25/08/19Xa kuziwa ekubambeni imifanekiso echanekileyo nethembekileyo kuphando lwezenzululwazi, umgangatho wedatha yakho uxhomekeke ngaphezu kwesisombululo okanye ubungakanani boluvo. Enye yezona zinto zibalulekileyo-kodwa ngamanye amaxesha zingahoywa-iimetrics yi-Signal-to-Noise Ratio (SNR). Kwiinkqubo zokucinga, i-SNR imisela ukuba ungahlula njani ngokucacileyo isiginali (ulwazi oluluncedo) kwingxolo engafunekiyo.
Kwizicelo zezenzululwazi zokucinga ezifana ne-microscopy, i-astronomy, kunye ne-spectroscopy, i-SNR engalunganga ingathetha umahluko phakathi kokufumanisa itekeni ekujoliswe kuyo kwaye uyiphose ngokupheleleyo. Eli nqaku liphonononga indlela i-SNR echazwa ngayo, kutheni ibalulekile, iwuchaphazela njani umahluko, kunye nendlela yokukhetha kunye nokwandisa ikhamera yesayensi esekwe kule metric ibalulekileyo.
Yintoni iSignal-to-Noise Ratiyo kwaye ichazwa njani?
ISiginali kwiNgxoxo yeRatio (SNR) ngowona mlinganiselo ubalulekileyo womgangatho womfanekiso wethu, osisiseko kuthelekiso lwemifanekiso, kwaye kaninzi yeyona nto iluncedo yokumisela ukuba ikhamera inobuntununtunu ngokwaneleyo na kwisicelo sakho.
Iinzame zokuphucula ubuntununtunu bekhamera zijikeleza zombini ukuphuculwa kophawu oluqokelelweyo:
● Ngokuphuculwa kobuchule bobungakanani okanye ukonyuka kobungakanani bepixel
● Ukunciphisa imithombo yengxolo exhomekeke kwikhamera
Imithombo yengxolo idibanisa kunye, kodwa ngokuxhomekeke kwiimeko umntu anokulawula, kwaye kufuneka igxininise xa uzama ukuphucula i-SNR - mhlawumbi ngokuphucula useto okanye ukuseta, okanye ukuphuculwa kwemithombo yokukhanya engcono, i-optics, kunye neekhamera.
Yinto eqhelekileyo indlela emfutshane yokuchaza imifanekiso ngokomlinganiselo wesignali ukuya kwingxolo, umzekelo ukubanga umfanekiso une-SNR ye-'15'. Nangona kunjalo, njengoko kubonakala kwigama, umlinganiselo wesignali ukuya kwingxolo uxhomekeke kumqondiso, oya kwahluka kwipixel nganye. Oku kusinika umfanekiso wethu.
I-SNR yomfanekiso ibhekisa kwi-SNR yencopho yomqondiso womdla ngaphakathi komfanekiso. Umzekelo, i-SNR esuka kumfanekiso weeseli zefluorescent kumqolo omnyama ingasebenzisa incopho yesignali yokuqina ukusuka kwiipikseli zesakhiwo somdla ngaphakathi kweseli.
Akumelanga ukuthatha, umzekelo, ixabiso eliqhelekileyo le-SNR yomfanekiso wonke. Kubuchule obufana ne-fluorescence microscopy apho imvelaphi emnyama ene-zero echongiweyo yeefotoni inokuqheleka, ezi pixels zesignali zero zine-SNR enguziro. Ke ngoko, nawuphi na umndilili kumfanekiso uya kuxhomekeka ekubeni zingaphi iipixels ezingasemva eziboniweyo.
Kutheni i-SNR ibalulekile kwiiCamera zeNzululwazi
Kumfanekiso wenzululwazi, i-SNR ichaphazela ngokuthe ngqo indlela onokuthi uchonge ngayo iinkcukacha ezibuthathaka, ukulinganisa idatha yobungakanani, kunye nokuvelisa iziphumo.
●Umfanekiso Ukucaca-I-SNR ephezulu inciphisa i-graininess kwaye yenza izakhiwo ezintle zibonakale.
●Ukuchaneka kwedatha-Ukunciphisa iimpazamo zomlinganiselo kwimifuniselo esekwe ngamandla.
●Ukusebenza kokukhanya okuphantsi-Ibalulekile kwi-microscopy ye-fluorescence, i-astrophotography yesibhakabhaka enzulu, kunye ne-spectroscopy, apho ukubalwa kweefoton kuphantsi ngokwendalo.
