CMONOC约束下的MODIS水汽分区域函数模型校正

MODIS PWV Correction Based on CMONOC and Regional Function Model

融合全球导航卫星系统(global navigation satellite system,GNSS)与中分辨率成像光谱仪(moderate-resolution imaging spectroradiometer,MODIS)可获得高精度、高空间分辨率的水汽分布信息。开展基于中国大陆构造环境监测网络(crustal movement observation network of China,CMONOC)观测资料的中国大陆地区MODIS水汽校正研究。首先,根据地理环境、海拔、气候类型等因素将中国大陆分为16个区域,开展区域MODIS水汽和GNSS水汽的相关性分析;其次,分区域、分季节选择不同的函数模型构建基于GNSS的MODIS水汽校正模型;然后,采取区域模型、单站点模型与实测GNSS水汽开展模型的可靠性检验;最后,通过分区域MODIS水汽校正和图像叠加,获得校正后的中国大陆地区MODIS水汽分布。研究表明,区域MODIS水汽校正模型精度与单站点模型相当,可取代单站点模型用于MODIS水汽校正。基于CMONOC的分区域函数模型可有效提高MODIS水汽精度,为短期天气预报和合成孔径雷达干涉测量大气校正提供参考。

Objectives:Using moderate-resolution imaging spectroradiometer(MODIS)can detect high spatial resolution but low precision precipitable water vapor(PWV),while global navigation satellite system(GNSS)can retrieve high precision but low spatial resolution PWV,in order to get high spatial resolution and precision PWV,it is necessary to integrate two kinds of data.Methods:Taking Chinese mainland as an example,MODIS PWV was done the correction based on GNSS observation and meteorological data provided by crustal movement observation network of China(CMONOC).Firstly,considering the geographical environment,altitude,climate type and other factors,Chinese mainland was divided into 16 regions,and the correlation analysis of regional MODIS PWV and GNSS PWV was carried out.And then,it was constructed for the correction-model of MODIS PWV by different regions and seasons based on GNSS PWV.After that,the regional model result,the single site model result and the measured GNSS PWV were compared to test the reliability of the model.Finally,MODIS PWV distribution in Chinese mainland can be obtained by MODIS PWV correction and image superposition.Results:The results show that the accuracy of the regional MODIS PWV correction model is similar to that of the single-site model,which can replace the single-site model for MODIS PWV correction.Conclusions:The MODIS PWV correction model of different regions can be used to effectively improve the precision of MODIS PWV.It can be used for providing reference for short-term weather prediction and interferometric synthetic aperture radar atmospheric correction.