Ukuqonda okukude kweLiDAR: Umgaqo, usetyenziso, izixhobo zasimahla kunye nesoftware

Izinzwa ze-Airborne LiDARIngabamba amanqaku athile kwi-laser pulse, eyaziwa ngokuba yi-discrete return measurements, okanye irekhode isignali epheleleyo njengoko ibuya, ebizwa ngokuba yi-full-waveform, ngamaxesha athile amiselweyo njenge-1 ns (egubungela malunga ne-15 cm). I-Full-waveform LiDAR isetyenziswa kakhulu kwi-forestry, ngelixa i-discrete return LiDAR inezicelo ezibanzi kwiindawo ezahlukeneyo. Eli nqaku lixoxa kakhulu nge-discrete return LiDAR kunye nokusetyenziswa kwayo. Kule sahluko, siza kugubungela izihloko ezibalulekileyo malunga ne-LiDAR, kubandakanya izinto zayo ezisisiseko, indlela esebenza ngayo, ukuchaneka kwayo, iinkqubo, kunye nezixhobo ezikhoyo.

Izixhobo ezisisiseko zeLiDAR

Iinkqubo zeLiDAR ezisekelwe emhlabeni zihlala zisebenzisa iilaser ezinamaza obude obuphakathi kwe-500–600 nm, ngelixa iinkqubo zeLiDAR ezisebenzisa umoya zisebenzisa iilaser ezinamaza obude obude, ukusuka kwi-1000–1600 nm. Useto oluqhelekileyo lweLiDAR olusebenzisa umoya luquka iskena selaser, iyunithi yokulinganisa umgama (iyunithi yokujikeleza), kunye neenkqubo zokulawula, ukujonga, kunye nokurekhoda. Ikwabandakanya neNkqubo yokuPhakamisa iHlabathi eDifferential (DGPS) kunye neYunithi yokuMelekisa i-Inertial (IMU), edla ngokudityaniswa kwinkqubo enye eyaziwa ngokuba yinkqubo yendawo kunye nokuqondisa. Le nkqubo inika indawo echanekileyo (i-longitude, i-latitude, kunye nokuphakama) kunye nedatha yokujolisa (ukuqengqeleka, i-pitch, kunye nesihloko).

 Iipateni apho i-laser iskena khona indawo zingahluka, kuquka iindlela ezizigzag, ezilinganayo, okanye ezizii-elliptical. Ukudibanisa idatha ye-DGPS kunye ne-IMU, kunye nedatha yokulinganisa kunye neeparamitha zokufakela, kuvumela inkqubo ukuba icwangcise ngokuchanekileyo amanqaku e-laser aqokelelweyo. La manqaku emva koko anikwa ii-coordinates (x, y, z) kwinkqubo yokulungelelanisa yejografi esebenzisa i-World Geodetic System ka-1984 (WGS84) datum.

Indlela iLiDARUkuva okukudeImisebenziCacisa ngendlela elula

Inkqubo yeLiDAR ikhupha ii-laser pulses ezikhawulezayo zisiya kwinto ekujoliswe kuyo okanye kumphezulu.

Iipulse zelaser zibonakala kwithagethi zize zibuyele kwisensor yeLiDAR.

Isenzi silinganisa ngokuchanekileyo ixesha elithathwa yi-pulse nganye ukuya kwindawo ekujoliswe kuyo nasemva.

Ngokusebenzisa isantya sokukhanya kunye nexesha lokuhamba, umgama oya kwindawo ekujoliswe kuyo uyabalwa.

Xa idibene nedatha yendawo kunye nolwalathiso oluvela kwiisensa zeGPS kunye ne-IMU, ii-coordinates ezichanekileyo ze-3D zokubonakaliswa kwelaser ziyachongwa.

Oku kubangela ilifu elixineneyo le-3D elimele umphezulu okanye into eskeniweyo.

Umgaqo woBuchule beLiDAR

Iinkqubo zeLiDAR zisebenzisa iintlobo ezimbini zeeleser: i-pulsed kunye ne-continuous wave. Iinkqubo ze-Pulsed LiDAR zisebenza ngokuthumela i-pulse emfutshane yokukhanya, emva koko zilinganise ixesha elithathwayo ukuze le pulse iye kwithagethi kwaye ibuyele kwi-receiver. Olu linganiso lwexesha lokujika nokubuyela lunceda ekumiseleni umgama oya kwithagethi. Umzekelo uboniswe kumzobo apho i-amplitudes yesignali yokukhanya edluliselweyo (AT) kunye nesignali yokukhanya efunyenweyo (AR) iboniswa khona. I-equation esisiseko esetyenziswa kule nkqubo ibandakanya isantya sokukhanya (c) kunye nomgama oya kwithagethi (R), okuvumela inkqubo ukubala umgama ngokusekelwe ekubeni kuthatha ixesha elingakanani ukuba ukukhanya kubuye.