Low-cost Absolute Altitude Measurement for UAV Based on Geospatial and Meteorological Data

According to the regulation of unmanned aerial vehicles (UAVs), the flight control requirements of absolute altitude for UAVs under the height of 120m are proposed. However, the current UAV flight altitude measurement is mainly for the pressure altitude of standard atmospheric pressure. The absolute altitude indicates the actual height between the UAV and the ground, which is a direct altitude indicator. In this work, based on geographic and meteorological data, we propose a UAV absolute altitude measurement scheme with a barometer. Besides, comparing sliding window, Kalman and improved Kalman filter, we finally choose Kalman filter for correction. The simulation results show that the variance using Kalman filter can be reduced by 96.75%. Further, through the design of UAV supervision network node and the application of flight experiments, the proposed mechanism is compared with the non-differential GNSS and real-time kinematic measurement schemes, showing the advantages of high accuracy and low cost of price.