Bai Giang Tin Hoc Ung Dung Ve Ban Do

8/13/2019 Bai Giang Tin Hoc Ung Dung Ve Ban Do

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MC LCLI NI U...........................................................................................................................1

DANH MC TVI T TT ...................................................................................................2

PHN A: L THUYT............................................................................................................3Chng 1: XY DNG CS D LI U BN .. .........................................................3

1.1. MT SKHI NIM CBN....................................................................................3

1.1.1. Khi nim bn .....................................................................................................3

1.1.2. Bn a chnh cs.............................................................................................3

1.1.3. Bn a chnh.......................................................................................................3

1.1.4. Bn a hnh ........................................................................................................5

1.1.5. Bn hin trng sdng t..................................................................................5

1.2. HQUY CHIU V HTOQUC GIA ...........................................................6

1.2.1. Qu trnh xy dng hquy chiu v htoQuc gia .........................................71.2.2. Cc yu cu ca mt hQuy chiu Quc gia...........................................................8

1.2.3. HQuy chiu v htoquc gia VN-2000 ........................................................9

1.3. HTHNG NH VTON CU.............................................................................10

1.3.1. Gii thiu................................................................................................................10

1.3.2. Cu trc cbn ca hthng GPS.........................................................................11

1.3.3. Nguyn l nh vGPS ..........................................................................................12

1.3.4. Thnh lp bn bng cng nghGPS .................................................................13

1.4. CSDLIU BN S ....................................................................................14

1.4.1. Khi nim bn s...............................................................................................141.4.2. Cc loi dliu v m hnh cbn ca bn s .................................................14

1.4.3. c im bn s ................................................................................................15

1.4.4. Tchc dliu bn s ......................................................................................16

1.4.5. Xut nhp dliu bn s...................................................................................16

1.5. CC PHNG PHP THNH LP BN S ....................................................17

1.5.1. Thnh lp bn tsliu o c ........................................................................17

1.5.2. Sho bn .........................................................................................................17

1.5.3. Thnh lp bn tnh vin thm........................................................................19

CU HI N TP CHNG 1.........................................................................................24Chng 2: M HNH DLI U BN ... ......................................................................25

2.1. KHI NIM M HNH DLIU..............................................................................25

2.2. NI DUNG CA M HNH DLIU ......................................................................25

2.3. M HNH DLIU VECTOR SPAGHETTI.............................................................25

2.3.1. Thng tin vvtr khng gian................................................................................26

2.3.2. Thng tin vquan hkhng gian...........................................................................27

2.3.3. Thng tin vthuc tnh ..........................................................................................27

2.4. M HNH DLIU VECTOR TOPOLOGY.............................................................27


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2.4.1. Thng tin vvtr khng gian................................................................................27

2.4.2. Thng tin vquan h khng gian..........................................................................28

2.4.3. Thng tin vthuc tnh ..........................................................................................30

2.5. XL THNG TIN BN TRONG CSDLIU BN .......................302.5.1. Cc bi ton xl thng tin bn .......................................................................30

2.5.2. Cc thut ton xl thng tin bn ....................................................................30

CU HI N TP CHNG 2.........................................................................................32

Chng 3:CHUN HO DLI U BN .....................................................................333.1. CHUN HO BN A CHNH .........................................................................33

3.1.1. Chun ho dliu bn .......................................................................................34

3.1.2. Chun vth hin i tng bn ......................................................................39

3.1.3. Chun vkhun dng (Format) dliu (Format Data Standard) ..........................41

3.1.4. Chun ho MetaData..............................................................................................423.1.5. Bn a chnh s ................................................................................................43

3.2. CHUN HO BN A HNH............................................................................44

3.2.1. Quy nh chung ......................................................................................................44

3.2.2. Phn lp v ni dung bn a hnh s...............................................................44

3.2.3. Quy nh cc chun cs......................................................................................46

3.2.4. Quy nh vghi l lch bn ...............................................................................47

3.2.5. Quy nh vkim tra v nghim thu......................................................................47

3.2.6. Quy nh hon thin v giao np sn phm...........................................................48

3.3. CHUN HO BN HIN TRNG SDNG T..........................................483.3.1. Quy nh chung vBn hin trng sdng t dng s...................................48

3.3.2. Ni dung ca Bn hin trng sdng t dng s............................................50

3.3.3 Quy nh vcc tp chun......................................................................................50

3.3.4. Quy nh vsai sv chnh xc ca dliu bn HTSDdng s..............50

3.3.5. Quy nh sha v bin tp bn hin trng sdng t dng s:....................51

3.3.6. Quy nh vkim tra, nghim thu bn hin trng sdng t dng s ............53

3.4. KTHUT SHO BN A CHNH, BN A HNH.........................54

3.4.1. Quy nh vti liu dng sho.......................................................................54

3.4.2. Quy nh vphng php sho...........................................................................543.4.3.Quy nh vsai sv chnh xc ca dliu bn sho...............................54

CU HI N TP CHNG 3.........................................................................................56

Chng 4: HTHNG PHN MM CHUN LP BN .........................................57

4.1. PHN MM MICROSTATION ..................................................................................57

4.1.1. Gii thiu................................................................................................................57

4.1.2. Tchc dliu ca MicroStation..........................................................................57

4.1.3. Giao din trong MicroStation.................................................................................58

4.1.4. Sdng chut trong MicroStaton..........................................................................59

4.1.4. Ca squan st VIEW...........................................................................................60


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4.1.5. Thanh cun Scroll bar ............................................................................................60

4.1.6. Bng cc thuc tnh hin th...................................................................................60

4.1.7. Cc chhtrtruy bt im (Snap) .................................................................60

4.1.8. iu khin lp........................................................................................................614.1.9. Sdng Fence........................................................................................................61

4.1.10. File tham chiu (Reference File)..........................................................................61

4.2. THNH LP BN A CHNH BNG PHN MM FAMIS...........................57

4.2.1. Chc nng lm vic vi csdliu tro..........................................................63

4.2.2. Chc nng lm vic vi csdliu bn a chnh ........................................65

4.3. HTHNG PHN MM MAPPING OFFICE...........................................................67

CU HI N TP CHNG 4.........................................................................................69

PHN B: BI TP THC HNH.......................................................................................70

BI S1: CC LNH VCBN CA MICROSTATION..............................................71BI S2: CC LNH BIN TP BN CA MICROSTATION.................................76

BI S3: XY DNG BN A CHNH BNG PHN MM FAMIS.....................80

BI S4: BIN TP BN A CHNH.........................................................................85

BI S5: SHO BN BNG MICROSTATION V MAPPING OFFICE.............91

BI S6: BIN TP BN CHUYN ......................................................................97

BI S7: IN N BN ...................................................................................................102

PHN PHL C ..................................................................................................................105

TI LIU THAM KHO....................................................................................................127


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LI NI U

Ngy nay, cng vi spht trin ca cc ngnh in t, tin hc, spht trin ca phncng ln phn mm my tnh, cc thit bo c, ghi tng, cc loi my in, my vc chtlng cao khng ngng c hon thin. Cng ngh thng tin thc s thm nhp vo milnh vc i sng x hi, c bit l trong lnh vc qun l ngun ti nguyn thin nhin t ai.Sra i ca hthng thng tin a l (GIS), hthng thng tin t ai (LIS), hthng nh vton cu (GPS) v Vin thm (RS) to mt bc ngot chuyn tphng thc o v, xl,qun l thcng trc y sang mt phng thc mi, qun l, xl dliu trn my tnh.

Bi ging mn hc Tin hc ng dng vbn c xy dng nhm truyn ti nhngkin thc cbn vp dng cc cng nghhin i, c bit l cng nghthng tin cho sinhvin khoa Ti nguyn v Mi trng, Trng i hc Nng nghip H Ni.

Bi ging ny c bin son theo cng mn hc Tin hc ng dng vbn cakhoa Ti nguyn v Mi trng, trng i hc Nng nghip H Ni. Bi ging nhm trang bcho sinh vin cc kin thc cbn vbn s, cc phng php thnh lp bn s, tchcdliu, cu trc dliu bn sv chun ha dliu bn s. Trn cs, sinh vin cthvn dng vo cng tc thnh lp bn theo ng quy trnh, quy phm ca BTi nguyn vMi trng.

Trong qu trnh bin son cun bi ging ny, chng ti c nhiu cgng tuy nhin dotrnh v thi gian c hn nn khng trnh khi nhng thiu st. Chng ti rt mong nhnc nhng kin ng gp tcc ng nghip, sinh vin v bn c.

Mi kin ng gp xin gi v: Bmn Trc a bn v Thng tin a l, Khoa TiNguyn v Mi Trng Trng i hc Nng Nghip H Ni, Tru Qu- Gia Lm H Ni.

T/M cc tc gi

Trn Quc Vinh


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DANH MC TVIT TT

BC Bn a chnh

CADDB Cadastral Document Database Management System

CSDL Csdliu

ESRI Environmental Systems Research Institute

EOS Earth Observing System

ETM Enhanced Thematic Mapper

FAMIS Field work And cadastral Mapping Intergrated Software

GIS Geographical Information System

GPS Global Positioning System

HRVIR High Resolution Visible Imaging SystemKT-VH-XH Kinh t- Vn ho X hi

LIS Land Information System

MDL MicroStation Development Language

NASA National Aeronautics and Space Administration

RS Remote Sensing

TM Thematic Mapper

TN&MT Ti nguyn v mi trng

UTM Universal Transverse Mercator

WGS World Geodetic System

ASTER Advanced Spaceborne Thermal Emission and Reflection Radiometer


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PHN L THUYT

Chng 1

XY D

NG C

S

D

LI

U B

N

Cng vi spht trin nhanh chng ca khoa hc kthut, ngnh xy dng bn cngpht trin vt bc v c nhiu thnh tu to ln. Bn giy dn c thay thbng bn scng nghcao, vi y nhng thng tin cn thit v chnh xc. Ngy nay, bn l cngc khng th thiu trong nhiu lnh vc ca khoa hc v i sng kinh t x hi, c bit ltrong qun l ti nguyn thin nhin v mi trng. Tuy nhin, qu trnh xy dng hthng c

sdliu bn li l mt qu trnh lu di, i hi c su tln vkinh tv kthut.gip ngi c hiu r hn vqu trnh ny, chng ny gii thiu khi qut nhng khi nimc bn v mt s loi bn thng dng trong ngnh a chnh nc ta, sau i su vonhng vn lin quan n xy dng csdliu bn , bao gm qu trnh xy dng hquychiu v htoquc gia; p dng hthng nh vton cu; bn s, tchc dliu bnsv cc phng php xy dng bn stsliu o, sho bn , v tnh vin thm.1.1. MT SKHI NI M CB N1.1.1. Khi nim bn

Bn l l sbiu ththu gn ca bmt tri t hay bmt ca thin thkhc trn mtmt phng theo nhng quy tc ton hc nht nh.

