Study On New Method Of Scanning Laser Radar Range - Free

Laser radar has a great many merits such as its high resolution in angle, range and speed, and therefore, it is widely used in civil and military fields. Compared to tranditional laser radar, the scannerless radar has the following advantages: it can image clearly objects in motion; it could have very high frame rate; it is low in power consumption and compact in size.In laser radar systems using phase-demodulation method, the transmitter-laser is usually modulated at high frequency. In order to achieve long measurement range, the power of the laser needs to be large. However, such modulation is difficult to be realized and even if it was done, the laser would give out quite a lot of heat, making it almost impossible to function. This paper presents a new approach of modulation on the laser, which can dramatically reduce the direct current of modulation, thus reduce the heat generated by the light source.In this paper the model and principle of the new approach are presented. Based on mathematical computation and software stimulation, the range solution is deduced in the "Four times" Method. Meanwhile, the main factors are analyzed. We find that although the high frequency noise increases, the image contrast is improved, and when parameters are appropriatedly chosen, system error can be reduced. To study the feasibility of this approach, an experiemental system is set up. Especially, the timing module is demonstrated in detail, with its hardware and software designs explained. Moreover, experiemts are conducted using our own system, and the advantages of this new approach are finally confirmed: less heat produced by the laser, no worse range images, and less system error.