Advanced surveying instruments

Surveying is considered as one of the oldest field of Civil Engineering. As days passes we can see lot of improvements in technology. In this ppt we can able to see latest instruments used for surveying

1. ADVANCED SURVEYING INSTRUMENTS AJEY KUMAR V G M.Tech- Construction Technology BMS COLLEGE OF ENGINEERING

2. Surveying ? Sur v e y in g is t h e s c ie n c e an d a r t of d ete r minin g the r ela tiv e p o s it i o ns o f p o i nts a b o v e, o n , or b e n e ath the e a rth ’s s u r fa c e and loca ti n g the p oints i n t h e fie l d.

3. The w ork of t he s u rve y or con s ists of 5 phases D e cisio n Ma k ing – s e le c ting meth o d , eq u ipm e n t a nd final poin t loc a tions. Field w o r k & D ata C o l l e ction – ma k in g me a s u reme nts a nd rec o rding d ata i n t h e field. Com p uti n g & Dat a Proces s ing – preparing c a lc u lation s b as e d u p o n t h e record e d d ata to d etermine lo c ation s i n a u s e a bl e form. Ma p ping or Dat a R epres e n tation – plottin g d ata to produ c e a map, plat , o r ch a rt i n the prope r f orm. Stak e o ut – lo c atin g a nd e s tablish in g mo n um e nt s or sta k e s i n the pro p e r loc a tions i n the field.

4. Different categories of Surveying Plane S urv e y i n g – su rv e y in g w i th the r efe r e nce b ase for fi eld wor k a n d c om p ut ati o n s a r e a s s um e d to b e a flat h orizo n t a l sur f a c e . Geodetic S u r v e y i n g – su rv e y in g t e c h niq u e to d ete r mine re la tiv e p o s it i o ns o f wi d e l y sp a c e d p o in ts, le n gth s , a n d d i r ec t io n s whi c h r e q uir e t h e co n s id e r at i o n o f the si z e an d shap e of the e a r t h . (Takes the ear t h’s cu rv ature in t o ac c ou n t.)

5. Types of surveying Phot o gram m etry – mapp i n g ut i l i z i n g dat a ob t a i ne d b y c a mera or othe r se n sors carried i n airplan e s o r s ate l l i tes. Boun d ar y Surve y ing – e s tab l i s hi ng pro pe rty c orners, b o un d ar i e s, an d are a s o f l an d p arc e ls. Engi n eeri n g Surve y ing – pr ovidin g po i nts a nd e levation s for the bu i l d i ng Civi l Eng i ne erin g pro j e cts Topographic Surve y ing – c ol l e ctin g da ta a n d pre pa ri ng maps s h owi n g the lo c atio n s o f n at ural ma n -made feature s an d e l evati o ns o f poi nts o f the gr o un d. Rout e Surve y s – top og r ap hi c a nd other s u rve y s for l o n g – na rrow pro j ec t s ass oc i ate d w ith Civi l Engi neer i n g proje cts ( H ighways, ra ilro a d s , pipelin es) H y drographic Surve y ing – mapp i n g o f s ho r e l i n e s an d the b ottom o f bod i e s o f wate r .

6. Instruments used for surveying past decades C h ain. Ranging. C r o s s S t af f . S t ee l ban d . Tape. P lan e tab l es. C ompa s s. Levelling. Theod olites . (Ver nie r & Micromete r ) Ta c heometer.

