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div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For the documentary, see <a href="/wiki/The_Ground_Truth" title="The Ground Truth">The Ground Truth</a>.</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 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.ambox{display:none!important}}</style><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Ground_truth" title="Special:EditPage/Ground truth">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Ground+truth%22">"Ground truth"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Ground+truth%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Ground+truth%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Ground+truth%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Ground+truth%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Ground+truth%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">June 2015</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p><b>Ground truth</b> is information that is known to be real or true, provided by direct observation and measurement (i.e. <a href="/wiki/Empirical_evidence" title="Empirical evidence">empirical evidence</a>) as opposed to information provided by <a href="/wiki/Inference" title="Inference">inference</a>. </p> <div id="toc" class="toc" role="navigation" aria-labelledby="mw-toc-heading"><input type="checkbox" role="button" id="toctogglecheckbox" class="toctogglecheckbox" style="display:none"><div class="toctitle" lang="en" dir="ltr"><h2 id="mw-toc-heading">Contents</h2><span class="toctogglespan"><label class="toctogglelabel" for="toctogglecheckbox"></label></span></div> <ul> <li class="toclevel-1 tocsection-1"><a href="#Etymology"><span class="tocnumber">1</span> <span class="toctext">Etymology</span></a></li> <li class="toclevel-1 tocsection-2"><a href="#Statistics_and_machine_learning"><span class="tocnumber">2</span> <span class="toctext">Statistics and machine learning</span></a></li> <li class="toclevel-1 tocsection-3"><a href="#Remote_sensing"><span class="tocnumber">3</span> <span class="toctext">Remote sensing</span></a> <ul> <li class="toclevel-2 tocsection-4"><a href="#Errors_of_commission"><span class="tocnumber">3.1</span> <span class="toctext">Errors of commission</span></a></li> <li class="toclevel-2 tocsection-5"><a href="#Errors_of_omission"><span class="tocnumber">3.2</span> <span class="toctext">Errors of omission</span></a></li> </ul> </li> <li class="toclevel-1 tocsection-6"><a href="#Geographical_information_systems"><span class="tocnumber">4</span> <span class="toctext">Geographical information systems</span></a></li> <li class="toclevel-1 tocsection-7"><a href="#Military_usage"><span class="tocnumber">5</span> <span class="toctext">Military usage</span></a></li> <li class="toclevel-1 tocsection-8"><a href="#See_also"><span class="tocnumber">6</span> <span class="toctext">See also</span></a></li> <li class="toclevel-1 tocsection-9"><a href="#References"><span class="tocnumber">7</span> <span class="toctext">References</span></a></li> <li class="toclevel-1 tocsection-10"><a href="#External_links"><span class="tocnumber">8</span> <span class="toctext">External links</span></a></li> </ul> </div> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(1)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="Etymology">Etymology</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=1" title="Edit section: Etymology" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-1 collapsible-block" id="mf-section-1"> <p>The <i><a href="/wiki/Oxford_English_Dictionary" title="Oxford English Dictionary">Oxford English Dictionary</a></i> (s.v. <i>ground truth</i>) records the use of the word <i>Groundtruth</i> in the sense of 'fundamental truth' from Henry Ellison's poem "The Siberian Exile's Tale", published in 1833.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(2)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="Statistics_and_machine_learning">Statistics and machine learning</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=2" title="Edit section: Statistics and machine learning" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-2 collapsible-block" id="mf-section-2"> <p>"Ground truth" may be seen as a conceptual term relative to the knowledge of the truth concerning a specific question. It is the ideal expected result.