sarvekshan patt

sarvekshan patt ki sahaayata se sarvekshan mein laga hua ek sarvekshak

sarvekshan patt ya 'plane tebul' (plane table ; 1830 ke pehle 'plain table') sarvekshan mein upayogi ek upakaran hai. sarvekshan patt ek thos samatal pradaan karta hai jis par draaing, chart aur maanachitr banaae jaate hain.

anukram

plane tebul sarvekshan

plenatebul sarvekshan (Planetable Survey) sarvekshan ki badi anokhi vidhi hai. sarvekshan ki anya adhikaansh vidhiyon mein pruthvi ki satah par binduon ki maap lekar, unka alag se pariklan evam aalekhan (plotting) kiya jaata hai. sarvekshan hetu vistrut kshetr mein pratyek vaanchhit bindu ki maap lekar aalekhan karna aasadhya parishramavaala hi naheen asambhav bhi hai. plenatebul sarvekshan mein yahi asaadhya adhyavasaaya atyant saadhya ban gaya hai. plenatebul sarvekshan ki kriya aisi hai ki ismein pruthvi ki satah par bina vaastavik maap liye binduon ki saapeksh sthitiyon ka seedha aur sahi aalekhan ho sakta hai. yaheen iski visheshata hai. iske atirikt prayukt upakaran saste aur saral evam kaaryavaahak saamaanya shikshaapraapt sarvekshak ho sakta hai. in aakarshak gunon ke kaaran sabhi deshon mein is vidhi ka vyaapak roop se prayog hota hai.

is kaarya mein nimnalikhit upakaran prayukt hote hain. (1) plenatebul ya patal, (2) tipaai (stand), (3) darsh rekhi (sight rule), (4) spirit lebil tatha talamaapi (spirit level) tatha (5) chunbakeeya diksoochak (magnetic compass).

upakaranon ka vivran

plenatebul banaane ke liye bhali prakaar mausam ke prabhaav se paki lakdi 12 se 15 semi. chaudi aur do se teen seinmi. moti pattiyon ko bhali prakaar jodkar 75 x 60 ya 60 x 50 varg seinmi. ka aayataakaar plenatebul takhta taiyaar kiya jaata hai. iski ek satah bhali prakaar chheelakar aur raindakar ekdam samatal kar di jaati hai. doosari or plenatebul ke kendra par dhaatu ki ek chakati laga di jaati hai, jismein tipaai par kasane ke liye choodiyaaain kati rahati hain.

tipaai mein teen pair pechon dvaara sir se jude rahate hain. pech dheele karke pair khiskaae ja sakte hain aur tipaai ka sir ekdam kshaitij kiya ja sakta hai. tipaai ke sir ke beechobeech bane chhed mein plenatebul kasa ja sakta hai. pairon ko khiskaakar plenatebul ko bhi spirit lebil se dekhkar kshaitij kiya ja sakta hai. plenatebul ko kasanevaale pech ko dheela karke takhte ko kshaitij tal mein ghumaaya ja sakta hai aur manachaahi sthiti mein kasakar sthir kiya ja sakta hai.

darsharekhi (sight rule)60 ya 75 seinmi. lambi, ek seinmi. moti aur lagbhag paaainch seinmi. chaudi dhaatu ya lakdi ka bana hota hai. iske donon lambe kinaare ekdam seedhe aur ek or ko dhaaloo hote hain, jisse seedhi aur sahi rekha kheenchna sambhav ho sake. darsharekhi ke donon siron par do drushya-vedhikaaeain ya pattiyaaain (sight vanes) lagi rahati hain. ek patti ke beech mein ek jhiri (slit) kati hoti hai, jismein se jhaaainkakar sarvekshak apne lakshya ko dekhta hai aur doosari patti ke beech ek dhaaga (thread) pirokar donon pattiyon ke siron par taan deta hai. ek patti mein kati jhiri, doosare mein piroya aur pattiyon ke siron par tana dhaaga is prakaar rakhe jaate hain ki vah ek hi samatal mein padein. jab darsharekhi kshaitij patal par rakha ho to jhiri aur dhaaga patal ke tal par lanb honge. yadi jhiri se jhaaainkakar dhaage se katata koi bhi door ka bindu ya vastu dekhi jaae to darsharekhi prekshak ki sthiti se us bindu ya vastu ki disha bataaega. yadi plenatebul par kaagaj madha ho aur usapar prekshak ki sthiti chinhit ha, to us samay darsharekhi ka ekarekhi kinaara prekshak ki kaagaj par lagi sthiti ko sparsh karta hua rakh jaae aur jhiri se hokar dhaage par katati vastu ya bindu dekhkar darsharekhi ke sparshi kinaare par rekha kheench di jaae to vah prekshak ki sthiti se us vastu ya bindu ki dishaarekha hogi, jise kiran (ray) kehte hain. yahi kriya kisi doosari sthiti se doharaane par ek hi bindu ki do sthitiyon se do kirnein aapas mein katakar pratichhed bindu (point of intersection) par usaki sahi saapeksh sthiti de deingi.