Mi bn c xy dng theo mt quy lut ton hc nht nh, biu th t l, phpchiu, bcc... ca bn

Ni dung thhin ca bn phthuc vo mc ch, c im vtr, tlbn .Phn loi bn : C nhiu cch phn bn khc nhau nhphn loi theo i tng th

hin (bn a l v bn thin vn), phn loi theo ni dung( bn a l ni chung v bn

chuyn ), phn loi theo tl, phn loi theo mc ch sdng, phn loi theo lnh th...1.1.2. Bn a chnh cs Bn a chnh csl bn gc c o vbng cc phng php o vtrc tip

thc a, o vbng phng php sdng nh chp tmy bay kt hp vi o vbsung thc a hay c thnh lp trn csbin tp, bin vtbn a hnh cng tl. Bn achnh csc o vkn ranh gii hnh chnh v kn khung, mnh bn .

Bn a chnh csl ti liu cbn bin tp, bin vv o vbsung thnh lpbn a chnh theo n vhnh chnh csx, phng, thtrn thhin hin trng vtr,din tch, hnh thv loi t ca cc tha c tnh n nh lu di.1.1.3. Bn a chnh

Bn a chnh l bn c o vtrc tip hoc bin tp, bin vtbn a chnh

cstheo tng n vhnh chnh x, phng, thtrn (gi chung l cp x). Bn a chnhc o vbsung o vtrn vn cc tha t, xc nh cc loi t theo chtiu thng kca tng chsdng t trong mi mnh bn v c hon chnh ph hp vi sliu tronghsa chnh.

Bn a chnh l loi bn t lln v tltrung bnh, c thnh lp theo n vhnh chnh x, phng, th trn. qun l c t ai, chng ta phi c c bn achnh, hsa chnh, giy chng nhn quyn sdng t. Ton bcc tliu ny phi phnnh tha t vi y 4 yu t:

- Yu ttnhin ca tha t nhvtr, hnh dng, kch thc, cht lng t- Yu tx hi ca tha t nhchsdng t, chsdng t, qu trnh bin ng

t ai


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- Yu tkinh ttha t nhgi t, thut, li nhun do kinh tmang li, gi trcccng trnh trn t

- Yu tphp l tha t nhcc vn bn giy txc nh quyn sdng, xc nhn quyhoch

Mt syu ttrn c ghi nhn trong hsa chnh, mt syu tkhc c thhintrn bn a chnh. Bn a chnh l cng cqun l t ai, trn ghi nhn cc yu ttnhin ca tha t v quan hvi cc yu ta l khc trong khu vc. Ngoi ra nhm mcch lin hvi hsa chnh ngi ta cn thhin tn chsdng t, loi t v mt syutquy hach sdng t.

Trc y, ngi ta thnh lp bn a chnh cho tng khu vc nh theo ta aphng. Lc ny trn hthng bn a chnh tng khu vc thhin c mi quan htai vmt tnhin cp a phng, vic qun l t ai bng bn bt u c thchin. Thi gian gn y k thut o c gii quyt c vic lp bn a chnh theo hthng ta thng nht trn ton quc. Loi bn a chnh ny thhin c mi quan htai trn tm vm ca cnc, t c tha ra c nhng phng n quy hoch sdngt hp l, hoch nh cc chnh sch t ai, iu chnh php lut t ai p ng cho pht trint nc.

Ni dung ca bn a chnh: Hin nay hthng bn a chnh nc ta c o ctheo hthng ta Quc gia thng nht. Ni dung bn a chnh bao gm:

- im khng chto, cao- a gii hnh chnh cc cp- Ranh gii tha t, ranh gii sdng t- Loi t- Cng trnh xy dng trn t- Hthng giao thng, Hthng thuvn- Cc im a vt quan trng- Mc gii quy hoch- Dng t

Tlbn a chnh c quy nh nhsau:- Khu vc t sn xut nng nghip, t nui trng thu sn, t lm mui, t nng

nghip khc: tlo vcbn l 1:2000 v 1:5000. i vi khu vc t sn xut nng nghipm phn ln cc tha t nh, hp hoc khu vc t nng nghip xen ktrong khu vc t th, trong khu vc t chn tlo vbn l 1:1000 hoc 1:500 v phi c quy nh rtrong thit kkthut - dton cng trnh.

- Khu vc t phi nng nghip m chyu l t v t chuyn dng:+ Cc thnh phln, cc khu vc c cc tha t nhhp, xy dng cha theo quy hoch,

khu vc gi trkinh tsdng t cao tlo vcbn l 1:200 hoc 1:500.+ Cc thnh ph, thx, th trn ln, cc khu dn cc ngha kinh t, vn ho quan

trng tlo vcbn l 1:500 hoc 1:1000.+ Cc khu dn cnng thn tlo vcbn l 1:1000 hoc 1:2000.- Khu vc t lm nghip, t trng cy cng nghip t lo vcbn l 1:5000 hoc

1:10000.- Khu vc t cha sdng: thng nm xen kgia cc loi t trn nn c o vv

biu thtrn bn a chnh o vcng tl. Khu vc t i, ni, khu duyn hi c din tcht cha sdng ln tlo vcbn l 1:10000.

- Khu vc t chuyn dng, t tn gio, tn ngng, t ngha trang, ngha a, t sng,


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sui, t c mt nc chuyn dng, t phi nng nghip: thng nm xen kgia cc loi t trnnn c o vv biu thtrn bn a chnh o vcng tlcho ton khu vc.

Trong trng hp thnh lp bn a chnh tlln hn hoc nhhn dy tlnu trn,phi tnh cthcc chtiu kthut nhm m bo yu cu vqun l t ai v m bo

chnh xc ca cc yu tni dung bn tlla chn trong thit kkthut - dton cngtrnh ca khu vc.1.1.4. Bn a hnh

Bn a hnh l bn biu thchi tit v chnh xc, phn nh mt cch y n mcc thcn cvo m hnh dung ra sli lm ca a hnh v cc a vt thc a.

Bn a hnh bao gm cc t l: 1:2000, 1:5000, 1:10.000, 1:25.000, 1:50.0001:100.000, 1:250000, 1:500000 v 1:1000000. Bn a hnh l ti liu cbn thnh lp ccloi bn khc.

Ni dung c bn ca bn a hnh l: thuh; cc im dn c; cc i tng cngnng nghip v vn ho; mng li ng giao thng; dng t (ng bnh v cao bnh

); cc ng ranh gii; cc vt nh hng; cao...1.1.5. Bn hi n trng sd ng tBn hin trng sdng t l bn thhin sphn bcc loi t theo quy nh v

chtiu kim k theo mc ch sdng t ti thi im kim k t ai v c lp theo n vhnh chnh cc cp, vng a l tnhin - kinh tv cnc.

Ni dung ca bn hin trng sdng t phi m bo phn nh trung thc hin trngsdng cc loi t theo mc ch sdng v cc loi t theo thc trng bmt ti thi imthnh lp.

Bn hin trng sdng t thng c xy dng cho tng cp hnh chnh x, huyn,tnh v cnc. u tin phi xy dng bn hin trng sdng t cp x sau sdng bncc x tng hp thnh bn cp huyn, tnh.

Tlca bn hin trng sdng t c quy nh da vo cp hnh chnh v quy mdin tch ca n vhnh chnh . Theo Quy nh vthnh lp bn hin trng sdng tca BTi Nguyn v Mi trng ban hnh ngy 17 thng 12 nm 2007, tlca bn hintrng sdng t c quy nh cthnhsau:

Bng 1-1. Quy nh vt l b n hi n trng sd ng t

n vthnh l p bn T l b n Quy m di n tch tnhin (ha)

Cp x1: 10001: 20001: 5000

1: 10 000

Di 120Trn 120 n 500Trn 500 n 3.000

Trn 3.000

Cp huyn1: 5.0001: 10.0001: 25.000

Di 3000Trn 3000 n 12.000Trn 12.000

Cp tnh1: 25.0001: 50.0001: 100.000

Di 100.000Trn 100.000 n 350.000Trn 350.000

Vng lnh th 1: 250.000Cnc 1: 1.000.000


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1.2. HQUY CHI U V HTO QU C GIAHquy chiu v HtoQuc gia l cston hc m mi quc gia nht thit phi c

thhin chnh xc v thng nht cc dliu o c bn phc vqun l bin gii Qucgia trn t lin v trn bin, qun l Nh nc va gii hnh chnh lnh th, iu tra cbn

v qun l ti nguyn v mi trng, theo di hin trng v quy hoch pht trin kinh t- x hi,m bo an ninh - quc phng, Hquy chiu v HtoQuc gia cn ng vai tr quan trngtrong nghin cu khoa hc vtri t trn phm vi cnc cng nhkhu vc v ton cu, d

bo bin ng mi trng sinh thi v phng chng thin tai. Hquy chiu v htoQucgia cn cn thit cho vic to lp cc dliu a l phc vo to, nng cao dn tr v cc hotng dn sca cng ng.

biu din bmt li lm v phc tp ca tri t ban u ngi ta sdng mt Geoid(c nh vt l ngi c Listing xut nm 1873), mt Geoid l mt nc trung bnh, yntnh ca cc bin v i dng mrng xuyn qua cc lc a, hi o thnh mt mt cong khpkn m tip tuyn vi n ti mt im bt ku vung gc vi hng dy di qua im .

Hnh 1-1: B m t Tri t, mt Geoid v mt ElipsoidTuy nhin Geoid khng phi l mt trn xoay, v thkh hnh thc ho ton hc. Cc nh

ton hc tm ra hnh bu dc trn xoay c tm trng vi tm ca tri t, thtch bng thtchtri t v gi l Elipsoid. Mt Elipsoid c xc nh theo phng php tng bnh phng nhnht (Tng bnh phng chnh cao so vi mt Geoid l nhnht)

Hnh 1-2. Hnh dng Elipsoid


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Cc thng sca Elipsoid: Mt Elipsoid c c trng bi cc thng ssau:

+ a: L bn trc ln

+ b: L bn trc nh

+ dt cc cc tri t:

a

baf

=

+ Se l lch tm:

e2= 2f f2hay f = 1 (1 e2)1/2

Hin nay c rt nhiu hnh Ellipsoid trn th gii c dng xp x b mt tri t(khong 15 ellipsoid) v tuthuc vo tng quc gia ngi ta chn mt Elipsoid v phng phpnh vElipsoid ph hp.

