ISSN:
1572-9559
Keywords:
Site testing
;
Atmospheric opacity
;
Submillimeter-wave astronomy
;
Anti-icing a radome
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We measured atmospheric opacity at 220 GHz at the summit of Mt. Fuji (alt. 3776 m) about one year in order to explore a feasibility of submillimeter-wave astronomical observations. For this purpose, a 220 GHz radiometer system enclosed in a radome (51×51×62 cm3) has been developed. The 220 GHz opacity was lower than 0.06 for a significant fraction (∼ 45 %) of time from November 1994 to March 1995. Diurnal variation of the opacity at the summit of Mt. Fuji is so small that continuous observation at submillimeter-wave is possible through day and night. Yearly variation of the opacity is studied from water vapor pressure data measured at the weather station for the past 3 years. To prevent accumulation of ice and snow on the Gore-Tex membrane in the radome, the outer membrane was supplied with a thermal flux of 0.63 kW m−2 and the adjacent metal radome surfaces were supplied with a flux of ∼0.9 kW m−2. We evaluate from the 220 GHz transmission data that this heat flux is sufficient to keep the membrane on the radome free of ice and snow during 83 % of the time in 5 winter months. The summit of Mt. Fuji appears to be a promising site for submillimeter-wave observations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02088912
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