Studies on Activities of the Jovian decametric Radiations Using the 50 km Mesh Baselind Interferometer

为测量木星十米波辐射源位置，研制了50公里长基线干涉仪。长基线干涉仪系统由三个观测站组成，Kawatabi和Zao之间的距离为75 km，Kawatabi和Yoneyama之间的距离为45 km，Yoneyama和Zao之间的距离为83 km，干涉仪系统的设计精度为0.5角秒，相当于木星上1500 km的分辨率。利用这个50公里基线干涉仪系统进行的观测提供的数据显示了木星源的特征<i>：与Io-A有关的源稳定地位于南磁极区。<ii>与Io-B和Io-C有关的源表明，源的位置在南北两极之间有明显的转换，其周期为几分钟。与源位置的确定同时进行的偏振测量结果表明，木星的十米波辐射是以L-O模式，这是预期从转换理论的立场，为产生行星辐射。

Long baseline interferometer with spacing of 50 km range have been developed for the measurements of source positions of the decametric wave radiation from Jupiter. The long base line interferometer system which consists of three observation stations with distances 75 km between Kawatabi and Zao, 45 km between Kawatabi and Yoneyama, and 83 km between Yoneyama and Zao, have been established by producing the Yoneyama stations.The interferometer system has been designed so as to have the accuracy of 0.5 arc sec, corresponding to 1500 km resolution at Jupiter. Observations using this 50 km base line interferometer system provided data which show the characteristics of sources at Jupiter as<i> ) The sources related to Io-A is located steadily at south magnetic pole region.<ii> ) The sources related to Io-B and Io-C indicate apparent switching of the source positions between the north and south poles with period of a few minutes.The results of the polarization measurement which has been carried out simultaneously with identification of the source position indicate that the Jovian decametric radiations take place in the form of the L-O mode which is expected from the standpoint of the conversion theory for the generation of the planetary radiation.