Bng 1-2: Mt s Elipsoid thng d ng qua cc thi k

Chiu di cc trcNm cngb TnElipsoid Trc ln a Trc b bd t 1/f Nhng ni sdng

1830 Everest 6377304 6356103 300.80Myanmar,Malaysia,Vit Nam, n ,

1841 Bessel 6877397 6356079 299.15Nht bn, TriuTin, Indonesia

1866 Clarke 1860 6878206 6356584 299.98M, Canada,Philippin, Vit

Nam

1880 Clarke 1880 6378249 6356515 293.46 Chu Phi, Trungng

1924 International 6378388 6356912 297Trung Quc, Chuu, Nam Phi

1940 Krasovsky 6378245 6356863 298.3 Nga, Vit Nam

1980 GRS-80 6378136 6356752 298.257 IUGS

1984 WGS-84 6378137 6356752 298.2572 GPS

1.2.1. Qu trnh xy dng hquy chi u v h to Qu c giaThi Php thuc: Khi Php t chn n ng Dng quyt nh sdng Hquy chiu

cho ton ng Dng vi Elipsoid Clarke, im gc t ti thp ct cH Ni, li chiu tophng Bonne v xy dng htobao gm hng nghn im phtrm ton ng Dng.

Nm 1956 khi Mti Min Namnc tacng quyt nh sdng hquy chiu ca Mcho khu vc Nam vi Elipsoid Everest, im gc to ti n , li chiu tophngUTM. H to c thit lp cho Min Nam nc ta ni vi cc im to caCampuchia, Thilan, n . Tsau gii phng Min Nam cho ti nay chng ta vn cn sdngnhiu tliu o c bn ca Mtrong hquy chiu v htony.

Hquy chiu v htoHN72:Nm 1959 Chnh Ph thnh lp Cc o c v Bn

Nh nc v giao nhim vxy dng li toQuc gia, thnh lp cc loi bn phc v


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cc mc ch xy dng v bo vt nc. Vi sgip ca cc chuyn gia Trung Quc, tnm 1959 n nm 1966, trn lnh thmin Bc nc ta (n vtuyn 17) c phkn licc im toNh nc hng I v hng II.

HQuy chiu c la chn l hthng chung cho cc nc x hi chngha vi Elipsoid

Krasovski (bn trc ln a=6378.425 m v dt f=1/298.3), im gc ti i thin vn Punkovo(ti Lin X c), li chiu to phng Gauu-Kruger. H toc truyn ti Vit Namthng qua li toQuc gia Trung Quc. Nm 1972, Chnh ph quyt nh cng bHquy chiu v htoQuc gia ni trn gi l hH Ni 72 (HN72) sdng thng nht chocnc.

Sau ngy gii phng min Nam thng nht cnc, cc o c v bn Nh nc tiptc pht trin li toNh Nc vo cc tnh pha Nam. Vi sgip tng phn ca ccchuyn gia Lin X c, n ht nm 1993 li toNh Nc c phkn gn ton blnh th. Nm 1990 Cc o c v Bn Nh Nc quyt nh sdng cng nghnh vton cu GPS hon chnh phn li to cn thiu trn cc a bn kh khn nh Ty

Nguyn, Sng B (c), Minh Hi (c), v phli totrn ton vng bin cho n cc othuc qun o Trng Sa. Do qu trnh xy dng li tothc hin trong mt thi gian di,phi p ng kp thi tov bn cho nhu cu sdng thc tnn ton mng li bchiact thnh nhiu khu vc ring bit, hnh thc xy dng li rt a dng bao gm ccng nghtruyn thng v cng nghhin i nht, ton hthng cha c xl thng nht.

Nhng hn chca Hquy chiu v htoquc gia HN72

- HQuy chiu Quc gia HN-72 thc cht l hquy chiu chung cho cc nc x hi chngha trc y, thiu ph hp vi lnh thVit Nam, c lch gia m hnh vt l v m hnhton hc ca tri t qu ln, t to bin dng ln lm suy gim chnh xc ca li tov bn .

- Hin nay cc nc thuc phe x hi chngha ccng thay i HQuy chiu Qucgia ca nc mnh, khng sdng HQuy chiu chung trc y, v vy HQuy chiu Qucgia H Ni 72 cng khng to c bt kmt lin kt khu vc no.

- HQuy chiu Quc gia H Ni 72 hon ton khng to iu kin thun li pht trincng nghnh vhin i gi l hthng nh vton cu GPS (Global Positioning System) mhin nay c phbin trn ton thgii v Vit Nam, sdng HQuy chiu Quc gia H

Ni 72 gy hu qusuy gim chnh xc nh vv to mt quy trnh cng nghqu phctp khi xl ton hc cc tro GPS.

- HQuy chiu Quc gia H Ni 72 gy kh khn ng ktrong vic lin kt tliu viquc tnhm gii quyt cc vn hoch nh bin gii, dn ng hng khng, hng hi...

- HtoQuc gia ca nc ta hin nay bchia ct thnh nhiu khu vc nh, thiu tnhthng nht trn a bn cnc, c chnh xc tng thkhng p ng c yu cu i hica thc tqun l hnh chnh, iu hnh kinh tv m bo an ninh Quc phng.

1.2.2. Cc yu cu ca mt hQuy chi u Quc giaVic la chn mt HQuy chiu Quc gia ph hp v xl ton hc nng cao tnh thng

nht v chnh xc HToQuc gia l mt nhim vbc xc cn thc hin.

HQuy chiu Quc gia cn c la chn theo nhng tiu chun sau:

- Ph hp nht vi lnh thVit Nam cc tliu o c - bn c bin dng nhnht.


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- To iu kin p dng v pht trin cc cng nghnh vhin i c chnh xc cao(cng nghnh vGPS hin l phng tin phbin v chyu xy dng li toti Vit

Nam)- HQuy chiu phi ph hp vi tp qun sdng nc ta v c tnh phdng trn th

gii.- Khi cn thit c khnng lin kt chnh xc vi cc tliu bn khu vc v ton cu

nhm gii quyt nhng vn chung.+ m bo tnh b mt tuyt i vHtoQuc gia.+ Chi ph ti thiu cho vic chuyn i hQuy chiu v htoQuc gia.

HtoQuc gia cn c xl ton hc m bo cc yu cu sau:- Thng nht trn a bn ton quc.- chnh xc cao nht trn cstp hp tro hin ti l chyu, khi cn thit c tho

bsung khng ng k.

- To iu kin sdng nhng phng php xl ton hc hin i theo nhiu phng ncho kt qutin cy tuyt i.1.2.3. H Quy chi u v hto qu c gia VN-2000

Tnm 1992 n nay, Cc o c bn Nh nc nay l BTN&MT tin hnh cngtrnh xy dng HQuy chiu v HtoQuc gia mi theo nhng tiu ch ni trn, bao gmnhng ni dung chnh sau y:

- nh gi li ton bHquy chiu v Htoquc gia H Ni 72 ang sdng.- Xy dng li tocp 0 cnh di, chnh xc cao bng cng nghnh vton cu

GPS bsung, thng nht v nng cao chnh xc ca li to xy dng; xc nh toim gc toquc gia.

- Tnh ton chnh l ton hc ton bhthng toquc gia phtrm cnc.- Nghin cu xut HQuy chiu v HToQuc gia ph hp.- Nghin cu xut gii quyt vn tnh chuyn tov hthng bn xut bn

sau khi cng bHquy chiu v hToQuc gia mi.Cng trnh do cc nh khoa hc v chuyn gia hng u ca ngnh o c - bn thc

hin, n nay t c nhng mc tiu ra. Cng trnh a ra mt sphng n la chnHquy chiu Quc gia v xl ton hc HtoQuc gia phn tch v so snh. Kt lunca cng trnh nghin cu ny l:

HQuy chiu Quc gia hp l bao gm cc yu t:+ Elipsoid quy chiu: WGS - 84 ton cu.

+ im gc ToQuc gia: im t trong khun vin Vin Nghin Cu a chnh,ng Hong Quc Vit, H Ni.

+ Li chiu tophng: Li chiu UTM quc t.+ Hthng bn cbn: chia mi v phn mnh theo hthng UTM quc t, danh php

tbn theo hthng hin hnh c ch thch danh php quc t.HtoQuc gia c xc nh thng qua vic xl ton hc cht chkt hp cc s

liu trc a, thin vn, trng lc, vtinh bng 3 chng trnh tnh ton khc nhau: mt ca ncngoi v hai chng trnh trong nc.

Cch la chn HQuy chiu v HToQuc gia nhvy m bo y cc tiu ch t ra trn.


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Ngy 12/7/2000, thtng Chnh phk quyt nh sdng HQuy chiu v HToQuc gia VN- 2000. Hquy chiu v htoQuc gia VN2000 c cc yu tchnh sau y:

- Elipsoid quy chiu: WGS-84 ton cu c kch thc nhsau:

+ Bn trc ln a=6378137,000 m

+dt =298,257223563-im gc toquc gia:im N(0,0) t trong khun vin Vin Nghin cu a chnh,

ng Hong Quc Vit, H Ni

- Li chiu tophng: Li chiu UTM quc t

- Chia mi v phn mnh hthng bn cbn: Theo hthng UTM quc t, danh phptbn theo hthng hin hnh c ch thch danh php Quc t.

1.3. HTHNG NH V TON C U

1.3.1. Gii thiu

Hthng nh vTon cu (Global Positioning System - GPS) l hthng xc nh vtr

da trn vtr ca cc vtinh nhn to, do BQuc phng Hoa Kthit k, xy dng, vn hnhv qun l tnm 1994, khi ngun ca n l hthng nh vdn ng bng vtinh thhu tin c tn gi l TRANSIT, ra i vo nm 1960.

H thng GPS thit lp mt mng li 24 vtinh bay trong 6 quo trn trong khnggian bao quanh tri t vi chu k12 gi, cao 20.200 km. Vi cch btr ny th trong sut24 giti bt kmt im no trn tri t cng squan st c t nht 4 vtinh. chnh xcnh vbng GPS c nng cao, v khc phc c nhc im vthi gian quan trc so vihTRANSIT vn chc tng cng 6 vtinh. Hin nay, theo Gio sRichard B Langley ngtrn tp ch GPS World s11-2009, svtinh GPS ln n con s35, tuy vy, chc 30 vtinh l c ci t khomnh cho ngi sdng.

