区域扫描模式下风云二号气象卫星姿态求解方法

针对风云二号气象卫星区域扫描模式下姿态求解问题，提出了分别基于区域观测图像、姿态预报和粗-精姿态关系模型3种不同的卫星姿态求解方法，并分析了它们的适用条件。利用FY-2E卫星获取的2013年7月8—14日的图像进行模拟分析，姿态计算结果表明:利用基于区域观测图像方法求解的姿态对区域观测云图进行定位，误差保持在2.5个红外像元以内，该方法适用于连续区域观测情况；利用基于预报的姿态求解方法对未来24 h内区域观测云图进行定位，平均误差达到1个红外像元，该方法适用于临时启动区域观测时前24 h的区域云图定位。利用粗-精姿态关系模型方法求解的姿态对区域观测云图进行定位，最大误差为4.9个红外像元，前24 h平均误差为3.6个红外像元，该方法可以在无精姿态数据时对区域观测图像进行应急定位。

FY 2 Meteorological Satellite Attitude Solving Method Under Area Scan Mode

Area observation is realized by the geostationary meteorological satellites of the United States and Europe. The timeliness of satellite observation is greatly improved, and an instance can be accomplished within several minutes. Geostationary meteorological satellites of FY-2 series have the capability of specific area observation, but due to the strip image navigation problem, the area observation of FY-2 satellites is not put into operational use. Therefore, the attitude determination technology of FY-2 satellites' area observation is studied and 3 solving methods are proposed, which are based on area images, attitude prediction, and the relation model between crude and precise attitude.The attitude determination method based on area images uses area images to calculate satellite attitude directly. This method is applicable to the condition that area images can be obtained continuously. When area images are accumulated for twenty-four hours, the method navigates the area image with the attitude gained by the method based on area images. The navigation deviation is in 2.5 infrared pixels. FY-2 satellite receives full disk images under normal observation mode, and receives high-frequency area images under emergency observation mode when special weather occurs. When using the attitude to navigate satellite image at the beginning of area observation, the image navigation accuracy maybe not ideal because the area images quantity is not enough. On this occasion, the attitude solving method based on attitude prediction can be used. With this method, the average deviation of image navigation can be reduced to 1 pixel. Based on the precise attitude which is gained through full disk images, this method predicts the future satellite attitude according to the variety rules of attitude. It is applicable to predict navigation parameter in future 24 hours with mathematics model while precise orbit attitude parameter is obtained. The attitude solving method based on relation model of crude-precise attitude uses the crude attitude which is calculated from telemetry data and the relation between the latest crude-precise attitude, and estimates precise attitude from the crude attitude which is calculated in real time. Using the attitude gained by this method to navigate the image, the max navigation deviation of area image is 4.9 infrared pixels, and the average deviation of former 24 hours is 3.6 infrared pixels. When precise attitude is not available, the attitude obtained by the method based on relation model of crude-precise attitude can be used to navigate area image during emergency situations.