{"id":9858,"date":"2018-03-19T15:18:42","date_gmt":"2018-03-19T14:18:42","guid":{"rendered":"http:\/\/projectes.xtec.cat\/zenit\/?p=9858"},"modified":"2018-09-12T10:06:15","modified_gmt":"2018-09-12T08:06:15","slug":"1-1-2-projeccions","status":"publish","type":"post","link":"https:\/\/projectes.xtec.cat\/zenit\/general\/1-1-2-projeccions\/","title":{"rendered":"1.1.2. Projeccions"},"content":{"rendered":"<div class=\"container\">\n<ul class=\"nav nav-tabs nav-pills\">\n<li class=\"nav-item\"><a class=\"nav-link active\" href=\"#consulta\" data-toggle=\"tab\">Consulta<\/a><\/li>\n<li class=\"nav-item dropdown\"><a class=\"nav-link dropdown-toggle\" href=\"#\" data-toggle=\"dropdown\">Practica<\/a>\n<div class=\"dropdown-menu\"><a href=\"#practica_1\" data-toggle=\"tab\">Projecci\u00f3 cil\u00edndrica<\/a><br \/>\n<a href=\"#practica_2\" data-toggle=\"tab\">Projecci\u00f3 c\u00f2nica<\/a><\/div>\n<\/li>\n<li class=\"nav-item\"><a class=\"nav-link\" href=\"#aplica\" data-toggle=\"tab\">Aplica<\/a><\/li>\n<\/ul>\n<div class=\"tab-content\" style=\"margin-top: 20px;\">\n<div id=\"consulta\" class=\"tab-pane active\">\n<p><i><b><a id=\"Coordenades_projectades\" name=\"Coordenades_projectades\"><\/a>Coordenades projectades<\/b><\/i><br \/>\nLes\u00a0<b>coordenades projectades<\/b>\u00a0s\u00f3n coordenades cartesianes que resulten de transformar les coordenades de longitud i latitud en coordenades planes rectangulars per mitj\u00e0 d&#8217;una\u00a0<b>projecci\u00f3 cartogr\u00e0fica<\/b>, que, a m\u00e9s de la funci\u00f3 de transformaci\u00f3, estableix tamb\u00e9 l&#8217;origen de coordenades rectangulars corresponent.<\/p>\n<div><img decoding=\"async\" class=\"aligncenter\" src=\"http:\/\/www.icc.cat\/var\/ezwebin_site\/storage\/images\/media\/images\/georeferenciacio-exemple-3\/395022-1-cat-ES\/Georeferenciacio-exemple-3.jpg\" alt=\"\" \/><\/div>\n<div>\n<p>Zones del sistema de coordenades UTM (<i>Universal Transverse Mercator coordinate system<\/i>), un dels sistemes de refer\u00e8ncia espacial m\u00e9s utilitzats. Font:\u00a0<a href=\"http:\/\/en.wikipedia.org\/wiki\/Universal_Transverse_Mercator_coordinate_system\" target=\"_blank\" rel=\"noopener noreferrer\">http:\/\/en.wikipedia.org\/wiki\/Universal_Transverse_Mercator_coordinate_system<\/a><\/p>\n<\/div>\n<p>Les coordenades projectades s\u00f3n tan antigues com la cartografia, at\u00e8s que convencionalment tot mapa \u00e9s una representaci\u00f3 de la superf\u00edcie terrestre en el pla i precisa una projecci\u00f3 cartogr\u00e0fica per a generar-lo. Les coordenades projectades s\u00f3n tamb\u00e9 les m\u00e9s emprades en els sistemes d\u2019informaci\u00f3 geogr\u00e0fica, amb prefer\u00e8ncia sobre les coordenades geogr\u00e0fiques cl\u00e0ssiques, at\u00e8s que els c\u00e0lculs geom\u00e8trics s\u00f3n m\u00e9s simples en una superf\u00edcie plana que en una superf\u00edcie esf\u00e8rica, utilitzant magnituds de longitud en lloc d&#8217;angulars.<\/p>\n<p>Les coordenades projectades tenen l&#8217;inconvenient d&#8217;introduir deformacions i variacions d&#8217;escala al llarg del mapa importants com a conseq\u00fc\u00e8ncia de les distorsions inevitables en tota projecci\u00f3 cartogr\u00e0fica. Per aquest motiu nom\u00e9s s&#8217;utilitzen preferentment en dades cartogr\u00e0fiques d&#8217;\u00e0mbits geogr\u00e0fics redu\u00efts, per a produir mapes d&#8217;escales grans i escollint projeccions cartogr\u00e0fiques que minimitzin les distorsions en l&#8217;\u00e0mbit geogr\u00e0fic d&#8217;aplicaci\u00f3.