Analysis and Wind Tunnel Tests of a Static Pressure Probe Used to Sense Altitude through Measurement of Static Pressure.

A static pressure probe was tested to determine the feasibility of using the probe, as an integral part of a missile nose, to sense missile altitude. Experiments were conducted at Mach 2.0 and at Mach 1.51. At Mach 2.0, the static pressure probe will perform within altitude specifications of 25,000 feet or - 2,000 feet at angles of attack ranging from - 8 to 8 degrees. At Mach 2.0, within an angle-of-attack ranging from 0 to 6 degrees, the probe will measure free stream static pressure within 4 percent a 4 percent error in measurement is equivalent to an altitude error of 900 feet. The missile nose shock will remain downstream of the probe pressure ports for flight Mach numbers above 1.5. Author