High‐altitude free fall

1996 ◽  
Vol 64 (10) ◽  
pp. 1242-1246 ◽  
Author(s):  
Pirooz Mohazzabi ◽  
James H. Shea
Keyword(s):  
2010 ◽  
Vol 78 (6) ◽  
pp. 616-619 ◽  
Author(s):  
Jan Benacka
Keyword(s):  

Author(s):  
Takehiko ISHIKAWA ◽  
Tatsuaki HASHIMOTO ◽  
Shujiro SAWAI ◽  
Yoshitaka SAITO ◽  
Yuko INATOMI ◽  
...  

2012 ◽  
Vol 5 (11) ◽  
pp. 2625-2633 ◽  
Author(s):  
T. J. Garrett ◽  
C. Fallgatter ◽  
K. Shkurko ◽  
D. Howlett

Abstract. We describe here a new instrument for imaging hydrometeors in free fall. The Multi-Angle Snowflake Camera (MASC) captures high-resolution photographs of hydrometeors from three angles while simultaneously measuring their fall speed. Based on the stereoscopic photographs captured over the two months of continuous measurements obtained at a high altitude location within the Wasatch Front in Utah, we derive statistics for fall speed, hydrometeor size, shape, orientation and aspect ratio. From a selection of the photographed hydrometeors, an illustration is provided for how the instrument might be used for making improved microwave scattering calculations. Complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than heavily rimed graupel particles of similar size.


2011 ◽  
Vol 89 (10) ◽  
pp. 1003-1008 ◽  
Author(s):  
Jan Benacka

In this study, the formulas for projectile velocity components and coordinates in a vacuum were derived with the altitude decrease in gravitational acceleration factored in. A model of cannon shell motion in the air is presented that accounts for the altitude dependence of gravitational acceleration, air density, the speed of sound up to an altitude of 84 km, and the speed dependence of the drag coefficient at trans- and supersonic speeds. The drag coefficient function is obtained by fitting to experimental data taken for the US M101 155 mm shell. The model gives flight parameters that agree with the published ones. The motion of the Paris Gun projectile is then modeled. The model shows that a range of 120 km is possible if the projectile mass is about 150 kg. A flat Earth approximation was used in the computations. Changing the launch angle to 90°, super high-altitude vertical ascent and free fall are modeled.


2013 ◽  
Vol 84 (9) ◽  
pp. 961-970 ◽  
Author(s):  
James M. Pattarini ◽  
Rebecca S. Blue ◽  
Luke T. Aikins ◽  
Jennifer Law ◽  
Andrew D. Walshe ◽  
...  

1994 ◽  
Vol 144 ◽  
pp. 365-367
Author(s):  
E. V. Kononovich ◽  
O. B. Smirnova ◽  
P. Heinzel ◽  
P. Kotrč

AbstractThe Hα filtergrams obtained at Tjan-Shan High Altitude Observatory near Alma-Ata (Moscow University Station) were measured in order to specify the bright rims contrast at different points along the line profile (0.0; ± 0.25; ± 0.5; ± 0.75 and ± 1.0 Å). The mean contrast value in the line center is about 25 percent. The bright rims interpretation as the bases of magnetic structures supporting the filaments is suggested.


Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.


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