A new approach to determining the attitude of
a rigid body is suggested, which does not rely on the use
of magnetometers. In the framework of this approach, the
problem of determining the attitude reduces to solving a
minimization problem for a function of three variables (angles
characterizing the initial attitude of the body). The
proposed method can be employed in precise geodetic measurements
carried out with the use of a geodetic pole with
a satellite antenna and an IMU installed on its top when,
for some reasons, the surveyor cannot position the pole vertically
(e.g., near walls or buildings). The use of the traditional
approach, which relies on a compass and accelerometers,
in this case does not ensure the desired accuracy of the
attitude determination due to magnetic disturbances (both
external ones and those induced by the receiver) affecting
badly compass readings. The discussion is illustrated by
results of field experiments