{"id":218,"date":"2021-01-22T17:32:41","date_gmt":"2021-01-22T17:32:41","guid":{"rendered":"https:\/\/noisetools.net\/users\/?page_id=218"},"modified":"2026-06-30T14:11:31","modified_gmt":"2026-06-30T13:11:31","slug":"changelog","status":"publish","type":"page","link":"https:\/\/noisetools.net\/users\/changelog\/","title":{"rendered":"Changes (changelog)"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">Version 1.8<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>New general calculation method: CNOSSOS-EU<\/li>\n\n\n\n<li>Roads <em><sub>(subscription only)<\/sub><\/em>\n<ul class=\"wp-block-list\">\n<li>Road prediction method: CNOSSOS-EU<\/li>\n\n\n\n<li>Road prediction method: CRTN-88<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Zones (ground factor, foliage, industry) <em><sub>(subscription only)<\/sub><\/em><\/li>\n\n\n\n<li>Ground factor for roof surfaces<\/li>\n\n\n\n<li>\u201cBroadband\u201d sound level option<\/li>\n\n\n\n<li>Receiver spectrum style<\/li>\n\n\n\n<li>Contour labels<\/li>\n\n\n\n<li>Improved Coordinates window<\/li>\n\n\n\n<li>New options for ground height screening, lateral paths, accessory lines for measurements.<\/li>\n\n\n\n<li>Improvements to cross section view<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">Some key differences between ISO9613-2 and CNOSSOS-EU:<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Meteorological conditions:\u00a0<\/strong>\n<ul class=\"wp-block-list\">\n<li>ISO9613-2 is intended for moderate downwind conditions (from source-to-receiver).\u00a0\u00a0<\/li>\n\n\n\n<li>CNOSSOS-EU separates neutral &#8220;homogeneous&#8221; and downwind &#8220;favourable&#8221; conditions with the ability to specify the percentage ratio of the two, intended for averaging over long periods.\u00a0\u00a0<\/li>\n\n\n\n<li>Favourable conditions have\u00a0<strong>curved sound rays<\/strong>, which can result in different diffracting edges and reflected paths. These curved sound rays can be viewed with the ray receiver.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Ground and building mass along the path:\u00a0\u00a0<\/strong>\n<ul class=\"wp-block-list\">\n<li>CNOSSOS-EU considers the ground shape and any buildings along the path in order to determine a &#8220;mean ground plane&#8221; that is used in the calculation for both ground effects and diffraction.\u00a0\u00a0<\/li>\n\n\n\n<li>ISO9613-2 only considers the potential diffraction upon the edges of peaks of ground\/buildings, otherwise ground shape does not affect the result.\u00a0\u00a0<\/li>\n\n\n\n<li>The need to calculate the ground terrain along the path is one of the main reasons why CNOSSOS is slower to calculate.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Lateral paths:\u00a0<\/strong>\n<ul class=\"wp-block-list\">\n<li>ISO9613-2 combines the two possible lateral paths into the barrier attenuation result for the path over the top edge, giving a single level. Note: This is now the displayed behaviour in the ray receiver results table.<\/li>\n\n\n\n<li>CNOSSOS-EU calculates the lateral paths as separate levels with their own ground effects and air absorption values along these lateral paths.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Reflection surface size:\u00a0<\/strong>\n<ul class=\"wp-block-list\">\n<li>A reflecting surface is compared to the wavelength of the sound wave in ISO9613-2, however this is not the case with CNOSSOS-EU, which has a standard condition of a minimum height and width of 0.5m.\u00a0 Due to this, smaller reflecting surfaces can create huge differences in calculated level between the two methods.\u00a0\u00a0<\/li>\n\n\n\n<li>This check can be toggled in the sidebar with the &#8220;Reflector surface size check&#8221; checkbox.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Retrodiffraction:\u00a0<\/strong>\n<ul class=\"wp-block-list\">\n<li>CNOSSOS-EU adds a new attenuation to reflected paths called retro-diffraction.\u00a0 This is not found in ISO9613-2.<\/li>\n\n\n\n<li>This phenomenon is best understood as being the complement of the diffraction that occurs at the top edge.\u00a0 It is the loss of energy at the upper edge of the reflecting surface due to it having diffracted around it.\u00a0 Therefore, the sound level of a reflected path will decrease as you approach the top of the barrier.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Air absorption and distance attenuation are the same in both methods.