热膨胀效应对GNSS短基线坐标时间序列影响研究

Influence of Thermal Expansion Effect on GNSS Short Baseline Coordinate Time Series

天线观测墩及基岩的热膨胀效应会造成全球卫星导航系统(GNSS)基准站坐标时间序列非线性变化,本文利用长期观测数据评估了热膨胀效应对GNSS短基线时间序列周期特性的影响.结果表明:热膨胀效应在高程上可以引起约1mm的季节性周年信号,可以很好地解释GNSS短基线时间序列中的周期信号,而对平面方向的贡献不大,但是观测墩因日光照射受热不均产生的热弯曲对平面方向上的影响应予以考虑.

Thermal expansion effect of antenna observation pier and bedrock can cause non-linear change of coordinate time series of global navigation satellite system(GNSS)reference station.In this paper,the effects of thermal expansion on the periodic characteristics of GNSS short baseline time series are evaluated using long-term GNSS observations.The results show that the thermal expansion effect can induce seasonal annual signal of about 1 mm in vertical,and can well explain the periodic signal of GNSS short baseline time series,but has little contribution to the plane direction.However,the effect of thermal bending caused by uneven sunlight irradiation on the plane direction should be considered.