Nokuba usebenzisa iIkhamera ye-sCMOSkwimifanekiso enesantya esiphezulu okanye iCCD epholileyo kwizicelo zokuvezwa ixesha elide, ukuqonda i-SNR kukunceda ulungelelanise urhwebo lwentsebenzo.
I-SNR iwuchaphazela njani uthelekiso lomfanekiso
Umahluko ngumahluko ozalanayo kubunzulu phakathi kweendawo ezikhanyayo kunye neendawo ezimnyama zomfanekiso. Kwizicelo ezininzi, ukuchasana okuhle komfanekiso phakathi kweendawo ezinomdla kuyinjongo yokugqibela.
Kukho izinto ezininzi ngaphakathi kwesihloko sokucinga, i-optical system kunye neemeko ze-imaging ezona zinto ziphambili zokumisela umahluko womfanekiso, njengomgangatho welensi kunye nobungakanani bokukhanya okungasemva.
●I-SNR ephezulu→ Ukwahlula okwahlukileyo phakathi kwemimandla eqaqambileyo nemnyama; imiphetho ibonakala ilungile; iinkcukacha ezifihlakeleyo zihlala zibonakala.
●I-SNR ephantsi→ Iindawo ezimnyama ziya ziqaqamba ngakumbi ngenxa yengxolo, iindawo eziqaqambileyo ziya ziba luzizi, kwaye umahluko womfanekiso uwonke uyacaba.
Umzekelo, kwi-microscopy ye-fluorescence, i-SNR ephantsi inokwenza isampulu ye-fluorescent ebuthathaka idibane ngasemva, yenze uhlalutyo lobungakanani lungathembeki. Kwi-astronomy, iinkwenkwezi ezibuthathaka okanye iminyele inokunyamalala ngokupheleleyo kwidatha enengxolo.
Nangona kunjalo, kukwakho izinto ngaphakathi kwekhamera ngokwayo - eyona nto iphambili yiSiginali yeNgxolo yeNgxolo. Ukuqhubela phambili, kwaye ngakumbi ekukhanyeni okuphantsi, ukuqina komfanekiso, indlela umfanekiso oboniswa ngayo kwimonitha, idlala indima enkulu kumohluko womfanekiso obonwayo. Ngengxolo ephezulu kwiindawo ezimnyama zomfanekiso, ii-algorithms zokulinganisa umfanekiso we-auto zinokuba nemida yazo ephantsi iseti ephantsi kakhulu ngexabiso eliphantsi leepikseli ezinengxolo, ngelixa i-high bound inyuswa yingxolo kwiipikseli zomqondiso ophezulu. Lo ngunobangela wophawu 'oluhlanjiweyo' lwembonakalo engwevu yemifanekiso ephantsi ye-SNR. Umahluko ongcono unokufumaneka ngokuseta umda osezantsi kwi-offset yekhamera.
Izinto ezichaphazela i-SNR kwiiCamera zeNzululwazi
Uyilo oluninzi kunye neeparamitha zokusebenza zinefuthe kwi-SNR yenkqubo yekhamera:
ITekhnoloji yoVavanyo
● I-sCMOS - Idibanisa ingxolo ephantsi yokufunda kunye namazinga aphezulu efreyimu, alungele ukulinganisa okuguquguqukayo.
● I-CCD - Ngokwembali inikezela ngengxolo ephantsi ekutyhilekeni okude, kodwa icotha kunoyilo lweCMOS lwangoku.
● I-EMCCD - Isebenzisa i-on-chip amplification ukunyusa iimpawu ezibuthathaka, kodwa inokwazisa ingxolo ephindaphindayo.
Ubungakanani bePixel kunye neFactor yokuZalisa
Iipikseli ezinkulu ziqokelela iifotoni ezininzi, zinyusa umqondiso kwaye ngaloo ndlela iSNR.
Ukusebenza kakuhle kwe-Quantum (QE)
I-QE ephezulu ithetha ukuba iifotoni ezininzi ezingenayo ziguqulelwa kwii-electron, ukuphucula i-SNR.
Ixesha lokungakhuseleki
Ukuboniswa ixesha elide kuqokelela iifotoni ezininzi, kwandisa uphawu, kodwa kunokonyusa ingxolo yangoku emnyama.
