The Study Of Framework Of Data Acquisition System For Lidar

Lidar has ultra-high resolution in time domain, frequency domain and spatial domain. Lidar has been widely used in guidance, target tracking, optical remote sensing, space rendezvous and docking, trajectory correction and other military field, as well as in traffic speed monitoring, environmental monitoring, geographic mapping and other civilian areas. There are varieties of Lidars with different working principle, such as imaging lidar, ranging lidar, Doppler lidar, differential absorption lidar, and so on. The data acquisition systems for various kinds of Lidars are different. There is no uniform data acquisition standard in Lidar research field.Some dedicated data acquisition devices was developed for few particular Lidars. These devices could not be transplanted to other Lidars. Most lidars used common data acquisition devices and commercial instruments. There were two drawbacks to these general-purpose equipments:the one hand, their applications are too broad and can’t match the requirements of lidars well; On the other hand, it is difficult to integrate these commercial products into the lidar system.For these reasons, it is necessary to summarize the characteristics and rules of lidar data acquisition and to establish a data acquisition framework with high reusability for lidar. The most commonly methods and techniques used in lidar data acquisition should be included in the framework. Most of lidar data acquisition systems can be quickly constructed under the framework. To achieve this goal, the following researches had been done:(1) After the status and trend of lidar development in the world was demonstrated, the general requirements of the data acquisition system for lidar was summarize.(2) The ways of working, detection range, working principle of lidar was systematically studied. The laser and detector of lidar were introduced. The lidar signal detection modes were discussed.(3) The needs in lidar data acquisition system framework were deeply analyzed, including signal acquisition, data flow control, timing control, centralized automation and control, database and so on. The signal conditioning, analog-to-digital conversion, photon counting, time measurement, data cache, data processing, centralized control, data communications, virtual instruments, database access in the framework was designed as modules and implemented based on the reconfigurable technology.(4) The framework had been applied in visibility lidar, Doppler lidar, differential absorption lidar, and intensity correlation imaging lidar. The tests showed that the framework could satisfy the requirements of these lidars. The innovations of this paper are:(1) Based on the systematical study on the working principle and detection methods of lidar, the rules and mode of lidar data acquisition were summarized. The concept of development under the framework with reconfigurability and reusability was introduced into the field of lidar data acquisition.(2) The lidar data acquisition system framework was proposed. For the framework, a series of hardware and software modules were designed and developed, the communication protocol was established. The framework had covered the most commonly used data acquisition techniques and methods of lidar, which can meet the needs of most of lidars.(3) The lidar data acquisition system framework had been successfully implemented in visibility lidar, Doppler lidar, differential absorption lidar, and intensity correlation imaging lidar, which meant that the framework had good prospects in the field of lidar research.