Calibration Method of Chang’E-7 Lunar Seismograph Payload

The Chang’E-7 mission will deploy China’s first independently developed lunar seismograph at the Moon’s south pole to record ground motions generated by moonquakes and meteoroid impacts. The instrument is designed for an eight-year operation lifetime aimed at characterizing the seismic activity and shallow interior structure of the Moon. To ensure measurement accuracy and long-term operational stability under the extreme conditions of the lunar environment, it is essential to establish a systematic calibration methodology. This will guarantee that the instrument’s key technical parameters and calibration indicators meet the requirements for scientific exploration and data inversion. Based on the technical criteria for ground-based seismograph network integration, and considering performance specifications such as bandwidth, dynamic range, and magnitude range, this paper proposes a comprehensive ground calibration test plan covering critical indicators, including amplitude-frequency response, sensitivity and sensitivity error, self-noise levels and measurement range. Furthermore, in accordance with the operational requirements during the lunar surface phase, an autonomous in-situ calibration scheme has been designed, along with a proposed manual source calibration method on the lunar surface. This study establishes a comprehensive calibration framework for the functionality and performance of the lunar seismograph, providing systematic procedures for performance testing and evaluation throughout all mission phases—from ground validation to in-situ operation on the lunar surface. The proposed framework lays an essential foundation for acquiring high-precision lunar seismic data and conducting subsequent scientific analyses.