{"id":3890,"date":"2016-11-17T17:48:08","date_gmt":"2016-11-18T00:48:08","guid":{"rendered":"http:\/\/blog.caida.org\/best_available_data\/?p=3890"},"modified":"2016-11-18T11:49:35","modified_gmt":"2016-11-18T18:49:35","slug":"geolocation-terminology-vantage-points-landmarks-and-targets","status":"publish","type":"post","link":"https:\/\/blog.caida.org\/best_available_data\/2016\/11\/17\/geolocation-terminology-vantage-points-landmarks-and-targets\/","title":{"rendered":"Geolocation Terminology: Vantage Points, Landmarks, and Targets"},"content":{"rendered":"<p>\nWhile reviewing a recent paper, it occurred to me there is a pretty serious nomenclature inconsistency across Internet measurement research papers that talk about geolocation. Specifically, the term <i>landmark<\/i> is not well-defined. Some literature uses the term <i>landmark<\/i> to refer to measurement infrastructure (e.g., nodes that source active measurements) in specific known geographic locations [<a href=\"http:\/\/www.caida.org\/publications\/bib\/networking\/entries\/Maziku2013EnhancingAccuracyIPGeolocation.xml\">Maziku2013<\/a>,<a href=\"http:\/\/itc.ktu.lt\/index.php\/ITC\/article\/view\/8353\">Komosny2015<\/a>].  In other literature the same term refers to locations with known Internet identifiers &#8212; such as IP addresses &#8212; against which one collects calibration measurements [<a href=\"http:\/\/www.caida.org\/publications\/bib\/networking\/entries\/Arif2010GeoWeightInternet.xml\">Arif2010<\/a>,<a href=\"http:\/\/www.caida.org\/publications\/bib\/networking\/entries\/Wang2011StreetLevelGeolocation.xml\">Wang2011<\/a>,<a href=\"http:\/\/www.caida.org\/publications\/bib\/networking\/entries\/Hu2012MillionsOfIPAddresses.xml\">Hu2012<\/a>,<a href=\"http:\/\/dl.acm.org\/citation.cfm?doid=2381056.2381058\">Eriksson2012<\/a>,<a href=\"http:\/\/ieeexplore.ieee.org\/abstract\/document\/7224839\">Chen2015<\/a>].\n<\/p>\n<p>\nIn pursuit of clarity in our field, we recommend the following terms and definitions:<\/p>\n<ul>\n<li> A <b>Vantage Point<\/b> (VP) is a measurement infrastructure node with a known geographic location.\n        <\/li>\n<li> A <b>Landmark<\/b> is a responsive Internet identifier with a known location to which the VP will launch a measurement that can serve to calibrate other measurements to potentially unknown geographic locations.\n        <\/li>\n<li> A <b>Target<\/b> is an Internet identifier whose location will be inferred from a given method.  Depending on the type of identifier and inference methodology, this may not be a single well defined location. Typically, some targets have known geographic locations (ground truth), which researchers can use to evaluate the accuracy of their geolocation methodology.\n        <\/li>\n<li> A <b>Location<\/b> is a geographic place that geolocation techniques attempt to infer for a given target.  Examples include cities and ISP Points of Presences (PoPs).\n        <\/li>\n<\/ul>\n<p> Not all papers need to use all terms. Below we depict a simple constraint-based geolocation algorithm to show how we understand these terms in practice. <\/p>\n<div id=\"attachment_3935\" style=\"width: 497px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/blog.caida.org\/best_available_data\/wp-content\/uploads\/2016\/11\/geo-constraints.png\"><img aria-describedby=\"caption-attachment-3935\" loading=\"lazy\" src=\"http:\/\/blog.caida.org\/best_available_data\/wp-content\/uploads\/2016\/11\/geo-constraints.png\" alt=\"A simple constraint-based geolocation algorithm. \" width=\"487\" height=\"550\" class=\"size-full wp-image-3935\" srcset=\"https:\/\/blog.caida.org\/best_available_data\/wp-content\/uploads\/2016\/11\/geo-constraints.png 487w, https:\/\/blog.caida.org\/best_available_data\/wp-content\/uploads\/2016\/11\/geo-constraints-266x300.png 266w\" sizes=\"(max-width: 487px) 100vw, 487px\" \/><\/a><p id=\"caption-attachment-3935\" class=\"wp-caption-text\">A simple constraint-based geolocation algorithm.<br \/><\/p><\/div>\n<p>[Potential useful resource, although not actively maintained: CAIDA&#8217;s <a href=\"http:\/\/www.caida.org\/projects\/cybersecurity\/geolocation\/bib\/\">Geolocation Bibliography<\/a>]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>While reviewing a recent paper, it occurred to me there is a pretty serious nomenclature inconsistency across Internet measurement research papers that talk about geolocation. Specifically, the term landmark is not well-defined. Some literature uses the term landmark to refer to measurement infrastructure (e.g., nodes that source active measurements) in specific known geographic locations [Maziku2013,Komosny2015]. [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1,50],"tags":[],"coauthors":[27],"_links":{"self":[{"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/posts\/3890"}],"collection":[{"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/comments?post=3890"}],"version-history":[{"count":34,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/posts\/3890\/revisions"}],"predecessor-version":[{"id":3937,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/posts\/3890\/revisions\/3937"}],"wp:attachment":[{"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/media?parent=3890"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/categories?post=3890"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/tags?post=3890"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/blog.caida.org\/best_available_data\/wp-json\/wp\/v2\/coauthors?post=3890"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}