7. By the 1970 ’ s, re l at i vely sma l l, l i ghtwei ght and ea s y -to- u s e el ectro nic di s tan c e measur i n g devic es, c al l e d ED M ’ s wer e i n use. The a dvance o f t e c hn ol o g y an d mini at uriz at i o n o f el ectronic c o mponents e n ab l e d the b u i l d i n g o f t he o do l it e s that mea s ure an gl es e l e ctronic a l ly , c al l e d Electronic Theodolite Co m binati o n o f an el ectro nic theodol i te a nd e l ec t ronic d is tan c e meter, an d softw are run n i n g o n a n extern a l l aptop c omput er k n own a s a data c o l lect or , c al l e d Tot al Station The Global Positioning S y st em (GPS) wa s d es i gn e d for mil i tary ap pl i c atio n s. Its pr i mary pu r po s e wa s to a l l ow s ol d i ers to k ee p track o f their po s it i o n a nd to as sist i n g uiding weapon s to th ei r t argets A c o mputer i z e d da ta b a s e man a geme nt syst em for c a pt ure, st ora ge , retrieval, an a lys i s, an d d ispl ay o f s pa tial data , c al l e d GIS

8. Advanced surveying equipments Electr o n i c Theo d oli t e EDM – Electr o n i c d i s t a nce meas u r e ment e q p. Auto L evel. Dig i tal L e vel. L ase r Le v e l . L ase r Dist a n c e m eter Total sta t io n. G P S – gl o ba l po s itio ni n g s y ste m.

9. 1. Elec t ronic Thoedoli t e For precis e surveys th e vernier theo d o l ite s ar e rep l ac e d b y mod e rn theodo l ite s such a s optica l and el ect ron i c the o do l ites. The e l ect ron i c theodo l ite s have o p tical system to scan both horizo n tal an d vert ic a l circles and dis p l a y them d i gita l l y o n a scr een

10. 2. EDM (E l ect r onic Distance me t er) 1 . ED M i s E l e ctronic D i stance meter Measurement o f d istanc e i s do n e b y a modu l ate d m i cro w av e or inf rare d carr i e r si g nal T h e d i stance i s d e termined by emit ti n g an d receiv i n g multip l e f req u enc i es , an d dete r min i n g the i n teger numbe r o f w av e lengths to the target for e a ch frequ e n c y.

11. Principle of EDM The g ene r al pr i n ci p le i n vol v es se ndi n g a mo du lated Electr o - m agnetic (EM) beam fr o m o n e trans m itter at t h e m as t er s t ati o n to a ref l ector at t h e re m o te s t ati o n and recei vi n g it b ack at t h e m as t er s t ati o n. The in stru m ent m e a su r es s lo p e di s tance betw e en t r an s m i t ter and recei v er b y m odulat i n g t h e co nt i nuou s car r ier wave at di f fe r ent f r eq u encie s, and t h en m eas ur i n g t h e p h ase di f fe r ence at t h e m as t er s t ati o n between t h e o utg o i ng and th e inc o m in g sig nal s . This es t ab l ish es t h e f o l l o wi n g re l ati o n s h ip f o r a d o ub le dis ta n ce ( 2 D):

12. Me a s u re m ent with EDMI in v o lv es f o ur bas i c s t ep s: Set up Aim Meas u re Record Se t t i ng up : The ins t ru m ent is c entered o v er a statio n b y m eans of tr i b r a c h . R efle c tor p r isms a re set o v er t h e re m o te stati o n o n tr i b r a c h . OPE R A TION WITH EDMI

13. ERR O R IN MEA S URE M ENT WITH EDMI 1 . I n s t rume n t er r o rs : cente r i n g at the m aster and s l ave stati o n. poi n t i ng/si g hting of reflecto r . en t ry of co r rect v al u es of p re v ail i n g at m o s p h er i c co n di t i o ns .

14. Atm o s p heric er r o rs : Meteo r ol o g ical co n di t i o n s ( t e m p erat u re, p re s s u re, hu m i d i t y , etc.) h ave to b e taken i n to ac c ount to co r rect f o r t he s y s t e m atic er r or arisin g d u e to th i s. The s e e r r o rs can b e re m ov ed b y ap p l y i n g an ap p r o pr i ate at m o s p h er i c co r rect io n m od el t h at ta k es care of d i f fe r ent m eteo r ol o g ical p ara m eters f r o m t h e s t an d ard o n e. I n s t rume n t a l er r o r : Co n s i s t s of th ree comp on en t s - scale e r r o r , z ero err or and cyclic er r o r . These are s y s t e m atic in nat u re

