Study on two methods for measuring temperature coefficients of electronics unit in electrostatic accelerometers: IMA and ICM

Abstract High-precision electrostatic accelerometers have become one of the key payloads for satellite gravity measurement and space-based fundamental physics experiments. In-depth research on the intrinsic temperature coefficients of electrostatic accelerometers plays a crucial role in improving the quality of post-processing. Meanwhile, due to the small measurement range of accelerometers, it is difficult to carry out temperature coefficient tests on the ground. This study proposes two methods, individual module assessment (IMA) and integrated closed-loop measurement (ICM), to measure the temperature coefficients of the electronics unit. Experimental testing was performed on the same sample of the accelerometer electronics unit using two methods. The IMA approach involves first determining the temperature coefficient of each individual module, then calculating the overall temperature coefficient contribution of the electronics unit through the transfer function. The experimental results show that the gain temperature coefficient is ( − 3.9 ± 0.9 ) × 10 − 5 ∘ C − 1 , and the zero-bias temperature coefficient is ( 1.5 ± 0.1 ) × 10 − 10 m s − 2 ∘ C − 1 . The ICM method employs a semi-physical platform to establish a virtual probe that simulates the accelerometers’ on-orbit closed-loop operational state, and directly measures the temperature coefficient of the electronics unit. The experimental results show that the gain temperature coefficient is ( − 3.8 ± 2.4 ) × 10 − 5 ∘ C − 1 , and the zero-bias temperature coefficient is ( 1 ± 36 ) × 10 − 11 m s − 2 ∘ C − 1 . The experimental results of the zero-bias temperature coefficient have significant errors, which are mainly caused by the limitations of the semi-physical platform.