chunbakeeya diksoochak ek aayataakaar, kaach ke dhakkanavaale, peetal ke vaks mein chunbak ki ek sui ko ek keeli par aalanbit karke banaate hain. prayog na hone par sui ko aalanb se uthaakar sthir karne ka upaaya bhi rahata hai. isse plenatebul ko pratyek sthiti par sahi dishaaon mein rakhane mein sahaayata milti hai.

spirit levil

kaach ki nali mein halaka drav bharakar donon or se aise band kiya jaata hai ki uske andar vaayu ka ek bulabula bana rahe. nali ka aakaar halaka vakr liye hota hai. ise dhaatu ki ek chaukor nali mein aise drudh band karte hain ki vakr nali ka ubhara bhaag dhaatu ki nali ki ek satah par kate chhed se dikhaai padta rahe. ise spirit levil ya talamaapi kehte hain. yadi spirit levil tipaai par kase chitrapatal par rakha jaae aur tipaai ke pair aise jama diye jaaeain ki talamaapi ko kisi bhi do samakon dishaaon mein plenatebul par rakhane se usaka bulabula keindrit (centred) rahe to plenatebul kshaitij ho jaata hai. plenatebul kshaitij na hone se binduon ki kheenchi gayi kirnein pradhaanat: bahut ooainche ya neeche mein sthit hone se galat hongi. at: binduon ki sahi saapeksh sthitiyaaain praapt naheen hongi.

kaaryavidhi

vargaankit kaagaj par sarvekshan hetu kshetr mein sthit, aise vinduon ka, jinke niyaamak gyaat hon, vaanchhit paimaane par aalekhan kar diya jaata hai. yeh kaagaj plenatebul par madh diya jaata hai. kaagaj madhne ke kai tareeke hain. yadi sarvekshan kaarya bahut thode samay ka ho to kaagaj batan pinon se takhte par madh diya jaata hai. yadi ek ya do saptaah ka sarvekshan ho, jismein kaagaj ekdam sthir rahana aavashyak ho, to kaagaj ke chaaron kinaaron par ek sabal patale kaagaj ki jhaalar ya magaji lagaakar, us jhaalar ke badhe bhaag ko patal par drudhta se chipka dete hain. lambi avadhi tak chalanevaale sarvekshan, ya jismein kaagaj ka poornataya sthir rahana aavashyak ho usamein, kaagaj ko patal se lagbhag 15 seinmi. adhik lambe aur chaude kapde par chipka dete hain. fir kapda plenatebul ki satah par drudhta se kheenchakar chipka diya jaata hai. jab kapde par chipka kaagaj plenatebul par lagaate hain to kaagaj par vargaankan aur niyantran vinduon ka aalekhan kaagaj ko patal par madhne ke baad karte hain.

taduparaant jis kshetr mein sarvekshan karna hota hai, sarvekshak usamein sthit ek aise niyantran vindu par plenatebul le jaata hai jo uske kaagaj par ankit ho. aise vindu ko station kehte hain. station ke oopar tipaai ko uske pair failaakar lagbhag kshaitij rakha jaata hai aur usapar patal kas diya jaata hai. usapar talamaapi ko do kramaanugat samakon sthitiyon mein rakhakar tipaai ke pairon ko aise jamaaya jaata hai ki bulabula keindrit rahe. isse plenatebul kshaitij ho jaata hai. iske baad diksthaapan kiya jaata hai.

