
bearings, they will still not yield the track profile directly. Relocation to
the beams joining the wheels to the central bearing will at least restrict the
complications and may yield the track profile directly provided the behaviour
of the central bearing has no hidden surprises in store.
Meanwhile attempts to deconvolve the inclinometry data to yield the track
profile continue. When data was taken with an azimuthal resolution of 1
the preferred technique rested on the approximation of the angle between the
wheels of the A-frames being 83
, (it is more accurately 83.2
),
which is co-prime with 360
, whence followed, from an arbitrary assumption
of the absolute height of the track at any azimuth, A, the height at (A+83),
(A+166), etc.. This progression covers each integral azimuth, returning to
azimuth A eventually, at which point any closing error may be removed by linear
interpolation. Interpretation of the results is proceeding,
but a poor comparison between the predicted ROLL and that of Fig.2
would seriously compromise our ability to predict YAW from the A-frame data.
Other, more direct, methods of determining the track profile are now described :