<\/p>\n<p>Alguns dels sistemes de coordenades projectades m\u00e9s utilitzats s\u00f3n el sistema de coordenades UTM, basat en la projecci\u00f3 cartogr\u00e0fica del mateix nom i v\u00e0lid per a tot el m\u00f3n. <a href=\"http:\/\/www.icgc.cat\/Ciutada\/Informa-t\/Diccionaris\/Georeferenciacio\" target=\"_blank\" rel=\"noopener noreferrer\">M\u00e9s informaci\u00f3<\/a><\/p>\n<\/div>\n<div id=\"practica_1\" class=\"tab-pane fade\">\n<h2>Projecci\u00f3 cil\u00edndrica<\/h2>\n<p>Determina les coordenades de les ciutats indicades i visualitza la forma en la que es transformen els angles que forma el punt a l&#8217;esfera i la seva representaci\u00f3 al mapa<\/p>\n<p><a href=\"https:\/\/www.geogebra.org\/material\/iframe\/id\/xxbZUNpW\/width\/1920\/height\/658\/border\/888888\/smb\/false\/stb\/false\/stbh\/false\/ai\/false\/asb\/false\/sri\/false\/rc\/false\/ld\/false\/sdz\/false\/ctl\/false\" target=\"_blank\" rel=\"noopener noreferrer\"><input type=\"button\" value=\"Veure en pantalla completa\" \/><\/a><br \/>\n<!--<button class=\"btn btn-primary\" type=\"button\" data-toggle=\"modal\" data-target=\"#finestraInfo\">Launch demo modal<\/button>--><\/p>\n<p><iframe loading=\"lazy\" style=\"border: 0px;\" title=\"Projecci\u00f3 cil\u00edndrica\" src=\"https:\/\/www.geogebra.org\/material\/iframe\/id\/xxbZUNpW\/width\/1920\/height\/658\/border\/888888\/smb\/false\/stb\/false\/stbh\/false\/ai\/false\/asb\/false\/sri\/false\/rc\/false\/ld\/false\/sdz\/false\/ctl\/false\" width=\"1600px\" height=\"500px\" scrolling=\"no\"> <\/iframe><\/p>\n<h4>Comprova el que has apr\u00e9s<\/h4>\n<\/div>\n<div id=\"practica_2\" class=\"tab-pane fade\">\n<h2>Projecci\u00f3 c\u00f2nica<\/h2>\n<p>Determina les coordenades de les ciutats indicades i visualitza la forma en la que es transformen els angles que forma el punt a l&#8217;esfera i la seva representaci\u00f3 al mapa<br \/>\n<a href=\"https:\/\/www.geogebra.org\/material\/iframe\/id\/KTYewNKQ\/width\/1920\/height\/809\/border\/888888\/smb\/false\/stb\/false\/stbh\/false\/ai\/false\/asb\/false\/sri\/false\/rc\/false\/ld\/false\/sdz\/false\/ctl\/false\" target=\"_blank\" rel=\"noopener noreferrer\"><input type=\"button\" value=\"Veure en pantalla completa\" \/><\/a><br \/>\n<!--<button class=\"btn btn-primary\" type=\"button\" data-toggle=\"modal\" data-target=\"#finestraInfo\">Launch demo modal<\/button>--><br \/>\n<iframe loading=\"lazy\" style=\"border: 0px;\" title=\"Projecci\u00f3 c\u00f2nica 3D\" src=\"https:\/\/www.geogebra.org\/material\/iframe\/id\/KTYewNKQ\/width\/1920\/height\/809\/border\/888888\/smb\/false\/stb\/false\/stbh\/false\/ai\/false\/asb\/false\/sri\/false\/rc\/false\/ld\/false\/sdz\/false\/ctl\/false\" width=\"2133px\" height=\"500px\" scrolling=\"no\"> <\/iframe><\/p>\n<\/div>\n<div id=\"aplica\" class=\"tab-pane\">\n<p>Et proposem que generis un tipus de projecci\u00f3 diferent a les exposades a l&#8217;apartat <em>Practica<\/em> amb el programa\u00a0<a href=\"https:\/\/www.giss.nasa.gov\/tools\/gprojector\/\">G.Projection-Global Map Projector<\/a>\u00a0de la NASA. En concret, una projecci\u00f3 azimutal de l&#8217;hemisferi nord de la Terra :<\/p>\n<p><a href=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/orthographic.png\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-10021 