Editing HIPAS Observatory (section)

{{Short description|Research facility}}
[[File:HIPAS Observatory April 2010 11.jpg|thumb|right|Electrical applications in the observatory shortly after closure]]
[[File:HIPAS Observatory April 2010 14.jpg|thumb|right|Interior, shortly after closure]]
The '''HIPAS''' ('''HIgh Power Auroral Stimulation''') '''Observatory''' was a research facility, built to study the [[ionosphere]] and its influence on [[radio]] communications. It was located 25 miles east of [[Fairbanks]], [[Alaska]] in the [[Fairbanks North Star Borough, Alaska|Fairbanks North Star Borough]] area.<ref>{{cite web |url=http://www.hipas.alaska.edu/ |title=Home Page |website=www.hipas.alaska.edu |access-date=13 January 2022 |archive-url=https://web.archive.org/web/20040606154036/http://www.hipas.alaska.edu/ |archive-date=6 June 2004 |url-status=dead}}</ref>

It was operated by the [[UCLA]] [[plasma physics]] laboratory from 1986 through 2007. A unique capability at that time, it could radiate 70 MW [[Effective radiated power|ERP]] at either 2.85&nbsp;MHz or 4.53&nbsp;MHz. These frequencies are close to a multiple of 2 and 3 of the electron gyro-frequency at ionospheric altitudes. Sending a pulse of HF-radio waves upward could accelerate the electrons in the ionosphere. Somewhat like waves on the ocean, the character of the ionosphere could be inferred from the [[backscatter]] signal. Other experiments attempted to combine RF and visible excitation where the latter probed metal ions such as [[sodium]].

The HIPAS facility also used a [[Lidar|LIDAR]] (LIght Detection And Ranging) instrument. Other projects included:
* A [[plasma torch]], used for experiments in [[hazardous waste]] disposal
* A 2.8-meter [[liquid-mirror telescope]], which uses a spinning bowl of [[Mercury (element)|mercury]] to form the mirror, used for [[laser]] experiments.
* An array of [[Antenna (electronics)|antennae]], which are used for exciting the ionosphere.

The [[High Frequency Active Auroral Research Program]] (HAARP) is a similar facility funded jointly by the [[US Air Force]] and [[US Navy]].

The HIPAS facility was shut down and much of the equipment sold as surplus in the Spring of 2010.<ref>{{Cite web|url=http://philosophyofscienceportal.blogspot.com/2009/12/hipas-observatory-closed.html|title=Philosophy of Science Portal: HIPAS Observatory closed|date=December 14, 2009}}</ref><ref>{{Cite web|url=http://www.newsminer.com/view/full_story/6804742/article-HIPAS-Observatory-auction-a-treasure-trove-of-technology-throwbacks--quirky-equipment-|archive-url=https://web.archive.org/web/20120409060308/http://www.newsminer.com/view/full_story/6804742/article-HIPAS-Observatory-auction-a-treasure-trove-of-technology-throwbacks--quirky-equipment-|url-status=dead|archive-date=April 9, 2012|title=Fairbanks Daily News-Miner - HIPAS Observatory auction a treasure trove of technology throwbacks quirky equipment|date=April 9, 2012}}</ref>