A method for distance determination with the help of range-gated viewing systems suitable for the arbitrary shape of the illumination pulse is proposed. The method is based on finding the delay time at which maximum of the return pulse energy takes place. The maximum position depends on the pulse and gate durations and, generally speaking, on the pulse shape. If the pulse length is less than or equal to the gate duration, the delay time appropriate to the maximum does not depend on the pulse shape. At equal pulse and gate durations, there is a strict local maximum, which turns into a plateau when pulse is shorter than gate duration. A delay time appropriate to the strict local maximum or the far boundary of the plateau (where non-strict maximum is) is directly related to the distance to the object. These findings are confirmed by analytical relationships for trapezoid pulses and numerical results for the real pulse shape. To verify the proposed method we used a vertical wall located at different distances from 15 to 120m as an observed object. Delay time was changing discretely in increments of 5 ns. Maximum of the signal was determined by visual observation of the object on the monitor screen. The distance defined by the proposed method coincided with the direct measurement with accuracy 1- 2m, which is comparable with the delay time step multiplied by half of the light velocity. The results can be useful in the development of 3-D vision systems.
The optical electronic system for far observing have been developed and tested. This system can use for detecting and tracking objects at night time at long distances. Also it can work in conditions of limited transparency of the atmosphere (the presence of atmospheric phenomena such as rain, snow, drizzle and fog). With the help of the system it is possible to distinguish details of objects with a size of 0.5 m at the maximum distance up to 7 km.
The new scheme of the reference channel of a remote gas analyzer has been offered and realized. The use of additional reflective elements with the low reflection factor allows to receive full interception of laser radiation and to provide a linear operating mode of a photodetector even for the strongest laser lines. At the measurement of a concentration of air pollutions on a differential method the weak dependence of reflection factors for used reflecting plates from wavelength can be easy to take into account by adding corresponding factors in the formula for calculations of air pollution concentrations. The application of the new optical scheme of the reference channel for the gas analyzer and the addition new correcting temperature constants in the calculations has allowed carrying out correct measurements of air pollutants with the high accuracy.