The visibility data are noisy and incompletely sampled, and we have used a maximum entropy method to perform the Fourier transform, making optimal use of the data available. Using the current antenna configuration at Jicamarca, the radar imaging technique is able to resolve structures within the radar beam that are a few tenths of a degree or less wide. By animating sequences of images, we can observe the evolution of ionospheric irregularities without confusing spatial and temporal variations.
A new antenna at Jicamarca, physically separated from the main antenna array, provides very long interferometry baselines up to 94 wavelengths long for imaging experiments. Up to 15 interferometry baselines can be constructed, now that Jicamarca has the capability to sample 6 quadrature receivers simultaneously. The particular receiving antenna arrangement we use is shown here. The north and south quarters of the antenna are used for transmission.
Details regarding the generation of the images can be found in a manuscript which is in HTML format. Here we present examples of animated images computed from several different experiments. The RTI maps in each case hint at the behavior of the ionosphere on a given night. Below each map is a selection of animations corresponding to different local time intervals from the map.
|1724-1748 LT||2140-2200 LT|
|1930-2020 LT||2020-2115 LT|
|1930-1950 LT||1955-2015 LT||2015-2055 LT|
|1940-2030 LT||2030-2110 LT||2110-2130 LT||2130-2200 LT|
|2037-2100 LT||2106-2136 LT|
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