Data Generator for a Satellite-Borne Three-Axis Accelerometer.
Abstract
Atmospheric drag has a significant effect on low-altitude trajectories. To measure this force, an accelerometer will be tested which senses this nonconservative acceleration. The information obtained will then be used to improve the orbit and obtain a more accurate gravity field model. When the raw data is first received, all known systematic effects will be removed. These include gravity gradient and pitch-rate induced accelerations. However, the preprocessed data will still contain anomalies of which there is little or no a priori knowledge. Satellite attitude thruster-induced vibrations are a major source of unmodeled noise. As for the instrument itself, each axis of the accelerometer adds an undetermined bias to the output accelerations. In addition, the conversion of the digital output to engineering units introduces a scale factor error. Other effects may take the form of additive correlated noise and white noise. The first instrument to be flown is the miniature electrostatic accelerometer (MESA). The MESA senses accelerations along the vehicle pitch, roll, and yaw axes. Relying on the accuracy of the vehicle's attitude control system, these axes are assumed to be along the R,R X V, and -R vectors, respectively. Hence, any attitude errors will be reflected in the measurements. The MESA also introduces undetermined scale factor errors and biases. Consequently, a computer program was designed which applies a filter to the processed accelerations. This filter should statistically remove most of the unmodeled corruptions. The filtered data is then input toa special version of the Celest orbit determination program.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1980
- Accession Number
- ADA082827
Entities
People
- Carol G. Branch
Organizations
- Naval Surface Warfare Center Dahlgren Division