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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.
The results of a climatological study of ionospheric disturbances derived from observations of cosmic sources from the Very Large Array (VLA) Low-frequency Sky Survey (VLSS) are presented. We have used the ionospheric corrections applied to the 74 MH
The results of contemporaneous summer nighttime observations of midlatitude medium scale traveling ionospheric disturbances (MSTIDs) with the Very Large Array (VLA) in New Mexico and nearby ionosondes in Texas and Colorado are presented. Using 132, 2
Geomagnetically-aligned density structures with a range of sizes exist in the near-Earth plasma environment, including 10-100 km-wide VLF/HF wave-ducting structures. Their small diameters and modest density enhancements make them difficult to observe
The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and resolution (~25
We present the results of a multi-scale analysis of TEC fluctuations using a roughly five-hour observation of the bright radio source Virgo A with the Very Large Array (VLA) at 74 MHz in its B configuration. Our analysis combines data sensitive to fi