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> This is used in <a href="/wiki/Statistical_model" title="Statistical model">statistical models</a> to prove or disprove <a href="/wiki/Research" title="Research">research</a> <a href="/wiki/Hypothesis" title="Hypothesis">hypotheses</a>. The term "ground truthing" refers to the process of gathering the proper <a href="/wiki/Objectivity_(philosophy)" class="mw-redirect" title="Objectivity (philosophy)">objective</a> (provable) data for this test. Compare with <a href="/wiki/Gold_standard_(test)" title="Gold standard (test)">gold standard</a>. For example, suppose we are testing a <a href="/wiki/Computer_stereo_vision" title="Computer stereo vision">stereo vision</a> system to see how well it can estimate 3D positions. The "ground truth" might be the positions given by a laser rangefinder which is known to be much more accurate than the camera system. </p><p><a href="/wiki/Bayesian_spam_filtering" class="mw-redirect" title="Bayesian spam filtering">Bayesian spam filtering</a> is a common example of supervised learning. In this system, the algorithm is manually taught the differences between spam and non-spam. This depends on the <i>ground truth</i> of the messages used to train the algorithm – inaccuracies in the ground truth will correlate to inaccuracies in the resulting spam/non-spam verdicts. </p> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(3)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="Remote_sensing">Remote sensing</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=3" title="Edit section: Remote sensing" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-3 collapsible-block" id="mf-section-3"> <p>In <a href="/wiki/Remote_sensing" title="Remote sensing">remote sensing</a>, "ground truth" refers to information collected at the imaged location. Ground truth allows image data to be related to real features and materials on the ground. The collection of ground truth data enables calibration of remote-sensing data, and aids in the interpretation and analysis of what is being sensed. Examples include <a href="/wiki/Cartography" title="Cartography">cartography</a>, <a href="/wiki/Meteorology" title="Meteorology">meteorology</a>, analysis of <a href="/wiki/Aerial_photography" title="Aerial photography">aerial photographs</a>, <a href="/wiki/Satellite_imagery" title="Satellite imagery">satellite imagery</a> and other techniques in which data are gathered at a distance. </p><p>More specifically, ground truth may refer to a process in which "<a href="/wiki/Pixel" title="Pixel">pixels</a>"<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> on a <a href="/wiki/Satellite" title="Satellite">satellite</a> image are compared to what is imaged (at the time of capture) in order to verify the contents of the "pixels" in the image (noting that the concept of "pixel" is imaging-system-dependent). In the case of a classified image, supervised classification can help to determine the accuracy of the classification by the remote sensing system which can minimize error in the classification. </p><p>Ground truth is usually done on site, correlating what is known with surface observations and measurements of various properties of the features of the ground resolution cells under study in the remotely sensed digital image. The process also involves taking geographic coordinates of the ground resolution cell with GPS technology and comparing those with the coordinates of the "pixel" being studied provided by the remote sensing software to understand and analyze the location errors and how it may affect a particular study. </p><p>Ground truth is important in the initial supervised classification of an image. When the identity and location of land cover types are known through a combination of field work, maps, and personal experience these areas are known as training sites. The spectral characteristics of these areas are used to train the remote sensing software using decision rules for classifying the rest of the image. These decision rules such as Maximum Likelihood Classification, Parallelopiped Classification, and Minimum Distance Classification offer different techniques to classify an image. Additional ground truth sites allow the remote sensor to establish an error matrix that validates the accuracy of the classification method used. Different classification methods may have different percentages of error for a given classification project. It is important that the remote sensor chooses a classification method that works best with the number of classifications used while providing the least amount of error. </p><p>Ground truth also helps with <a href="/wiki/Atmospheric_correction" title="Atmospheric correction">atmospheric correction</a>. Since images from satellites have to pass through the atmosphere, they can get distorted because of absorption in the atmosphere. So ground truth can help fully identify objects in satellite photos. </p> <div class="mw-heading mw-heading3"><h3 id="Errors_of_commission">Errors of commission</h3><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=4" title="Edit section: Errors of commission" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div> <p>An example of an error of commission is when a pixel reports the presence of a feature (such a tree) that, in reality, is absent (no tree is actually present). Ground truthing ensures that