查看“︁海洋干涉测量法”︁的源代码

'''海洋干涉测量法'''（{{lang-en|Sea interferometry}}），也称为'''海崖干涉测量法'''，是一种利用从[[海洋]][[反射 (物理学)|反射]]的[[无线电波]]产生[[干涉 (物理学)|干涉]]图案的[[射电天文学]]技术。<ref name="CSIRO">{{Cite web|date=2008-02-05|title=Radio Astronomy at Dover Heights: Sea interferometry|url=http://outreach.atnf.csiro.au/about/history/doverheights/#DoverInterferometry|access-date=2010-03-18|publisher=[[CSIRO]]|archive-date=2006-08-19|archive-url=https://web.archive.org/web/20060819125613/http://www.outreach.atnf.csiro.au/about/history/doverheights/#DoverInterferometry|dead-url=no}}</ref> 它是[[劳埃德镜]]的无线电波模拟。<ref name="BoltonSlee">{{Cite journal |last=Bolton |first=J. G. |author-link=John Gatenby Bolton |author2=Slee, O. B. |date=December 1953 |title=Galactic Radiation at Radio Frequencies V. The Sea Interferometer |journal=Australian Journal of Physics |volume=6 |issue=4 |pages=420–433 |bibcode=1953AuJPh...6..420B |doi=10.1071/PH530420 |doi-access=free}}</ref> 这项技术于1945年至1948年间在[[澳大利亚]]发明。<ref name="Sullivan">{{Cite conference |last=W. T. III |first=Sullivan |date=1991 |title=Some highlights of Interferometry in early Radio Astronomy |pages=132 |bibcode=1991ASPC...19..132S |book-title=Radio interferometry: Theory, techniques, and applications; Proceedings of the 131st IAU Colloquium, ASP Conference Series (ASP: San Francisco)}}<!--| accessdate = 2010-03-18--></ref>

== 过程 ==
[[File:Locating_galactic_radio-frequency_sources_using_Lloyd's_mirror.svg|alt=Locating galactic radio-frequency sources using Lloyd's mirror|frame|原理示意图]]
在悬崖上方放置一个接收[[天线]]<ref name="BoltonSlee" />接收从源直接传播的无线电波和从水面反射的无线电波。<ref name="CSIRO" /> 然后将两组波合并成一个干涉图案，就像由两个单独的天线产生的那样。<ref name="CSIRO" />反射的[[波阵面|波前]]在到达探测器之前会额外行进 <math>2h\sin(\alpha)</math> 距离，其中 <math>h</math> 为悬崖高度，<math>\alpha</math> 为入射波前的倾斜度（或[[高度角]]）。它充当了第二个天线，其高度是第一个悬崖下面的两倍。<ref name="GossMcGee">{{Cite book
  | last = Goss
  | first = W. M.
  |author2=McGee, Richard X.
  | title = Under the Radar: The First Woman in Radio Astronomy: Ruby Payne-Scott
  | publisher = Springer-Verlag
  | date = 2010
  | pages = 97–99
  | url = https://books.google.com/books?id=YyTZrE04ap0C&pg=PA97
  | doi = 10.1007/978-3-642-03141-0
  | isbn = 978-3-642-03141-0}}</ref>

海上干涉测量仪是「漂移仪器」，即它们固定，指向随着地球的旋转而改变。<ref name="Heywood">{{cite book
 | last = Heywood
 | first = John
 | title = Radio Astronomy and How to build your own Telescope
 | publisher = Arc Books inc
 | edition = 2nd
 | date = 1969
 | location = New York
 | pages = 90
}}</ref>其干涉模式在光源上升到地平线以上时就开始急剧变化，而非普通干涉测量仪那样逐渐减弱。<ref name="BoltonSlee"/>由于它只由一个探测器组成，因此不需要连接电缆或[[前置放大器]]。<ref name="GossMcGee" />海上干涉仪的灵敏度也是一对探测器在相同距离下的两倍。<ref name="GossMcGee" />这种仪器大大提高了仪器的[[角度分辨率]]。

== 参考文献 ==
{{Reflist}}

[[Category:射电天文学]]