空速的GPS试飞校准方法

 通过“往返试飞”消除风速影响从而由 GPS测得的地速求得真空速,运用近似理想气体理论,建立Ma数真值与真空速、大气总温的关系,解算出 Ma数真值,得到“GPS速度法”;或者考虑真实大气与标准大气的差异,在水平航线上引入气压高度常值偏差及航路气压修正系数,建立 GPS几何高度与气压高度的关系,结合“速度法”求得的任一 Ma数点的校准量,解算出气压高度真值,得到“GPS高度法”。通过对某型飞机的飞行试验,验证了这些方法的可靠性与实用性。

GPS FLIGHT-TEST METHOD FOR PITOT-STATIC CALIBRATIONS

Regarding real gases as perfect gases approximately, the authors find the relationship between the true Ma number, true airspeed and total temperature. Using GPS ground speed, the true airspeed is calculated by “go and back flight test” to eliminate the influence of wind speed, and then the true Ma number is obtained. The “GPS-speed method” is produced. Or, considering the difference of real atmosphere from standard atmosphere, one can introduce the pressure altitude constant deflection and the flight path pressure calibration coefficient in level lines, and establish the relationship between the true pressure altitude and geometrical altitude in flight airspace. Combining the correctional increment, which has been obtained by “GPS-speed method” on any Ma number point, one can calculate the true pressure altitude and produce “GPS-altitude method”. By flight-test on XX aircraft, the reliability and practicability of these methods are shown.