{"id":1178,"date":"2022-09-22T20:07:36","date_gmt":"2022-09-22T18:07:36","guid":{"rendered":"https:\/\/turid.se\/?p=1178"},"modified":"2023-10-13T16:55:07","modified_gmt":"2023-10-13T14:55:07","slug":"min-forsta-astrofix","status":"publish","type":"post","link":"https:\/\/turid.se\/en\/2022\/09\/22\/min-forsta-astrofix\/","title":{"rendered":"My first astrofix."},"content":{"rendered":"\n
\n

Jakob:<\/p>\n<\/blockquote>\n\n\n\n

Ig\u00e5r h\u00f6ll jag mig p\u00e5 landbacken men f\u00f6r att \u00e4nd\u00e5 tr\u00e4na astronomisk navigation gjorde jag en lunchutflykt till J\u00e4rn\u00e4sklubb n\u00e5gra mil s\u00f6der om Ume\u00e5 [karta]<\/a>. D\u00e4r \u00e4r klipporna sl\u00e4ta och horisonten fri mot s\u00f6der – ideall\u00e4ge f\u00f6r sextant\u00f6vningar.<\/p>\n\n\n\n

F\u00f6r att f\u00e5 lite nytt att \u00f6va p\u00e5 hade jag spanat in att m\u00e5nen var i nedan, en m\u00e5nsk\u00e4ra lite till h\u00f6ger om solen p\u00e5 himlen. Jag anv\u00e4nder timeanddate.com<\/a> f\u00f6r detta, utm\u00e4rkt tydliga \u00f6versikter \u00f6ver himlakropparnas l\u00e4gen.<\/p>\n\n\n\n

\"\"
Himlen i s\u00f6der 21 september vid 12-tiden (timeanddate.com)<\/figcaption><\/figure>\n\n\n\n

Att b\u00e5de solen och m\u00e5nen var synliga samtidigt ville jag utnyttja eftersom inm\u00e4tning av tv\u00e5 himlakroppar i olika riktning ger tv\u00e5 sk\u00e4rande linjer med en fix – en positionsbest\u00e4mning – d\u00e4r de m\u00f6ts. Om man enbart m\u00e4ter solen vid ett enstaka tillf\u00e4lle f\u00e5r man egentligen ingen positionspunkt utan svaret blir bara en linje d\u00e4r man b\u00f6r befinna sig.<\/p>\n\n\n\n

Hur gick det d\u00e5? Det var faktiskt lite sv\u00e5rt att ta m\u00e5nh\u00f6jden. Det var inte helt l\u00e4tt att se var m\u00e5nsk\u00e4rans underkant slutade s\u00e5 jag hade inte s\u00e5 stora f\u00f6rhoppningar om ett bra resultat.<\/p>\n\n\n\n

Jag gjorde en l\u00e5ng serie m\u00e4tningar och har inte r\u00e4knat p\u00e5 alla men n\u00e4r jag plottade den sista solh\u00f6jden och mot den sista m\u00e5nh\u00f6jden blev det s\u00e5 h\u00e4r:<\/p>\n\n\n\n

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Sol- och m\u00e5nfix i Nordmalingsfj\u00e4rden<\/figcaption><\/figure>\n\n\n\n

AP \u00e4r min antagna position, n\u00e4rmaste hela latitud- och longitudminut fr\u00e5n klippan p\u00e5 J\u00e4rn\u00e4sklubb.<\/p>\n\n\n\n

