Ibanga Phakathi Kwamadolobha: Ukukala Umugqa Oqondile Kuphlanethi Eyindilinga
Uma ubuza ukuthi idolobha elithile likude kangakanani kwelinye, empeleni kunezimpendulo ezimbili ezahlukene. Enye ibanga inyoni ebendiza ngqo isuka kwenye indawo iye kwenye. Enye ibanga imoto yakho ehambe khona ngempela, izombezela izintaba, imifula, kanye nemingcele. Ithuluzi Lebanga Phakathi Kwamadolobha likunika inombolo yokuqala — ibanga elingu-great-circle, elifana nendlela yenyoni ebhalele — elibalwa ngokushesha kwibrawuza yakho ngokususela kumagondo endawo alelo nalelo dolobha.
Leyo nombolo yomugqa oqondile iyisisekelo esiqotho. Ikutshela ukuhlukana kwangempela kwezindawo ezimbili kwezendawo, ngaphandle kokuthi imigwaqo iyiphi noma umsindo wemoto usezingeni elingakanani. Uma sewazi lokho, zonke ezinye izinhlobo zamabanga ziba lula ukuzicabangela.
Ibanga lomugqa oqondile ngokumelene nebanga lokushayela
Ibanga lomugqa oqondile alinaki lutho olukhona phakathi: awukho umgwaqo, akukho izwe, azikho izindlela zokuzombeza. Yileli banga elifushane kunazo zonke elikala ngqo esiqongweni somhlaba. Ngakolunye uhlangothi, ibanga lokushayela lilandela imigwaqo yangempela egobayo izombezela amachibi, ikhuphuke izintaba, futhi ihloniphe imingcele yezombusazwe.
Umehluko phakathi kwalezi zombili uyaqagelwa ngendlela emangalisayo. Ezindaweni eziningi, izindlela zokushayela ziba yisikhathi esiyi-1.2 kuya ku-1.5 zibude kunomugqa oqondile, ngesilinganiso esejwayelekile esingu-1.3 e-United States. Emadolobheni ahlukaniswa amanzi noma izintaba — njengeSan Francisco, iPittsburgh — leso silinganiso singadlula i-2.0 kwezinye izinhambo. Izindiza, ngakolunye uhlangothi, zilandela kakhulu indlela ye-great-circle: izindlela ezinde ngokuvamile zengeza kuphela amaphesenti ambalwa, phakathi kuka-2 no-10, kunebanga eliqondile.
Ngakho-ke uma ithuluzi likutshela ukuthi amadolobha amabili akude ngamakhilomitha angu-500 ngomugqa oqondile, ungalindela uhambo lokushayela olungaba ngamakhilomitha angu-600 kuya ku-750 kanye nokundiza okuqhelelene kancane nesilinganiso samakhilomitha angu-500.
Indlela ibanga le-great-circle elibalwa ngayo
Ngenxa yokuthi uMhlaba uyindilinga, indlela emfushane kunazo zonke phakathi kwamaphoyinti amabili aphezu komhlaba akuwona umugqa oqondile ohamba phakathi kwephlanethi — kuwuchungechunge olugobayo lulandela isiqongo. Lolo chungechunge luyingxenye ye-great-circle, isiyingi esikhulu kunazo zonke ongasidweba esiqongweni sendilinga. Yingakho izindlela zezindiza ezinde zibonakala zigobile lapho zidwetshwe emephini eyisicaba: empeleni ziqondile ekuphileni kwangempela, kodwa zigotshwa uhlobo lokuzidweba.
Ukukala lolo chungechunge, ithuluzi lisebenzisa i-haversine formula. Ngamazwi alula, ithatha i-latitude ne-longitude yedolobha ngalinye, ibheke umehluko phakathi kwazo, bese ibala i-engeli phakathi kwamaphoyinti amabili njengoba ibonwa isuka enkabeni yoMhlaba. Phindaphinda leyo engeli ngeradiyasi yephlanethi — cishe amakhilomitha angu-6,371 ngokwesilinganiso — bese uthola ibanga lesiqongo. Indlela ye-haversine ihlala izinzile ngezibalo ngisho namaphoyinti aseduze kakhulu, yingakho abaqondisi bemikhumbi bethembele kuyo iminyaka ngeminyaka.
Umphumela uwukulinganisela, kodwa okuhle kakhulu. Ngenxa yokuthi uMhlaba uyi-ellipsoid encikile kancane esikhundleni sendilinga egcwele — ibanzi ku-equator kunokuba phakathi kwamapholi — iphutha lihlala ngaphansi kwengxenye eyodwa yekhulu. Ekuhleleni uhambo, ekulinganiseleni izokuthutha, kanye nasekuzelweni yimincili yansuku zonke, lokho kunembeka kwanele nakakhulu.