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.7<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Alternative storage option &#8211; complex models saved in &#8220;Local&#8221; browser site data <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>New .dbmap backup file format <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Reflection\/Absorption Coefficient &#8220;Spectrum&#8221; option<\/li>\n\n\n\n<li>Baseline level <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Transform multiple objects <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Advanced node editing with the Shift key (add, delete, snap to)<\/li>\n\n\n\n<li>Pin a Snapshot <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Images \/ Google Maps displayed in the 3D View <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Better mobile\/touch support including two finger pan and pinch-to-zoom.<\/li>\n\n\n\n<li>Grid values &#8220;dot&#8221; option<\/li>\n\n\n\n<li>Unwanted alerts can now be silenced by clicking the icon<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.6<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">Guidance update (ISO9613-2:2024)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">An update to the International Standard (ISO) for outdoor sound propagation, originally released in 1996, was recently published and dBmap.net v1.6 introduces the necessary changes from this guidance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Some key points to consider:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The <strong>reflection coefficient<\/strong> estimates have been replaced with a recommended default value of 0.9 for building facades and surfaces of industrial facilities of unknown absorption.<\/li>\n\n\n\n<li>The <strong>barrier attenuation<\/strong> method has changes that are described as <em>&#8220;to eliminate well known shortcomings with low barriers and large source-to-receiver distances&#8221;.&nbsp; <\/em><\/li>\n\n\n\n<li>The <strong>ground effect<\/strong> method has a modification that reduces the level of ground absorption (or reflection) over short distances.&nbsp;<\/li>\n\n\n\n<li>The <strong>reflection <\/strong>method, specifically where a surface is determined as sufficient in size to be reflecting, has a small clarification that may result in more reflections being included compared to past models.&nbsp; This feature can be found in the Global Settings sidebar as the &#8220;ISO reflector surface size check&#8221; option.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Due to the changes made with this update you may find some differences in the results of your calculated levels compared to older models. Please <a href=\"https:\/\/dbmap.local\/users\/support\/\" data-type=\"page\" data-id=\"61\">get in touch<\/a> for more information about these changes or if you wish to modify an existing Snapshot or Short URL to use an older version of the tool.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>Other new features and improvements:<\/strong><\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Area sources and surface sources on buildings <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>JSON\/GeoJSON file support added to Export and Import with full model configuration saved to file.  KML Import also added.<\/li>\n\n\n\n<li>&#8220;Duplicate object&#8221; button added.<\/li>\n\n\n\n<li>Toggle A-weighting in receiver tables.<\/li>\n\n\n\n<li>Button to swap an existing (or missing) image for another.<\/li>\n\n\n\n<li>Drag-and-drop to re-order coordinates.<\/li>\n\n\n\n<li>Bookmarks<strong> <\/strong>now include the current 3D view (when active)<\/li>\n\n\n\n<li>More Keyboard shortcuts have been added.&nbsp; <a href=\"https:\/\/noisetools.net\/users\/keyboard-shortcuts\">These are listed here<\/a>.<\/li>\n\n\n\n<li>The color scheme for <strong>France (NF S31-130) <\/strong>has been added.<\/li>\n\n\n\n<li><strong>Performance improvements:<\/strong>\n<ul class=\"wp-block-list\">\n<li>New ground height triangulation method is much faster when there are many ground heights.<\/li>\n\n\n\n<li>New reflections pre-calculation method has had a significant improvement in calculation speed, especially when there are many sources and many reflecting surfaces.