The impact of atmospheric fluctuations on degree-scale imaging of the cosmic microwave background

Fluctuations in brightness due to water vapor in the Earth’s atmosphere are an important source of noise for ground-based instruments attempting to measure the anisotropy of the Cosmic Microwave Background. This paper presents a Kolmogorov model of atmospheric fluctuations, and derives simple expres...

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Bibliographic Details
Main Authors: Oliver P. Lay, Nils W. Halverson
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2000
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.337.629
http://arxiv.org/pdf/astro-ph/9905369v2.pdf
Description
Summary:Fluctuations in brightness due to water vapor in the Earth’s atmosphere are an important source of noise for ground-based instruments attempting to measure the anisotropy of the Cosmic Microwave Background. This paper presents a Kolmogorov model of atmospheric fluctuations, and derives simple expressions to predict the impact of fluctuations on experimental measurements for three instrument configurations: chopped beam, swept beam and interferometer. Data from the South Pole and from the Atacama Desert in Chile, two of the driest places on Earth, are used to characterize the fluctuations at each site. Using an interferometric instrument as an example, the data suggest that the South Pole is the superior site for observations of the Cosmic Microwave Background at degree angular scales. Subject headings: atmospheric effects — instrumentation: interferometers — methods: analytical — cosmic microwave background 1.