Betreff: C-GHGF (Polar 6) AIMMS-20 Calibration Coefficients Von: Bruce Woodcock Datum: 06.11.2012 23:33 An: Kopie (CC): 'Martin Gehrmann' , Hi Daniel, First my apologies for taking so long to work on this for you. I was initially passed your calibration data file way back in late May / early June and being totally snowed under with work it kept slipping down my list of to do items. Steve passed along your reminder approximately a week ago and I have been working on it on and off since then. In future, please just keep reminding me on a more frequent basis to speed me up J. First a few comments: 1) Analysis of the data from the inertial attitude data went very well. Probably the best inertial data I have seen from an installation. The Cross-Axis Error Coefficients predicted from the Extended Kalman Filter (EKF) converged well and were very stable. 2) The calibration analysis for determining the Aerodynamic Calibration Coefficients posed a bit more of a challenge however, which is the reason I have been working on and thinking about this for the past week. All the sensor channels are present and all responding reasonably, however the mean DC levels for both the TAS and non-dimensional angle-of-attack signals are not similar to those I was observing for the Polar 5 calibration. As a result, I was wondering if you could send me the three airspeeds you were using for the calibration. Having said this, I was still able to determine a set of calibration coefficients from the flight which produced a reasonable looking wind solution. However, the resulting calibration coefficients were much different than those derived for Polar 5. At this point we should post-process with these coefficients, and see what the data looks like, however longer term we should also resolve why the coefficients are so much different, i.e. is it due to installation differences, aerodynamic differences, etc. The updated set of calibration coefficients for C-GHGF (Polar 6) are: Setup: Antenna Baseline Length = +23.620 m ADP Offset = +9.750 m Magnetic Declination = -31.40 Cross-Axis Alignment Errors: d_Roll d_Pitch d_Yaw Roll Gyro (P) -0.725 +0.000 Pitch Gyro (Q) -1.175 +0.875 Yaw Gyro (R) -0.400 +0.420 X Accel. (A1) +0.000 +0.000 Y Accel. (A2) +0.000 +0.000 Z Accel. (A3) +0.000 +0.000 ADP Roll Offset: -0.680 ADP Yaw Offset: +1.020 Air Data Calibration Parameters: Cp_0 = +0.84307 Cp_alpha = -0.80279 Cp_beta = +0.01761 B_0 = +10.423 B_alpha = -10.113 B_beta = +10.577 A_0 = -13.843 A_alpha = +16.189 A_beta = -0.110 Dynamic Heating Coefficient = +0.42 Magnetic Calibration Coefficients: Mag. X_off = +5.96 Mag. Y_off = +2.51 Mag. Z_off = +0.41 I have also attached an input file for the post-processing code which contains the updated coefficients above. If you have any questions, or require additional assistance, please do not hesitate to contact me. Best Regards, Bruce Bruce Woodcock Advanced Products Engineering Aventech Research Inc. 110 Anne Street South, Unit 23 Barrie, Ontario, Canada L4N 2E3 Tel: (705) 722-4288 x222 Fax: (705) 722-9077 Cell: (705) 627-2536 Email: bwoodcock@aventech.com Web: http://www.aventech.com Anhänge: C-GHGF.dat 264 Bytes