In this report, the two subjects for elevating the availability of this method were discussed. (1) The velocity of balloons by the wind channel test was examined to evaluate accuracy of the measurement. It can be seen that the velocity of balloons was in direct proportion to the air velocity in wind channel, the inclinations of correlation line were more than 0.8 ; and the correlation coefficients were more than 0.9. (2) The automatic algorism to track balloons in pictures was developed to ease the operation of the measurement. And the algorism was useful as speed and accuracy.
