基于陆态网的区域电离层TEC空间变化特性分析

Analysis of Spatial Variation Characteristics of Regional Ionospheric TEC Grid Based on Crustal Movement Observation Network of China

为研究中国陆态网区域电离层TEC在空间小尺度、高分辨率情况下的变化特性及适用精度范围,利用陆态网260个GNSS连续运行观测站数据,解算并生成2016-2017年731天陆态网区域电离层RIM格网,并进行精度验证.在同一RIM格网中,分别在经度和纬度方向上对间隔不同经纬度的TEC格网点作差分析.结果表明:陆态网区域内经度方向上TEC最大变化率和平均变化率分别为0.30 TECU·(°)^-1和0.11 TECU·(°)^-1;经度间隔1°时,TEC差值小于2 TECU,且随着经度间隔的增大,其TEC差值也随之增大,并表现出一定的半年和周年变化规律;纬度方向上TEC最大变化率和平均变化率分别为1.7TECU·(°)^-1和0.46 TECU·(°)^-1;陆态网区域内电离层TEC随纬度减小而增大,纬度间隔1°时,99.4%的TEC差值小于4 TECU,且随着纬度间隔的增大,其TEC差值也随之增大,并表现出一定的半年和周年变化规律;间隔相同情况下,纬度方向上TEC的变化比经度方向上大.

In order to study the variation characteristics and the applicable accuracy range of ionospheric TEC in small-scale,high-resolution space in the Crustal Movement Observation Network of China(CMONOC)region of China,260 CORS data of the CMONOC are used to generate the731-day CMONOC ionospheric RIM grids from 2016 to 2017,and the accuracy is verified.In the same RIM grid,the TEC grid points with different latitudinal and longitudinal are analyzed in the longitude and latitude directions respectively.The results show that the maximum change rate of the TEC difference in the longitudinal direction of the CMONOC region is about 0.3 TECU·(°)^-1,and the average rate of TEC change is about 0.11 TECU·(°)^-1.When the longitude interval is1°,the TEC difference is less than 2 TECU.As the longitude interval increases,its TEC difference also increases and shows a certain half-year and annual variation.The maximum value of the TEC difference in the latitudinal direction is about 1.7 TECU·(°)^-1.The average change rate of TEC is approximately 0.46 TECU·(°)^-1.The ionospheric TEC in the CMONOC region increases with the decrease of latitude.When the latitude interval is 1°,99.4%TEC differences are less than 4 TECU.As the latitude interval increases,the TEC difference also increases.It also shows a certain half-year and annual variation law.In the case of the same degree of interval,the change of TEC in the latitudinal direction is larger than that in the longitudinal direction.