基于GPS接收机的程控目标跟踪方法的气球飞行试验

简要介绍了基于ＧＰＳ接收机的程控目标跟踪方法原理和１９９８ 年５ 月的一次气球飞行试验结果．成功的飞行试验证明该方法对于用准直器限制视场的Ｘ 射线和＄射线气球天文观测非常适用，可提高观测灵敏度和简化数据处理过程，特别是在长距离飞行时可做到多目标自动对准和跟踪的自主闭环系统

TEST OF OBJECT POINTING AND TRACKING BY PROGRAMMED CONTROL WITH GPS RECEIVER DURING A BALLOON FLIGHT

The key to the object pointing and tracking on the basis of programmed control lies in the coordinate transformation from the equatorial system to the horizontal one. In this process one needs to know three quantities, i.e.geographic longitude, geographic latitude and time, which are variables when an astronomical observation is made during a balloon flight. However, they can be provided by a GPS reveiver in real time. The authors have designed and made such a pointing and tracking system and tested it during a balloon flight for X ray observation in the night of May 16, 1998. The block diagram of the system is shown in Fig.1. Figs.2a and 2b illustrate the trajectory of balloon flight and height variation based on the data given by the GPS. The results of the test (variations of azimuth angle and zenith distance read out from the pointing system under programmed control) are given in Figs.3a and 3b. From these results it is demonstrated that the method described above is feasible and reliable in the balloon flight condition. It is useful for balloon astronomical observations and especially for balloon borne X\|ray observations in long duration flights.