Error analysis of laser spot position measurement considering the dead zone of quadrant detectors

The Quadrant Detector (QD) is widely used in the fields of guidance and tracking. This paper investigates the effect of the dead zone width of QD on tracking accuracy. A spot centroid calculation model considering the dead zone of QD is established based on Gaussian spot, and Gaussian distributed noise is introduced to build a measurement error model of QD under noise interference. To verify the accuracy of the model, numerical calculations and comparative analysis of the standard deviation of the measurement error are conducted. The results indicate that when the signal-to-noise ratio is fixed, enlarging the dead zone will reduce the standard deviation of the measurement error, while the presence of the dead zone will increase the standard deviation of the measurement error when the incident optical power is fixed. This error model quantitatively reflects the influence of dead zone width on the standard deviation of measurement error of QD under noise interference, providing theoretical reference for improving the tracking accuracy of laser seeker.