TM6对遥感主成分分析监测土壤含水率的影响

Impacts of TM6 Data on Soil Moisture Monitoring by Principal Component Analysis of Remote Sensing

研究TM6波段对遥感监测土壤含水率的影响。以2003年10月到2005年3月宝鸡峡灌区二支渠土壤含水率实测数据及同步TM数据为基础,将TM数据以TM1-TM5、TM7和TM1-TM7分为两种组合,分别进行主成分分量提取,建立两种土壤含水率监测模型。以2005年6月28日遥感数据为基础,将采用两种模型所得的土壤含水率计算值与实测值进行相关分析及精度分析。结果表明,用TM1-TM5、TM7数据组合所得结果,其精度为57.75%-85.40%。当加入热红外波段TM6后,即TM1-TM7数据组合,最低精度可提高至67.79%-86.35%,明显高于前者,而且,在监测土壤含水率较低或较高的地区时更为敏感。因此,加入TM6波段的遥感主成分分析方法,可望在较高精度水平上监测土壤含水率有广阔的应用前景。

The study was to explore the impacts of TM6 data on soil moisture monitoring by remote sensing.In this study,the second branch irrigation canal of Baojixia Irrigation District was used as the field site for monitoring soil moisture by using spot data obtained from October,2003 to March,2005.Principal component analysis was performed for the data of Band TM1-5,TM7 and Band TM1-7 of Landsat-TM,and two numerical models for extracting raw spot data were developed with extracted principal component.Based on established models and remote sensing data in June 28,2005,correlation analysis between the calculated soil moisture using two models and the measured values in the field,was performed,and accuracy analysis was also conducted.Compared with the accuracy in the range of 57.75% to 85.40% by using Band TM 1-5,and 7,the inclusion of TM 6 of significantly improved the accuracy of calculation,particularly,with the minimum value reaching 67.79% to 86.35%.It was demonstrated that Band TM 1-7 can be used for monitoring sites with relatively low or high contents of soil moisture at higher level of sensitivity,compared with Band TM 1-5 and 7.The results of this study have significant implications for promising application of the remote sensing method including Band TM 6 to the monitoring of field soil moisture at enhanced level of accuracy.