利用无线传输的BDS--R土壤湿度反演系统

针对野外地区土壤湿度监测时间长、数据采集量大的需求，提出了基于无线传输的BDS—R土壤湿度反演系统。以UM220—III N和GPRS DTU为核心构建了北斗信号数据处理与无线传输模块，将圆极化天线采集的北斗信号数据处理成NMEA 0183格式串行数据，并经GPRS与Internet传送至COMWAY无线串口服务器，再通过Microsoft Visual Studio 2008软件构建的数据存储软件提取服务器上的数据，并保存至本地磁盘。选取了连续1个月的北斗C05卫星信号信息进行反射系数法反演土壤湿度实验，反演结果与原位湿度值相关系数达0.69，平均相对误差为16.86%，表明系统工作可靠性强，适用于长期远距离的野外地区土壤湿度反演。

BDS--R soil moisture retrieving system using wireless transmission

Aiming at requirements of long time field area soil moisture monitoring and large quantity of data collection,soil moisture retrieving system,BeiDou satellite system-reflectometer(BDS—R)based on wireless transmission is proposed. Constituted by UM220—III N and GPRS DTU modules as its core,BeiDou signal processing and wireless data transmission modules are built up,BeiDou signal are collected by circularly polarized antenna and processed into NMEA 0183 format serial data and transmitted to wireless serial server COMWAY via GPRS and the Internet. Log on serial server and use data saving software compiled by Microsoft Visual Studio 2008 software to extract data and save it into local disks. One month consecutive signal information of BeiDou C05 satellite are selected for soil moisture inversion experiment by reflection coefficient method,correlation coefficient between inversion results and the in-situ humidity values reach to 0. 69,average relative error is 16. 86%,which proves that reliability of the system is really good,it is suitable for long distance field area soil moisture inversion for a long time.