{"id":608,"date":"2020-06-11T10:42:30","date_gmt":"2020-06-11T10:42:30","guid":{"rendered":"https:\/\/beta.research.ece.ncsu.edu\/osl\/?p=608"},"modified":"2020-06-11T10:42:30","modified_gmt":"2020-06-11T10:42:30","slug":"dual-beam-cross-correlation-spectrometer-for-radial-velocity-measurements","status":"publish","type":"post","link":"https:\/\/research.ece.ncsu.edu\/osl\/2020\/06\/11\/dual-beam-cross-correlation-spectrometer-for-radial-velocity-measurements\/","title":{"rendered":"Dual-beam cross-correlation   spectrometer for radial   velocity measurements"},"content":{"rendered":"<p>Abstract: Measuring the radial velocity of an object can be achieved by quantifying the Doppler shift of Fraunhofer lines. Measurements are typically made using high-resolution conventional spectroscopy, in which the Doppler shift is calculated numerically on a computer. An alternative technique includes cross-correlation spectroscopy, which performs an optical correlation of the incident spectrum against a reference spectrum embedded in the instrument. Many existing correlation spectrometers leverage a chrome mask and obtain a single beam measurement, making the sensors more sensitive to atmospheric turbulence without moving parts. In this paper, we present a static dual-beam polarization-based technique for acquiring cross-correlation spectra that is insensitive to atmospheric turbulence and contains no moving parts. The instrument is based on acquiring light both inside and outside of the solar Fraunhofer lines using a twisted nematic liquid-crystal spatial light modulator. Correlation spectra can be calculated as a ratio of these two components. A model of the dual-beam cross-correlation spectrometer is presented and subsequently validated with experimental observations of Venus. Radial velocity accuracies, as calculated against reference ephemerides, yielded an absolute error less than 0.24%.<\/p>\n<div class=\"csl-bib-body\">\n<div class=\"csl-entry\">\n<div class=\"csl-right-inline\">M. W. Kudenov and B. Pantalone, &#8220;Dual-beam cross-correlation spectrometer for radial velocity measurements,&#8221; Appl. Opt., AO <b>58<\/b>(33), 9310\u20139317 (2019).<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Abstract: Measuring the radial velocity of an object can be achieved by quantifying the Doppler shift of Fraunhofer lines. Measurements are typically made using high-resolution&#8230;<\/p>\n","protected":false},"author":103,"featured_media":609,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[6],"tags":[],"class_list":["post-608","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research-papers"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/posts\/608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/users\/103"}],"replies":[{"embeddable":true,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/comments?post=608"}],"version-history":[{"count":1,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/posts\/608\/revisions"}],"predecessor-version":[{"id":610,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/posts\/608\/revisions\/610"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/media\/609"}],"wp:attachment":[{"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/media?parent=608"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/categories?post=608"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/research.ece.ncsu.edu\/osl\/wp-json\/wp\/v2\/tags?post=608"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}