基于磁强计的皮卫星姿态角测量误差

Error analysis of pico-satellite attitude angle measurement based on magnetometer

采用三轴磁强计测量地磁场矢量,与轨道演化和国际地磁场参考模型(IGRF)计算获得的地磁场矢量进行比较,获得姿态角度信息的方法适合体积小、重量轻、功耗低的皮卫星应用环境。地磁场矢量实际测量误差和轨道模型演化计算的地磁场矢量误差是皮卫星姿态角测量的两大误差源。通过分析获得磁强计A/D采样、磁传感器误差、温度漂移、铁磁材料等因素导致地磁场矢量实际测量误差为1.74°。皮卫星自身的特点不允许采用复杂的SPG4轨道演化模型,基于Kepler轨道模型和IGRF地磁场模型计算获得的地磁场矢量误差为0.5°。因此,基于三轴磁强计的皮卫星姿态角测量误差为2.24°。

The method of obtaining attitude angle by the comparison of the magnetic field vector from actual measurement using 3-axis magnetometer with the data calculated from orbit propagation and International Geomagnetic Reference Field （IGRF） model is suitable for pico-satellite application of small volume, light weight, and low power consumption. The attitude angle error consists of magnetic field vector measurement error and magnetic field vector calculation error. After the analysis, it was clear that A/D converter, magnetic sensor error, temperature, nearby ferrous materials, etc. will result in measurement error up to 1.74°. And the calculated magnetic field vector error is about 0.5° when Kepler orbit propagator and IGRF model was used. Therefore, the total attitude angle error is 2.24°.