{"id":3137,"date":"2020-07-04T16:34:46","date_gmt":"2020-07-04T20:34:46","guid":{"rendered":"http:\/\/www.apex-telescope.org\/ns\/?page_id=3137"},"modified":"2024-06-19T17:45:46","modified_gmt":"2024-06-19T21:45:46","slug":"former-spectrometers","status":"publish","type":"page","link":"https:\/\/www.apex-telescope.org\/ns\/observing\/the-telescope\/instruments\/former-spectrometers\/","title":{"rendered":"Former spectrometers"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">XFFTS<\/h2>\n\n\n\n<p>The RPG eXtended bandwidth Fast Fourier Transform Spectrometer (XFFTS) was optimised for a wide range of radio astronomical applications. The digitiser and analyser boards made use of the latest versions of GHz analogue-to-digital converters (ADC) and the most complex field programmable gate array (FPGA) chips commercially available at the time. <\/p>\n\n\n\n<p>These state-of-the-art chips made it possible to build a digital spectrometer with instantaneous bandwidth of 2.5 GHz and 32768 (32K) spectral channels. The APEX facility XFFTS consisted of two units which had a fixed overlap region of 1.0 GHz, hence covering the entire IF bandwidth of <a href=\"http:\/\/www.apex-telescope.org\/ns\/instruments\/shefi\/\">SHeFI<\/a>. The number of spectral channels was fixed at 32768 channels.<\/p>\n\n\n\n<p>For more information you can check the spectrometer paper: <\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>High-resolution wide-band fast Fourier transform spectrometers<\/p><cite>B. Klein, S. Hochg\u00fcrtel, I. Kr\u00e4mer, A. Bell, K. Meyer, R. G\u00fcsten, <a href=\"https:\/\/ui.adsabs.harvard.edu\/abs\/2012A%26A...542L...3K\/abstract\" target=\"_blank\" rel=\"noreferrer noopener\">Astronomy &amp; Astrophysics, Volume 542, id. L3,&nbsp;6&nbsp;pp.<\/a><br><\/cite><\/blockquote>\n\n\n\n<p>The XFFTS spectrometers were decommissioned in 2019, to be replaced by the <a href=\"http:\/\/www.apex-telescope.org\/ns\/instruments\/if-and-ffts-spectrometers\/\">more powerful and wider bandwidth dFFTS4G units<\/a>, currently in place.<\/p>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">FFTS <\/h2>\n\n\n\n<p>The facility Fast Fourier Transform Spectrometer consisted of two units with a bandwidth of 1 GHz each. Both units were configurable to provide up to 8192 spectral channels, thus providing a spectral resolution of up to 122 kHz. The two units could be connected to one receiver each, or the two units could be configured to produce a single backend&nbsp;with almost 2 GHz bandwidth. The placement of each unit is restricted by the IF range of the receiver.<\/p>\n\n\n<div class='w3eden'><!-- WPDM Link Template: Call to Action 3 -->\n\n<div class=\"well c2a3\">\n    <div class=\"media\">\n        <div class=\"mr-3\" align=\"left\">\n            <img decoding=\"async\" class=\"wpdm_icon\" alt=\"Icon\"   src=\"http:\/\/www.apex-telescope.org\/ns\/wp-content\/plugins\/download-manager\/assets\/file-type-icons\/pdf.svg\" \/>\n        <\/div>\n        <div class=\"media-body\">\n            <h3 class=\"media-heading\" style=\"padding-top: 0px;border:0px;margin: 0 0 5px 0;font-size:12pt;\">\n                <a style=\"font-weight: 700\" href=\"https:\/\/www.apex-telescope.org\/ns\/download\/ffts-fact-sheet\/\">FFTS fact sheet<\/a>\n                <span style=\"font-size:8pt;font-weight:300\" class=\"text-muted ml-4\">\n                    <i class=\"fas fa-hdd mr-1\"><\/i> 693.81 KB\n                    <i class=\"ml-3 far fa-arrow-alt-circle-down mr-1\"><\/i> 160 downloads\n                <\/span>\n            <\/h3>\n            by B. Klein (14-07-2015)\n...