15. 3. Auto L e v e l N o w most c om m on l y use d leve l ling i n struments a re - A u to l e v e l . A uto l eve l, a s nam e sou n d s i t ha s a aut o l e vel compensator an d corr ects automatica l l y i f i nst rumen t go e s out of l e vel w i thin it’s range. With aut o lev e l : - S u rvey w or k can b e do n e fast, Les s cha n ces o f e r r or, Mag n ifi c ati o n av a i l abl e i s more, R a ng e i s mor e, I m ag e i s erec t so l e ss cha n ces of er r or.

16. 4. Digit a l L e v e l Th e y ar e no t po p ul a r i n stead aut o lev e ls ar e more e x tensiv e l y use d. The T rimble D i N i D i gita l Lev e l : D e ter m i n e accurat e he i gh t i n for m ation 60 % fast e r than w ith automati c leve l i n g E l im i n a te error s a n d redu c e rew o rk with di g ita l read i ngs Transfer dat a t o the of fic e e asi l y Measure to a fi e l d o f jus t 3 cm

17. 5. L a s e r L e v e l The w or d laser i s a n acrony m for Li g ht Ampl i fication b y Stimul a ted Emiss i o n of R a di a tion an d i s the n am e appl i e d to a n i n tense bea m o f h i g hl y monochromatic, coh e rent l i g ht. L a ser rang e fin d er s us e t h e se relati o nsh i p s to c a lc u l ate D i stance Distanc e = sp e e d of light * (t ime/2) The time refe r s to time o f p uls e to g o fr o m the i n strument to the tr e e a n d b a ck ag a in By usi n g this Lase r distanc e met e r w e can ca l cu l at e the distanc e, are a and vo l um e accura t ely We can us e this i n ni g h t also

18. 6. GPS – Global P o sit i o n ing S y stem. What is GPS? GP S , w h ic h stan d s for Glo b a l P o sit i o n i n g System , i s the o nl y system to d a y ab l e to show you your e x ac t pos i tion o n the E ar t h anytime , i n an y we ather, anywh ere. Glob a l P o siti o nin g System – A netw o rk o f satel l ite s (24 tota l – 2 1 i n use , 3 spares) that conti n uo u sly t ransmi t c o de d i n for m ati on w h ic h makes i t p oss i b l e to prec i se l y i d e n tify l o catio n s o n eart h b y m eas u ring distance f ro m the sat el l ite s .

19. 7.EDM + T h e o dol i te E D M i s use d to meas u re the h o rizo n tal distanc es . S o me E D M a re at tach e d with el ect ron i cs the o do l it e w h ic h ha s the a d a p ter system. S o me a re advance d mode l s w h ic h itse lf reads the distanc e w i thout theodo l ite

20. 8.Tot a l Stat i on A T o tal statio n i n tegrates the functi o ns o f a Electronic theodoli t e for measuring an g l es, a n ED M for measuring distanc es, di g ita l dat a an d a d a ta record e r A n gl e s an d distances , coord i nate s and he i gh t dif ference s an d many othe r items can b e computed, dis p l a yed an d stored i nto i nterna l mem ory.

21. F e atur e s of Tot a l Stat i on Total soluti o n for s u r v e yi n g w ork, Most accur a te a n d use r fri e n d ly, Giv e s p o s i tion o f a p o in t ( x, y a n d z) w . r. t. known p o in t ( b a se p o int), C o mpatibility wit h computers, Measur e s dis t a n ce a n d a n gle s a n d displa y s coor d inates, Auto le v e l c omp e nsato r i s a v aila b le, C a n w o rk i n le s ser visibili t y also, C a n measure dis t a n ces e v e n withou t pris m atic tar g e t for lesse r distances, Is w ater pr o of, On b o a r d s oftwar e a r e a v aila b le, C a n b e use d for c u r ve lay o u t afte r f e e din g d ata

