This study deals with the optimization of the upper and lower thresholds of intermittent maneuvers used to improve the observability. In the intermittent maneuver, there are upper and lower thresholds of the line-of-sight rate for the relative range. By adjusting the guidance command, the line-of-sight rate is maintained between the upper and lower thresholds. The upper and lower thresholds have two design parameters. The first design parameter, $\alpha$ , is the ratio of the relative range at the moment the guidance command is turned on, and the second design parameter, $\kappa$ , represents the relationship between the relative range and the line-of-sight rate. The magnitude and frequency of the intermittent maneuver are determined according to the two design parameters, and the observability improved by the intermittent maneuver varies. Therefore, optimization of both design parameters should be performed to maximize the observability. First, it is necessary to quantify the observability according to two design parameters. The concept of the Fisher information matrix can be a quantitation method. Among them, a method of maximizing the lower bound of the determinant of the Fisher information matrix is used. An analytic solution for the lower bound of the determinant of two design parameters and the Fisher information matrix is derived, and optimization is performed by setting it as an optimization objective function. Also, system performance is considered a constraint. The performance of the design variables obtained through optimization is verified through simulation comparing the convergence performance of the filter and the guidance performance according to the change of the design parameters.