Hotunan Hemisphere

Hemispherical daukar hoto, wanda aka fi sani da canopy daukar hoto, wata dabara ce don kimanta Hasken rana da kuma nuna yanayin shuke-shuke ta amfani da hotunan da aka dauka suna kallon sama ta hanyar ruwan tabarau mai zurfi ko ruwan tabarau (Rich 1990). Yawanci, kusurwar kallo tana kusanci ko daidai da digiri 180, don haka duk hanyoyin sararin samaniya suna bayyane a lokaci guda. Hotunan da suka samo asali suna yin rikodin lissafin sararin samaniya, ko kuma akasin haka lissafin sarari ta hanyar shuke-shuke ko wasu siffofin kusa da ƙasa. Ana iya auna wannan lissafin daidai kuma ana amfani dashi don lissafin radiation na hasken rana da aka watsa ta hanyar (ko kuma ta tsayar da) shuke-shuke, da kuma kimanta fannoni na tsarin shuke-fuki kamar alamar yankin ganye. Paul Rich (1989, 1990) da Robert Pearcy (1989) sun ba da cikakkun magunguna na filin da kuma hanyoyin nazari.

## Tarihi
Gilashin hemispherical (wanda aka fi sani da fisheye ko ruwan tabarau na sararin noma) Robin Hill ne ya tsara shi (1924) don duba sararin samaniya don nazarin yanayin yanayi na samar da girgije. Masu kula da gandun daji da masu ilimin muhalli sun yi amfani da dabarun daukar hoto don nazarin yanayin haske a cikin gandun daji ta hanyar bincika yanayin shimfidar shimfidar. Musamman, Evans da Coombe (1959) sun kiyasta hasken rana ta hanyar budewar gandun daji ta hanyar shimfida zane-zane na hanyar rana a kan hotuna na hemispherical. Daga baya, Margaret Anderson (1964, 1971) ta ba da cikakkiyar magani don lissafin watsawa kai tsaye da rarraba abubuwan da ke cikin hasken rana ta hanyar buɗewa ta amfani da hotuna na hemispherical. A wannan lokacin nazarin hotunan hemispherical ya buƙaci ƙididdigar jagora mai banƙyama na overlays na sararin samaniya da kuma hanyar rana. Tare da zuwan kwamfutocin mutum, masu bincike sun haɓaka dabarun dijital don nazarin saurin hotunan hemispherical (Chazdon da Field 1987, Rich 1988, 1989, 1990, Becker et al. 1989). A cikin 'yan shekarun nan, masu bincike sun fara amfani da kyamarori na dijital don tallafawa kyamarori masu fim, kuma ana haɓaka algorithms don rarraba hoto ta atomatik da bincike. Shirye-shiryen software na kasuwanci daban-daban sun zama samuwa don nazarin hotunan hemispherical, kuma an yi amfani da dabarar don amfani daban-daban a cikin ilimin muhalli, yanayin yanayi, gandun daji, da aikin gona.

## Aikace-aikacen
An yi amfani da hotunan Hemispherical cikin nasara a cikin aikace-aikace masu yawa waɗanda suka haɗa da halayyar microsite da kimantawar hasken rana kusa da ƙasa da ƙarƙashin rufin shuke-shuke. Misali, an yi amfani da hotunan hemispherical don nuna wuraren zama na hunturu don malamin sarki (Weiss et al. 1991), tasirin gefen gandun daji (Galo et al. 1991), tasirin rassan bishiyoyin gandun daji akan sake farfado da bishiyoyi (Rich et al. 1993), bambancin sararin samaniya da na lokaci na haske a cikin gandun daji na wurare masu zafi (Clark et al. 1996), tasirin guguwa a kan yanayin gandun daji da ke cikin al. 1997), don ingantaccen yankin yankin da kuma kula da ruwan inabi na al.

 

## Ka'idar

### Ƙididdigar Hasken rana
Ana lissafin abubuwan kai tsaye da rarraba na hasken rana daban (duba Ma'aunin radiation na duniya). Ana lissafin radiation kai tsaye a matsayin jimlar duk radiation kai kai tsaye (hasken rana) wanda ya samo asali ne daga hanyoyin sararin samaniya (marasa duhu) tare da hanyar rana. Hakazalika, ana lissafin hasken rana a matsayin jimlar duk hasken rana (wanda aka warwatsa daga yanayi) wanda ya samo asali ne daga kowane hanyar sararin samaniya mai ganuwa (ba a rufe shi ba) (duba hasken sararin samaniya). Adadin abubuwan da ke kai tsaye da rarraba suna ba da radiation na duniya.

