Refining Satellite Methods for Pitot-Static Calibration

The advent of the global positioning satellite system (GPS), with its accuracy and inexpensive GPS receivers, quickly spurred innovative thinking in its application to the time-space-position instrumentation challenges required by flight test. The pitot-static calibration is among the most basic of flight-test ppractices because of the criticality of credible air data. Accurate calibration of an airplane's static source requires either true tapeline altitude, or true airspeed. Legacy methods have been either expensive or ungainly. Consequently, a variety of GPS methods have been developed and explored for use by general aviation practitioners. This Note decribes the most reliable of current methods and an improved algorithm for the determination of true airspeed from GPS ground-track and ground-speed data.