MEMS-based air data unit (ADU), composed of pressure and temperature sensors, is design and fabricated as UAV subsystem for autopilot.
Microprocessor manipulates pitot airspeed by air temperature calibration in accurate true airspeed for flight control referring to GPS velocity. For terrain-sensitive cruise altitude, the barometric altitude should be calibrated according to real time atmospheric pressure and environment temperature. The QNH calibration process resets atmospheric pressure to
airborne computer via GPRS data uplink for an UAV. The proposed MEMS-based real time calibrated precision ADU system offers most accurate aerodynamic measurements for UAV autonomous flight system.In a terrain UAV mission, 3D profile waypoints are constructed in reference to the pronounced geographical altitude for ground proximity avoidance.The proposed ADU system integration is presented with feasibility comparisons to verify its reliability and performance for terrain mission.