H. S. WILLIAMS and G. E. BELLING,
Quasi-harmonic Patterns of Pendulous gyroscopes
during protracted oscillation
Introduction
Azimuth determinations by gyroscopic methods have, during the
past two-and-a-half years especially, fired the interest of the sur
veying community. In particular, the Wild GAKi gyro-attachment
appears to have made the biggest impact on the Western World
most probably because of its operational simplicity and competitive
cost. Its applications and potential uses have been enumerated
frequently enough in the past and quite conceivably other uncon
sidered fields may yet be found to supplement the already im
pressive list of achievements of this instrument.
In May 1966, a modified Wild T2 theodolite and GAKi gyro-
attachment were made available by Messrs. Wild of South Africa
to the authors for research purposes. Initially, the object of the
research was to attempt to determine the accuracy of the GAKi
gyro-attachment by using a single second theodolite for obser
vation of the oscillations, as opposed to the generally recommended
i or Tl6 types (both these instruments having observational
least counts of approximately five seconds of arc). Secondly it
was felt that with a sufficiently large number of suitable observa
tions, some accuracy comparison between the "tracking" and
transit [1] methods could be made. As will be obvious from this
paper, far more than the above objects were achieved, and in
dications are that many more empirical as well as theoretical
investigations will need to be undertaken before complete under
standing of the pendulous gyroscope's behaviour can be claimed.
Equipment
The equipment used in the series of tests consisted of the fol
lowing
(i) GAKi gyro-attachment No. 3139, modified for Wild T2
theodolite,
GKKi converter, No. 2970/GKK,
(iii) Wild T2 theodolite, No. 92765, and
(iv) Sierra portable tape recorder.
University of the Witwatersrand, Johannesburg, South Africa:
A bstract
Secondary Harmonic behaviour patterns of a quasi-systematic nature
l"en ?End to £e Present m pendulous gyroscopes during protracted
oscillations. The results obtained along a known test line 9 km long suggest
the acquisition of a "high-low" range of azimuth values in a set if the most
reliable result is sought Accuracy analyses of the tracking and transit meth
ods are presented with conclusions that the procedures are comparable.