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.5<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Compare two scenarios <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Objects window<\/li>\n\n\n\n<li>Ray-receiver breakdown<\/li>\n\n\n\n<li>Export to KML file<\/li>\n\n\n\n<li>Improved accessory lines styling<\/li>\n\n\n\n<li>Styled contour lines<\/li>\n\n\n\n<li>Language support<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.4<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ground height lines <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Building roof options<\/li>\n\n\n\n<li>Barriers slope with ground level <sub><em>(subscription only)<\/em><\/sub><\/li>\n\n\n\n<li>Multi-heights<\/li>\n\n\n\n<li>New PDF Report chart styles <sub>(<em>subscription only<\/em>)<\/sub><\/li>\n\n\n\n<li>New bitmap sizing handle<\/li>\n\n\n\n<li>An extract of BS5228 sound power levels added<\/li>\n\n\n\n<li>White receiver dots and &#8220;label off&#8221; option<\/li>\n\n\n\n<li>DXF output now includes dB contours<\/li>\n\n\n\n<li>Improved calculation method<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.3<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Receiver design option &#8220;Dot&#8221;<\/li>\n\n\n\n<li>Export PDF Report <sub>(<em>subscription only<\/em>)<\/sub><\/li>\n\n\n\n<li>Bookmark viewpoints <sub>(<em>subscription only<\/em>)<\/sub><\/li>\n\n\n\n<li>Decimal precision option<\/li>\n\n\n\n<li>ISO17534 lateral path recommendation option<\/li>\n\n\n\n<li>Compressed URL<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.2<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Cross Section snap to a building facade <sub>(<em>subscription only<\/em>)<\/sub><\/li>\n\n\n\n<li>Sound level adjustment by +dB or &#8220;% on time&#8221;<\/li>\n\n\n\n<li>Receiver &#8220;match grid height&#8221; option<\/li>\n\n\n\n<li>Line source reflections added <sub>(<em>subscription only<\/em>)<\/sub><\/li>\n\n\n\n<li>Floating &#8220;add objects&#8221; toolbar<\/li>\n\n\n\n<li>Improved DXF export and import<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.1<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Save images to user account <sub>(<em>subscription only<\/em>)<\/sub><\/li>\n\n\n\n<li>Manual adjustment of (x, y) coordinates.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 1.0<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>New subscription-only features added:\n<ul class=\"wp-block-list\">\n<li>Line sources<\/li>\n\n\n\n<li>Cross section mode<\/li>\n\n\n\n<li>Ground levels and ground heights mode <\/li>\n\n\n\n<li>3D view<\/li>\n\n\n\n<li>Snapshots feature &#8211; shortens URL and saves a thumbnail to user account.<\/li>\n\n\n\n<li>Colour schemes saved to user account<\/li>\n\n\n\n<li>Source levels saved to user account<\/li>\n\n\n\n<li>Multi-threading (faster calculations)<\/li>\n\n\n\n<li>Custom grid text linked to user account<\/li>\n\n\n\n<li>Light theme option<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Improved reflections method allows for screening along the entire path.<\/li>\n\n\n\n<li>New vertical edge path finder. Finds up to two paths within the horizontal plane inclined along the source-to-receiver direct line.\n<ul class=\"wp-block-list\">\n<li>Convex only path option added<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>New direct path option includes all barriers with top-edge diffraction as recommended in ISO 17534-3<\/li>\n\n\n\n<li>Ground reflections options as recommended in ISO 17534-3<\/li>\n\n\n\n<li>Google Static Maps improved with preview and edit zoom added<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Version 0.5<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Initial 2015 release<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-right wp-block-paragraph\"><em>Updated June 2026<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Version 1.8 Some key differences between ISO9613-2 and CNOSSOS-EU: Version 1.7 Version 1.6 Guidance update (ISO9613-2:2024) An update to the International Standard (ISO) for outdoor sound propagation, originally released in 1996, was recently published and dBmap.net v1.6 introduces the necessary changes from this guidance. Some key points to consider: Due to the changes made with <a href=\"https:\/\/noisetools.net\/users\/changelog\/\" class=\"more-link\">&#8230;<span class=\"screen-reader-text\">  Changes (changelog)<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"pmpro_default_level":"","inline_featured_image":false,"footnotes":""},"class_list":["post-218","page","type-page","status-publish","hentry","pmpro-has-access"],"lang":"en","translations":{"en":218},"pll_sync_post":{},"_links":{"self":[{"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/pages\/218","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/comments?post=218"}],"version-history":[{"count":27,"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/pages\/218\/revisions"}],"predecessor-version":[{"id":1169,"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/pages\/218\/revisions\/1169"}],"wp:attachment":[{"href":"https:\/\/noisetools.net\/users\/wp-json\/wp\/v2\/media?parent=218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}