This paper introduces the first results of observations with the Ultra-Long-Wavelength (ULW) —- Low Frequency Interferometer and Spectrometer (LFIS) on board the selenocentric satellite Longjiang-2. We present a brief description of the satellite and focus on the LFIS payload. The in-orbit commissioning confirmed a reliable operational status of the instrumentation. We also present results of a transition observation, which offers unique measurements on several novel aspects. We estimate the RFI suppression required for such a radio astronomy instrumentation at the Moon-distances from Earth as order of − 80 dB. We analyse a method of separating Earth- and satellite-originated radio frequency interference (RFI). It is found that the RFI level at frequencies lower than a few MHz is smaller than the receiver noise floor.

本文介绍了龙江二号硒心卫星搭载的超长波（ULW）——低频干涉仪和光谱仪（LFIS）的首次观测结果。. 我们简要介绍了卫星并重点介绍了 LFIS 有效载荷。在轨调试证实了仪器的可靠运行状态。我们还介绍了过渡观察的结果，它提供了几个新颖方面的独特测量。我们估计这种射电天文仪器在与地球的月球距离上所需的 RFI 抑制为 − 80 dB 的量级。我们分析了一种分离源自地球和卫星的射频干扰 (RFI) 的方法。结果发现，频率低于几 MHz 时的 RFI 电平小于接收器本底噪声。