\n        <\/div>\n        <div class=\"ml-3\" align=\"right\">\n            <a class='wpdm-download-link download-on-click btn btn-primary btn-sm' rel='nofollow' href='#' data-downloadurl=\"https:\/\/www.apex-telescope.org\/ns\/download\/ffts-fact-sheet\/?wpdmdl=3144&refresh=6a05bf01ca2721778761473\">Download<\/a>\n        <\/div>\n    <\/div>\n\n<\/div>\n<style>\n    .well.c2a3 .btn {\n        padding: 11px 30px;\n        font-size: 11pt;\n    }\n\n    .well.c2a3 .media-body {\n        font-size: 11pt;\n    }\n\n    .well.c2a3 .wpdm_icon {\n        height: 42px;\n        width: auto;\n    }<\/style>\n<\/div>\n\n\n\n<p>The FFTS units were decommissioned in July 2011, to be replaced by the more powerful and higher bandwidth XFFTS units.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>XFFTS The RPG eXtended bandwidth Fast Fourier Transform Spectrometer (XFFTS) was optimised for a wide range of radio astronomical applications. The digitiser and analyser boards made use of the latest versions of GHz analogue-to-digital converters (ADC) and the most complex <a href=\"https:\/\/www.apex-telescope.org\/ns\/observing\/the-telescope\/instruments\/former-spectrometers\/\" class=\"read-more\">Read More &#8230;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":10,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"ngg_post_thumbnail":0,"spay_email":"","footnotes":""},"class_list":["post-3137","page","type-page","status-publish","hentry"],"featured_image_urls":{"full":"","thumbnail":"","medium":"","medium_large":"","large":"","1536x1536":"","2048x2048":"","education-hub-thumb":""},"post_excerpt_stackable":"<p>XFFTS The RPG eXtended bandwidth Fast Fourier Transform Spectrometer (XFFTS) was optimised for a wide range of radio astronomical applications. The digitiser and analyser boards made use of the latest versions of GHz analogue-to-digital converters (ADC) and the most complex field programmable gate array (FPGA) chips commercially available at the time. These state-of-the-art chips made it possible to build a digital spectrometer with instantaneous bandwidth of 2.5 GHz and 32768 (32K) spectral channels. The APEX facility XFFTS consisted of two units which had a fixed overlap region of 1.0 GHz, hence covering the entire IF bandwidth of SHeFI. The number&hellip;<\/p>\n","category_list":"","author_info":{"name":"apex","url":"https:\/\/www.apex-telescope.org\/ns\/author\/apex\/"},"comments_num":"0 comments","featured_image_urls_v2":{"full":"","thumbnail":"","medium":"","medium_large":"","large":"","1536x1536":"","2048x2048":"","education-hub-thumb":""},"post_excerpt_stackable_v2":"<p>XFFTS The RPG eXtended bandwidth Fast Fourier Transform Spectrometer (XFFTS) was optimised for a wide range of radio astronomical applications. The digitiser and analyser boards made use of the latest versions of GHz analogue-to-digital converters (ADC) and the most complex field programmable gate array (FPGA) chips commercially available at the time. These state-of-the-art chips made it possible to build a digital spectrometer with instantaneous bandwidth of 2.5 GHz and 32768 (32K) spectral channels. The APEX facility XFFTS consisted of two units which had a fixed overlap region of 1.0 GHz, hence covering the entire IF bandwidth of SHeFI. The number&hellip;<\/p>\n","category_list_v2":"","author_info_v2":{"name":"apex","url":"https:\/\/www.apex-telescope.org\/ns\/author\/apex\/"},"comments_num_v2":"0 comments","_links":{"self":[{"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/pages\/3137","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/comments?post=3137"}],"version-history":[{"count":7,"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/pages\/3137\/revisions"}],"predecessor-version":[{"id":3153,"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/pages\/3137\/revisions\/3153"}],"up":[{"embeddable":true,"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/pages\/10"}],"wp:attachment":[{"href":"https:\/\/www.apex-telescope.org\/ns\/wp-json\/wp\/v2\/media?parent=3137"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}