Solar Radio Observation and RFI

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Solar Radio Observation and RFI
Wei Wang Zhijun Chen Solar Radio Group, NAOC
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Introduction

• Solar Radio Observation in NAOC
• Studies on solar radio astronomy began in 1959
  Since 1994, SRG has developed a broadband solar
  radio spectrometer with frequency coverage of
  1.0-7.6GHz at Huairou station of NAOC
• Instruments
• 1.0-2.0GHz, 2.84GHz, 2.6-3.8GHz, 5.2-7.6GHz
  Spectrometers
• Chinese Spectral Radio Heliograph
• Finished prototype experiment at Miyun Station in
  2005.

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2.0m
3.0m
7.3m
Schematic array center part
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Observation results
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Interference

• The signal from solar is lower than interference
  form airport radar.

interference
signal
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Chinese Spectral Radio Heliograph

• The CSRH will be a solar-dedicated radio
  interferometric array that will be optimized to
  carry out imaging spectroscopy of the Sun, to
  produce high spatial resolution (maximum 1.3),
  high time resolution (lt100ms) and high frequency
  resolution (about 1) images of the Sun
  simultaneously at a wide range of frequencies.
• The broadband synthesis-imaging array demand a
  site with low levels of Radio Frequency
  Interference (RFI) over this entire frequency
  band (0.2GHz-15GHz).
• We want to find a radio-quiet zone for CSRH.

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RFI Test for CSRH

• A survey of 400MHz15GHz spectrum environment was
  performed during late 2004 and early 2005 at
  Zhengxiangbaiqi site in Inner Mongolia.

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Summary

• We want to find a radio-quiet zone that minimizes
  band occupancy of Radio Frequency Interference
  (RFI) for CSRH.
• We hope the frequency for solar radio astronomy
  can be protected to prevent more interferences.

Thank you!