{"id":268,"date":"2011-10-01T06:31:18","date_gmt":"2011-10-01T06:31:18","guid":{"rendered":"http:\/\/ahay.org\/blog\/?p=268"},"modified":"2015-08-04T23:51:36","modified_gmt":"2015-08-04T23:51:36","slug":"program-of-the-month-sfagc","status":"publish","type":"post","link":"https:\/\/ahay.org\/blog\/2011\/10\/01\/program-of-the-month-sfagc\/","title":{"rendered":"Program of the month: sfagc"},"content":{"rendered":"<p><a href=\"\/RSF\/sfagc.html\">sfagc<\/a> implements <em>Automatic Gain Control<\/em>, a popular technique for normalizing signal amplitudes.<br \/>\nThe algorithm is simple: divide the signal by its smoothed absolute value. The smoothing is controlled by <strong>rect#=<\/strong> and <strong>repeat=<\/strong> parameters, similar to the ones used by <a href=\"\/RSF\/sfsmooth.html\">sfsmooth<\/a>.<br \/>\nThe following example from <a href=\"\/RSF\/book\/rsf\/rsf\/sfagc.html\">rsf\/rsf\/sfagc<\/a> illustrates the application of <strong>sfagc<\/strong> in comparison with the application of <strong>sfpow<\/strong>, which applies a gain based on a power of time. The gains are applied to a shot gather from Alaska from the collection of shot gathers by Yilmaz and Cumro. A similar example appears on page 236 in Jon Claerbout&#8217;s <a href=\"http:\/\/sepwww.stanford.edu\/sep\/prof\/iei2\/40_04.pdf\">Imaging the Earth&#8217;s Interior<\/a>.<br \/>\n<img decoding=\"async\" src=\"\/RSF\/book\/rsf\/rsf\/sfagc\/Fig\/arctic.png\" wiidth=\"463\" height=\"316\" alt=\"\" \/><br \/>\nFor a more accurate algorithm, try <a href=\"\/RSF\/sfshapeagc.html\">sfshapeagc<\/a>, which computes the gain function using <a href=\"\/RSF\/book\/jsg\/shape\/paper_html\/\">shaping regularization<\/a>.<br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"\/RSF\/book\/rsf\/rsf\/sfagc\/Fig\/agc.png\" width=\"449\" height=\"321\" alt=\"\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>sfagc implements Automatic Gain Control, a popular technique for normalizing signal amplitudes. The algorithm is simple: divide the signal by its smoothed absolute value. The smoothing is controlled by rect#= and repeat= parameters, similar to the ones used by sfsmooth. The following example from rsf\/rsf\/sfagc illustrates the application of sfagc in comparison with the application [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","activitypub_content_warning":"","activitypub_content_visibility":"","activitypub_max_image_attachments":4,"activitypub_interaction_policy_quote":"anyone","activitypub_status":"","footnotes":""},"categories":[3],"tags":[],"class_list":["post-268","post","type-post","status-publish","format-standard","hentry","category-programs"],"_links":{"self":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/268","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/comments?post=268"}],"version-history":[{"count":1,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/268\/revisions"}],"predecessor-version":[{"id":647,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/268\/revisions\/647"}],"wp:attachment":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/media?parent=268"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/categories?post=268"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/tags?post=268"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}