Mathematical modelling of an earth sensor
Abstract
The purpose and nature of mathematical modeling of attitude control system components is considered with particular attention to sensors. The requirements of the system designer are discussed, and the practical value of a mathematical model to the component designer is demonstrated. As an example, a model of a two-axis infra-red earth sensor is presented. This sensor is being developed for high accuracy earth pointing of geostationary satellites. The physical operation of the sensor is described, and the basic input-output equations are derived. Then the impact of quantization of the internal measurements is analyzed. It is shown that the resulting quantization of the output signals is not regular and that a cross-coupling between the pitch and roll axes occurs. The amplitude and frequency characteristics of the sensor output noise are examined, and the effectiveness of a first-order filter is demonstrated.
- Publication:
-
7th Symposium on Automatic Control in Space, Volume 2
- Pub Date:
- 1976
- Bibcode:
- 1976acsr....2..412M
- Keywords:
-
- Mathematical Models;
- Pointing Control Systems;
- Remote Sensors;
- Satellite Attitude Control;
- Synchronous Satellites;
- Block Diagrams;
- Electronic Equipment;
- Pitch;
- Position Errors;
- Roll;
- Signal To Noise Ratios;
- Systems Engineering;
- Spacecraft Instrumentation