The Udaipur, India GONG station was commissioned on 5 October, completing deployment of the full six-site network. Routine operations have begun, and the data have been processed all the way through the pipeline to produce p-mode frequencies, which have been distributed to the scientific community. While it has been a full eleven-year solar cycle since conception, the deployment went very quickly and smoothly, and operations have been uneventful to date. In short--GONG works!!
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The Udaipur, India site is watched over by a temple in the background.
An important figure-of-merit of the network's performance is the reduction of the 1/day sidelobes, which generate ghosts in single site observations. Here is the spectrum of the observing window (1 if any of the stations were guiding on the Sun, 0 otherwise) for the first 25 days of network observations, compared to that from a good single site (Big Bear). The daily sidelobe is reduced by more than a factor of 2200. The duty cycle for the network was 97.7% during this period, and the longest completely clear period has been 128.9 hours (5.4 days). The performance will be reduced slightly when bad images (e.g. condors in the beam) are rejected.
While preliminary inversions on the internal rotation and sound speed variation have already been performed, the Scientific Teams are working towards a first presentation of results at the January AAS meeting with publication in a special issue of Science in the late spring.
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Power spectra of observing windows for one site (left) and full GONG network (right).