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Venus radar mapper attitude reference quaternionPolynomial functions of time are used to specify the components of the quaternion which represents the nominal attitude of the Venus Radar mapper spacecraft during mapping. The following constraints must be satisfied in order to obtain acceptable synthetic array radar data: the nominal attitude function must have a large dynamic range, the sensor orientation must be known very accurately, the attitude reference function must use as little memory as possible, and the spacecraft must operate autonomously. Fitting polynomials to the components of the desired quaternion function is a straightforward method for providing a very dynamic nominal attitude using a minimum amount of on-board computer resources. Although the attitude from the polynomials may not be exactly the one requested by the radar designers, the polynomial coefficients are known, so they do not contribute to the attitude uncertainty. Frequent coefficient updates are not required, so the spacecraft can operate autonomously.
Document ID
19860058539
Document Type
Conference Paper
Authors
Lyons, D. T. (California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1986
Subject Category
SPACECRAFT DESIGN, TESTING AND PERFORMANCE
Report/Patent Number
AAS PAPER 85-416
Funding Number(s)
CONTRACT_GRANT: NAS7-918
Distribution Limits
Public
Copyright
Other