Hnh 1-3. Qu o bay ca cc vtinh GPS trong v tr Mc d thit kban u ca GPS nhm phc vcho mc ch qun s, nhng ngy nay

c ng dng rng ri trong cc hot ng kinh t, x hi v trc a, bn . Hthng nh vton cu mi ra i nhng nhanh chng trthnh mt cng cquan trng trong cc lnh vcnghin cu khp mi quc gia v trong mi quy m nhcc tnh u vit ca n. Trc htnhn mt cch tng quan, trong iu kin hin nay mi quc gia v tchc nghin cu khoa hc c thtrang bcho mnh loi k thut ny, cphn cng v phn mm. Thhai l vic sdng my GPS rt n gin v tin li, khng i hi mt qu trnh o to ng kno khin

cho n ddng phbin v pht trin. Thba l GPS o c cngy ln m, trong mi iu
http://vi.wikipedia.org/wiki/V%E1%BB%87_tinh_nh%C3%A2n_t%E1%BA%A1ohttp://vi.wikipedia.org/wiki/V%E1%BB%87_tinh_nh%C3%A2n_t%E1%BA%A1ohttp://vi.wikipedia.org/wiki/V%E1%BB%87_tinh_nh%C3%A2n_t%E1%BA%A1ohttp://vi.wikipedia.org/wiki/V%E1%BB%87_tinh_nh%C3%A2n_t%E1%BA%A1ohttp://vi.wikipedia.org/wiki/V%E1%BB%87_tinh_nh%C3%A2n_t%E1%BA%A1ohttp://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/B%E1%BB%99_Qu%E1%BB%91c_ph%C3%B2ng_Hoa_K%E1%BB%B3http://vi.wikipedia.org/wiki/V%E1%BB%87_tinh_nh%C3%A2n_t%E1%BA%A1o


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kin thi tit. Mt u im ni bt ca GPS na l khng cn tm nhn thng ca cc im o,do khng mt thi gian v cng sc pht cy, thng hng, trnh cht ph rng, bo vtinguyn, mi trng.

nc ta, trong nhng nm u ca thp k90 ngnh o c v bn nghin cu v

ng dng thnh cng h thng nh vton cu. Ngy nay thit bthu tn hiu GPS c phttrin ngy cng hon thin cvphn cng v phn mm, cng vi spht trin kthut xltn hiu GPS em li kt qunh vchnh xc vi tin cy cao v phm vi ng dng ngycng mrng.

Cng c tnh nng tng tnhhthng GPS ang hot ng cn c hthng GLONASSca Nga. Hin nay Lin minh Chu ucng ang pht trin h dn ng v tinh ca mnhmang tn Galileo, dkin a vo hot ng nm 2013. Trung Qucth pht trin hthng nhvton cu ca mnh mang tn Bc u bao gm 35 vtinh.

1.3.2. Cu trc cb n ca hth ng GPS

GPS l mt hthng nh vkhng gian csphtrm sng trn ton cu, c thxc nh

vn tc, thi gian v vtr theo c3 chiu trn 24 ging h. GPS sdng vtinh trong khnggian xc nh mi vtr trn Tri t. Theo sphn bkhng gian ngi ta chia hthng GPSthnh 3 thnh phn nhsau:

Hnh 1-4: Cc thnh phn ca hth ng GPS- on sdng (User Segment):Bao gm ngi sdng, thit bthu GPS v phn mm

xl sliu. Thit bthu GPS l thit bthu sng c bit, c thit knhn tn hiu sngchuyn tvtinh xung, xc nh v tnh ton vtr cc i tng trong khng gian. My thuGPS c tht cnh trn mt t hoc t trn cc phng tin chuyn ng nhtn la, my

bay, t...Cc loi my thu GPS c phn ra lm 3 loi:

+ Loi dn ng:Sdng chyu dn ng, iu tra ngun ti nguyn thin nhin,lp bn tlnh. Loi ny tng i rtin, dsdng, chnh xc thp (10-15m) v hnchvlu trthng tin
http://vi.wikipedia.org/wiki/Li%C3%AAn_minh_Ch%C3%A2u_%C3%82uhttp://vi.wikipedia.org/wiki/Galileohttp://vi.wikipedia.org/wiki/Trung_Qu%E1%BB%91chttp://vi.wikipedia.org/wiki/Trung_Qu%E1%BB%91chttp://vi.wikipedia.org/wiki/Trung_Qu%E1%BB%91chttp://vi.wikipedia.org/wiki/Trung_Qu%E1%BB%91chttp://vi.wikipedia.org/wiki/Galileohttp://vi.wikipedia.org/wiki/Li%C3%AAn_minh_Ch%C3%A2u_%C3%82u


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+ Loi kho st:Chyu dng cho vic xy dng bn v thu thp dliu GIS vi chnh xc cao. Loi ny t tin hn, c nhiu chc nng hn v hot ng phc tp hn, bnhnhiu hn v Download dliu tt. Sai snh vim t3 n 5m.

+ Loi dng o li lp bn tlln:c sdng o dc li trc a, lp bn

tlln... Loi ny c gi thnh cao v chnh xc caoThit b thu GPS c th l mt my thu ring

bit hot ng c lp (nh v tuyt i), c th lmt nhm my thu hot ng ng thi (nh vtngi), hoc hot ng theo chmt my thu lm vaitr my chpht tn hiu cho cc my thu khc (nhvvi phn).

-on Khng gian (Space Segment): onkhng gian gm 24 v tinh GPS v 3 v tinh d tr,

bay trong 6 mt phng quo nghing 550so vi mt

phng xch o, mi mt phng c 4 hoc 5 v tinhvi cao 20.200 Km. mi vtinh c trang btn lay iu chnh qu o v c thi hn s dngkhong 7,5 nm.

-on diu khin (Control Segment):Bao gm5 trm mt t c phn bu quanh Tri t trong c mt trm ch(Master Station) v 4 trm theo

Hnh 1-5. My thu GPS chnhxc cao Hiper Ga

di (Monitor Station) c ththeo di v iu khin c vtinh. on iu khin c nhim vliu khin mi hot ng v cc chc nng ca vtinh trn cstheo di chuyn ng quoca vtinh

1.3.3. Nguyn l nh v GPSa.nh vtuyt i.

Nguyn tc cbn ca GPS l php o c tam gic tvtinh. p dng php o c tamgic ny, bphn thu so khong cch tmy thu n vtinh. My thu GPS c mt ng h

bn trong, ng bvi ng htrn vtinh. Khi vtinh gi tn hiu, thi gian c ghi litrn GPS. My thu GPS sso snh thi gian trn vtinh vi thi gian trn ng hca n, tnhra skhc nhau vthi gian, kt hp vi vn tc nh sng tm ra khong cch tmy thu nvtinh. Vmt hnh hc c thm tsnh vti mt thi im nhsau:

Hnh 1-6. Nguyn l nh v GPS


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- Vi mt vtinh GPS th im cn o snm trn mt mt cu c tm l vtr vtinh, bnknh bng khong cch tmy thu GPS n vtinh

- Vi 2 vtinh GPS th im o nm trn mt cu th2, c tm l vtinh th2, c bn knhl khong cch tmy thu n vtinh th2. Kt hp tro n 2 vtinh th vtr im o nm

trn 2 mt cu trong khng gian, l mt vng trn- Nu c vtinh th3, tng tvtr trn im o l giao ca mt cu th3 vi ng trn

trn th kt qucho ta 2 vtr trong khng gian- Nu c vtinh th4 th kt qul tng hp scho mt nghim duy nht, l vtr chnh

xc im. Ngoi ra vtinh th4 cn c nhim vhiu chnh sai s. Cng thu c tn hiu tnhiu vtinh th chnh xc nh vcng cao.b.nh vtng i.

Do nh hng ca sai svtr cc vtinh trn quo, do sai sng hv cc yu tmitrng truyn sng khc dn n chnh xc im n thp, t khong 20-30m. Vi chnhxc ny khng th p dng cho cng tc trc a. V vy ngi ta dng phng php nh v

chnh xc hn l nh vtng i. Phng php nh vny khc vi nh vtuyt i chln sdng ti thiu 2 my thu tn hiu vtinh ng thi. Phng php ny c tht chnhxc n cm1.3.4. Thnh lp bn b ng cng nghGPSa. Cc phng php o GPS

-o GPS tuyt i: L kthut xc nh toca im t my thu tn hiu vtinh tronghtoton cu WGS 84. Kthut nh vny l vic tnh toca im o nhvic gii

bi ton giao hi nghch khng gian da trn cskhong cch o c tcc vtinh n mythu v toca cc vtinh ti thi im o. Do c nhiu ngun sai snn chnh xc vtrthp, khng dng c cho vic o c chnh xc, dng chyu cho vic dn ng hoc cc

mc ch o c khc khng cn chnh xc cao.- o GPS tng i: o GPS tng i l cch o t chnh xc cao do loi bcnhiu loi sai s. Phng php ny c dng trong o c, xy dng li khng chtrc a vtrong cng tc o c bn cc t l. o GPS tng i c chia thnh o GPS tnh, tnhnhanh v o GPS ng:

+ o GPS tnh, tnh nhanh da trn cst hai hay nhiu my thu cnh thu tn hiu GPSti cc im cn o totrong khong thi gian khong 1 gi. o GPS tnh c chnh xc cao,t khong 1cm, thng c dng thnh lp li khng chtrc a.

+ o GPS ng c tin hnh vi mt my t ti trm cnh v nhiu trm my khcdi ng n cc im o. o GPS ng l gii php nhm gim thiu thi gian o so vi o GPStnhnhng vn m bo c chnh xc o ton cm

b. Thnh lp bn a chnh bng cng nghGPSNu khu vc o vbn a chnh csiu kin p dng cng nghGPS th c th

p dng cng nghGPS ng thnh lp bn a chnh.C hai phng php sdng cng ngho GPS ng l phng php o phn sai GPS

v phng php GPS ng thi gian thc:+ Phng php phn sai GPS (Differential GPS- DGPS): Da trn csmt trm my t

my thu tnh (ti im a chnh cs) v mt strm my thu ng (t lin tip ti cc im o).Sliu ti trm tnh v trm ng c xl chung ci chnh phn sai cho gia stogiacc trm tnh v trm ng. Tutheo thloi thit bv khong cch gia trm tnh v trm ng,

phng php ny c tht chnh xc tm n dm


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+ Phng php GPS ng thi gian thc (GPS Real Time Kinematic- GPS RTK): Phngphp ny cng da trn csmt trm my thu tnh t ti im a chnh csv mt strmthu ng t lin tip ti cc im o chi tit. S liu trm o tnh c gi tc thi ti trmng bng thit bthu pht sng v tuyn (Radio link) xl tnh ton totrm ng theo

totrm tnh. Tutheo thloi thit bthu GPS phng php ny c tht chnh xc t5cm n 1 cm

Vic p dng cng ngho GPS ng o vbn a chnh cschi hi cc ima chnh cst cc trm tnh, khng cn pht trin tng dy cc im a chnh cp 1 vcc cp thp hn

1.4. CS D LI U BN S

1.4.1. Khi nim bn s

Trc y, bn thng c vbng tay trn giy, cc thng tin c thhin nhccng nt, mu sc, hthng k hiu v cc ghi ch.

Ngy nay, cng vi spht trin ca cc ngnh in t, tin hc, spht trin ca phn

cng ln phn mm my tnh, cc thit bo c, ghi tng, cc loi my in, my vc chtlng cao khng ngng c hon thin. Cng nghthng tin thc s thm nhp vo milnh vc i sng x hi, c bit l trong lnh vc qun l ngun ti nguyn thin nhin t ai.Sra i ca hthng thng tin a l (GIS) v hthng thng tin t ai (LIS) to mt bcngot chuyn tphng thc qun l thcng trc y sang mt phng thc mi, qun l, xl dliu trn my tnh.

