Wireless sensor networks consist of sensor nodes with sensing and communication capabilities, which differ from traditional communication networks in several ways: sensor networks have severe energy constraints, redundant low-rate data, and many-to-one flows. Conduction of data aggregation is required. By the way of extracting reference data set and constructing linear regression mode, a data aggregation algorithm was proposed for WSN which composed of many correlated sensors. Taking a greenhouse air temperature, relative air humidity and soil temperature data sample collected by WSN in a demonstration base as research object, we analyzed performance of the algorithm. Results show that data compression ratio could reach as high as 40.72

Wireless sensor network technology has the potential to reveal fine-grained, dynamic changes in monitored variables of outdoor landscape. But there are significant problems to be overcome in order to realize the vision in working systems, such as effective utilize of energy, prolong network life and improve sensor accuracy. This paper describes the design and evaluation of a sensor network with an effective data aggression algorithm applied in orchard microclimate monitor. A novel feature of the solution is its data compression algorithm design, in which all sensors were encoded with Morton code and a logical multi-lays cluster was constructed among the nodes. Making use of the similarity of the output of the sensors, the algorithm reduces network data amount and power cost significantly to prolong life of the network. Tests and experiments results are shown in diagrammatic form. The system was field tested over one month in Nankou farm located in Beijing province of China. The experimental results demonstrate that effective collecting of environmental information can be achieved by using our proposed system.

Wireless sensor network is an effective method to gather the remote information and also the important part of whole wireless sensor network application system to accept and process the farmland information which is gathered by wireless sensor network. Aiming at the characteristics of data acquisition using wireless sensor network, the construction of the data processing server for the system was studied. A data processing server based on the non-blocking I/O sockets communication was designed and implemented. The server utilized the technologies of thread pool and I/O multiplexing. Cyclic queue was adopted as the data buffer, which could better solve the problems such as the multi-connection TCP communication and the high-speed concurrent processing performance of a large number of real-time monitoring data. Through using the object-oriented programming method, the class hierarchy was built up to increase the ability of code reuse.

需求分析是信息系统工程的关键,随着农业信息化的发展,农业信息系统工程的需求定义和分析也逐渐得到重视.该文针对农业软件系统研制中经常发生的需求无法得到准确描述的问题,在农业信息采集平台的研制过程中引入ARIS需求分析建模方法.通过对农业信息采集平台的需求建模,研究了ARIS 5种视图在农业信息系统建模中的应用,采用EPC建立流程模型.最后结合软件研制实例分析了ARIS需求分析建模方法在农业领域应用软件研制中的优势.

To reach the goal of sustainable farmland data acquisition and longer living of field wireless sensor network, Data Acquisition Platform for Farmland Soil Monitoring is studied, which mainly focus on node structure of software and hardware, realization way of node low power. Hardware system is composed of high-performance, sleep mode supported MCU ATmega128L and low-power consumption RF IC CC1000; a routing algorithm added packet recording and network graded control is introduced based on the flooding routing, based on which Synchronous and periodic network dormancy can be resolved. Results show that node structure of software and hardware is simple and practical. With the improved communication protocols and the new dormancy mechanism, time-synchronization is achieved in network layer, with power consumption reducing maximally 80%. The system meets the demands of farmland monitoring to a certain extend.