摘要
对FDR(Frequency Domain Reflectometry)型土壤水分仪进行改造,将FDR和半导体测温技术相结合,以提高自动土壤水分观测仪的温度适用性,降低土壤水分观测精度受地温变化的影响。通过集成基于频域反射原理的土壤水分传感器和半导体测温器件,设计可同时测量土壤水分及温度的传感器,并在实验室和郑州农业气象试验观测站进行对比试验、建模验证。结果表明:①土壤温度变化对FDR型土壤水分传感器精度有较大影响,传感器测量误差和地温呈负相关关系,且随着土壤深度增加愈加明显;②在土壤温度20℃时,对传感器测量精度影响最小,高于20℃时传感器测量的土壤水分值大于实际值,低于20℃时传感器测量的土壤水分值小于实际值。地温变化引起了FDR型土壤水分传感器振荡频率的偏移,利用传感器测量频率的温度修正模型,可有效降低土壤水分观测数据受地温变化的影响,提升观测精度。
Soil moisture monitor,the type of FDR(Frequency Domain Reflectometry),was transformed by the combination of FDR and semiconductor temperature measurement technology to improve its temperature applicability and to reduce the influence of soil temperature change on the soil moisture observation accuracy.By integrating a soil moisture sensor that works based on frequency domain reflection principle and a semiconductor temperature measuring device,the designed sensor can measure soil moisture and temperature simultaneously.The newly designed sensor was compared and verified through experiments carried out in laboratory and the Zhengzhou Agricultural Meteorological Experimental Station.The results showed that:①The variations of soil temperature had a great influence on the accuracy of FDR soil moisture sensor.The measurement error of FDR soil moisture sensor was negatively correlated with the soil temperature and the correlation became more significant with the increase of soil depth;②When the soil temperature was 20℃,it had the least impact on the measurement accuracy of the sensor.The measured value was greater than the actual value when the soil moisture was higher than 20℃ and when the soil moisture was lower than 20℃,the soil moisture measured by the sensor was less than the actual value.The variation of soil temperature causes the shifts of the oscillation frequency of the FDR soil moisture sensor.The temperature correction model of the sensor's measurement frequency can effectively reduce the influence of soil temperature on the observation data of soil moisture and improve the observation accuracy.
作者
陈海波
陈涛
胡锦涛
赵国强
师丽魁
CHEN Hai-bo;CHEN Tao;HU Jin-tao;ZHAO Guo-qiang;SHI Li-kui(CMA·Henan Agrometeorological Support and Applied Technique Key Laboratory,Zhengzhou 450003,China;Henan Institute of Meteorological Sciences,Zhengzhou 450003,China;The 27th Research Institute of China Electronics Technology Group Corporation,Zhengzhou 450047,China)
出处
《节水灌溉》
北大核心
2022年第8期24-29,共6页
Water Saving Irrigation
基金
河南省科技攻关项目(222102320458)
中国气象局·河南省农业气象保障与应用技术重点开放实验室开放研究基金重点项目(AMF202201,AMF202102)。
关键词
FDR
土壤水分
地温
传感器
FDR
soil moisture
ground temperature
sensor