22. F e atur e s of Tot a l Stat i on N e w t otal stat i ons hav e a t mospheric correctio n , a n d aut o-focus. In ad d iti o n , these series i n corporates a qu i ck distanc e measuring mode an d a hi g h dat a s torag e cap a city for i n creased prod u ctiv i ty. The n e w Total stat i on giv e s the un i que op p ortunit y for l o n g range d i stance monitoring o f u p t o 90 m to a sing l e prism. Us i n g the scan functiona l it y o f s of tw a re al l ow s ful l y automate d m on i toring o f the pris m i n directio n o f the l i n e o f s i ght.

23. Parts of Tot a l Stat i on

24. tion m . in f init y - proj e ct. org The Carut h Insti tut e f o r E ngine e rin g Educ a tion Enginee ring Edu ca for toda y ’s classroo

25. US E S: - T o t al S ta tions ca n be used f or: Gene r al purpos e an g l e measu r eme n t Gene r al pu r pose d i s t ance measu r eme n t P r o v i sion of c o n t r ol su r v e y s Co n t our and d e t ail mappi n g S e t ti n g o ut and c on s truct i on w ork

26. S T OR A GE M ost TS h ave o n - b o ard s t o r age of re c o r ds us i ng PCMCIA m e m o r y cards of d i f fe r ent c apacit y . The card m e m o ry unit can b e co nn ected to a n y ex t er n al comp uter or t o a s p ecial card rea d er f o r d ata tran s fe r . The o b servatio n s c a n also be downl o aded di r e c tly i n to i n tel l i g ent elect r on ic d ata logg er s. Bo t h s y s t e m s can b e u s ed i n re v er s e t o l o ad i nf o rm a t i o n i n to t h e i n s t r u m en t s. S o m e in stru m ents and/ or data lo g gers c a n be i n te r faced d i r ectly wi t h a c o m puter f o r im m ed i ate pr o cess i n g and p l ot t i n g of t h e data ( Kava n ag h , 2003).

27. FIELD OPER A TION WITH TS V ari o us f i eld o perati o ns in TS are in th e f o rm of wi d e v ar i ety of p r o g ra m s i n te g ra t ed with m ic r opr o cess o r and imple m en t ed wi t h t h e h elp of da t a col l ecto r . All t h ese pr o g ra m s n eed t h at t h e in s t r u m ent s t ati o n and at least o n e refere n ce stat i on be i d ent i f i ed so th at all s ub se qu ent s t ati o n s can b e i d en t i f ied in te r m s of (X, Y , Z). T yp ical pr o g ra m s i n cl ud e t h e fol l o wi n g f u nct i o n s:

28. P o int lo cation Mi s s i n g lin e m e a s u re m ent (MLM) Resecti o n Re m o t e di s tance and el e vation m e a su r e m ent O f f s et m eas u re m en t s Lay out o r s ett i n g out o p erat i o n Area c o m p u tat i on F o r d etai l s on ab o v e f u ncti o ns, o n e can re f er to t h e u ser m an u al of a n y TS.

29. D iffe r ent T ypes of TS and acce s so ries T r i m b l e( 5 6 I R)

30. F ac t o r s i nf l u e nc i n g the us e o f T o t al S t a tio ns: A clear l i ne o f s ig h t b e t w een the in s tr u me n t and the measu r ed po i n ts is esse n tial. The p r eci s ion of t he in s tr u me n t is depende n t o n the r a w r epe a t abilities o f the d i r ect io n and d i s t ance measu r eme n ts. A w ell d e f i ned mea s u r eme n t poi n t or t a r g e t /pr i s m is r equ i r ed t o ob t ain opt i mal p r eci s i o n and ac c u r ac y . The accu r acy of d i r ection and di s t ance measu r eme n t is subjec t t o a numbe r of i n s trume n t al er r o r s and the c or r ect f ield p r oc e du r es.

