METHOD FOR MEASURING INITIAL VELOCITY OF PROJECTILE BY LASER FIBER-OPTIC SYSTEM Russian patent published in 2021 - IPC G01S5/00 

FIELD: checkout technique.

SUBSTANCE: invention relates to control and measuring equipment and can be used for non-contact measurement of the initial velocity of a projectile, which is one of the most important ballistic characteristics of a weapon that affects its combat properties. To do this, electromagnetic energy is emitted in the direction of the projectile movement, receive electromagnetic energy reflected from the projectile by two optical telescopic systems with Doppler frequencies ƒ_d1 and ƒ_d2. At the same time, the angle α between the optical axes of telescopic systems is known and unchanged. The received radiation from each of the telescopic systems is combined with the laser radiation in two optical mixers, receiving signals with different radiation frequencies after the first mixer (ƒ₀-ƒ_d1) and (ƒ₀-ƒ_d2) after the second mixer. Then the signals after the first mixer and after the second mixer are summed in the third mixer, receiving a signal with a difference frequency (ƒ_d1-ƒ_d2). Initial velocity of the projectile is determined by the formula: ,

where λ is the laser wavelength and corresponding frequency ƒ₀; (ƒ₀-ƒ_d1) is the difference radiation frequency after the first mixer; (ƒ₀-ƒ_d2) is the difference radiation frequency after the second mixer; (ƒ_d1-ƒ_d2) is the difference radiation frequency after the second mixer.

EFFECT: increased accuracy of measuring the initial velocity of the projectile at small angles between the optical axes of telescopic systems.

1 cl, 7 dwg