
Altitude Measurement Methods 

mass of rocket  96 g 
amount of water  150 ml 
launch tube length  20 cm 
launch tube  21 mm 
nozzle Ø  21.5 mm 
pressure  8 bar 
diameter of vessel  65 mm 
volume of rocket  520 ml 
The person taking the SEAM measurements was 4 m above launch level, in a distance of 56 m (that was too short) and later 83 m away from the launcher. The launching person took the time measurements that we needed for Dean's method.
The results are given in this table:
S E A M 
D E A N  
Units:  m 
m base 
°  m Drift  ° Drift  m  sec  sec  sec  sec  m  m  m/s  
Rocket 
m  r  alpha  s  beta  h SEAM  T_{up}  T_{dwn}  T_{tot}  dT  h Corr  h simple  V_{t}  Cd  Comment 
Gollump 4f  4  56  62  12  40  118,0  4,48  5,37  9,85  0,89  117  116,3  T_{up} probably too long  distance timetaker to Launcher only 20m  
Gollump 4f  4  83  50  27  15  118,5  3,88  5,80  9,68  1,92  111  112,3  29  0,57  probably most correct measurement of T_{up}. 
Gollump 4f  4  83  53  36  90  114,1  4,00  5,78  9,78  1,78  113  114,6  31  0,5  T_{up}=3,44 measured was too short  observation apogee insecure. T_{up}=4s guessed 
Gollump 4f  4  83  58  37  155  110,0  3,81  9,56   
109,4  Lost sight of rocket (watched watch!)  almost hit: in r=40m, impact <2m left of me! T_{up} (??) too large.  
Hubschrap 1  4  56  52  14  75  78,0  3,99  4,35  8,34  0,36  83  82,6  52  0,24 ? 
shattered into 3 pieces, bottle thread ripped out at impact. PET fins undamaged! Helicopter blades did not unfold. 34 bar better! 
Meaning of variables 

h_{SEAM } 
=  altitude determined with my SEAM method 
h_{Corr} 
=  determined with Deans' Rocket Apogee Correlation pdf file 
h_{simple} 
=  Deans's "simplest correlation": h_{simple} [m] = 1.23 * T_{tot}^{2}  3 
T_{up} 
=  up time = apogee time 
T_{tot} 
=  total flight time = T_{end} 
T_{down} 
=  down time = T_{tot}  T_{up} 
dT 
=  T_{tot}  2T_{up} 
v_{t} 
=  terminal speed of the rocket, derived from T_{up} and T_{tot} 
Cd 
=  211.7 * mass [gram] / (Diam [cm]^2 * v_{t} [m/s]^2) 
All data were entered right after each launch into my trusted Psion 5 palmtop computer. The cells marked grey are the ones which contained formulas.
To the launch report with pictures.
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