The Global Oscillation Network Group site survey, 2: Results

Gonzalez, R); Saa, O; Solis, H; Duhalde, O; Palle, P. L.; Sanchez-Martinez, F.; Kadiri, S; Benkhaldoun, Z; Abdulsamad, MS; Alkhashlan, AS; Ambastha, A; Bhatnagar, A; Sumin, X; Zhen, H; Cole, DG; Kennewell, JA; Yasukawa, EA; Garcia, GJ; Sousa, EM; Lu, WMT; Labonte, BJ; Hieda, LS; Webster, L; Ulrich, RK; Zirin, H; Libbrecht, KG; Ingram, RL; Clay, Donald W.; Stebbins, Robin T.; Kupke, Renate; Jones, Patricia B.; Jones, Harrison P.; Leibacher, John W.; Grier, Jennifer; Forgach, Suzanne; Fischer, George; Hill, Frank
Bibliographical reference

Solar Physics, vol. 152, no. 2, p. 351-379

Advertised on:
7
1994
Journal
Number of authors
37
IAC number of authors
2
Citations
43
Refereed citations
36
Description
The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile. Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable networks assembled from the individual site records is compared using a statistical principal components analysis. An accompanying paper descibes the analysis methods in detail; here we present the results of both the network and individual site analyses. The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 x 10-4 with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum.