A Design Of Agro-meteorological Observation System Base On WSN

Agricultural meteorological service based on meticulous observation is the foundation of modern agricultural development. With the development of wireless sensor networks, WSN network is gradually applied to agricultural meteorological observation.This paper implemented the agro-meteorological observation system which is based on WSN, the system includes field microclimate observing subsystem, temperature and humidity observations subsystem between crops and the growth of crops observations subsystem. The growth of crops ovservation subsystem judge the development of the crops by image analysis techniques via HD real-time image. The temperature and humidity observations subsystem observe temperature and humidity between crops.Normally it can achieve the observation of temperature and humidity at 30cm and 60cm. According to the hight of crops, it selectively implement temperature and humidity data acquisition at 150cm or 300cm.The main jobs are as follows:1.Realize a tree network.2.The hardware design of temperature and humidity nodes.3. Systems integration and field testing.This paper chooses lithium battery and solar panel to powered on to ensure that the node is running for a long time in the wild. The charging efficiency of LTC4121 can achive more than 80%. Combined with CN302, realized an efficient power management system. According to independent designed routing protocol this paper implemented a tree network communication, which contains tree typies of nodes, coordinator, routers, terminal node. The routers is responsible for transmit the data of child nodes.It Implementated the self-healing function of the tree network.If a node does not receive the broadcast information for more than three cycles,than it will re-start the function to join the network.The results of test show that the node can work continuously for more than 15 days in rainy days,and the missing data rate of WSN network is 0%.Compared to traditional agricultural meteorological observation system, the agricultural meteorological observation system in this paper is distributed, the samples are more comprehensive, and more representative. It has broad application prospects.