aligncenter\" src=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/orthographic-1024x512.png\" alt=\"\" width=\"508\" height=\"254\" srcset=\"https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/orthographic-1024x512.png 1024w, https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/orthographic-300x150.png 300w, https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/orthographic-768x384.png 768w, https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/orthographic.png 1690w\" sizes=\"auto, (max-width: 508px) 100vw, 508px\" \/><\/a><\/p>\n<ul>\n<li>Descarrega la\u00a0 versi\u00f3 del programa <a href=\"https:\/\/www.giss.nasa.gov\/tools\/gprojector\/download\/\">G.Projector<\/a>\u00a0per al sistema operatiu del teu ordinador. El programa necessita que l&#8217;ordinador tingui instal\u00b7lada la <a href=\"https:\/\/www.java.com\/en\/download\/\">m\u00e0quina virtual de Java<\/a>.<\/li>\n<li>Instal\u00b7la i obre el programa. Si fas servir <em>MS Window<\/em>s, has d&#8217;extreure els continguts del fitxer descarregat <strong><em>G.ProjectorWin.zip<\/em><\/strong> i fer doble clic en el fitxer <em><strong>G.Projector.exe<\/strong>.<\/em><a href=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/splash.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-10024 aligncenter\" src=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/splash.png\" alt=\"\" width=\"128\" height=\"226\" srcset=\"https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/splash.png 317w, https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/splash-170x300.png 170w\" sizes=\"auto, (max-width: 128px) 100vw, 128px\" \/><\/a><\/li>\n<li>Quan s&#8217;inicia el programa, et demana quin mapa vols obrir. Escull el mapa <em><strong>world_topo_bathy.jpg<\/strong>.<\/em><a href=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/open.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-10025 aligncenter\" src=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/open.png\" alt=\"\" width=\"270\" height=\"138\" srcset=\"https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/open.png 425w, https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/open-300x153.png 300w\" sizes=\"auto, (max-width: 270px) 100vw, 270px\" \/><\/a><\/li>\n<li>Confirma la finestra seg\u00fcent (Input Map Image) i podr\u00e0s veure la\u00a0finestra principal del programa, amb 5 pestanyes a la part inferior. treballarem a la pestanya\u00a0<strong><em>Projection<\/em><\/strong>.<a href=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/projection.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-10027 aligncenter\" src=\"http:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/projection.png\" alt=\"\" width=\"389\" height=\"108\" srcset=\"https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/projection.png 389w, https:\/\/projectes.xtec.cat\/zenit\/wp-content\/uploads\/usu1639\/2018\/03\/projection-300x83.png 300w\" sizes=\"auto, (max-width: 389px) 100vw, 389px\" \/><\/a><\/li>\n<li>Abans de generar\u00a0la projecci\u00f3 que\u00a0t&#8217;hem proposat, visualitza primer les dues que ja coneixes : la cil\u00edndrica (<strong><em>Mercator<\/em><\/strong>) i la c\u00f2nica (<strong><em>Lambert Conformal Conic<\/em><\/strong>). Fes la tria de projecci\u00f3 en el desplegable i ajusta els par\u00e0metres :\n<ul>\n<li>Mercator : Centrada a longitud 0\u00ba, latitud m\u00e0xima 75\u00ba.