| Forest, as one of the most valuable resources which the mankind depends on for living, plays an irreplaceable role in sustainable economic and social development. However, forest fires which cause serious damage and threat to the ecological environment system and human life occur frequently in recent years. Therefore, the governments around the world pay more and more attention to the work of preventing the forest fire. The traditional forest fire prevention way mainly relies on manpower, which leads to lower degree of automation and lower fire positioning accuracy. So how to make use of the high and new technology, such as wireless sensor networks technology and satellite remote sensing technology, to monitor and locate the forest fire becomes an important point.By analyzing the method of the current forest fire monitoring system and the characteristics of the wireless sensor networks, this article proposes a new forest fire positioning algorithm based on wireless sensor networks. In this method, temperature sensor, humidity sensor and combustible gas density sensor are used to collect physical parameters in the forest monitoring area, and then these parameters are sent to the 3G module through the wireless sensor networks. Through the Internet, 3G module will transmit them to the remote fire monitoring center which has the function of real-time monitoring and real-time alarm.The design content of this paper mainly includes two aspects: the research on node localization technology in wireless sensor networks and the design of forest fire positioning system. Among them, the research of this article focuses on the DV-Hop localization technology. Since the DV-Hop localization algorithm has low location accuracy and a poor ability to adapt the environment, this article proposes an improved DV-Hop positioning algorithm using continuous hop count based on RSSI. In this method, the DV-Hop algorithm is improved mainly in two aspects: one is the improvement in the RSSI ranging model which can facilitate its application in the complex environment of forest, the other is the introduction of continuous hop count definition which help the DV-Hop algorithm obtain more accurate average hop distance and achieve higher position accuracy. Simulation results have verified the validity and reliability of the improved DV-Hop algorithm.The design of forest fire positioning system mainly includes the hardware and software design of the fire parameter collection node and the gateway node, and the design of the fire remote monitoring center. The hardware design mainly introduces the selection of chip and the circuit diagram of each module. The software design describes the program flow chart of each part. The human-computer interaction interface of the remote fire monitoring center which has the function of real-time monitoring and real-time alarm is developed by using c # language. Finally, the system test verifies the feasibility of the design. |
