Amasu Okubala Indawo Yomkhumbi Usebenzisa Izinkanyezi
Phakathi kwentuthuko kumadivayisi okuzulazula e-GPS kanye nedijithali, inqubo yokubala indawo yomkhumbi usebenzisa isayensi yezinkanyezi (ukuzulazula kwezinkanyezi noma ukuzulazula kwasezulwini) isasebenza. Ngaphezu nje kokuchitha isikhathi sothando kwamatilosi esikhathi esidlule, leli khono lisebenza njengesipele esibalulekile lapho izinhlelo ze-elekthronikhi ziphazamiseka, izimpawu zilahleka, noma imishini ihluleka. Ngokusebenzisa izidalwa zasezulwini—iLanga, iNyanga, amaplanethi, nezinkanyezi—umhambi angakwazi ukunquma ngokuzimela indawo yomkhumbi olwandle oluvulekile. Lesi sihloko sixoxa ngezimiso eziyisisekelo, amathuluzi asetshenziswayo, kanye nezinyathelo ezisebenzayo zokubala indawo yomkhumbi usebenzisa isayensi yezinkanyezi.
1. Izimiso Eziyisisekelo Zokuzulazula Kwezinkanyezi
Ukuzulazula kwezinkanyezi kusekelwe ekulinganiseni i-engeli yokuphakama (ukuphakama) komzimba wasezulwini uma kuqhathaniswa nomkhathizwe ngesikhathi esithile. Uma sazi:
1) isikhathi sokubuka esinembile kakhulu,
2) indawo yezinto zasezulwini ngaleso sikhathi (kusukela kudatha yezinkanyezi), kanye
3) i-engeli elinganisiwe yokuphakama komzimba wasezulwini,
Ngemuva kwalokho singadweba umugqa wesikhundla (i-LOP) emephini. Ngokuhlanganisa ama-LOP amabili noma ngaphezulu kusukela ekubonweni kwezinto zasezulwini ezahlukene, sithola indawo yokuhlangana eba yindawo elinganisiwe yomkhumbi (ukulungiswa).
Ngokomqondo, uma inkanyezi iphakeme kakhulu ngaphezu komkhathizwe, umkhumbi uba sendilinga enkulu ebusweni boMhlaba ebizwa ngokuthi indilinga yokuphakama okulinganayo. Ngenxa yokuthi indilinga inkulu kakhulu eshadini lolwandle, ingxenye encane yayo ingabhekwa njengomugqa oqondile: yi-LOP.
2. Imishini Edingekayo
Ukuze kwenziwe izibalo zezinkanyezi zezindawo zomkhumbi, imishini eyinhloko ihlanganisa:
– I-Sextant: ithuluzi lokulinganisa i-engeli phakathi kwezinto zasezulwini kanye nomkhathizwe (ukuphakama kwezinto zasezulwini).
– I-Chronometer: iwashi lomkhumbi elinembile, elisethwe ngesikhathi esijwayelekile (ngokuvamile i-UTC/GMT).
– I-Nautical Almanac: iqukethe idatha yehora ngezindawo zezinto zasezulwini (kanye nokulungiswa kwemizuzu/isekhondi).
– Amathebula okunciphisa noma izindlela zokubala: isibonelo Amathebula Okunciphisa Ukubona (HO 249/HO 229) noma ukubala kwe-trigonometric ngesandla.
– Amashadi olwandle, ipensela, irula kanye ne-plotter: ukudweba i-LOP nokuthola izilungiso.
– I-Compass kanye ne-speed log (ongakukhetha kodwa kuyasiza): ukulinganisa indawo yokuqala ngaphambi kokulungiswa kwezinkanyezi.
Nakuba manje sekukhona ama-calculator nezinhlelo zokusebenza, isimiso esiyisisekelo sisalokhu sifana: ukulinganisa i-sextant + isikhathi esinembile + i-almanac + ukunciphisa + i-plot.
3. Ukulinganisa Nge-Sextant: Ukubona “Ukubona”
Isinyathelo sokuqala ukwenza umbono (ukubona). Isibonelo, ngeLanga:
1) Khetha into: Ilanga livame ukusetshenziswa ngoba libonakala kalula; izinkanyezi zisetshenziswa ekushoneni/ekuseni; amaplanethi nenyanga nakho kungasetshenziswa.
2) Linganisa ukuphakama kwento yasezulwini (Hs): khomba i-sextant kuze kube yilapho isithombe sento yasezulwini “sithinta” umugqa we-horizon.
3) Qopha isikhathi se-UTC ngokunemba kwemizuzwana: ngoba ukushintsha kwezikhundla zezinto zasezulwini kushintsha ngokushesha, isikhathi esingeqi ngemizuzwana emi-4 singasho cishe imayela elilodwa le-nautical ku-longitude (cishe, ngoba umhlaba ujikeleza ama-15° ngehora).
4) Phinda izikhathi eziningana: thatha izilinganiso eziningana bese uthatha isilinganiso ukuze unciphise amaphutha.
Ngezinkanyezi, ukubonwa kuvame ukwenziwa lapho umkhathizwe usabonakala kahle: ukuhwalala kwezwe. Ngelanga lasemini, inqubo evamile ukukala ukuphakama ukuze uthole umugqa wesikhundla esinamandla (i-LOP) kanye nokuthola i-latitude yendlela ye-meridian (ukuphela).
4. Ukulungiswa kwe-Sextant: Kusukela ku-H kuya ku-Ho
I-engeli efundwe yi-sextant (Hs) ayilungele ukusetshenziswa. Kumelwe ilungiswe ibe ukuphakama okubonwayo (Ho) kusetshenziswa izilungiso eziningana ezijwayelekile:
– Iphutha Lenkomba (IE): iphutha elingelona iphutha ku-sextant. Kukhokhelwa ngokulungiswa kwenkomba.
