Simple Altitude Estimator using Air-Data and GPS Measurements

For obtaining the height information, a vertically damped inertial navigation system (INS) using the height reference of barometer measurements is conventionally instrumented. Since it requires delicate construction of INS system, in many cases, it has been costly. In this paper, a novel altitude estimation system is proposed by effectively combining the information of the GPS height and air data measurements such as ambient air pressure and temperature. Based on the fact that the barometer errors mainly consist of bias and scale factor errors, a filter to estimate the bias and scale factor using the GPS height is derived by means of multiple hypothesis Gaussian approximation filter technique. The estimated bias and scale factor is used to compensate the baro-altitude. Simulation results show that this method can construct a good altitude measurement system with relatively low cost.