Hnh 1-7.Bn m hnh l p th Bn l mt thnh phn quan trng, l mt trong hai dng d liu cbn ca mt h

thng thng tin a l. Cc i tng a l c thhin trn bn da trn m hnh ton hctrong khng gian 2 chiu hoc 3 chiu. Bn sc thc hiu nhl mt tp hp c tchc

cc dliu bn c lu tr, xl, hin th, thhin hnh nh bn trn my tnh. Bn sc lu trbng cc File dliu lu trong bnhmy tnh, c ththhin hnh nh bn ging nhbn truyn thng trn mn hnh my tnh, c ththng qua cc thit bmy in, myvin ra giy nhbn thng thng.

1.4.2. Cc loi dli u v m hnh cb n ca bn s - C s d liu bn c hnh thnh t bn dng d liu c bn: dng im, dng

ng, dng vng v dng ch gii, ch thch

+ Sliu dng im (point):l dng sliu n gin nht. Chng l nhng i tng vhng chc vtr trong khng gian, khng c chiu di.

+ S liu dng ng (Line, Arc): ng (bao gm c cc cung) l cc i tng hai

chiu, chng khng nhng c vtr trong khng gian m cn c cdi.


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+ Sliu dng vng (Polygon, area): Vng l cc i tng hai chiu, chng khng nhng cvtr, di trong khng gian m cn c crng (Ni cch khc, chng c din tch).

+ Sliu dng ch thch, m t(Annotation, Text)

- Cc loi dliu trn c lu trtrong hai m hnh dliu khng gian cbn l m hnhvector v m hnh raster.

+ M hnh Vector: Trong m hnh Vector vtr ca cc im, ng, a gic u c xcnh chnh xc. Vtr ca mi i tng c nh ngha bi mt cp ta (X,Y) hoc l mtchui cc cp ta .

Mt im c xc nh bng mt cp ta . Mt ng thc cht l tp hp ca cc imc xc nh bng chui cc cp ta . Mt vng thc cht l tp hp ca cc ng v khp kndo c xc nh bng chui cc cp ta nhng cp ta u v cui l trng nhau.

Hnh 1-8. Cc loi dli u im, ng, vng trong m hnh Vector+ M hnh Raster:M hnh Raster l phng php n gin nht lu trcc s liu

khng gian. Trong dng m hnh ny, cc sliu khng gian c tchc thnh cc Picel. Mimt im c m t bng mt Picel. Mi ng c m t bi chui cc picel. Cu trcRaster t ph hp cho vic biu din cc ng v thng lm xut hin sgp khc cho ccng. Mt a gic c biu din bng mt nhm cc picel.

Hnh 1-9. Cc loi dli u im, ng, vng trong m hnh Raster1.4.3. c im bn s

Bn sc mt scc c im sau:- Mi bn sc mt cston hc bn nht nh nhhquy chiu, hto... Cc

i tng bn c thhin thng nht trong cston hc ny.

- Ni dung, mc chi tit thng tin, chnh xc ca bn sp ng c hon toncc yu cu nhbn trn giy thng thng, nhng hnh thc p hn. Bn skhng c tlnhbn thng thng. Kch thc, din tch cc i tng trn bn sng bng kchthc cc i tng ngoi thc a.

- Khi thnh lp bn s, cc cng on thu thp dliu, xl dliu i hi kthut vtay nghcao, tun theo cc quy nh cht chvphn lp i tng, cu trc dliu, tchc dliu.... Nu thnh lp bn a chnh sth ginguyn c chnh xc ca sliu o c,khng chu nh hng ca sai sho.

- Nghin cu nh gi a hnh va khi qut, va tm- Hn chlu trbn bng giy. V vy cht lng bn khng bnh hng bi cht

liu lu tr. Nu nhn bn nhiu th gi thnh bn srhn.


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- Chnh l, ti bn ddng, nhanh chng, tit kim.- Bn sc tnh linh hot hn hn bn giy thng thng, c thddng thc hin

cc cng vic nh:+ Cc php o tnh khong cch, din tch, chu vi...

+ Xy dng cc bn theo yu cu ngi sdng.+ Phn tch, xl thng tin to ra cc bn chuyn rt kh thc hin bng tay

nh: bn 3 chiu, ni suy ng bnh thnh lp bn dc, chng ghp bn ...+ In bn ra nhiu tlkhc nhau theo yu cu.+ Tm kim thng tin, xem thng tin theo yu cu.+ ng dng cng ngha phng tin, lin kt dliu thng qua hthng mng cc

b, din rng, ton cu.+ ng dng cng nghm phng.

1.4.4. Tch c dli u bn s

Cc i tng ca bn s c t chc phn thnh cc lp thng tin (layer, level,theme, table...). Phn lp thng tin l sphn loi logic cc i tng ca bn sda trn cctnh cht, thuc tnh ca cc i tng bn . Cc i tng bn c phn loi trong cngmt lp l cc i tng c chung mt stnh cht no . Cc tnh cht ny l cc tnh cht ctnh c trng cho cc i tng. Vic phn lp thng tin nh hng trc tip n nhn bit ccloi i tng trong bn s.

Mi bn c ti a 63 lp khc nhau c nh st1 n 63 hoc c t tn ring.Cc lp trong bn c cng mt hto, cng tl, cng hsthu phng. Lp l mt thnh

phn ca bn v, c thbt (on) hoc tt (off) trn mn hnh. Khi tt ccc lp c bt, ta cmt bn hon chnh.

Trong mt lp thng tin, cc i tng ch thuc vo mt loi i tng hnh hc duynht: im (point), ng (polyline), vng (polygon), hoc ch gii, ch thch (text). Cc itng trong bn c cc thuc tnh: vtr (location); lp (level, layer); mu sc (color); kiung nt (line style); lc nt (line weight).1.4.5. Xut nhp dli u bn s

Khnng xut nhp dliu bn sphthuc vo format dliu (khun dng dliuca file bn ). Forrmat dliu l yu tc bit quan trng trong vic trao i thng tin giacc ngi dng khc nhau trong cng hthng v gia cc hthng vi nhau.

Format dliu dng trao i, phn phi thng tin cn phi thomn cc yu cu sau:- Format phi c khnng biu din y cc loi i tng.

- Format c cng bcng khai (c tnh m).Thng thng, dliu bn ca cc phn mm khc nhau giao din vi nhau thng quamt format trung gian. Hin nay nc ta sdng cc chun format thng dng sau:

- Chun format d liu ca Vin Nghin cu cc h thng v mi trng M(Environmental Systems Research Institute ESRI USA). ESRI l hng xy dng phn mmARC/INFO, ARCVIEW v l mt trong nhng hng dn u vcng nghGIS.

- Chun format dliu ca hng Integraph. Integraph l mt trong nhng hng dn du thgii vcc phn mm nh sv cng nghGIS. Chun ca Integraph l Standard InterchangeFormat SIF. Format ny c pht trin trao i dliu gia Intergaph v cc hthng khc.

Ngoi chun SIF, format DGN cng trthnh mt trong nhng chun phbin trao i dliu hin nay.


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- Chun format d liu ca hng AutoDesk M. AutoDesk l hng xy dng phn mmAutoCAD rt phdng hin nay. Format dliu DXF ca AutoDesk lun l format trao i ca

phn ln cc hthng GIS hin nay trn thgii.

- Chun format d liu ca hng MAPINFO, USA. Format Mapinfo Interchange Format

ca MAPINFO l file ASCII, m tcc i tng di theo m hnh SPAGHETTI, cho phplu dliu ho(trong file MIF) v dliu thuc tnh (MID).

1.5. CC PHNG PHP THNH LP BN S Cc ngun dliu thnh lp bn sbao gm:

- Sliu o c mt t(bng cc loi my ton c, ton c in t, GPS ...). Kt quca qu trnh o c c ghi trong so hoc lu trtrong cc bnh(trong hoc ngoi) camy. Sliu o c thng l cc cp to(X,Y,Z) ca cc im o hoc cc gi tro gc,khong cch ttrm my n im o v cao im o.

- Cc loi bn trn giy, diamat, phim nh ... c sn (bn c sn). thnh lp,qun l bn s, dliu tcc loi bn c sn l mt ngun dliu quan trng v rtin

nht. Tuy nhin, m bo chnh xc cho bn s, cc loi bn ni trn phi m bomt s yu cu nh: bn phi r rng, khng nhu nt, khng can v hoc Photocopy linhiu ln... Vi cc loi bn yu cu chnh xc cao nhbn a chnh, bn a hnhth c cc quy nh ring (scp n sau).

- nh hng khng v nh vtinh. Hin nay phng php sdng nh hng khng, vtinhang c nghin cu, sdng trong cng tc thnh lp bn v phn tch khng gian. Sliutnh hng khng, vtinh phn nh trung thc bmt ca khu vc bay chp ti thi im chpnh. Tuy nhin, tlca bn thnh lp phi ph hp vi tlchp nh v phn gii nh.Phng php ny rt c hiu qui vi vic thnh lp bn tlnh.

Cn cvo ngun sliu thu thp c, ta c cc phng php thnh lp bn snhsau:

1.5.1. Thnh lp bn t s li u o c- Sliu o c c lu trtrong bnhca my.

Cc s liu ny c truyn vo my tnh thng qua cc phn mm chuyn dng (phnmm SDR, FAMIS, ITR...). Sau , nhcc chc nng ca ca phn mm, cc im o chin thln mn hnh my tnh. Cn cvo sni, chng ta c ththnh lp c bn

bng phng php ni bng tay hoc ni tng.

- Sliu o c c ghi stheo phng php truyn thng: u tin, sliu o c cnhp vo my tnh bng tay di dng cc file sliu lu trim o. Cu trc file dliu lutrim o phthuc vo phn mm sdng. Sau , phng php thnh lp bn hon tontng tnhphng php trn.

- Sliu tGPS.nhn loi d liu ny chng ta sdng cc phn mm chuyn dng nhp d liu t

GPS, cc phn mm ny c thl Mapsource, GPS suvey... Dliu tGPS sau khi truyn vomy tnh thng l cc cp to. Sdng cc phn mm chuyn dng lp bn hoc cc

phn mm GIS thnh lp bn snh: Famis, Arcview...

