标题： 低纬度地区用大型射电望远镜测量的电离层密度变化的谱分析 显示英文标题

标题： Spectral Analysis of ionospheric density variations measured with the large radio telescope in the Low-Latitude region

摘要： The low-latitude ionosphere is a dynamic region with a wide range of disturbances in temporal and spatial scales. The Giant Metrewave Radio Telescope (GMRT) situated in the low-latitude region has demonstrated its ability to detect various ionospheric phenomena. It can detect total electron content (TEC) variation with precision of 1 mTECU and also can measure TEC gradient with an accuracy of about $\rm7\times 10^{-4}\,TECU\,km^{-1}$. This paper describes the spectral analysis of previously calculated TEC gradient measurements and validates them by comparing their properties using two bands. The analysis tracked individual waves associated with medium-scale traveling ionospheric disturbances (MSTIDs) and smaller waves down to wavelengths of $\sim$ 10 km. The ionosphere is found to have unanticipated changes during sunrise hours, with waves changed propagation direction as the sun approached the zenith. Equatorial spread $F$ disturbances during sunrise hours is observed, along with smaller structures moving in the same direction. 显示英文摘要

摘要： The low-latitude ionosphere is a dynamic region with a wide range of disturbances in temporal and spatial scales. The Giant Metrewave Radio Telescope (GMRT) situated in the low-latitude region has demonstrated its ability to detect various ionospheric phenomena. It can detect total electron content (TEC) variation with precision of 1 mTECU and also can measure TEC gradient with an accuracy of about $\rm7\times 10^{-4}\,TECU\,km^{-1}$. This paper describes the spectral analysis of previously calculated TEC gradient measurements and validates them by comparing their properties using two bands. The analysis tracked individual waves associated with medium-scale traveling ionospheric disturbances (MSTIDs) and smaller waves down to wavelengths of $\sim$ 10 km. The ionosphere is found to have unanticipated changes during sunrise hours, with waves changed propagation direction as the sun approached the zenith. Equatorial spread\,$F$ disturbances during sunrise hours is observed, along with smaller structures moving in the same direction.