31. Aux i lia r y E qu i p me n t R equ i r ed T a r g e ts or Pr i sms t o accu r a t ely d e f i ne the t a r g et po i n t o f a d i r ect io n measu r eme n t. A d a t a r e c o r der if o ne i s not i n t eg r a t ed i n t o the t o t al st a ti on. A d o wnload c able a n d sof t w a r e on a PC t o c a p tu r e and p r oces s the c a p tu r ed d igi t al d a t a t o p r oduc e c o n t ou r and de t ail ma p s.

32. N o rmal A c c uracy a n d ran g es of total stations Angu l ar a c cura c y up to 1” Dis t a nce me asu r e d with lase r u p t o 2 KM Dis t a nce me asu r e d with in frar e d r a y s u p to 4K M .( with sin gle p r ism) Cap a b l e o f st orin g u p t o 20 , p oin ts.

33. Basic Principle of Total Stations These inst r u m ents are m e a s uri n g th e d i stances of p r ism p o les m o u nted with p r is m s with the help of L as e r beam or Inf r ared ray s. These sig n als are e m itted by th e inst r u m ent EDM and refle c ted back to in stru m ents by the prism m o u nted on the p r ism p oles. The ti m e in terval betwe e n e m issio n and r e c epti o n hel p s to c alculate th e d i stance as the speed of these sig nals are p r e c isely k n ow n. D = ( t /2) x v D - Distance, t - Total ti m e taken, v - Velocity

34. Sett i ng up of Tot a l Stat i on C e ntering: P l ac e t h e le g s a t e q u a l i n tervals a n d the he a d i s appro x imatel y l e vel Fix th e t ri p o d sho e s i n the ground P l ac e the instru m en t o n the t ripod s tand S u pp or ti n g the i nst rumen t w ith on e ha n d, tighten the centering screw o n the botto m o f the un it L o ok i n g through the o p tical p l umme t eye pi e ce focus o n the Surveyi n g po i nt

35. Le v el l ing: Adjust the foot s c re w s to c e nte r the s u rvey i ng poin t i n t h e optica l plumme t reticule C e nte r the bub b l e i n t h e ci r c u la r leve l b y s h o rtening o b y lengthenin g the tripod leg Turn the levelin g s c re w s unti l the bub b l e i s c e ntere d i the center ci r cle Loo s e n the ho r iz o nta l clamp to turn the upp e r pa r t of the in strument unti l the plat e leve l i s paralle l to a line betwe e n levelin g foot s c re w s A & B C e nte r the ai r bub b l e u s in g levelin g foot s c re w s A & simul t aneou s ly Turn the upp e r pa r t o f the in strument through 900 The plat e l eve l i s no w pe r pen d ic u la r to the foot s c re ws A & B C e nte r the ai r bub b l e u s in g levelin g foot s c rew C

36. Elimi n at i ng para l lax This is t h e rel at i ve d i splace ment o f the t a r g et ima g e w i th r esp e ct to the retic l e whe n the observer’ s hea d i s m ove d sligh t l y befor e the e y e piece . Parallax can b e re mo v e d b y f ocus i n g the retic le Format of Stor a ge i n Total Sta t ion Point Id Easting (x – Coordinate) North i ng (y – Coordinate) Elevat i on ( z -Coordinate) Point code [ Str i ng l i ke TR for t r ee CW for co m pound wall etc ]

37. Remote Elevated Mea s urement (REM) An REM is a func t io n u se d t o mea s u r e the he i gh t to a p oi n t whe r e a t arge t ca n n o t b e d i r ec t ly ins t a l le d s u c h as p o we r lin e s, ove r h e a d c a bles et c .,

38. 9. REMO T E SENSING Scie n ce and art of o b t ain i ng inf o rm a t i on ab o ut an object, area, or p h en o m en o n t h r o ug h t h e anal y s i s of d ata acq ui r ed by a de v ice th at is n o t in c on tact wi t h t h e o b ject, area, or p h en o m en o n u n d er i nv es t i g ation