the error matrices have a higher accuracy percentage than would be the case if no pixels were ground-truthed. This value is the inverse of the user's accuracy, i.e. Commission Error = 1 - user's accuracy. </p> <div class="mw-heading mw-heading3"><h3 id="Errors_of_omission">Errors of omission</h3><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=5" title="Edit section: Errors of omission" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div> <p>An example of an error of omission is when pixels of a certain type, for example, maple trees, are not classified as maple trees. The process of ground-truthing helps to ensure that the pixel is classified correctly and the error matrices are more accurate. This value is the inverse of the producer's accuracy, i.e. Omission Error = 1 - producer's accuracy </p> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(4)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="Geographical_information_systems">Geographical information systems</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=6" title="Edit section: Geographical information systems" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-4 collapsible-block" id="mf-section-4"> <figure typeof="mw:File/Thumb"><a href="/wiki/File:GroundTruth_processModel01.png" class="mw-file-description"><noscript><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6c/GroundTruth_processModel01.png/420px-GroundTruth_processModel01.png" decoding="async" width="420" height="169" class="mw-file-element" data-file-width="548" data-file-height="220"></noscript><span class="lazy-image-placeholder" style="width: 420px;height: 169px;" data-src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6c/GroundTruth_processModel01.png/420px-GroundTruth_processModel01.png" data-width="420" data-height="169" data-srcset="//upload.wikimedia.org/wikipedia/commons/6/6c/GroundTruth_processModel01.png 1.5x" data-class="mw-file-element"> </span></a><figcaption>The <i>ground truth representations</i> are the GIS elements (fields or objects), and each element is representing (by a cartographic process) a real world object.</figcaption></figure> <p>In GIS the spatial data is modeled as <i>field</i> (like in <a href="#Remote_sensing">remote sensing raster images</a>) or as <i>object</i> (like in <a href="/wiki/Vector_Map" title="Vector Map">vectorial map</a> representation).<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> They are modeled from the real world (also named <i>geographical reality</i>), typically by a cartographic process (illustrated). </p><p><a href="/wiki/Geographic_information_system" title="Geographic information system">Geographic information systems</a> such as GIS, GPS, and GNSS, have become so widespread that the term "ground truth" has taken on special meaning in that context. If the location coordinates returned by a location method such as GPS are an estimate of a location, then the "ground truth" is the actual location on Earth. A smart phone might return a set of estimated location coordinates such as 43.87870,-103.45901. The ground truth being estimated by those coordinates is the tip of George Washington's nose on <a href="/wiki/Mount_Rushmore" title="Mount Rushmore">Mount Rushmore</a>. The accuracy of the estimate is the maximum distance between the location coordinates and the ground truth. We could say in this case that the estimate accuracy is 10 meters, meaning that the point on earth represented by the location coordinates is thought to be within 10 meters of George's nose—the ground truth. In slang, the coordinates indicate where we think George Washington's nose is located, and the ground truth is where it really is. In practice a smart phone or hand-held GPS unit is routinely able to estimate the ground truth within 6–10 meters. Specialized instruments can reduce GPS measurement error to under a centimeter.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(5)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="Military_usage">Military usage</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=7" title="Edit section: Military usage" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-5 collapsible-block" id="mf-section-5"> <p>US <a href="/wiki/Military_slang" title="Military slang">military slang</a> uses "ground truth" to refer to the facts comprising a tactical situation—as opposed to intelligence reports, mission plans, and other descriptions reflecting the conative or policy-based projections of the industrial·military complex. The term appears in the title of the <a href="/wiki/Iraq_War" title="Iraq War">Iraq War</a> documentary film <i><a href="/wiki/The_Ground_Truth" title="The Ground Truth">The Ground Truth</a></i> (2006), and also in military publications, for example <i><a href="/wiki/Stars_and_Stripes_(newspaper)" title="Stars and Stripes (newspaper)">Stars and Stripes</a></i> saying: "Stripes decided to figure out what the ground truth was in Iraq."