Loko u languta wachi ya nkarhi wa n'weti eka webusayiti leyi, u vona mbuyelo wa tinhlerero to hambana leti tirhisanaka. Laha, hi ta vona tinhlerero ta mathematika na tialgorithm leti nga endzhaku ka nkarhi wa n'weti — ku suka eka ku hlera ku hambana ka nkarhi ku ya eka ku profeta swiyimo swa n'weti.
J2000.0 Epoch: Nhlavutelo ya Nkarhi
Tinhlerero hinkwato ta nkarhi wa n'weti ti sungula eka nhlavutelo — nkarhi lowu tiviwaka lowu tirhisiwaka tanihi masungulo a ku hlera. Hi tirhisa J2000.0 epoch: January 1, 2000 eka 12:00:00 UTC.
Epoch leyi i nhlavutelo ya astronomia leyi tirhisiwaka misaveni hinkwayo. Hi ku hlera masiku ku suka eka J2000.0, hi nga kumisisa nkarhi eka nkarhi wihi na wihi lowu hundzeke kumbe wa vulavula.
Ku Hlera ku Hambana ka Nkarhi
Nkarhi eka N'weti wu ya emahlweni ka UTC hi mpimo wo tiyiseka:
• Mpimo wa ku hambana: +56.02 microseconds hi siku (ku seketeriwa hi General Relativity) • Fomula: drift = masiku_ku_suka_eka_J2000 × 56.02µs • Nkarhi wa LTC: UTC + drift kambirhi
Mpimo lowu wu tekela enhlokweni swikombiso swinharhu swa gravitational: ku hambana ka ndhavuko ya ku kukerisa ya xivandla exikarhi ka Misava na N'weti, swikombiso swa orbital swa nkarhi wa xiviri, na swikombiso swa tidal swa ku yisa swintsongo.
ΔT: Ku Langanisa Nkarhi wa Misava
Eka tinhlerero to kongomeka ta xivandla, hi fanele hi tekela enhlokweni ΔT — ku hambana exikarhi ka nkarhi wa misava na nkarhi wa athomu. Misava yi nonoka hi ku ya hi nkarhi hikwalaho ka swikombiso swa tidal, ku endla leswaku masiku ya ha ya ma leha.
Fomula ya ΔT ya hina: ΔT = 69.36 − 0.06 × (lembe − 2020)
Ku oloxa loku ka polynomial ku kongomeka eka kwalomu ka 2015-2035 naswona ku seketeriwa hi data ya IERS (International Earth Rotation Service).
Algorithm ya Meeus yo Hlera Xiyimo xa N'weti
Ku profeta swiyimo swa n'weti, hi tirhisa algorithm ya Jean Meeus ku suka eka buku ya yena Astronomical Algorithms (Chapter 49). Ku katsa:
• 25 wa swivulwa swa xikhongelo swa ku lulamisela ku profeta • Ku kongomeka eka ~2 wa timinete ku ri na USNO • Ku hlera swiyimo hinkwaswo swa mune: n'weti wuntshwa, quarter yo sungula, n'weti lowu taleke, quarter yo hetelela
Algorithm yi hlera Julian Date yo hambana, yi tirhisa tifomula ta trigonometric leyi hoxaka ku pimisiwa ka n'weti, dyambu, na Jupiter, kutani yi profeta nkarhi wo kongomeka wa xiyimo xin'wana na xin'wana xa n'weti.
Ku Veka Hinkwaswo Swin'we
Wachi ya nkarhi wa n'weti yi hlanganisa tinhlerero leti hinkwato:
1. Hlera masiku ku suka eka J2000.0 ku fikelela eka nkarhi wa sweswi 2. Tirhisa mpimo wa ku hambana (56.02µs/siku) ku hlera nkarhi kambirhi 3. Yengeta ku hambana eka UTC ku kuma nkarhi wa LTC 4. Tirhisa Meeus ku hlera xiyimo xa n'weti, ku vonakala, na swiyimo swo biha
Mbuyelo i nkarhi lowu kongomekaka wa astronomia lowu sasekisiwaka siku na siku — lowu u wu vonaka eka pheji leyi.