用于火星电离层探测的星-星无线电掩星技术

Satellite-to-satellite radio occultation technology for martian ionosphere exploration

火星和地球类似,周围束缚了不同密度的电离层.利用无线电掩星技术可以对火星电离层进行观测.星-地无线电掩星在探测精度和探测区域方面都受到一定的限制.中俄联合火星探测计划将于2011年10月一箭双星发射俄罗斯的Phobos-Grunt探测器和中国的萤火1号火星探测器.该计划将开展国际上首次火星电离层的星-星无线电掩星观测试验,重点是对星-地无线电掩星无法观测的正午和子夜区域的火星电离层进行探测.星-星无线电掩星观测试验采用双频工作模式,接收机灵敏度为-145dBm,相位测量精度优于5%周.在地面对接收机进行了动态模拟测试,测试得到的相位数据能很好地反演出火星电离层电子密度廓线.

Like the Earth, Mars is surrounded by an ionosphere of different densities. This can be explored using radio occultation technology, but there are limitations in the precision and range of exploration. In October 2009, the Phobos-Grunt and Yinghuo-1 satellites will be launched as part of the joint Russian and Chinese Martian exploration project, and the first international satellite-to-satellite radio occultation experiment on the Martian ionosphere will be implemented. This will focus on the midday and midnight ionosphere which cannot be sounded by satellite-to-Earth radio occultation. Dual bands will be selected in the satellite-to-satellite experiment. The sensitivity of the radio occultation receiver is --145dBm, and the phase measurement error less than 5% of a cycle. The receiver has been tested with dynamic simulation on the ground, and from the data acquired it is found that the Martian ionosphere density profiles are inversed quite well.