Wadannan lissafi suna buƙatar rarrabawar ka'idoji ko ƙwarewa na radiation kai tsaye da rarraba a buɗe, ba tare da canopy ko wasu shingen sama ba. Yawancin lokaci ana yin lissafi don ko dai radiation mai aiki na photosynthetic (400-700 nanometers) ko insolation da aka haɗa a kan dukkan wavelengths, auna a cikin kilowatt-hours a kowace murabba'in mita (kW h / m2).

Babban zaton shi ne cewa mafi yawan hasken rana ya samo asali ne daga hanyoyin sararin samaniya masu ganuwa (maras duhu), tasirin tsari na farko mai ƙarfi, kuma cewa hasken da aka nuna daga rufin ko wasu siffofin kusa da ƙasa (maras ganuwa ko hanyoyin sararin sama masu duhu) ba shi da mahimmanci, ƙaramin sakamako na biyu. Wani zato shine cewa lissafin sararin samaniya (maras duhu) ba ya canzawa a lokacin da ake yin lissafi.

### Ƙididdigar Canopy
Alamun canopy, irin su alamar yankin ganye (LAI), sun dogara ne akan lissafin ɓangaren rata, rabo na sararin samaniya mai ganuwa (marasa duhu) a matsayin aikin shugabanci na sama. Ana lissafin yankin ganye yawanci a matsayin yankin ganye a kowane yanki na ƙasa wanda zai samar da rarrabawar raguwa da aka lura, idan aka ba da zaton rarraba kusurwar ganye, ko kuma sanannen rarraba kusurwa da kuma matakin tarawa. Lissafin LAI ta amfani da wannan hanyar kai tsaye na iya zama ba daidai ba. Don ƙarin bayani duba yankin yankin ganye.

## Alamomi

Direct Site Factor (DSF) shine rabo na radiation na hasken rana kai tsaye a wani wuri da aka ba da dangi ga wanda a buɗe, ko dai an haɗa shi a tsawon lokaci ko an warware shi bisa ga lokutan rana da / ko kakar.

Indirect Site Factor (ISF) shine rabo na hasken rana a wani wuri da aka ba shi dangane da wannan a bude, ko dai an haɗa shi a tsawon lokaci don duk hanyoyin sama ko kuma an warware shi ta hanyar jagorancin sararin sama.

Global Site Factor (GSF) shine rabo na hasken rana na duniya a wani wuri da aka ba da dangi dangane da wannan a buɗe, wanda aka lissafa a matsayin jimlar DSF da ISF da aka auna ta hanyar gudummawar dangi na abubuwan da ke cikin kai tsaye da rarraba. Wani lokaci ana kiran wannan alamar **Total Side Factor (TSF).**

Ana iya **gyara** alamomi ba tare da gyara su ba ko kuma gyara su don kusurwar abin da ya faru dangane da shimfidar wuri. Ƙididdigar da ba a gyara ba tana da nauyin hasken rana wanda ya samo asali daga dukkan bangarori daidai. Daidaita dabi'u suna da nauyin hasken rana ta hanyar cosine na kusurwar abin da ya faru, lissafin ainihin tsayarwa daga hanyoyin da suka dace zuwa saman tsayarwa.

Leaf Area Index shine jimlar yankin ganye a kowane yanki na ƙasa.

Gap Fraction (GapF) shine adadin a cikin kashi na canopy dangane da duk yankin auna.

## Hanyar da ake amfani da ita
Hemispherical daukar hoto ya ƙunshi matakai biyar: samun hoto, digitization, rajista, rarrabawa, da lissafi. Ana yin rajista, rarrabuwa, da lissafi ta amfani da software na nazarin daukar hoto na hemispherical.

### Samun hoto
Ana samun hotunan da ke kallon sama a ƙarƙashin hasken sararin samaniya, da wuri ko marigayi a rana ko a ƙarƙashin yanayin duhu. Sanannen daidaitawa (zenith da azimuth) yana da mahimmanci don rajista mai kyau tare da tsarin daidaitawa na hemispherical. Ko da hasken wuta yana da mahimmanci don daidaitaccen rarraba hoto. Hawan kai tsaye (gimbals) na iya sauƙaƙa saye ta hanyar tabbatar da cewa kyamarar ta daidaita don nuna kai tsaye zuwa zenith. Kamara yawanci ana daidaita ta yadda arewa (cikakke ko magnetic) ke daidaitawa zuwa saman hoton.

