Autonomous Latitude Determination Using an Inertial Measuring Unit

The novel latitude determination method on the fixed base is presented. The method uses the Inertial Measurement Unit (IMU). The IMU comprises accelerometers, gyroscopes, and a signal-processing circuit. Two new expressions for autonomous latitude determination of a location for a fixed base are obtained. Along with the previously obtained expression, there are only three complete analytical expressions for determining latitude. This makes it possible to determine latitude in three ways. Triple counting undoubtedly improves the reliability of latitude calculations. The constant tilt of the IMU relative to the horizon plane, as well as the deviation of the IMU in azimuth, does not affect the determination of the initial latitude of the location. A full error model of the latitude determination method is developed. It is assumed that the latitude determination error depends on errors of gyroscopes and accelerometers and the difference between geocentric latitude, measured by GNSS, and geodetic latitude. The results of the calculation data are presented to demonstrate the performance of the new latitude determination method. Experiments have confirmed this method. The experiments have been provided on IMU with MEMS gyroscopes and accelerometers and wavelet de-noising of output signals.