主/被动微波遥感数据融合的土壤湿度产品的CDF改进研究  

Improvement of CCI Soil Moisture Product Based on CDF Technique

作　　者：张玲[1] 安如[1] 王喆[1] 

机构地区：[1]河海大学地球科学与工程学院,南京211100

出　　处：《科学技术与工程》2015年第30期1-8,共8页Science Technology and Engineering

基　　金："十二五"国家科技支撑计划(2013BAC03B0401);江苏省"六大人才高峰"项目(XXRJ-011);国家自然科学基金(41271361);973计划(2009CB421105)资助

摘　　要：土壤水分是控制陆地和大气间水热能量交换的关键因子之一,在地球生态系统中起着重要的作用。定量化获取土壤水分信息对农业生产、应对全球变化、保护生态环境等众多领域都有着重要意义。目前,获取精度较高的大区域土壤湿度信息依然是研究的热点和难点问题。气候变化倡议项目（climate change initiative,CCI）土壤湿度数据集是由多种主、被动微波数据融合的大尺度土壤湿度数据集,对其在中国区域的数据质量改进具有较高的实际应用价值。研究利用累积概率分布函数（cumulative distribution function,CDF）匹配方法对CCI土壤湿度产品进行改进。选择有较多实测数据的河北、山西、天津等部分区域,获得2009-2010年每月三旬（共72旬）的土壤湿度插值数据,以此为基础利用CDF进行重调整,建立逐像元的CCI土壤湿度数据的改进模型;然后利用站点实测数据进行该方法的有效性验证。结果表明,CDF调整前的偏差、均方根偏差和平均相对误差分别集中在0.05-0.09、0.05-0.1、0.20-0.45,调整后分别降低在0-0.04、0-0.05、0-0.2范围。可见,CDF调整后的误差明显减小,调整后的CCI土壤湿度的精度得到了明显的提高。Soil moisture heavily influences the energy exchange between land and the atmosphere,and it plays an important role in ecological systems. Quantitatively acquiring soil moisture information is important for agricultural production,ecological protection and other fields. Presently,it is still a hot and difficult problem to acquire accurate and large-region soil moisture information. The Climate Change Initiative（ CCI） soil moisture dataset was generated using a variety of active and passive microwave space-borne instruments,and it has a high practical value for the improvement of the data quality in China. Hebei,part of Shanxi,Tianjin and Shandong,with many in-situ measurements,was selected as the study area. And Cumulative Distribution Function（ CDF） matching technique was used to improve the CCI soil moisture product based on the interpolated soil moisture data every ten days from2009 to 2010（ a total of 72）. And then the improved model was established for each pixel. Finally,the meteorological dataset was used to validate the results of the model. The results showed that BIAS,RMSE and MRE before amelioration were respectively concentrated in 0. 05 - 0. 09,0. 05 - 0. 1,0. 20 - 0. 45. And after amelioration they were respectively 0 - 0. 04,0 - 0. 05,0 - 0. 2. The errors after CDF amelioration were obviously decreased,so the accuracy of the rescaled CCI soil moisture was obviously improved.

关 键 词：CCI土壤湿度产品 主/被动微波遥感融合 实测土壤湿度 CDF匹配 精度改进 

分 类 号：P237[天文地球—摄影测量与遥感]