INDEPENDENT METHOD OF DETERMINING INITIAL ORIENTATION OF INSTRUMENT COORDINATE SYSTEM OF GIMBALLESS INERTIAL UNIT OF CONTROLLED OBJECT RELATIVE BASE COORDINATE SYSTEM Russian patent published in 2010 - IPC G01C21/00 

FIELD: physics.

SUBSTANCE: signals from accelerometers are used to determine the increment of the projection of the apparent velocity vector on the axis of the instrument coordinate system (ICS). The velocity and acceleration vector is then determined. Angular velocity of the gimballess inertial unit (GIU) is measured using sensors. Angular position of the instrument coordinate system relative the base (start) coordinate system (BCS), latitude of the test site, position of the axes of the gimbals relative the base coordinate system and projection of Earth's angular velocity on the axis of the gimbals are determined from measurement results of acceleration and the Earth's angular velocity. Detecting elements of the gimballess inertial unit are then calibrated and initial orientation of the instrument coordinate system relative the base coordinate system is repeatedly determined.

EFFECT: increased accuracy.