39. REMO T E SENSING SYESTEM A ty p i cal re m o t e s en sin g s y s t em co n s i s t s of th e f o llo wi n g s u b - s y s t e m s: sce n e s en sor p r oces sin g ( g r o u n d) se g m ent V ar i ou s s ta g es in t h ese s u b - s y ste m s are in d i c a ted in t h e ne xt fi g ure. The electr o - m agnetic (EM) ene r gy fo r m s the f u nd a m en t al comp on ent of a RS s y s t em

40. AP P LIC A TION OF RE M OTE SENSING Agri c ul t u r e:- Crop c o n d i tio n assess m ent. Crop yield esti m ation U r b a n Plannin g : - Inf r astr u cture m app i n g. L a nd u s e change detectio n. F u tu r e u r ban expansi o n plan n ing

41. I N C Y C L ONE: C y c lo n e Le h ar b y KA L P A N A 1 C y c lo n e Helen b y Ma n g al ay an E x am p l e: M I T I GA T I O N P R EPARE D N E SS R E SC U E REC O V ERY S A TEL L I TES U SE D : R i s k modelling; vulne r a b ili t y a n al y s i s. E arly w arning; l o n g- r a n g e c lim at e modelli n g I d e n ti fy i n g esca p e routes; cri si s ma pp i n g ; im p act assess m en t ; cyclo n e m o n it o ri n g ; st o rm surg e p red i cti o n s . Dama g e as s ess m e n t; s p a tial pla n ni n g. KAL P AN A -1; IN S A T- 3 A; QuikS c a t r a d ar; M et eo s a t

42. IN E A R THQ U AK E S: Th e W orld A g en cy of Plane t a r y Moni t oring and E a r thqua k e Ri s k R ed u c tion ( W APM E RR) u se s r e m o t e s e n s i ng t o i mp r o v e k n o w le d g e o f bu il d i n g s t oc k s — f o r e x a mp le t h e n umb er a n d h eig h t o f bu il d i n gs. High r esol u ti o n i m a g e r y c an al s o h elp h a z a r d m a pp i n g t o g u i d e bu il d i n g c ode s a n d d i sa s t er p r e p a r e dn ess s t r at e g ies. M ITI G A TION PRE P AREDN E SS R E SC U E R E C O VE R Y S A TEL L IT E S U S E D B u i ld i n g st o ck assess m e n t ; h a z ard m a pp i n g . Measur i n g stra in accum u la t i o n . Pla n n i n g ro u tes f or search a n d rescue; d ama g e assess m en t ; e v ac u ati o n p la n n i n g ; d eformat i o n ma p p i ng . Dama g e assess m en t ; i d ent ify i n g s ites f or reh ab i l itati o n . PALS A R; IKO NO S 2; I n SAR ; SP O T ; IRS

43. I N F L OODS : Se n ti n e l Asia — a t eam o f 51 o rg anis a tio n s f r o m 18 c o u n tries — d eli v e r s r e m o t e se n s i n g d at a via t h e I n t er n e t as ea s y- t o-i n t er p r e t i nf o r m a ti o n f o r b ot h early w arni n g a n d f l o o d d a m a g e as ses s m e n t a c r o s s Asia. I t u se s t h e D art mou t h Flood O b se r v at or y' s ( D FO 's) Ri v er W at c h f l o o d d et e c ti o n a n d m eas u r e m e n t s y s t e m , b ased on AMS R -E d at a, t o m ap f l o o d h a z a r d s a n d w arn d i sa s t er m a n a g e r s a n d r esi d e n ts in f lo o d - p r on e a r eas when ri v e r s a r e li k ely t o b u r s t t h e ir b a n k s. F l o o d In U t t a r akhand F l o o d In A ss a m M ITI G A TION PRE P AREDN E SS R E SC U E R E C O VE R Y S A TEL L IT E S U S E D Ma p pi n g fl o o d -p r one a r ea s; deli n e a ti n g fl o o d -plai n s; la nd - u s e ma p ping. F lo o d d et ecti o n ; early w ar n ing; r ai n f all ma p ping. F lo o d ma p ping; e v acu a ti o n pla n ni n g; dama g e assessme n t. Dama g e assessme n t; s p a tial pla n ni n g. T r o p i c al Rai n f all M o n i t o ri n g Mi ss i o n ; A M SR -E; KAL P A N A I;

