World Library  
Flag as Inappropriate
Email this Article

Unwin Radar

Article Id: WHEBN0022055741
Reproduction Date:

Title: Unwin Radar  
Author: World Heritage Encyclopedia
Language: English
Subject: La Trobe University, Lunar swirls, Atmospheric dynamo, TWINS, List of satellites which have provided data on Earth's magnetosphere
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Unwin Radar

The Unwin Radar array at Awarua

The Unwin Radar is a scientific radar array at Awarua, near Invercargill, New Zealand .

Unwin is part of the Super Dual Auroral Radar Network (SuperDARN), an international radar network for studying the upper atmosphere and ionosphere that operates in the High Frequency (HF) bands between 8 and 22 MHz.

The radar and associated research provides greater understanding of atmospheric weather, to assist with weather prediction, prediction of telecommunication interference and provide a better understanding of the effects of atmospheric magnetic fields on power grid management.[1]

The facility is operated by La Trobe University and was named after Bob Unwin, a pioneer in auroral radar research,[2] who first proposed the concept behind the project in the 1960s[1]

Operation

Bursts of short-wave radio pulses are transmitted from the radar in a southern arc that includes the South Magnetic Pole. The ensuing reflections from micro-meteorites, the ionosphere, ocean and aurora are detected at the station and resolved there.

The TIGER-Unwin is a monostatic, pulsed radar that operates in the 8 MHz - 20 MHz range. The transmitting antenna consists of an array of 16 log periodic antennas.

  • These antennas form a narrow beam ~4 degrees (at 12 MHz) that is swept across the radar footprint in 16 steps (one step per antenna array).
  • In the vertical direction the beam is ~30 degrees with a maximum in the range of 15 degrees (at 20 MHz) to 35 degrees (at 8 MHz).

An additional four antennas placed some distance behind the transmitting array. These antennas are used to form an interferometer receiving array that measures the elevation angle of echoes. In the standard operation mode the radar uses frequency hopping where the transmission frequency changes to accommodate changing ionospheric conditions. This frequency hopping is done by ongoing scanning the frequency band to determine automatically which channels are free of interference and provide the best coverage.

The data from Unwin is transmitted back to La Trobe University where it is made available over the Internet to users. The Unwin Radar and its counterpart at Bruny Island in Tasmania form the Tasman International Geospace Environment Radar (TIGER).[1]

The Southland region is regarded as an ideal location for such a facility because of the southerly aspect, low radio noise and unobstructed horizon.[1]

References

  1. ^ a b c d Unwin Radar on Venture Southland website, retrieved 2011-04-12
  2. ^ G.J. Fraser The antecedents and subsequent development of scientific radar in New Zealand in Journal of Atmospheric and Solar-Terrestrial Physics, Volume 67, Issue 15, October 2005, Pages 1411-1418



This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.