Den gr\u00f6na linjen f\u00e5r jag av ber\u00e4knad solh\u00f6jd, den r\u00f6da av ber\u00e4knad m\u00e5nh\u00f6jd. D\u00e4r de sk\u00e4r varandra \u00e4r min ber\u00e4knade position (cirkeln). Gr\u00f6na linjen (solh\u00f6jden) ligger 0,7 distansminuter = 1,3 km fr\u00e5n min verkliga observationsplats p\u00e5 klippan n\u00e4ra AP och den r\u00f6da linjen (m\u00e5nh\u00f6jden) ligger 2,2 distansminuter (4,1 km) fr\u00e5n klippan. Totalt \u00e4r allts\u00e5 felet under 2,5 distansminuter (4,6 km). Solh\u00f6jdens noggrannhet \u00e4r j\u00e4ttebra, inte undra p\u00e5 n\u00e4r det inte gungade under f\u00f6tterna. M\u00e5nh\u00f6jden duger men kunde vara b\u00e4ttre.<\/p>\n\n\n\n

Men i stort \u00e4r jag n\u00f6jd med min f\u00f6rsta riktiga sextantsfix, jag fick en fast best\u00e4md position som skulle duga bra f\u00f6r att n\u00e4rma sig ok\u00e4nt land fr\u00e5n havet.<\/p>\n","protected":false},"excerpt":{"rendered":"

Jakob: Ig\u00e5r h\u00f6ll jag mig p\u00e5 landbacken men f\u00f6r att \u00e4nd\u00e5 tr\u00e4na astronomisk navigation gjorde jag en lunchutflykt till J\u00e4rn\u00e4sklubb n\u00e5gra mil s\u00f6der om Ume\u00e5 [karta]. D\u00e4r \u00e4r klipporna sl\u00e4ta och horisonten fri mot s\u00f6der – ideall\u00e4ge f\u00f6r sextant\u00f6vningar. F\u00f6r att f\u00e5 lite nytt att \u00f6va p\u00e5 hade jag spanat in att m\u00e5nen var i… Continue reading Min f\u00f6rsta astrofix.<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":1180,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"cybocfi_hide_featured_image":"yes","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[31,9],"tags":[20],"class_list":["post-1178","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bat","category-turid-ii","tag-navigation","entry"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2.jpg","jetpack_sharing_enabled":true,"rttpg_featured_image_url":{"full":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2.jpg",2000,2000,false],"landscape":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2.jpg",2000,2000,false],"portraits":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2.jpg",2000,2000,false],"thumbnail":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2-150x150.jpg",150,150,true],"medium":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2-300x300.jpg",300,300,true],"large":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2-1024x1024.jpg",1000,1000,true],"1536x1536":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2-1536x1536.jpg",1536,1536,true],"2048x2048":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2.jpg",2000,2000,false],"trp-custom-language-flag":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2.jpg",12,12,false],"post-thumbnail":["https:\/\/turid.se\/wp-content\/uploads\/2022\/09\/DJI_0050.00_00_24_05.Still001-2-1568x1568.jpg",1568,1568,true]},"rttpg_author":{"display_name":"Jakob Norstedt","author_link":"https:\/\/turid.se\/en\/author\/jakob\/"},"rttpg_comment":0,"rttpg_category":"B\u00e5t<\/a> Turid II<\/a>","rttpg_excerpt":"Jakob: Ig\u00e5r h\u00f6ll jag mig p\u00e5 landbacken men f\u00f6r att \u00e4nd\u00e5 tr\u00e4na astronomisk navigation gjorde jag en lunchutflykt till J\u00e4rn\u00e4sklubb n\u00e5gra mil s\u00f6der om Ume\u00e5 [karta]. D\u00e4r \u00e4r klipporna sl\u00e4ta och horisonten fri mot s\u00f6der – ideall\u00e4ge f\u00f6r sextant\u00f6vningar. F\u00f6r att f\u00e5 lite nytt att \u00f6va p\u00e5 hade jag spanat in att m\u00e5nen var i……","_links":{"self":[{"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/posts\/1178","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/comments?post=1178"}],"version-history":[{"count":7,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/posts\/1178\/revisions"}],"predecessor-version":[{"id":1253,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/posts\/1178\/revisions\/1253"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/media\/1180"}],"wp:attachment":[{"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/media?parent=1178"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/categories?post=1178"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/turid.se\/en\/wp-json\/wp\/v2\/tags?post=1178"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}