Iinkqubo zokupholisa
Ukupholisa kunciphisa ubumnyama bangoku, kuphucula kakhulu i-SNR yokubonisa ixesha elide.
Optics kunye nokukhanyisa
Iilensi ezikumgangatho ophezulu kunye nokukhanya okuzinzileyo kwandisa ukuthathwa kwesignali kunye nokunciphisa ukuguquguquka.
Imizekelo yeNqaku ePhakamileyo ye-SNR
Kumfanekiso, i-PSNR ihlala ibhekisa kubuninzi bethiyori xa kuthelekiswa nokuzaliswa kwepixel. Nangona kukho umahluko kwimixholo yemifanekiso, iimeko zokucinga kunye nobuchwepheshe bekhamera, kwiikhamera zenzululwazi eziqhelekileyo, imifanekiso enomlinganiselo ofanayo wesignali ukuya kwingxolo inokufana. Iqondo 'lobunkozo', ukwahluka ukusuka kwisakhelo ukuya kwisakhelo, kwaye ukuya kumlinganiselo othile umahluko, zonke zinokufana kuzo zonke iimeko zahlukeneyo. Ngoko ke, kunokwenzeka ukuba ufumane ukuqonda kwamaxabiso e-SNR kunye neemeko ezahlukeneyo kunye nemingeni abayithethayo kwimifanekiso emele, njengaleyo iboniswe kwitheyibhile.
PHAWULA: Incopho yexabiso lesignali kwii-photoelectrons kumqolo ngamnye inikwe ngebhlowu. Yonke imifanekiso ebonisiweyo nge-auto histogram scaling, ukungahoywa (i-saturating)0.35% yeepixels eziqaqambileyo nezimnyama. Ikholamu yemifanekiso emibini ekhohlo: Umfanekiso osekwe kwiLens wethagethi yovavanyo lomfanekiso. Iintsika ezine zasekunene: I-Ascaris ifakwe kwi-fluorescence ngenjongo ye-10x yemakroskopu. Ukubonisa ukwahluka kwesakhelo ukuya kwisakhelo kumaxabiso epixel kwiSNR esezantsi, izakhelo ezintathu ezilandelelanayo zinikiwe.
Umfanekiso osekwe kwilensi yethagethi yovavanyo, kunye nomfanekiso wemicroscopy wefluorescence zombini zibonisiwe, kunye nemboniselo esondisiweyo yomfanekiso wefluorescent obonisa umahluko phakathi kwezakhelo ezi-3 ezilandelelanayo. Incopho yokubala ye-elektroni yefoto kwinqanaba ngalinye lomqondiso likwanikezelwa.
Lo mzobo ulandelayo ubonisa iinguqulelo ezipheleleyo zale mizekelo yemifanekiso ukuze ireferensi.
Imifanekiso enobungakanani obupheleleyo esetyenziselwa umqondiso-kwingxolo yemizekelo yetheyibhile
Khohlo: Ithagethi yovavanyo lwemifanekiso efotwe ngelensi.
Kunene: Isampulu yecandelo le-Ascaris nematode worm lijongwe nge-fluorescence microscopy ku-10x magnification.
SNR kwizicelo
I-SNR ibaluleke kakhulu kwiinkalo ezahlukeneyo:
● I-Microscopy - Ukubona i-fluorescence efileyo kwiisampulu zebhayoloji kufuna i-SNR ephezulu ukuphepha iinegative ezibubuxoki.
● I-Astronomy - Ukuchonga iminyele ekude okanye ii-exoplanets kufuna utyhileko olude kunye nengxolo encinci.
● I-Spectroscopy - I-SNR ephezulu iqinisekisa imilinganiselo echanekileyo yobunzima bencopho kuhlalutyo lweekhemikhali.
● Ukuhlolwa kweShishini - Kwimigca yendibano yokukhanya ephantsi, i-SNR ephezulu inceda ukufumanisa iziphene ngokuthembekileyo.
Ukukhetha iKhamera yeNzululwazi ene-SNR eLungileyo
Xa uvavanya ikhamera yenzululwazi entsha:
●Jonga iiNgcaciso ze-SNR- Thelekisa amaxabiso e-dB phantsi kweemeko ezifanayo nesicelo sakho.
●Ulungelelaniso lwezinye iiMetrics-Qwalasela ukusebenza kakuhle kwe-quantum, uluhlu oluguquguqukayo, kunye nereyithi yesakhelo.