Amakhilomitha noma amamayela
Ibanga liyilinganiso nje lobude, ngakho ukuguqula phakathi kwezilinganiso kulula: ikhilomitha eyodwa ilingana namamayela angu-0.621, futhi imayela elilodwa lilingana namakhilomitha angu-1.609. Ithuluzi likhombisa zombili izilinganiso ukuze ungazihluphi ngezibalo. Uma umphumela ufunda amakhilomitha angu-800, lokho kuseduze namamayela angu-497; ukuhlukana kwamamayela angu-1,000 kucishe kube amakhilomitha angu-1,609. Isibalo esiyisisekelo se-great-circle siyafana kuzo zombili izikhathi — kuguquka kuphela ilebula esenombeni.
Ukusetshenziswa okusebenzayo
Ukwazi ibanga eliqondile phakathi kwamadolobha amabili kusiza ezimeni eziningi zansuku zonke. Abahambi basebenzisa lokhu ukuhlola ubuqiniso besikhathi sokundiza futhi baqhathanise ukuthi ukushayela noma ukundiza kunengqondo yini kolunye uhambo. Amaqembu ezokuthutha nokuthumela impahla athembela enombeni yomugqa oqondile njengesisekelo esisheshayo ngaphambi kokungeza isici sokuzombeza komgwaqo ukulinganisela amabanga wangempela okuthunyelwa kanye namafutha. Abantu abahlela ukuthuthela kwenye indawo, uhambo lomgwaqo, noma ukufuduka basebenzisa lokhu ukuqonda ukuthi izindawo ezimbili zikude kangakanani ngempela.
Futhi ngezinye izikhathi kuba yinsangatsheliso nje — idolobha lakini likude kangakanani nedolobha obulokhu ufisa ukulivakashela? Inombolo yomugqa oqondile iyaphendula lokho ngendlela engenakwenziwa yimephu yomgwaqo ozombezelayo. Uma ufuna ukugxila kakhulu emagondweni angemuva kwendawo, hlanganisa leli thuluzi nokubheka kwethu i-geolocation, noma ubheke amathebula wereferensi ngezilinganiso ezihlobene kanye nokuguqulwa.
Konke kubalwa ngokwesikhathi sangempela kwibrawuza yakho ngokususela emagondweni edolobha, ngakho akukho lutho okudingeka ufake, futhi awulindele iseva. Faka amadolobha amabili, ufunde uchungechunge, bese uba nesilinganiso esinembile somhlaba ophakathi kwawo.
Imibuzo evame ukubuzwa
Kusho ukuthini ibanga elifana nendlela yenyoni ebhalele?
Yibanga lomugqa oqondile, i-great-circle, elikalwa ngqo esiqongweni soMhlaba, lingananaki imigwaqo, izwe, nezithiyo. Yibanga elifushane kunazo zonke elingaba khona phakathi kwamaphoyinti amabili endilingeni.
Kungani ibanga le-great-circle lifushane kunebanga lokushayela?
Ibanga lokushayela lilandela imigwaqo yangempela ezombezela amanzi, izintaba, nemingcele, ngakho cishe njalo liba lide kakhulu. Izindlela zokushayela ngokuvamile ziba yisikhathi esiyi-1.2 kuya ku-1.5 zebanga lomugqa oqondile.
Inembeke kangakanani isibalo se-haversine?
Sinembe cishe ngengxenye eyodwa yekhulu. Iphutha elincane likhona ngoba uMhlaba uyi-ellipsoid encikile kancane esikhundleni sendilinga egcwele, kodwa ngenjongo yokuhamba nokuhlela, umphumela unembe ngokwedlulele.
Ngingawubona yini umphumela ngamakhilomitha nangamamayela ngesikhathi esisodwa?
Yebo. Ithuluzi likhombisa zombili izilinganiso ziqhathaniswa. Ikhilomitha eyodwa ilingana namamayela angu-0.621 futhi imayela elilodwa lilingana namakhilomitha angu-1.609, ngakho awuyikudinga ukuguqula ngesandla.
Isibalo siyayithumela yini idatha yami eseva?
Cha. Ibanga libalwa ngokugcwele kwibrawuza yakho ngokususela emagondweni amadolobha amabili. Akukho okulayishwayo, futhi umphumela uvela ngokushesha.
Kungani izindlela zezindiza ezinde zibonakala zigobile emephini?
I-great-circle empeleni iqondile endilingeni, kodwa uhlobo lokuzidweba emephini eyisicaba luyayigoba. Ukugoba okubonayo emephini kuwuhlobo lokudweba olusonta indlela eyindlela emfushane kunazo zonke ekuphileni kwangempela.