摘要
为了研究农田环境中传感器节点短程无线电传播性能,选择冬小麦苗期、拔节期和抽穗期3个典型生育期,进行无线电传播路径损耗试验,通过测量不同天线高度、不同传输距离处的接收信号强度指示(RSSI),研究农田作物障碍对无线电传播衰减的影响.试验结果表明:3个生育期中2.4GHz无线电信号在6个天线高度条件下的路径损耗均符合对数距离路径损耗模型,平均路径损耗指数分别为1.96,2.13和2.42.作物植株高度和冠层密度可以作为农田环境动态变化下影响无线电传播的重要特征参数,与无线电的路径损耗指数之间具有明确的相关关系.
In order to evaluate the performance of short-range radio propagation in crop fields, testing of path loss was performed to determine RSSI levels at different heights and distances in wheat seedling stage, booting stage and jointing stage. The results showed that pass loss of radio propagation over a 2.4 GHz frequency band at each height could be described by the log-distance path loss model. Average path loss indexes in three different stages were 1.96,2.13 and 2.42 respectively. In addition, two factors of crop structure, height of canopy and DFIN（diffuse non-interceptanee） were chosen to describe cropland environment, which could interfere with radio propagation. Correlationships between the two factors and path loss index were proved.
出处
《江苏大学学报（自然科学版）》
EI
CAS
北大核心
2010年第1期1-5,共5页
Journal of Jiangsu University：Natural Science Edition
基金
"863"国家高技术研究发展计划项目(2006AA10Z216)
北京市自然科学基金资助项目(4072011)
国家"十一五"科技支撑计划课题(2008BAB38B06
2009BADA1B01)
关键词
无线传感器网络
精细农业
无线电传播
路径损耗
wireless sensor networks
precision agriculture
radio propagation
path loss