diksthaapan plenatebul ki us dasha ko kehte hain jab plenatebul ke chitr par ankit niyantran vinduon ko kaagaj par jodnevaali rekhaaeain unheen vinduon ko pruthvi par jodnevaali rekhaaon ke samaanaantar ho jaaeain. yeh dasha praapt karne ke liye sarvekshak nimn kriya karta hai : kalpana karein, sarvekshak bhoomi par bane A vindu par khada hai jiski kaagaj par lagi a sthit hai. isi prakaar ek doosare vindu ki bhaumik aur aalekhit sthitiyaaain kramash: B aur b hon, to sarvekshak apne darsharekhi ka ek kinaara aise rakhata hai ki (i) vah a aur b par sparshi rahe, (ii) dhaagevaali lakshya-vedhika b ki or aur jhiri waali lakshya-vedhika a ki or rahe. tab vah plenatebul ko tipaai par aise ghumaata hai ki darsharekhi ki jhiri se B bindu dhaage par katata dikhaai de. aisi dasha praapt hone par vah plenatebul kas deta hai. is prakaar patalachitr apni sahi ki dishaaon mein sthaapit ho jaata hai. is dasha mein yadi darsharekhi nirdeshak (fiducial) dhaar sarvekshak ki sthiti a aur kisi bhi doosare aalekhit vindu ko sparsh karti rakhi jaae to jhiri se dekhne par dekhe jaanevaale vindu ki bhaumik sthiti dhaage par kategi. yeh smaraneeya hai ki jhiri sadaiv prekshak ki or tatha dhaage waali drushyavedhika dekhe gaye vindu ki or rahegi.

uparyukt dasha mein patalachitr laakar, sarvekshak apni aalekhit sthiti a vindu par apni peinsil ke sahaare darsharekhi ki dhaar vindu ke sparshi rakhakar, anya vinduon ko jhiri se aagevaale jharokhe mein dhaage par katata dekhta hai aur unki or kirnein kheenchata hai. aisi kirnein vah un sabhi vinduon ki or kheenchata hai jinhein vah maanachitr par darshaana chaahata hai, jaise gaaainv, nadi, sadkon aadi ke mod aur sangam. mod aur sangam vindu hi isliye neta hai ki riju bhaag to vah vindu milaati rekhaaon se bhi bana sakat hai. yahi kriya vah doosare stationon par doharaat hai. isse kinheen bhi do stedhanon se di gayi ek hi bindu ki kirnein aapas mein katakar, pratichhedan par vindu ki sahi saapeksh sthiti de deingi. yeh sthitiyaaain usi paimaane par hongi jispar chaaaindon ka aalekhan hoga. yeh patalachitran ki pratichhed vidhi (method of intersection) kahalaati hai. yadi kirnein kheenchakar, unheen vinduon ki kramash: doori naapakar, kiran par paimaane se kaat li jaae to bhi sahi vindu praapt ho jaata hai. ise sarvekshan ki vikirn (radiation) vidhi kehte hain. kisi nadi, nahar, maarg aadi rekhak cheejon ke kinaare sthit ek station se door sthit adrushya station tak kramaanugat kirnein dekar doori naapakar, vindu lagaate hue unka sarvekshan ho to use chankraman (traverse) sarvekshan kehte hain.

kate vinduon ko rekhaaon dvaara milaakar sarvekshak vastuon ki aakrutiyaaain bana deta hai. maanachitr ko dekhkar bhoomi par aur bhoomi se maanachitr par bani vastuon ko pahachaanane ke liye saanketik chihnon ka vah prayog karta hai, jisse saamaan aakrutiyon mein bhi vibhedan ho sake. udaaharanaarth, nahar, sadak, relamaarg aadi ke sthaan par keval rekhaaeain baneingi, kintu sarvekshak unhein bhinn rangon aur dhangon se kheenchakar doosaron ko samajhaane mein samarth hota hai.

vinduon ke beech ki saapeksh ooainchaaiyaaain sarvekshak samochch (contour) rekhaaon se pradarshit karta hai. iske liye patalachitran ki kriya sarvottam hai. bhoomi saamane hai aur maapan, aalekhan aur chitran kriyaaeain saath saath chalti jaati hain. saapeksh ooainchaaiyaaain nikaalne ke liye natimaapi (clinometer) ka prayog hota hai. is yantr se prekshak apni sthiti par kisi bhi doosare vindu ki ooainchaai mein bhinnata ke kaaran bane kon (x) ka seedha sparshajya (tangent) padh sakta hai. patalachitr se us vindu ki apne se doori (d) nikaal sakta hai aur tab us vindu ki saapeksh ooainchaai (d tan x) nikaal leta hai. is prakaar sabhi vinduon ki saapeksh ooainchaaiyaaain gyaat kar leta hai. sarvekshak ki bhinn-bhinn sthitiyon se nikaali saapeksh ooainchaaiyon mein ekaroopata rakhane ke liye ooainchaaiyaaain kisi aadhaaratal se naapi jaati hain. yeh aadhaaratal saamaanyat: jvaar bhaate ka dhyaan rakhakar naape gaye samudra ka ausat tal maana jaata hai. is tal se samaan ooainchaai par sthit vinduon ko jodti rekha ko samochch rekha kehte hain. ise kheenchakar sarvekshak ooainchaai ka aabhaas karaata hai.

baahari kadiyaaain