<\/li>\n<li>Lambert Conformal Conic : Centrada a longitud 0\u00ba i latitud 45\u00ba, con tangent a latitud 45\u00ba i visi\u00f3 fins a latitud 135\u00ba.<\/li>\n<\/ul>\n<\/li>\n<li>Genera a continuaci\u00f3 la projecci\u00f3 proposada :\n<ul style=\"list-style-type: circle;\">\n<li>Projecci\u00f3\u00a0: Orthographic.<\/li>\n<li>Centrada a longitud 0\u00ba i latitud 90\u00ba.<\/li>\n<li>Radi visible de 90\u00ba.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div>\n<div id=\"recursos\" class=\"tab-pane\">\n<h2>Recursos<\/h2>\n<\/div>\n<\/div>\n<\/div>\n<p><!-- Modal --><\/p>\n<div id=\"finestraInfo\" class=\"modal fade\" style=\"width: 90%; height: 500px; margin: 5%; padding: 3%; background-color: #ffffff;\" tabindex=\"-1\">\n<div class=\"modal-dialog\" style=\"width: 90%; height: 490px;\">\n<div class=\"modal-header\">\n<h3 id=\"modalHeader\">Coordenades geogr\u00e0fiques<\/h3>\n<p><button class=\"close\" type=\"button\" data-dismiss=\"modal\">\u00d7<\/button><\/p>\n<\/div>\n<div id=\"missatge\" class=\"modal-body\"><iframe loading=\"lazy\" style=\"border: 0px;\" title=\"Coordenades geogr\u00e0fiques 3D-v6\" src=\"https:\/\/www.geogebra.org\/material\/iframe\/id\/FQueZpPD\/width\/2133\/height\/976\/border\/888888\/smb\/false\/stb\/false\/stbh\/false\/ai\/false\/asb\/false\/sri\/false\/rc\/false\/ld\/false\/sdz\/false\/ctl\/false\" width=\"1020px\" height=\"400px\" scrolling=\"no\"> <\/iframe><\/div>\n<div class=\"modal-footer\"><button class=\"btn\" data-dismiss=\"modal\">Tancar<\/button><\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<ul class=\"nav nav-tabs nav-pills\">\n<li class=\"nav-item\"><a class=\"nav-link active\" href=\"#consulta\" data-toggle=\"tab\">Consulta<\/a><\/li>\n<li class=\"nav-item dropdown\"><a class=\"nav-link dropdown-toggle\" href=\"#\" data-toggle=\"dropdown\">Practica<\/a><br \/>\n<a href=\"#practica_1\" data-toggle=\"tab\">Projecci\u00f3 cil\u00edndrica<\/a><br \/>\n<a href=\"#practica_2\" data-toggle=\"tab\">Projecci\u00f3 c\u00f2nica<\/a>\n<\/li>\n<li class=\"nav-item\"><a class=\"nav-link\" href=\"#aplica\" data-toggle=\"tab\">Aplica<\/a><\/li>\n<\/ul>\n<p><a id=\"Coordenades_projectades\" name=\"Coordenades_projectades\"><\/a>Coordenades projectades<br \/>\nLes\u00a0coordenades projectades\u00a0s\u00f3n coordenades cartesianes que resulten de transformar les coordenades de longitud i latitud en coordenades planes rectangulars&hellip;  <a href=\"https:\/\/projectes.xtec.cat\/zenit\/general\/1-1-2-projeccions\/\" title=\"Read 1.1.2. Projeccions\">Llegeix m\u00e9s\u00bb<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"categories":[1],"tags":[306,313],"class_list":["post-9858","post","type-post","status-publish","format-standard","hentry","category-general","tag-plafo","tag-ud_cartografia"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/posts\/9858","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/comments?post=9858"}],"version-history":[{"count":4,"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/posts\/9858\/revisions"}],"predecessor-version":[{"id":10663,"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/posts\/9858\/revisions\/10663"}],"wp:attachment":[{"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/media?parent=9858"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/categories?post=9858"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/projectes.xtec.cat\/zenit\/wp-json\/wp\/v2\/tags?post=9858"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}