We have used a relatively long, contiguous VHF observation of a bright cosmic radio source (Cygnus A) with the Very Large Array (VLA) to demonstrate the capability of this instrument to study the ionosphere. This interferometer, and others like it, can observe ionospheric total electron content (TEC) fluctuations on a much wider range of scales than is possible with many other instruments. We have shown that with a bright source, the VLA can measure differential TEC values between pairs of antennas (delta-TEC) with an precision of 0.0003 TECU. Here, we detail the data reduction and processing techniques used to achieve this level of precision. In addition, we demonstrate techniques for exploiting these high-precision delta-TEC measurements to compute the TEC gradient observed by the array as well as small-scale fluctuations within the TEC gradient surface. A companion paper details specialized spectral analysis techniques used to characterize the properties of wave-like fluctuations within this data.
Seismic-ionospheric disturbances in ionospheric TEC and plasma parameters associated with the 14 July 2019 Mw 7.2 Laiwui earthquake detected by the GPS and CSES
Automatic Characterization of Mid-latitude Multiple Ionospheric Plasma Structures from All-sky Airglow Images using Deep Learning Technique
Indian Institute of Technology Roorkee（印度理工学院鲁尔基分校）；KTH Royal Institute of Technology（瑞典皇家理工学院）；Lancaster University（兰卡斯特大学）；Aryabhatta Research Institute of Observational Sciences（阿亚巴塔观测科学研究所）
Reassessment of Ionospheric Responses to GRB~221009A: Disentangling Instrumental, Illumination and Geophysical Effects
National Space Science Center, Chinese Academy of Sciences（中国科学院国家空间科学中心）；Hainan National Field Science Observation and Research Observatory for Space Weather, National Space Science Center, Chinese Academy of Sciences（中国科学院国家空间科学中心海南空间天气野外科学观测研究站）；Haystack Observatory, Massachusetts Institute of Technology（麻省理工学院海斯塔克天文台）；University of Colorado, Boulder（科罗拉多大学博尔德分校）；Deep Space Exploration Laboratory/School of Earth and Space Sciences, University of Science and Technology of China（中国科学技术大学深空探测实验室/地球与空间科学学院）；Beijing National Observatory of Space Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences（中国科学院地质与地球物理研究所北京空间环境国家野外科学观测研究站）
Multi-instrument constraints on a hemispherically asymmetric positive ionospheric storm in the 60-180 deg E sector during the 12-13 November 2025 geomagnetic storm
Institute of Earthquake Forecasting, China Earthquake Administration（中国地震局地震预测研究所）；National Space Science Center, Chinese Academy of Sciences（中国科学院国家空间科学中心）；Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University（香港理工大学土地测量及地理资讯学系）；Istituto Nazionale di Geofisica e Vulcanologia（意大利国家地球物理与火山学研究所）；Space Research Institute, Russian Academy of Sciences（俄罗斯科学院太空研究所）
Predicting low-latitude ionospheric Total Electron Content (TEC) over the Indian sector under variable space weather conditions using solar wind parameters
Indian Institute of Geomagnetism（印度地磁研究所）；School of Environmental Science, Jawaharlal Nehru University（贾瓦哈拉尔·尼赫鲁大学环境科学学院）
t-STEP: An interpretable model for Total Electron Content predictions and irregularities estimations
Interdisciplinary Center for Security, Reliability and Trust (SnT), University of Luxembourg（安全、可靠性与信任跨学科中心（SnT），卢森堡大学）；Istituto Nazionale di Geofisica e Vulcanologia（国家地质物理与火山学研究所）；Mission Space | Space Weather（空间任务 | 空间天气）
