USING PHASE MEASUREMENTS FOR DETERMINING A VEHICLE'S ATTITUDE PARAMETERS BY A GPS-AIDED INERTIAL SYSTEM IN THE SEA TESTS

摘要

The problem of determining a vehicle's attitude parameters is considered. The solution to this problem is based on integration of the data from a Strapdown Inertial Measurement Unit (SIMU) on MEMS sensors and two receivers of the Global Navigation Satellite System (GNSS) with spaced antennas with the aim to form phase measurements. The algorithms and errors of a GPS-aided inertial system-an Integrated Attitude and Navigation System (IANS)-in attitude determination of a moving vehicle are studied. Coprocessing of data is carried out with the use of an algorithm of an extended Kalman filter (EKF) with the feedback for the whole state vector of the system. A specific feature of the IANS considered here is that the data from the SIMU and GNSS Receiver Unit (RU) are integrated with primary phase measurements from two receivers with antennas spaced on a certain base. Resolution of phase measurement ambiguity is made possible due to the SIMU data. The results of the office studies of the data obtained during the sea tests of an SIMU prototype on MEMS sensors, developed by the CSRI Elektropribor, and a GNSS unit with two receivers (Ashtech G12 and Kotlin developed by the Russian Institute of Radionavigation and Time, JSC (RIRT)).