In order to increase the measurement precision of the distance between two wide-angle sky screens,a project based on laser aim that can adjust two sky screens is presented.

The principle for measuring motion parameters of projectiles using two sky screens in vertical intersection manner;

Bases on the principle and apptication characteristic of sky screens,the levs and slits for consisting the optical system in sky screens,the function of optical trausformation,as well as the relation ship between them have been discusses in the present paper.

Study on technology of anti-interference of sky screen based on CPLD;

A circuit to automatically recognize projectiles signal on sky screen;

The traditional methods of measuring projectile′s velocity with sky screen and the problems confronted within measuring motion of duplex ammunition and repeated firing ammunition are described briefly.

The system of the velocity measurement is made up of the electronic chronometer and the light screens or the sky-screens.

To improve a kind of JYJ-90 skyscreens which is applied to measure the initial velocity,based on the principle of the apparatus which forming a sensor wall on the sky called skyscreens,by using of photoelectronical testing techniques,the paper introduces the method to sense the initial velocity of bullets.

The paper mainly narrates the system of skyscreens accuracy measurement which is improved and studied.