1.5.2. Sho b n Dng phng php sho bn xy dng csdliu bn . Trc khi sho bn

th phi c mt schuyn i gia ta ca cc i tng trn bn vi ta ca mytnh. Schuyn i ny c thc hin thng qua hthng cc im kim sot. Thng thngchng ta thng dng 5 im, 4 im 4 gc tbn lm 4 im kim sot, im th 5 gia

dng kim tra sai s. i vi mi im kim sot ny ta phi xc nh c chnh xc ta


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ca n, v nhp vo my thng qua bn phm. Bng cch so snh cc ta ny, chng trnhmy tnh stnh ton c ta thc cho tt ccc i tng trn bn v nhvy cho phpchng ta lu trcc ta thc cuchng. Khi sho bn , ti vtr ca cc ng ct nhauchng ta phi to cho n mt im nt trnh cc li xy ra trong qu trnh sho.

a. Sho bn bng bn sho Digitizer (Tablet digitizer)S ho bn bng bn sho Digitizer l mt phng php nhp bn vo my

tnh.Tbn cn sho c t p st vo bmt ca bn Digitizer, v con chut dng can (sho) cc i tng trn bn . Trong bn sthng dng mt li cc dy mn gn chtvo trong bn. Dy thng ng ghi ta X v dy nm ngang sghi ta Y ca bn s. Mt

bn sthng c mt hnh chnht gia gi l vng hot ng v phn nm ngoi ranh giihnh chnht gi l vng lit v cc ta khng c ghi vng ny.Gc thp nht bn trica vng hot ng c ta X=0 v Y=0. V vy bn cn phi c t trong vng hotng ca bn s. Con chut ca bn sthng c 4 nt hoc 16 nt dng iu khin chngtrnh ca bn sho. Khi mt nt ca con chut (thng l nt gc cao tri) c n th mt duhiu in tc truyn n vtr ca chthp v cm ng xung bn s. Vtr ny c cnh bng mt cp dy thng ng v dy nm ngang. Nhvy mt cp ta trong bn sc ghi nhn v gi n my tnh.

Vic dng bn sho yu cu ngi sho phi c knng sho cao, c thtrnh ccli khi sho, em li chnh xc cho bn . Hin nay, phng php ny thng t c sdng v cc l do: chnh xc ca bn khng cao, khng hiu quvmt thi gian, skhkhn khi sho cc bn phc tp. Bn sau khi sho sl mt bn dng Vector.

Hnh 1-10. Bn sho v chu t ca bn shob. Sho trn mn hnh (Headup digitizing)Dng my qut Scanner qut bn , phim nh vi phn gii thch hp (thng t

200 300 DPI). Sn phm l mt nh bn dng raster. Sdng cc phn mm chuyn dngsho cc i tng hnh nh bn trn mn hnh my tnh.

Phng php ny c s dng rng ri v n c cc u im sau: Tn dng c ccchc nng hosn c ca phn mm nhphng to, thu nhv mt schc nng htrchoqu trnh sho khc; chnh xc bn cao hn v tit kim ng kthi gian sho. inhnh ca cc phn mm sho bn tng bn l hthng phn mm Mapping Office catp on Intergraph.


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Hin nay trn thtrng Vit Nam xut hin mt sphn mm tng Vector ho. Tuynhin hin nay do gi thnh cn tng i cao v sn phm Vector ho cht lng cha cao, phthuc nhiu vo cht lng bn gc nn cc phn mm ny cha c sdng rng ri. Vthphng php chyu sho bn vn l phng php sho bn tng.

Hnh 1.11. My qut bn kh A01.5.3. Thnh lp bn t nh vin thma. Khi nim vvin thm

Vin thm (Remote Sensing) c nh ngha nhmt khoa hc v cng ngh m nhncc tnh cht ca vt thquan st c xc nh, o c hoc phn tch m khng cn tip xctrc tip vi chng.

D liu vin thm l loi d liu c th thu c v mt din rng hng trm ngn kmvung trong mt khong thi gian ngn bng cc thit bkthut ghi nhn cc bc xhay phn x

cc vng phkhc nhau ca i tng to ra cc thng tin m kt qu l hnh nh chnh itng . Cc tliu vin thm c u vit l nhanh, kp thi, tm bao qut rng. Ct li ca vinthm chnh l gi trphphn xca cc i tng trn bmt tri t tng khong bc sng.

Cng nghVin thm c bit hiu qui vi nhng i tng m khnng tip cnnghin cu trc tip ngoi thc a kh khn nhi li trong rng, nhng khu vc ni cao trngip. Phng php vin thm c u vit hn hn nhng phng php cin khc khi nghincu din bin mt vn no trong khng gian, thi gian, vkinh ph, ta c ththeo di qutrnh din bin tnhin cng nhdi tc ng ca con ngi trong vng hng chc nm trli.

c im quan trng ca nh vin thm l c chu k lp li nhanh chng, c im nycho php phn tch nhanh chng trng thi cy trng nng nghip, cc qu trnh pht trin ca

trng thi xi mn t... Stn ti tng i lu ca vtinh trn quo cng nhkhnng lpli ng bay ca n cho php theo di nhng bin i theo ma, theo chu knm hoc lu hn,din bin pht trin ca sa mc, nn ph rng nhit i...

b. Gii on nh vin thm

Gii on nh vin thm l qu trnh tch thng tin nh tnh cng nhnh lng tnhda trn cc tri thc chuyn ngnh hoc kinh nghim ca ngi gii on nh. Vic tch thngtin trong vin thm c thchia thnh 5 loi:

- Phn loi a ph: L qu trnh tch gp thng tin da trn cc tnh cht ph,khng gianv thi gian ca i tng.

- Pht hin bin ng: L pht hin v tch cc bin ng da trn tliu nh a thi gian

(So snh nh cng mt khu vc ti cc thi im khc nhau)


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- Chit tch cc thng tin tnhin: Chit tch cc thng tin tnhin tng ngvi vic onhit , trng thi kh quyn, cao ca vt thda trn cc c trng ca phhoc thsai cacp nh lp th.

- Xc nh cc chs: L vic tnh ton cc chsmi, v dchsthc vt.

- Xc nh cc i tng c bit: L xc nh cc c tnh hoc cc hin tng c bitnhthin tai, cc cu trc tuyn tnh, cc biu hin tm kim kho c.

Qu trnh tch thng tin tnh c ththc hin theo phng php shoc gii on nhbng mt.

Vic gii on nh bng mt c u im l c thkhai thc c cc tri thc chuyn ngnhv kinh nghim ca con ngi. Mt khc vic gii on nh bng mt c thphn tch cc thngtin phn bkhng gian. Tuy nhin phng php ny c nhc im l tn km thi gian v ktquthu c khng ng nht.

Vic gii on nh bng sc u im l cho nng sut cao, thi gian xl ngn, c tho c cc chsc trng tnhin. Tuy nhin, n c nhc im l kh kt hp vi tri thc

v kinh nghim con ngi, kt qu phn tch thng tin km. khc phc nhc im ny,nhng nm gn y ngi ta nghin cu cc hchuyn gia, l cc chng trnh my tnh ckhnng m phng tri thc chuyn mn con ngi phc vcho vic gii on nh tng.

Qu trnh gii on nh vin thm thc hin qua cc bc sau:

- Hiu chnh nh.

- Tng cng cht lng nh.

- Gii on nh vin thm.

- nh gi chnh xc kt qu.

1.Hiu chnh nh.

- Hiu chnh bc x: Tt ccc tliu nh hu nhbao gicng chu mt mc nhiuxnht nh. Nhm loi trcc nhiu kiu ny cn phi thc hin mt sphp tin xl. Khithu c cc bc xtmt t trn cc vt mang trong vtr, ngi ta thy chng c mt sskhc bit so vi trng hp quan st cng i tng khong cch gn. iu ny chng tnhng khong cch xa nhvy tn ti mt lng nhiu gy bi nh hng ca gc nghing vcao mt tri, mt siu kin quang hc kh quyn nhshp th, tn x, m...chnh vvy, m bo c stng ng nht nh vmt bc xcn thit phi thc hin vic hiuchnh bc x.

- Hiu chnh kh quyn:Bc xmt tri trn ng truyn xung mt t bhp th, tn xmt lng nht nh trc khi n ti c mt t v bc xphn xtvt thcng bhp thhoc tn x trc khi ti c bcm. Do vy bc xm bcm thu c cha ng khng

phi chring nng lng hu ch m cn nhiu thnh phn nhiu khc. Hiu chnh kh quyn lmt cng on tin xl nhm loi trnhng thnh phn bc xkhng mang thng tin hu ch.

- Hiu chnh php chiu bn : Php chiu bn c sdng chiu bmt Elipsoidln mt mt phng. y l mt php nh xkhng hon ho v mt mt cu khng bao gicthtri thnh mt mt phng. V vy, lun tn ti cc sai skhc nhau.

- Hiu chnh hnh hc:Mo hnh hc c hiu nhssai lch vtr gia tonh thc t(o c) v tonh l tng c to bi mt bcm c thit khnh hc l tng v trongiu kin thu nhn l tng. Mo hnh hc c chia thnh loi ni sai gy bi tnh cht hnh hcca bcm v ngoi sai gy bi vtr ca vt mang v hnh dng ca vt th.

Nhm a cc tonh thc tvtonh l tng cn thit phi thc hin hiu chnhhnh hc. Bn cht ca hiu chnh hnh hc l xy dng c mi tng quan gia htonh


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o v htoquy chiu chun. Htoquy chiu chun c thl htomt t (Vunggc hoc a l) hoc htonh khc.


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2. Tng cng cht lng nh v chit tch c tnh.

- Tng cng cht lng nhTng cng cht lng l thao tc chuyn i nhm thhinnh vi cng , tng phn ph hp vi thit bhin thnh; nhm tng tnh dc, dhiu ca nh cho ngi gii on.

- Chit tch c tnhl mt thao tc nhm phn loi, sp xp cc thng tin c sn trong nhtheo cc yu cu hoc chtiu a ra di dng cc hm s.

Nhng php tng cng cht lng c bn thng c s dng l chuyn i cp xm, chuyn i histogram, thp mu, chuyn i mu gia hai hRGB v HSI...

Sau khi tng cng cht lng nh, mt trong nhng u im ca phng php xl nhs l c thchn cc thp mu tu. Thp mu c ngha l gn 3 mu cbn Red (),Green (Xanh lc), Blue (chm) cho 3 knh phno .

+ Thp mu tht (true color): l thp mu c mu Blue c gn cho knh 1 (knh Blue),mu Green c gn cho knh 2 (knh Green) v mu Red oc gn cho knh 3 (knh Red)

+ Thp mu gi: l cc thp mu cn li, c cch gn mu khc vi thp mu tht

+ Thp mu gichun: l thp mu c mu Blue c gn cho knh knh Green, muGreen c gn cho knh Red v mu Red c gn cho knh Near Infared. Trong thp muny thc vt c mu , t trng thng c mu trng, nc c mu xanh.

3. Gii on nh

* Gii on nh bng mt.

Trong vic xl thng tin vin thm th gii on bng mt l cng vic u tin, phbinnht v c thp dng trong mi iu kin c trang b tn gin n phc tp v c thpdng trong nhiu lnh vc nghin cu khc nhau nha l, a cht, lm nghip, nng nghip,thuvn, mi trng...

Gii on nh bng mt l sdng mt thng hoc c strgip ca cc dng cquanghc tn gin n phc tp nhmy tnh, knh lp, knh lp th, knh phng i, my tng hpmu... Csgii on nh bng mt l da vo kha gii on nh. Khi gii on mt itng cth, ngi gii on cn nm vng bn cht phphn xca cc i tng, sthhinca chng trn t liu mnh ang x l xy dng kha gii on nh. Kha gii on nhc xy dng thng qua 8 chun gii on nh sau:

- Chun kch thc:Kch thc cc i tng tnhin c xc nh bng cch ly kchthc o c trn nh nhn vi mu slnh. Vic o kch thc tn cy trn nh c li

phn bit cc loi cy khc nhau nhng c nh tn cy ging nhau.

