{"id":20070,"date":"2013-04-23T17:39:56","date_gmt":"2013-04-23T06:39:56","guid":{"rendered":"http:\/\/yewenyi.net\/wpblog\/?p=20070"},"modified":"2013-04-23T17:39:56","modified_gmt":"2013-04-23T06:39:56","slug":"magentic-north-versus-true-north","status":"publish","type":"post","link":"https:\/\/yewenyi.net\/wp\/old\/?p=20070","title":{"rendered":"Magentic North Versus True North"},"content":{"rendered":"<p style=\"text-align: justify\"><a href=\"http:\/\/yewenyi.net\/wpblog\/wp-content\/uploads\/2013\/04\/20130423-163934.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full alignright\" alt=\"20130423-163934.jpg\" src=\"http:\/\/yewenyi.net\/wpblog\/wp-content\/uploads\/2013\/04\/20130423-163934.jpg\" width=\"200\" height=\"300\" \/><\/a>For a long time I thought our house pretty much faced north (well within a few degrees). I need to know the angles to get an idea of what to do for the solar design of the house extensions.<\/p>\n<p style=\"text-align: justify\">But where we live True North and Magnetic North are not the same. According to the Australian Government web site they are about 11 degrees different.<\/p>\n<p style=\"text-align: justify\"><a href=\"http:\/\/www.ga.gov.au\/oracle\/geomag\/agrfform.jsp\">Australian Geomagnetic Reference Field Computation<\/a><\/p>\n<p style=\"text-align: justify\"><a href=\"http:\/\/www.ga.gov.au\/oracle\/cgi\/geoAGRF.sh?latd=-37&amp;latm=49&amp;lats=4.3&amp;lond=145&amp;lonm=21&amp;lons=54&amp;elev=870&amp;year=2013&amp;month=04&amp;day=18&amp;Ein=D&amp;Ein=d\">Requested: Latitude -37o 49&#8242; 4.3&#8243;, Longitude 145o 21&#8242; 54&#8243;, Elevation 870 km, Date 2013\/04\/18 <\/a><\/p>\n<p style=\"text-align: justify\">Calculated: Latitude -37.8179o, Longitude +145.3650o, Elevation 870.00 km, Epoch 2013.2932 (Actual &#8211; 37.817884S, 145.365076E)<\/p>\n<p style=\"text-align: justify\">Magnetic Field Components<\/p>\n<p style=\"text-align: justify;padding-left: 30px\">D = 10.931 deg<br \/>\ndD = -0.003 deg\/yr<\/p>\n<p style=\"text-align: justify\">My question the was, foes the iPhone compass measure true north or magnetic north? Well it turns out the iPhone compass does both. You just tell it which one to say. I made sure it was set to true north and whalla! The angle of the house was measured. I was surprised to find it faces so much to the east.<\/p>\n<p style=\"text-align: justify\">The house actually points about 27 degrees east of north.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>For a long time I thought our house pretty much faced north (well within a few degrees). I need to[&#8230;]<\/p>\n","protected":false},"author":2,"featured_media":20069,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[871,2191,3837],"class_list":["post-20070","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-diary","tag-compass","tag-magnetic-north","tag-true-north"],"_links":{"self":[{"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=\/wp\/v2\/posts\/20070"}],"collection":[{"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=20070"}],"version-history":[{"count":0,"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=\/wp\/v2\/posts\/20070\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=\/"}],"wp:attachment":[{"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yewenyi.net\/wp\/old\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}