●Tshatisa iTekhnoloji yokuSebenzisa iCase- Kwimifanekiso eshukumayo enesantya esiphezulu, ikhamera ye-sCMOS inokulunga; kwizifundo ezingaguqukiyo ezinokukhanya okuphantsi kakhulu, iCCD epholileyo okanye i-EMCCD inokuqhuba ngcono.
●UQhagamshelwano lokuSebenza ngokuFanelekileyo-Ngelixa ingachaphazeli ngokuthe ngqo i-SNR, iimpawu ezinje nge-HDMI imveliso inokuvumela ukuphononongwa komfanekiso wexesha lokwenyani, kukunceda ukuba uqinisekise ngokukhawuleza ukuba useto lwakho lokufumana lufezekisa i-SNR oyifunayo.
Ukuqukumbela
I-Signal-to-Noise Ratio (SNR) yi-metric ephambili yokusebenza echaphazela ngokuthe ngqo ukucaca kunye nokuthembeka kwemifanekiso yesayensi. Ukuqonda indlela i-SNR echazwe ngayo, izinto ezichaphazelayo, kunye nefuthe lemilinganiselo eyahlukeneyo ye-SNR ivumela abaphandi kunye nabasebenzisi bezobugcisa ukuba bahlole iinkqubo zokucinga ngokufanelekileyo. Ngokusebenzisa olu lwazi—enoba kukukhetha entshaikhamera yenzululwaziokanye ukwandisa ukuseta okukhoyo-unokuqinisekisa ukuba i-imaging workflow yakho ibamba idatha kunye nenqanaba lokuchaneka elifunekayo kwisicelo sakho esithile.
Ii-FAQs
Yintoni ethathwa njenge "lungile" i-SNR yeekhamera zesayensi?
I-SNR efanelekileyo ixhomekeke kwisicelo. Ngomsebenzi onzima kakhulu, ubuninzi bomsebenzi-ofana ne-fluorescence microscopy okanye i-astronomy-i-SNR engaphezulu kwe-40 dB iyacetyiswa ngokubanzi, njengoko ivelisa imifanekiso kunye nengxolo encinci ebonakalayo kwaye igcina iinkcukacha ezintle. Ukusetyenziswa ngokubanzi kwebhubhoratri okanye ukuhlolwa kwemizi-mveliso, i-35-40 dB inokwanela. Nantoni na engaphantsi kwe-30 dB iya kubonisa okuziinkozo okubonakalayo kwaye inokuphazamisa ukuchaneka, ngakumbi kwiimeko ezisezantsi.
Ngaba ukusebenza kakuhle kwe-quantum (QE) kuyichaphazela njani i-SNR?
Ukusebenza kwe-Quantum kulinganisa ukuba isivamvo siguqula njani iifotoni ezingenayo zibe zii-electron. I-QE ephezulu ithetha ukuba ukukhanya okuninzi okukhoyo kubanjwe njengomqondiso, ukunyusa inani le-numerator kwi-equation ye-SNR. Oku kubaluleke ngakumbi kwiimeko zokukhanya okuphantsi, apho yonke ifoton ibala. Ngokomzekelo, ikhamera ye-sCMOS ene-QE ye-80% iya kufumana i-SNR ephezulu phantsi kweemeko ezifanayo xa kuthelekiswa ne-sensor ene-50% ye-QE, ngenxa yokuba ibamba isignali esebenzayo ngakumbi.
Yintoni umahluko phakathi kwe-SNR kunye ne-Contrast-to-Noise Ratio (CNR)?
Ngelixa i-SNR ilinganisa amandla ophawu ngokubanzi xa kuthelekiswa nengxolo, i-CNR igxile ekubonakaleni kwento ethile ngokuchasene nemvelaphi yayo. Kumfanekiso wenzululwazi, zombini zibalulekile: I-SNR ikuxelela ukuba "ucoceke" njani umfanekiso xa uwonke, ngelixa i-CNR imisela ukuba into ethile enomdla ime ngokwaneleyo ukuba ibonwe okanye ilinganiswe.
Uyafuna ukufunda ngakumbi? Jonga amanqaku anxulumeneyo:
Ubuchule beQuantum kwiiKhamera zeNzululwazi: Isikhokelo sabaQalayo
Tucsen Photonics Co., Ltd. Onke amalungelo agciniwe. Xa ucaphula, nceda wazise umthombo:www.tucsen.com
