Rev:
1.00
Date:
11.22.2013
Page:
15 of 40
AIMMS-20
OPERATING MANUAL
Document-P/N:
AIMMS20-OM
© Aventech Research Inc. 2013. All Rights Reserved.
3.3 Calibration Flight Procedure
The following section describes the manoeuvres that are to be flown, while
recording data, during the calibration flight. The resulting data file provides the
required information so that the calibration coefficients that have to be programmed
into the AIMMS-20 can be determined in order to provide a real-time wind solution.
Two different procedures exist for flight calibration. The first procedure is required to
determine aerodynamic errors induced by the aircraft itself (see Section 3.3.2). The
second procedure is required to capture small alignment errors (i.e. cross-axis
error) between the gyros, accelerometers, GPS antenna baseline and the primary
reference frame of the IMU (see Section 3.3.3). Data required for analysis of the
aerodynamic calibration flight is automatically recorded in the FLASH memory on-
board the CPM, which can be downloaded after landing using the
aimcfg
software
utility (Section 4.4.1). However, data requirements for the GPS-IMU cross-axis
calibration are such that all raw system data must be recorded. Raw data can be
captured using the
aimcfg
utility (see Section 4.4.4).
Step by step instructions are provided followed by a graphical depiction of the flight
segment.
3.3.1 Pre-Flight Procedure
i) Power up the AIMMS-20 system.
ii) Start aircraft, taxi and ascend to an altitude at which you will be insured smooth
air with a constant wind field. Depending on the prevailing meteorological
conditions this may be well above the temperature inversion and/or cloud top.
3.3.2 Aerodynamic Calibration Manoeuvres
i) Select three true air speeds (TAS) within a range from a comfortable margin
above aircraft stall to a comfortable margin below maximum cruise. The mid-
range TAS is typically selected at your spray release airspeed. Select the
minimum and maximum calibration speeds in consultation with the operations
manager and pilot flying the calibration flight.
ii) Start the calibration procedure by setting up on a true north heading at the lowest
airspeed selected in step 3 above.
