Imaging simulation of a linear interferometer array on lunar orbit

Ground-based observation of the sky at frequencies below 30 MHz is hindered by the ionosphere of the Earth and radio frequency interference (RFI). To map the sky at this low frequency band, we have proposed the Discovering the Sky at the Longest wavelength mission (DSL, also known as the “Hongmeng” mission, which means "Primordial Universe" in Chinese) concept, which employs a linear array of micro-satellites flying around the Moon. Such an array can be deployed to the lunar orbit by a single rocket launch, and it can make interferometric observations which are capable of achieving good angular resolution despite the small size of their antennas. For the purpose of high-resolution mapmaking, we develop an end-to-end simulation which can be divided into two parts. The first part is the simulated observation to obtain mock visibilities, the observed quantity. The second part is to get the physical quantities we need by analyzing the observed data. Then the code “dslpy” and the relevant data are publicly available.