93选型，果然给力。
MPX5700有带导管的型号，可选绝对压力/相对压力，可惜量程只有700kpa。
MPX5999是freescale量程最大的气压传感器，达到1MPa。可惜没导管，而且只能测压差。
所以看来和93同学保持一致比较好。选MPX5700A，绝压的型号有利于防水。
700kpa对应最大空速量程大约是M3

大气数据处理相关资料
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Indicated airspeed (IAS) is the airspeed read directly from the airspeed indicator on an aircraft, driven by the pitot-static system.（直接测压差）
For navigation, it is necessary to convert IAS to TAS and/or ground speed (GS) using the following method:
correct IAS to calibrated airspeed (CAS) using an aircraft-specific correction table;
correct CAS to true airspeed (TAS) by using Outside Air Temperature (OAT), Pressure-altitude and CAS on an E6B flight computer or equivalent functionality on most GPSs;
convert TAS to ground speed (GS) by allowing for the effect of wind.
With the advent of Doppler radar navigation and, more recently, GPS receivers, with other advanced navigation equipment that allows pilots to read ground speed directly, the TAS calculation in-flight is becoming unnecessary for the purposes of navigation estimations.