- Chun en:en ca cc i tng trn nh c thc bin thin ten n trng. Dosphn x, bc xnng lng mt tri ca cc i tng khc nhau vi mc khc nhau, dnn sthhin trn nh c en hoc sc nh skhc nhau. V d: ct kh phn xmnh nnnh c sc nh trng, cn ct t do phn xkm hn nn c mu ti hn trn nh en trng.

- Chun hnh dng:Trn nh hng khng, nh v trhnh dng c trng cho mi itng khi nhn ttrn cao xung v c coi l chun on c quan trng

- Chun bng: Bng ca cc i tng d dng nhn thy khi ngun sng khng nmchnh xc nh u hoc trng hp chp nh xin. Da vo bng ca cc i tng trn nhc thxc nh c chiu cao ca n.

- Chun cu trc:Cu trc l tp hp nhiu hnh mu nh. Cu trc nh ca cnh ng laxanh tt thuc dng cu trc mn, cu trc ca rng thuc dng cu trc sn si. Cu trc ca nhc lin quan n tlnh.


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- Chun phn b:Chun phn b l tp hp ca nhiu hnh dng nhphn btheo mtquy lut nht nh trn ton nh v c mi quan hvi i tng cn tm kim. Rung bc thangthng thy vng i ni, nhng di rung trng la hp chy ven cc thung lng ...

- Chun mi quan htng h: Cc i tng trn mt t c sp xp theo nhng quy

lut nht nh v c mi quan htng hvi nhau. V dcc loi doi ct nm dc theo bsnghoc gia sng ma nc cn, ng ngm li qua sui c lin quan n ng mn hai bn

bsui.

- Chun mu sc:Mu sc l mt chun quan trng trong vic xc nh cc i tng. Nhchun mu sc ta ddng pht hin ra cc loi thc vt khc nhau, cc i tng khc nhau cmu khc nhau, c bit l khi sdng nh tng hp mu.

Nhm trgip cho cng tc on c nh, ngi ta thnh lp cc mu gii on nh. Mugii on l tp hp cc chun gii on nh on c cho mt i tng nht nh. Kt qugii on phthuc vo mu gii on. Mu gii on c xy dng trn nhng vng nghincu thnghim c iu tra klng.

Tt c8 chun gii on nh cng vi cc thng tin vthi gian chp nh, ma chp nh,tlnh u c a vo mu gii on nh. Mt bgii on nh bao gm mu nh v phnm tbng li.

Da vo mu gii on, tin hnh khoanh vcc i tng trn nh bng tay (i vi nhtng t) hoc sho trn mn my tnh (i vi nh s). Qu trnh sho, khoanh vphthucnhiu vo kinh nghim, trnh v cm hng ca ngi gii on.

* Gii on nh theo phng php s(phn loi nh)

Phn loi nh l qu trnh my tnh xl nh da trn gi trphn xphca cc pixel.Yu cu ca ngi sdng c a vo my, sau my tnh stng phn loi v cho ktqudi dng nh (bn dng Raster) c phn loi. Thng thng ngi ta sdng cc

dliu a phphn loi nh. C 2 phng php phn loi cbn l phn loi phi kim nhv phn loi c kim nh:

+ Phn loi phi kim nh (Unsupervised): Php phn loi chda trn cc c trng hoctnh cht trn nh. My tnh yu cu cung cp thng tin vs lng lp cn phn loi, tptrung ca cc lp thng qua lch chun, v tr tng i ca cc lp trong khng gian

ph...Sau my tnh stng tm v gp cc picel li theo yu cu ca ngi sdng.

+ Phn loi kim nh (Supervised): Php phn loi c sdng dliu kim tra ngoi thca. Trong qu trnh phn loi my tnh syu cu mt skin thc ca ngi sdng vkhuvc cn phn loi. Nhng kin thc ny c c trn cskho st thc a v cc tliu bnchuyn . Cc nhm phn loi kim nh thng dng l phn loi hnh hp, phn loi theo

khong cch ngn nht, phn loi xc sut cc i. Tt ccc phng php phn loi ny uyu cu chun btp mu (training sites). Tp mu l mt phng php thng tin ca ngi phntch cung cp cho my tnh vi tng mnh cn phn loi. V vy, vng mu cn c chnsao cho m bo tnh i din theo nguyn tc xc sut thng k cho i tng trn phm vi tonnh. Ngi sdng thng qua chtng tc trc tip vi my svch ln nh nhng vngmu i din cho cc i tng cn phn tch. Phn mm my tnh da vo tp mu sphn loinh. Phng php phn loi nh thng dng l phng php xc sut cc i (Maximumlikelihood).

4.nh gi chnh xc bn sau gii on.

Phng php nh gi chnh xc ca bn sn phm trong qu trnh gii on nhvin thm l kim tra i sot ngoi thc a. c im ca bn gii on nh l lun c hnh

dng kch thc ging nhngoi thc a do nh vin thm phn nh trung thc bmt tri t


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ti thi im chp nh. V vy, nh gi chnh xc ca bn sau gii on nh a thi gianl nh gi chnh xc ca cc loi hnh sdng t.

Cng vic kim tra i sot cc loi hnh sdng t thng thng c tin hnh vi strgip ca cn ba phng v GPS cm tay. Sau khi thu thp cc im mt t ca tt ccc loi

hnh sdng t, cn xc nh sim ng ca mi loi hnh sdng t nh gi chnhxc ca tng loi hnh sdng t. Sau tng hp nh gi chnh xc ca ton bn .

CU HI N TP CHNG 1

1. Khi nim mt sloi bn cbn ca ngnh TN&MT.2. Trnh by qu trnh xy dng hquy chiu v htoquc gia nc ta.3. Nu nhng hn chca hquy chiu v htoquc gia HN72

4. Trnh by cc yu cu ca mt hquy chiu quc gia. Cc thng scbn ca hquychiu v htoVN2000.5. Cc bphn cu thnh hthng GPS?6. Trnh by cc phng php o GPS ng dng trong lp bn a chnh.7. Bn sl g? Cc m hnh v kiu dliu cbn ca bn s? Skhc nhau giam hnh vector v m hnh raster?8. Cc c im cbn ca bn s? Trnh by nhng u im ca bn sso vi bngiy thng thng?9. Trnh by cch t chc d liu ca bn s. Cho v d c th vi phn mmMicroStation?

10. Xut nhp dliu bn l g? Nu cc nh dng phbin ca bn shin nay?11. Trnh by quy trnh thnh lp bn stsliu o c?12. So snh u, nhc im ca sho bn trn bn sho v sho trn mn hnh?13. Vin thm l g? u im ca phng php vin thm?14. Cc chun gii on nh bng mt? Trnh by phng php gii on nh bng mt.15. Trnh by phng php gii on nh s?


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Chng 2

M HNH DLIU BNKhi xy dng bn , cc i tng thc tngoi thc a u c m tbng nhng k

hiu khc nhau trn bn . Vy chng c biu din ra sao v bng nhng quy lut no? gip ngi c hiu r hn vcch thc biu din cc i tng bn dng scng nhmiquan hca chng, chng ny gii thiu vcc m hnh dliu cbn c p dng trong xydng bn s nc ta, c bit l Bn a chnh, bao gm m hnh d liu VectorTopology v m hnh dliu Spaghetti.ng thi, chng ny cng gii thiu mt vi thut toncbn trong xl thng tin bn da trn nguyn l ca cc m hnh dliu.

2.1. KHI NIM M HNH DLI U

M hnh dliu khng gian (Spatial data model) l mt m hnh ton hc m tcch biudin cc i tng bn di dng s.

m tcc i tng bn , hin nay tn ti nhiu m hnh d liu khng gian khc

nhau. Chun vm hnh dliu khng gian cho bn sc xc nh da trn vic xem xtcc kha cnh sau :

- Tnh cht chvmt ton hc.

- Tnh phbin, c sdng rng ri trong cc csdliu bn Vit nam v thgii.

- Thhin c cc tnh cht mang tnh c th ca bn Vit nam.

Hin ti, c mt sm hnh dliu khng gian khc nhau c p dng :

- M hnh dliu VECTOR

- M hnh dliu RASTER

- M hnh dliu QUATREE

- M hnh scao (DEM: Digital Elevation Model)

i vi dliu bn dng Vector, hai m hnh dliu c sdng rng ri nht VitNam l m hnh dliu Vector topology v Vector Spaghetti.

2.2. NI DUNG CA M HNH DLI U

Nghin cu xem xt mt m hnh dliu, chng ta phi xem xt cc thng tin ca cc itng bn .

Thng tin ca cc i tng bn bao gm:Thng tin vvtr khng gian (Spatial data)Thng tin vquan hkhng gian (Relational Spatial data)Thng tin thuc tnh, phi khng gian (Attribute data)

Trong cc m hnh dliu khng gian, cc i tng bn c quy v4 kiu i tnghnh hc cbn:

im (Point). V d: mc a gii, mc quy hochng (Line). V d: ng ranh gii tha, knh 1 ntVng (Polygon, Area). V d: tha t, sng...Ch thch, m t(Annotation, Text). V d: shiu tha, tn ph...

2.3. M HNH DLI U VECTOR SPAGHETTI

M hnh spaghetti l m hnh n gin v dhiu. Cc i tng c biu din thng quacc im, ng v vng. Nu c hai vng knhau th ng ranh gii gia hai vng phi cghi nhn hai ln, mi ln cho mt vng. Trong cu trc dliu ca File th tt ccc i tngc ghi nhn bi gi trca cc cp to. Chnh v vy, tt ccc php phn tch v tnh ton


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khng gian c lin quan n mi quan hca cc i tng u thc hin mt cch kh khn. Tuyvy m hnh dliu ny vn c sdng rng ri thnh lp cc bn di dng sv l dliu u vo cho cc chng trnh in, v. Bi v cc dliu ny dtrnh by, bin tp, sa cha...

Thng tin ca cc i tng bn trong m hnh dliu ny c m tnhsau:

2.3.1. Thng tin vv tr khng giani tng kiu im: Cc i tng thuc kiu im c m tnhsau :

i tng kiu ng :Cc i tng thuc kiu ng c m tnhsau :

Id: chsca i tng ( chslin kt )

i tng kiu vng: Cc i tng thuc kiu ng c m tnhsau :

Id: chsca i tng ( chslin kt )

yxId ,, (Id: Identifier: Chslin kt)

( )[ ]{ }2;,1;,, = nniyxId ii

( ) ( ) ( )[ ]{ }nnii yxyxnniyxId ,,;3;,1;,, 11 =


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2.3.2. Thng tin vquan h khng gianCu trc m tthng tin vquan hkhng gian khng c m tmt cch tng minh

trong m hnh dliu vector Spaghetti. Cc mi quan hny c suy ra tvtr toca cci tng. iu ny c ngha l chng ta cn phi c cc thut ton v xy dng cc cng c

phn mm c c cc quan hkhng gian gia cc i tng. y chnh l nhc im lnnht ca m hnh vector spaghetti.

