Accession Number:

AD0729430

Title:

Digital Attitude Reference System (DARS),

Descriptive Note:

Corporate Author:

AEROSPACE CORP EL SEGUNDO CALIF ENGINEERING SCIENCE OPERATIONS

Personal Author(s):

Report Date:

1970-12-21

Pagination or Media Count:

27.0

Abstract:

A family of digital attitude reference systems DARS is developed for three-axis-stabilized, earth-oriented satellites. It includes the complete DARS configuration, which utilizes measurements from a sun sensor in addition to the horizon sensors and gyros in use on conventional analog gyrocompassing-type reference systems CARS. The complete configuration also utilizes statistically optimal Kalman filtering to process these measurements to estimate and compensate for important measurement errors as well as to estimate the spacecraft attitude. Various suboptimal configurations of DARS are also studied. Based on simulation results, the attitude accuracies of the two most promising DARS configurations are approximately 0.03 and 0.04 deg, respectively, and the convergence time of both systems is less than 20 sec. Thus, DARS is shown to fill the important gap between low-accuracy gyrocompassing systems using horizon sensors and gyros and high-accuracy systems requiring star sensors or trackers by achieving intermediate attitude accuracy at the expense of low-to-medium complexity. Author

Subject Categories:

  • Unmanned Spacecraft
  • Spacecraft Trajectories and Reentry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE