RASAero Comparisons with Altitude Data

 

The accuracy of the RASAero flight simulation altitude predictions for high power rockets is shown in the Table below, where RASAero flight simulation altitude predictions are compared with barometric altimeter, optical tracking, and accelerometer-based altitude flight data for a representative set of high power rockets.  RASAero rocket files (.alx1 files) for most of these rockets are included in the RASAero software download.


Rocket Motor Diameter (in) Flight Data Altitude (ft) RASAero
Predicted
Altitude (ft)
Percent
Error
Our Project R Rocket R17971 10.500 Time to Apogee from Onboard Video
(See Note 1)
94000 102402 8.94%
Proteus 6 P9381 (Loki) 6.000 Integrated Accelerometer Data
(See Note 2)
85067 86799 2.04%
Full Metal Jacket - BALLS 005 O10000 Kos 4.000 Optical Track 37981 38820 2.21%
Full Metal Jacket - Black Rock-6 O10000 Kos 4.000 Optical Track 30038 32646 8.68%
Kline-Rogers L500 Rocket L500 Ace 2.260 Optical Track 24771 26485 6.92%
Laser/LOC-2.1 J125 2.260 Optical Track 15818 14868 -6.01%
Laser/LOC-2.1 J125 2.260 Optical Track 13219 14616 10.57%
Torrent M1850GG (AMW) 4.000 Barometric Altimeter 12807 13852 8.16%
Rabia L1080BB (AMW) 3.000 Barometric Altimeter 12745 12777 0.25%
Hubbub L1080BB (AMW) 4.024 Barometric Altimeter 10750 10883 1.24%
Rabia - Short Fin Can L730 (CTI) 3.126 Barometric Altimeter 10584 10376 -1.97%
Blister K1075GG (AMW) 3.000 Barometric Altimeter 9026 8347 -7.52%
Raven J570W (AT) 1.750 Barometric Altimeter 8815 9288 5.37%
EZI-65 J125 J125 3.998 Optical Track 8068 7436 -7.83%
Ion Drive K550W (AT) 4.000 Barometric Altimeter 8027 8642 7.66%
Cancer Descending M1297W (AT) 6.000 Barometric Altimeter 6188 6328 2.26%
Byrum J570W (AT) 3.000 Barometric Altimeter 5732 5280 -7.89%
EZI-65 J100 J100 3.998 Optical Track 5671 6472 14.12%
Caliber Isp 05 ARO-414 I285 (CTI) 3.100 Barometric Altimeter 5085 4842 -4.78%
Caliber Isp 05 ARO-414 I285 (CTI) 3.100 Barometric Altimeter 4930 4831 -2.01%
McGarvey J350W-L (AT) 3.000 Barometric Altimeter 4246 4862 14.51%
EZI-65 J450ST (AMW) 4.000 Barometric Altimeter 3965 4214 6.28%
Caliber Isp 04 AVTC Team 3 I205 (CTI) 3.100 Barometric Altimeter 3964 3871 -2.35%
Gibb I284W (AT) 3.000 Barometric Altimeter 3913 4310 10.15%
Caliber Isp 04 AVTC Team 1 I205 (CTI) 3.100 Barometric Altimeter 3837 3943 2.76%
Caliber Isp 04 AVTC Team 2 I205 (CTI) 3.100 Barometric Altimeter 3710 3871 4.34%
Thunder & Lightning I284W (AT) 3.100 Barometric Altimeter 3577 3989 11.52%
             
          Average
Error =
3.25%
             
          81.5% of Flights
Error < 10%
             
          40.7% of Flights
Error < 5%
 
Note 1:  Altitude based on time to apogee from onboard video (Reference: Postflight Analysis of the OuR Project R Rocket Flight, High Power Rocketry magazine, July 1997).  From onboard video rocket spin rate 0.26-0.37 revolutions/sec.  RASAero flight simulation based on 3.5 degree coning angle from onboard video.
Note 2:  Altitude based on integration of onboard accelerometer data.  Altitude based on the average of the apogee altitude from the two onboard accelerometers.  Rocket also included barometric altimeter and GPS unit.  Data from barometric altimeter and GPS unit stopped above 46000 ft. Integrated accelerometer data agreed well with barometric altimeter data up to 46000 ft, barometric altimeter data agreed well with GPS data below 46000 ft during parachute descent.

Comparison of RASAero altitude predictions with high power rocket barometric altimeter, optical tracking, and accelerometer-based altitude flight data.

 
As can be seen in the Table above, for this representative set of high power rocket barometric altimeter, optical tracking, and accelerometer-based altitude flight data, for 81.5% of the flights the RASAero flight simulation altitude prediction is within +/- 10% of the flight data, and for 40.7% of the flights the RASAero flight simulation altitude prediction is within +/- 5% of the flight data.