– Ukucwila (ukulungiswa komkhathi): ngoba umqapheli ungaphezu kolwandle, umkhathi ubonakala “uwehla”. Ukucwila kuncike ekuphakameni kweso kusuka ebusweni.
– Ukufiphaza (ukufiphaza komoya): umkhathi ugoba ukukhanya ukuze izinto zibonakale ziphakeme.
– Ukulungiswa kwelanga/iNyanga: eLangeni naseNyangeni kukhona ukulungiswa okwengeziwe njenge-semidiameter (ukulinganisa umkhawulo ophezulu/ophansi) kanye ne-parallax (ikakhulukazi iNyanga).
Ngemva kokusetshenziswa kwazo zonke izilungiso, kutholakala u-Ho. Leli nani lika-Ho lisetshenziswa enqubweni yokunciphisa ukuthola i-LOP.
5. Thola idatha ngezinto zasezulwini ezivela ku-Almanac
Ku-Nautical Almanac, umshayeli wesikebhe uthathe:
– I-GHA (i-Greenwich Hour Angle): i-engeli yehora yomzimba wasezulwini uma iqhathaniswa ne-Greenwich meridian, ehlobene ne-longitude.
– Ukwehla (Disemba): “i-latitude yasezulwini” yento, enyakatho (+) noma eningizimu (-).
Njengoba ama-almanac ngokuvamile enikeza amanani ehora, ukuhunyushwa kwenziwa imizuzu nemizuzwana yesikhathi sokubuka. Ukunemba kokuhunyushwa kubalulekile, ikakhulukazi eNyangeni ehamba ngokushesha.
6. Indlela Yokunqamula (Marcq St. Hilaire)
Indlela evame kakhulu yokubala i-LOP yesimanje yindlela yokuvimba. Empeleni, siqhathanisa ukuphakama "kwesikhundla esicatshangelwayo" kusuka endaweni ecatshangelwayo (AP) nokuphakama kwangempela okubonwayo (Ho).
Izinyathelo ezisheshayo yilezi:
1) Nquma indawo elinganisiwe (DR/EP): kusukela ekubaleni okungapheli (inkambo kanye nebanga elihanjiwe) noma indawo yokugcina elinganisiwe.
2) Khetha Indawo Ecatshangelwayo (AP): ezungezwe ukuze kube lula ukubala (isb. i-latitude eyindilinga kanye ne-LHA eyindilinga).
3) Bala i-LHA (i-Angle Yehora Lendawo):
I-LHA = GHA ± i-longitude (izimpawu ezilungisiwe: i-longitude yasempumalanga ivame ukususwa, i-longitude yasentshonalanga iyengezwa—kuye ngokuthi ithebula lisetshenziswe kanjani).
4) Bala ukuphakama kwezibalo (Hc) kanye ne-azimuth (Zn) ye-AP usebenzisa ithebula le-HO noma ifomula ye-trigonometry eyindilinga.
5) Qhathanisa i-Ho ne-Hc:
I-Intercept = Ho − Hc (ngemizuzu ye-arc; 1′ ≈ 1 imayela lasemanzini).
– Uma u-Ho > Hc: “ubheke” (umkhumbi useduze nomzimba wasezulwini kune-AP)
– Uma u-Ho < Hc: “kude” 6) Hlela i-LOP: kusuka ku-AP, dweba umugqa we-azimuth ubheke ku-Zn bese ulinganisa i-intercept ebheke/ekude, beka iphuzu. Kusukela kulelo phuzu dweba umugqa oqondile oya ku-azimuth—okungukuthi i-LOP. Ngokubona okukodwa, sithola umugqa owodwa wesikhundla. Okungenani imigqa emibili yesikhundla evela ezindikimbeni ezimbili zasezulwini (noma izikhathi ezimbili ezihlukene) iyadingeka ukuze kulungiswe. 7. Ukuthola I-Fix: Ukuhlanganisa ama-LOP amabili noma amathathu Kunezindlela eziningana zokwakha i-fix: - Imizimba emibili yasezulwini ehlukene ngezikhathi eziseduze (isb., izinkanyezi ezimbili ekuhlweleni). - Ilanga kabili ngesikhawu (i-fix egijimayo): i-LOP yokuqala "iyashukunyiswa" ngokuya ngokunyakaza komkhumbi kuze kube yisikhathi se-LOP yesibili. - Imizimba emithathu yasezulwini: inikeza i-fix eqinile futhi ivumela ukutholwa kwamaphutha (ama-LOP akha unxantathu omncane). Ngesikhathi sokuhlwa, abashayeli bezindiza bavame ukuthatha izinkanyezi ezingu-3-5 ngoba: 1) izinkanyezi zikhiqiza ama-azimuth ahlukahlukene (ama-LOP ahlangana ngama-engeli amahle), 2) isikhathi sokubuka sifushane, 3) umkhathi usacacile. Imiphumela emihle kakhulu ivame ukuba lapho ama-LOP amabili ehlangana eduze kwama-90°, njengoba ukungaqiniseki kokulinganisa kuholela endaweni encane yamaphutha. 8. Ukubala i-Latitude Kusukela Ekuvuthweni Kwelanga (Ukubona Kwasemini) Ngaphandle kwendlela yokuvimba, inqubo ewusizo kakhulu yakudala ukubona kwasemini kwe-latitude. Lapho iLanga lifika endaweni yalo ephezulu yansuku zonke (umzila we-meridian), isiqondiso seLanga sisenyakatho/eningizimu kanye nokubala kwe-latitude kuba lula:
