Improving the wind and temperature measurements of an airborne meteorological measuring system

Abstract

The Aircraft Integrated Meteorological Measuring System 20 Hz (AIMMS-20) has been used by the Hong Kong Observatory (HKO), China in data collection for tropical cyclone situations over the South China Sea and windshear and turbulence measurement at the Hong Kong International Airport (HKIA). This paper discusses possible methods for further enhancing the quality of the wind and temperature measurements from the system. For wind measurement, the enhancement methods include: error modelling of the accelerometer (e.g., bias offset and cross-axis rate sensitivity), global positioning system (GPS) phase lag consideration, better representation of the inertial measurement unit (IMU) velocity based on the GPS velocities and considering their location differences, consideration of the slower update of GPS velocity, and wing flexure. For temperature measurement, the methods include the consideration of the temperature sensor response and the sensor housing response. The results of typical flights using AIMMS-20 show that the accuracy of the wind and temperature data could be improved by 20%–30%. Though the discussion in the present paper is related mainly to a specific meteorological measuring system on a particular aircraft, the techniques so employed should be a useful reference for similar systems installed on other aircraft.