ASSESSMENT OF THE PERFORMANCE OF THE ELDO FIRST PROGRAM ATTITUDE REFERENCE UNIT IN AN INERTIAL ROLE.
ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND)
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The report presents numerical results for velocity and position errors accrued by an imperfect inertial navigator, when the gyroscopes and accelerometers comprising the instrument are subjected to the acceleration history expected from a launch trajectory of the ELDO-A Satellite Lauch Vehicle. The inertial navigator under consideration consists of the ELDO First Program Attitude Reference Unit modified for an inertial role by the addition of three accelerometers and associated electronic circuits. The sources of error considered are discussed briefly. Results are presented for three trajectories of importance, a medium altitude 550 km circle, a medium altitude 700 km circle with two levels of thrust in the third stage, and a low altitude 200 km circle with parking periods. Methods of reducing the errors are discussed. No account is taken of the effect of instrument errors on the closed guidance loop, or of the vibration environment to be met with during flight. The dynamic response of the hardware capture amplifiers, gimbal servos etc is also neglected. Author
- Unmanned Spacecraft
- Spacecraft Trajectories and Reentry