<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (October 2014)">citation needed</span></a></i>]</sup> </p> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(6)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="See_also">See also</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=8" title="Edit section: See also" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-6 collapsible-block" id="mf-section-6"> <ul><li><a href="/wiki/Baseline_(medicine)" class="mw-redirect" title="Baseline (medicine)">Baseline (science)</a></li> <li><a href="/wiki/Calibration" title="Calibration">Calibration</a></li> <li><a href="/wiki/Foundationalism" title="Foundationalism">Foundationalism</a></li></ul> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(7)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="References">References</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=9" title="Edit section: References" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-7 collapsible-block" id="mf-section-7"> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"> <style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFEllison1833" class="citation book cs1">Ellison, Henry (1833). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=nzRcAAAAcAAJ"><i>Mad moments, or first verse attempts by a born natural</i></a>. p. 362<span class="reference-accessdate">. Retrieved <span class="nowrap">2014-10-24</span></span>. <q>As the Groundtruth of her own Existence it must be regarded, thro' Him in its highest, purest Aspect shown!</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Mad+moments%2C+or+first+verse+attempts+by+a+born+natural&rft.pages=362&rft.date=1833&rft.aulast=Ellison&rft.aufirst=Henry&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DnzRcAAAAcAAJ&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGround+truth" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLemoigneCaner2006" class="citation book cs1">Lemoigne, Yves; Caner, Alessandra (2006). <i>Molecular Imaging: Computer Reconstruction and Practice</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Molecular+Imaging%3A+Computer+Reconstruction+and+Practice&rft.date=2006&rft.aulast=Lemoigne&rft.aufirst=Yves&rft.au=Caner%2C+Alessandra&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGround+truth" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFisher1997" class="citation journal cs1">Fisher, P (1997). "The Pixel: A Snare and a Delusion". <i>International Journal of Remote Sensing</i>. <b>18</b> (15): 679–685. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1997IJRS...18..679F">1997IJRS...18..679F</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1080%2F014311697219015">10.1080/014311697219015</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=International+Journal+of+Remote+Sensing&rft.atitle=The+Pixel%3A+A+Snare+and+a+Delusion&rft.volume=18&rft.issue=15&rft.pages=679-685&rft.date=1997&rft_id=info%3Adoi%2F10.1080%2F014311697219015&rft_id=info%3Abibcode%2F1997IJRS...18..679F&rft.aulast=Fisher&rft.aufirst=P&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGround+truth" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text">Goodchild, M., "<a rel="nofollow" class="external text" href="http://www.geog.ucsb.edu/~good/papers/172.pdf">Geographical data modeling</a>". Computers & Geosciences, vol. 18, no.4, pp. 401-408, 1992.</span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPickles1995" class="citation book cs1">Pickles, John (1995). <i>Ground Truth: The Social Implications of Geographical Information Systems</i>. p. 179.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Ground+Truth%3A+The+Social+Implications+of+Geographical+Information+Systems&rft.pages=179&rft.date=1995&rft.aulast=Pickles&rft.aufirst=John&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGround+truth" class="Z3988"></span></span> </li> </ol></div></div> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(8)"><span class="indicator mf-icon mf-icon-expand mf-icon--small"></span><h2 id="External_links">External links</h2><span class="mw-editsection"> <a role="button" href="/w/index.php?title=Ground_truth&action=edit&section=10" title="Edit section: External links" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> <span class="minerva-icon minerva-icon--edit"></span> <span>edit</span> </a> </span> </div><section class="mf-section-8 collapsible-block" id="mf-section-8"> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20060911012029/http://forest.esf.edu/unsupervisedClass.html">Forestry Organization Remote Sensing Technology Project</a> (includes an example of an error matrix)</li></ul>    </section></div> <noscript><img src="https://login.m.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1&mobile=1" alt="" width="1" height="1" style="border: none; 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