I-TTFF yithuba elithatha idivayisi yeGPS ukufumana isikhundla sakho
Isikhathi sokuqala sokuQinisekisa (TTFF) sichaza ixesha kunye nenkqubo efunekayo kwidivaysi yeGPS ukufumana iimpawu zesatellite ezaneleyo kunye nedatha ukubonelela ngokuchanekileyo. Igama elithi "lungisa" apha lithetha "isikhundla."
Imiqathango eyahlukeneyo inokuchaphazela i-TTFF, kuquka indawo kunye nokuba idivayisi ye-GPS ingaphakathi okanye ngaphandle, ikhululekile ekukhuselweni phakathi kwesixhobo kunye nama-satellites.
I-GPS kufuneka ibe neeseti ezintathu zedata phambi kokuba inganikezela indawo echanileyo: Iimpawu ze-GPS zedatha, idatha ye- almanac kunye nedatha ye-ephemeris.
Qaphela: Isikhathi sokuQala ukuQala ngezinye izihlandlo sithuba se-first-to-first-fix .
Imibandela yeTTFF
Kukho iindidi ezintathu kwi-TTFF iyahlula phakathi:
- Iqela "lokubanda" okanye "umbane" libhekisela kwimeko apho idivayisi yeGPS kufuneka izuze yonke idatha ukuze iqalise ukuhamba, njengokuthi ifowuni yinto entsha okanye isandul I-TTFF ingathatha i-12 imizuzu.
- Ukufudumala "ukufudumala" ukuqala kuthetha ukuba iGPS ineyona mininzi yedatha ayifunayo kwimemori kwaye iza kuqala ngokukhawuleza - ngomzuzu okanye ngaphantsi. Isiqalo esifudumeleyo senzeka xa isixhobo siphelelwe usuku okanye kunjalo, kodwa kungabi kude ixesha elide ukuba idatha yalo iphelelwe yisikhathi.
- "Umlilo" okanye "umlindi" xa idilesi yeGPS ingafumana isalathiso ngokukhawuleza njengoko isele isithuba esilungileyo kwaye ichane i-almanac nedatha ye-ephemeris. Isixhobo ngokuqhelekileyo siye sahamba ngeeyure ezimbalwa nje. I-TTFF kule meko ngamanye amaxesha ibizwa ngokuba yi "Ixesha lokuThuthukiswa kweNgcaciso" (TTSF).
Oku ngakumbi kwiTTFF
Ukuba ifowuni ye-GPS intsha, ikhutshwe ixesha elide, okanye ithathelwe umgama omde ukususela ekugqibeleni, kuya kuthatha ixesha elide ukufumana ezi setekethi zeenkcukacha uze ufumane ixesha lokuQala ukuQala. Oku kungenxa yokuba idatha yeGPS ayiphelelwe yisikhathi kwaye ifuna ukukhuphela ulwazi olusesikhathini.
Abakhi be-GPS basebenzisa iindlela ezahlukeneyo ukukhawulezisa i-TTFF, kubandakanywa nokukhuphela kunye nokugcina idatha ye-almanac kunye ne-ephemeris ngokusebenzisa uxhumano lwenethiwekhi engenazintambo ukusuka kumsebenzisi weselula endaweni yeetellethi. Oku kubizwa ngokuba kuncediswe i-GPS , okanye i-GPS.