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Photographic Volume Estimation of CPAS Main ParachutesCapsule Parachute Assembly System (CPAS) flight tests regularly stage a helicopter to observe inflation of 116 ft D o ringsail Main parachutes. These side views can be used to generate 3-D models of inflating canopies to estimate enclosed volume. Assuming a surface of revolution is inadequate because reefed canopies in a cluster are elongated due to mutual aerodynamic interference. A method was developed to combine the side views with upward looking HD video to account for non-circular cross sections. Approximating the cross sections as elliptical greatly improves accuracy. But since that correction requires manually tracing projected outlines, the actual irregular shapes can be used to generate high fidelity models. Compensation is also made for apparent tilt angle. Validation was accomplished by comparing perimeter and projected area with known line lengths and/or high quality photogrammetry.
Document ID
20170003950
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Ray, Eric S.
(Jacobs Technology, Inc. Houston, TX, United States)
Date Acquired
April 27, 2017
Publication Date
June 5, 2017
Subject Category
Aerodynamics
Report/Patent Number
JSC-CN-38970
Meeting Information
Meeting: AIAA Aerodynamic Decelerator Systems Technology Conference
Location: Denver, CO
Country: United States
Start Date: June 5, 2017
End Date: June 9, 2017
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Public Use Permitted.
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