Gilashin da aka yi amfani da shi a cikin daukar hoto na hemispherical gabaɗaya fisheye ne mai zagaye, kamar ruwan tabarau na Nikkor 8mm fisheye. Cikakken fisheye ba su dace da daukar hoto na hemispherical ba, saboda kawai suna kama cikakken 180 ° a fadin diagonal, kuma ba sa samar da cikakken ra'ayi na hemisphere.

A farkon shekarun dabara, an samo mafi yawan hotunan hemispherical tare da kyamarori 35 mm (misali, Nikon FM2 tare da ruwan tabarau na Nikkor 8mm fisheye) ta amfani da babban bambanci, fim din ASA mai baƙar fata da fari. Daga baya, amfani da fim mai launi ko zane-zane ya zama ruwan dare. Kwanan nan ana samun yawancin hotuna ta amfani da kyamarori na dijital (misali, Kodak DCS Pro 14nx tare da ruwan tabarau na Nikkor 8mm fisheye).&nbsp;

Lokacin da aka samo hotuna daga wurare tare da manyan bambance-bambance a buɗewa (alal misali, wuraren rufewa da gibin canopy) yana da mahimmanci don sarrafa bayyanar kyamara. Idan an ba da izinin kyamarar ta daidaita bayyanar ta atomatik (wanda ke sarrafawa ta hanyar buɗewa da saurin rufewa), sakamakon shi ne cewa ƙananan buɗewa a cikin yanayin rufewa za su kasance masu haske, yayin da buɗewa iri ɗaya a cikin yanayin buɗewa za su zama duhu (alal misali, wuraren canopy a kusa da rata). Wannan yana nufin cewa a lokacin nazarin hoton za a fassara ramuka masu girman iri ɗaya a matsayin "sama" a cikin hoton rufe-canopy da "canopy" a cikin hoto mai buɗewa. Ba tare da sarrafa fallasawa ba, ainihin bambance-bambance tsakanin yanayin rufe- da bude-canopy za a rage su.

### Digitization
Ana sarrafa hotuna kuma ana adana su a cikin daidaitattun tsarin hoto. Ga kyamarorin fim wannan mataki yana buƙatar na'urar daukar hoto mara kyau ko slide ko mai sarrafa bidiyo. Ga kyamarori na dijital wannan mataki yana faruwa yayin da ake samun hotuna.

### Rijistar
Rijistar daukar hoto ta haɗa da daidaita hotunan tare da tsarin daidaitawa na hemispherical da aka yi amfani da shi don bincike, dangane da fassarar (tsakiya), girman (haɗuwa da gefen hoto da sararin samaniya a cikin tsarin daidaitawa), da juyawa (haɗakarwa ta azimuthal dangane da hanyoyin compass).

### Rarraba
Rarrabawar hoto ya haɗa da ƙayyade wane pixels na hoto ke wakiltar bayyane (ba a rufe shi ba) da ba a gani ba (ba a gani ba) hanyoyin sararin samaniya. Yawanci an kammala wannan ta amfani da ƙofar hulɗa, inda aka zaɓi ƙofar da ta dace don dacewa da rarrabawar binary tare da lura da hangen nesa na sama, tare da ƙimar ƙarfin pixel sama da ƙofar da aka rarraba a matsayin bayyane da ƙimar ƙarfi na pixel a ƙasa da ƙofar an rarraba shi a matsayin wanda ba a gani ba. Kwanan nan an sami ci gaba a cikin haɓaka ƙofar ƙofar atomatik, duk da haka ana buƙatar ƙarin aiki kafin waɗannan su zama cikakke abin dogaro

### Ƙididdiga
Lissafin hoto na Hemispherical yana amfani da algorithms waɗanda ke lissafin raguwar rata a matsayin aikin shugabancin sama, da lissafin lissafin lissafi da ake so da / ko alamun hasken rana. Don hasken rana, ana yin lissafi mai sauri sau da yawa ta amfani da teburin binciken da aka riga aka lissafa na ƙididdigar ƙididdigarsa ta hasken rana ko ƙididdiga wanda ɓangaren sama ko matsayi a cikin hanyar rana ya warware.

## Dubi kuma

* Leaf area index
* Panoramic photography
* View factor
* Whole sky camera

## Bayanan da aka ambata