Estimation of rotation angles based on GPS data from a UX5 Platform

Data integration from INS and GPS sensors is applied in aeronautical navigation as a basic conception for determination of aircraft position. A GPS sensor is used to estimate coordinates (X, Y, Z) and velocity (Vx, Vy, Vz) also in a navigation solution. On the other hand, an INS sensor provides rotation angles (heading, pitch and roll) and acceleration parameters (Ax, Ay, Az). The GPS sensor is preferred to obtain an approximate value of rotation angles. In this paper, the results of studies on determination of heading, pitch and roll angles using GPS technology are presented. For this purpose, GPS data from a single-frequency L1 receiver from a UX5 platform were used. Calculations were executed in the HPR_GPS software, whose source code was written in Scilab 5.4.1 language. The software operation and an algorithm for estimation of heading, pitch, roll angles there is described. The preliminary results of rotation angles from the HPR_GPS software show that heading, pitch and roll values are very similar to raw INS measurements. The mean difference between the GPS data (after Kalman filter operation) and the INS data for the heading angle is equal to 0.32( with a standard deviation of 5.41(, for the pitch angle is equal 4.98( with a standard deviation of 5.06( and for the roll angle is about 0.06( with a standard deviation of 0.69).