ANALYSIS OF THE INFLUENCE OF MEASUREMENT FOR THE CONTROL CIRCUIT OF GRAVITY GRADIOMETER ON GRAVITY GRADIENT MEASUREMENT

In order to study the influence of the measurement and control circuit system on gravity gradient components, the analysis started from the amplification gain and initial phase angle of the control circuit. The impact of gain discrepancies and initial phase angle errors in the control circuit on gravity gradients were analyzed, leading to certain conclusions. The adder and voltage amplifier gain errors in the control circuit have a significant effect on the gradient measurement. The amplification gain of the control circuit system has a greater impact on larger gradient components and a smaller impact on smaller gradient components. The initial phase angle error and the amplification gain of the measurement and control system have opposite effects on the gradient components. Finally, a method for achieving precise positioning of the initial phase angle using trigger pulse was proposed. Through experiments with the control system, when the sampling rate is 10Hz, the maximum gradient error was 0.1Eu, meeting the experimental requirements.