44. IN O THER DI S A S TE R S: PRE P AREDN E SS R E C O VE R Y DI S A S TER M ITI G A TION R E SC U E S A TEL L IT E S U S E D D RO U GHT Ri s k m o d ell in g ; v u l n era b i l ity a n alysi s; la n d a n d water ma n a g e m ent p la n n i n g . Weather f orecasti n g ; vegetati o n m o n i t o ri n g ; crop water req u irement ma pp i n g ; ear l y war n i ng . Mo n it o ri n g vegetati o n; da m age ass e ssmen t . I n f ormi n g d ro ugh t miti g a t i o n . FEW S N E T ; A V H R R ; M O DIS; S P O T V O L CANO Ri s k model l in g ; ha zard m a ppin g ; dig i t al eleva t i o n model s . Em iss i o n s m o ni t o ri n g ; t he r m al a l er ts . Mapp i n g l a va f l ows ; evacu a t i o n p l ann i n g . Dam a g e a ss es s m en t ; s pa t i a l pl a nnin g . M O DIS a n d A V H R R ; H ype rion FIRE Ma pp i n g f i r e -p ro n e areas; m o n it o ri n g fu el l o a d ; ri s k m o d ell ing . Fi re d etectio n ; p red i cti n g spr ead/ d irecti o n o f f i r e; early warn i ng . C oo rd inat i n g f i r e f i ght i n g e ff o rts. Dama g e assess m en t . M O DIS; SE R V I R ; S e n t inel Asi a; AFIS LANDSLIDE Ri s k mo d el l i n g ; h a z ard m a pp i n g ; d i g ital ele v ation m o d el s. M o n it o r in g r a i n fa ll a n d s l ope stabi l i ty. Map p i n g affect e d areas; Dama g e assess m en t ; spa tial p la n n i n g ; su g g esti n g ma n a g e m ent p ract i ces. P AL S A R ; I K ONO S 2; In S A R ; S P O T ; I R S

45. 10.LiDAR LiDAR (Light Detection And Ranging, also LADAR) is an optical remote sensing technology that can measure the distance to, or other properties of a target by illuminating the target with light, often using pulses from a laser..

46. Basic Principle LiDAR is fundamentally a distance technology. From an airplane or helicopter, LiDAR systems actively sends light energy to the ground. This  pulse  hits the ground and returns to the sensor. Basically, it measures how long it takes for the emitted light to return back to the sensor. In the end, it gets a variable distance to the Earth.

47. 11.Drones(UAV) in surveying An  unmanned aerial vehicle  ( UAV ), commonly known as a  drone , is an  aircraft  without a human  pilot  onboard. UAVs are a component of an  unmanned aircraft system (UAS) ; which include a UAV, a ground-based controller, and a system of communications between the two.  Drone technology allows for safe mapping of terrains and property, producing high-quality surveying results that equal or surpass traditional methods, and is a cost-efficient way to complete more projects in less time .

48. Advantages of drone surveying Risk Reduction  - Safety and accidents related to falling due to rugged terrain or land elevations can add to construction budgets and impact construction workflow . Faster Acquisition of Data  - While 'time is money', in the construction industry time is generally not valued over and above the quality of data - because in the long run, quality information will save time and money . Improved Data Resolution  - For construction projects that may have used manned helicopters or planes to retrieve topographic data, drones can fly closer to the ground surface and supply much-improved data resolution for aerial surveying and photography . Access to Unreachable Locations  - The most common use for drone surveyance is in measuring locations where vehicles and personnel can not otherwise access.

49. THANK YOU