
The Aircraft Integrated Meteorological Measurement System (AIMMS-20)

The The AIMMS-20 mounted in the underwing pylons on D-CALM
The AIMMS-20 instrument was purchased by the ARSF in September 2005 from
Aventech Research Inc. in
Canada in preparation for the ACTIVE atmospheric campaign in Darwin during
2005 & 2006. It is mounted in the underwing PMS type pylons which are installed upon request.
The instrumentation consists of three distributed measurement modules:
- a module measuring the physical properties of the flow about the aircraft (barometric pressure, pitot-static pressure for true airspeed, aircraft angle-off-attack, aircraft sideslip, temperature and humidity),
- a GPS Module providing position, velocity, carrier-phase and satellite emphemeris data for two GPS antennae located on the aircraft wing tips,
- an inertial measurement module providing three-axis accelerations and rates representative of the aircraft motion.
The sensor data collected by the individual measurement modules at a rate of 40Hz is transferred to a high-performance digital signal processing module via a high-speed digital serial network bus. The GPS velocity and differential carrier-phase data are combined with the inertial data to precisely define the attitude and velocity of the aircraft at all times to within fractions of one degree and fractions of one metre-per-second respectively. This precise information is combined with fully compensated air-data measurments to compute wind speed with an accuracy of 1/2 knot and wind direction with an accuracy of 5-10 degrees. The processed data are available via a standard RS-232 serial port.