Calculation of the potential distribution area of the target in bi-station bearing-crossing locating

In evaluation of the capture probability of the anti-ship missile (ASM) and the probability of the target in the launching envelope of the missile, the potential distribution area of the target should be taken into account, which is determined by the errors in locating the target. But the calculation equations of the distribution area are always too complex to use in practice where they may slow down the reaction of the missiles. The paper presents equivalent equations for the calculation of the probability density function (PDF) of the target location error in bi-station bearing-crossing locating, based on the characteristics of the potential distribution area of the target. The equivalent has simple form and is easy for calculating, which gains for the ASM fast reaction speed and improvement of its effectiveness in operational uses. The validity of the equivalent is verified in simulations.