2.3.3. Thng tin vthu c tnh

Thng tin vthuc tnh c thhin bng mt bn ghi tng ng trong cc bng dliuthuc tnh ca i tng. Cc bng thuc tnh c cu trc l cc bng csdliu quan h. Milin hca cc bng c thng qua trng kho (chs).

2.4. M HNH DLI U VECTOR TOPOLOGYM hnh d liu Vector topology l mt m hnh phc tp, cc i tng c qun l

khng chbi tom cn bng cmi quan hkhng gian gia cc i tng. M hnh dliu ny m ttrn vn cc thng tin ca cc i tng khng gian bao gm:

- Thng tin v v tr khng gian (Spatial data): Thng tin c th hin theo m hnhvector, bng cc ta m tvtr, hnh dng, ng bin ca cc i tng.

- Thng tin vquan hkhng gian (Relational Spatial data Topology). M hnh dliuTopology thhin quan hkhng gian di 3 kiu quan hl:

+ Lin thng vi nhau: thhin di dng file ng - im ni (ARC _ NODE)

+ Knhau: thhin di dng file m tng bao (ARC_POLYGON)

+ Nm trong nhau, phnhau.

Slin hgia thng tin khng gian v thng tin thuc tnh c thc hin qua chsxcnh (Identifier)

2.4.1. Thng tin vv tr khng gian

i tng kiu im ( Point)

Cc i tng a l chc mt vtr n, c lp sc phn nh nhi tng kiu im

Dliu khng gian: nh ngha bi mt cp to( x,y).

i tng kiu ng ( Line)

Cc i tng a l c dng tuyn, hoc mng s c phn nh nh i tng kiung.


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Dliu khng gian: c m tdi dng 1 dy cc cp to. Mt ng bt u v kt

thc bi im giao (Node). di ng c nh ngha bng to.

Quan hkhng gian ca cc i tng kiu ng c thhin qua quan hlin thngvi nhau. Quan hlin thng c m tcu trc ARC_NODE.

i tng kiu vng ( Area, Polygon)Cc i tng a l l mt vng lin tc c xc nh bi mt ng bao c phn nh

nhmt i tng kiu vng.

Dliu khng gian: dliu khng gian ca cc i tng vng c nh ngha l mt tpcc i tng ng nh ngha ng bao v mt im nhn. Mt im nhn nm trong mti tng vng v c ngha xc nh cho vng ny.

2.4.2. Thng tin vquan h khng gianQuan hkhng gian ca cc i tng kiu vng c thhin qua quan hknhau. Quan

hny c m ttheo m hnh ARC_POLYGON.

M hnh Topology dng cc quan hkhng gian nh ngha cc c tnh khng gian ca

cc i tng.


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Cc quan hkhng gian Cc c tnh khng gian

Mi mt ng (arc) c im bt u v kt thc tiim nt (node).

di ca ng.

Hng ng (Directionality).

Cc ng (arc) ni vi nhau ti cc im nt (node). Tnh ni nhau (Connectivity)

Cc ng (arc) ni vi nhau to thnh ng baoca vng (polygon).

Din tch vng, chu vi vng

Cc ng tham gia nh ngha vng chai bn:phi v tri.

Tnh k nhau hoc tnh lin tc.(Adjacency or contiguity)

M hnhng-im nt (Arc-node topology)

M tquan hkhng gian vtnh lin thng (Connectivity) (bng nt, bng cung)

M hnh ng-im nt (Arc-node topology) nh ngha mi quan hgia cc i tngng v im nt. Cu trc ca mi quan hny cho php ngi sdng xc nh c ctnh quan trng l hng v tnh ni nhau. Phn ln cc php phn tch a l u cn nhng ctnh ny.

Hng : Hng c nh ngha tim nt u (from-node) v im nt ti (to-node).

Tnh ni nhau (Connectivity) Cc ng c ni nu shiu ca im nt u hoc cui

ca ng ny trng vi shiu u hoc cui ca ng khc.M hnh Vng-ng (Polygon-arc topology)

M tquan hkhng gian vtnh knhau hoc lin tc (Adjacency or contiguity)

M hnh Vng-ng (Polygon-arc topology) nh ngha mi quan hgia cc i tngng vi i tng vng m cc ng ny to nn ng bao ca vng. Cu trc ca miquan hny cho php ngi sdng xc nh c c tnh quan trng ca vic nh ngha vngv tnh knhau (adjacency). Hu ht cc php phn tch a l u i hi nhng c tnh ny.

Tnh knhau (Adjacency) Cc ng to nn ng bao vng c sdng chung bi 2vng knhau ( vng phi v vng tri ng).


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Vng phi v tri (Left and right polygons) Vng phi v tri ca ng c xc nh theodi chuyn tim nt u n im nt ti. Vng phi ca ng l chsca vng bn pha phidi chuyn, vng tri l chsvng pha bn tri di chuyn. (Bng vng)

nh ngha vng (Area definition) Mt tp cc ng ni nhau theo vng snh nghang bao ca mt vng. Trong ng bao ca mt vng, cho php tn ti cc vng nm trntrong gi l o (island).2.4.3. Thng tin vthu c tnh

i tng dng im:c thhin bng mt bn ghi tng ng trong bng quan hthuctnh ca im.

i tng dng ng:c thhin bng mt bn ghi tng ng trong bng quan hthuc tnh ca ng.

i tng dng vng:c thhin bng mt bn ghi trong cc bng thuc tnh tngng ca vng. Cc bng thuc tnh c cu trc l cc bng csdliu quan h. Mi lin hcacc bng c thng qua trng kho (chs).2.5. XL THNG TIN B N TRONG C S D LI U BN 2.5.1. Cc bi ton xl thng tin b n

phc vngay trong csdliu cng nhphc vsn xut bn cho nhu cu x hi,cn phi gii quyt mt sxl thng tin trong lnh vc bn . Cc bi ton cthnhsau:

- Cp nht cc lp thng tin bn trn csdliu tliu nh mi.- Chuyn i tov hquy chiu.- Bin v, tng hp bn tbn tlln hn.- Bin tp cc bn chuyn theo nhng chnht nh.- Tnh ton cc sliu thng k, chng ghp bn .- Phn tch, bin i cc yu ttheo thi gian.- Phn tch cc quy lut tnhin, kinh t, x hi ca cc i tng a l.

Ngoi ra cn c nhiu loi bi ton phc vcho cc chuyn ngnh khc.2.5.2. Cc thut ton xl thng tin b n a. Thit lp topology

Thit lp, m ho cc quan hgia cc im, cc cung v cc vng to nn cc thc th.Trong qu trnh thit lp topology mt sbng mi c thit lp lu cc im nt, cc cung

v cc vng. Cc bc chnh sphi tin hnh khi thit lp topology bao gm:


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- Sp li dliu trong tp lu tobn sao cho trc y tng dn.- Loi bbt cc im v cc ng dtha.- Kin to bng nt.- Kin to bng cung.- Kin to bng vng.

b. Loi bim dtha

Tt ccc phng php sho bn u pht sinh ra nhiu im, on thng hn slngcn thit. Sliu m my tnh nhn c tbn sho l cc toim ca mt lp (layer). Cclp a l c to ra nhmt dy lin tc ca cc im ni vi nhau tng i mt.

E={(X1,Y1), (X2,Y2),..., (Xn,Yn)}

Cc tony c pht sinh do ngi sdng nhn bn phm mt cch ngu nhin. Vvy hai im lin tip c pht sinh c thtrng nhau, c thcng nm trn mt ng thnghoc c thgn nhau n mc khng cn thit.

Phng php ny c sdng sau khi to topology cho bn , c ngha l chng ta

c bng nt (node) v bng cung (arc) ttp dliu skhai.

Coi tothnht ca cung l im cht v tocui l im di ng. Hai im ny tothnh mt on thng. Trn hnh vl on thng d: (x1,y1),(x6,y6). Tnh tt ccc khong cchtcc im nm gia im cht v im di ng ti on thng d ta c cc gi trt1, t2, t3, t4.

Nu tt ccc khong cch u nhhn gi trT cho php th d l mt phn ca lp (Layer)bn ang xt. Cc im nm gia im cht v im di ng c loi b. im cnh mil im di ng hin hnh, v im di ng sc gn li. Nu iu kin khng thomn, cngha l c im phi c gili. im c khong cch t>T v xa im cht nht trthnhim di ng mi. Trn hnh vim (x5,y5) c chn. Cng vic c tip tc vi on thngni tim cht ti im di ng mi. Kt qul tt ccc im ng vai tr im cnh sc gili cho lp bn .

c.Phv vng mPh l chc nng cbn trgip quyt nh ca h thng thng tin bn . Chng cho

php suy din lp dliu mi tlp dliu c trong CSDL. Ct li ca qu trnh xy dngphv vng m l tnh din tch ca phn i tng a l ba gic hay hnh trn ph. Ta xem xt hai loi phthng dngnht trong hthng bn s:

- Pha gic: Xt phn giao ca 2 a gic: a gic phv a gic i tng bn .

1. Tm cc im giao nhau (cc im 1,2,3,4) ca cccnh;

2. Thit lp cc a gic mi (P1, P2, P3...) theo thut


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ton thit lp topology;

3. Tnh din tch ca vng trn bn .

- Phng trn: Xt phn giao ca ng trn vi a gic.

1. Tm cc im giao A, B, C, D ca hnh trn vi a gic.2. Tcc a gic mi AFB, CDE... Tm cc a gic con lgiao ca hnh trn v a gic ln, tnh din tch ca chng.

3. Tm cc hnh vin phn l mt phn giao gia ngtrn v a gic ln.

4. Tnh din tch hnh vin phn.

5. S=R2arccos(x/R)-xy

d. Xc nh vtr t nhn trn bn

Bn l tp hp cc dliu a l. Trong qu trnh khai thc, hthng c khnng npchng cc lp khc nhau. Khi sdng hthng vo vic nghin cu, nh gi, hthng c kh

nng hin th nhiu loi im khc nhau theo nhucu nh hin th tn, din tch... Thut ton giphin thtn cc tin ch vo bn mt cch hp lnht.

Theo hnh vbn, cc hnh trn l v tr cacc biu tng chim trn bn , cc hnh chnht

bao quanh vtr cc xu k t(12 xu k t). Vtrt tn cho im c u tin t1-12. Yu cu t ra l: tn ca tin ch khng c: ln tnca tin ch khc; ln biu tng ca tin ch; ln mp bn . Thut ton c nghin cunhm nng cao tc xc nh vtr c thcho tn tin ch trn bn .

1. Sp xp li cc ta hin thtn tin ch theo thttng dn ca y, nu tn ti ccta c cng gi try th sp xp theo thttng dn ca x;

2. Gn i=1 l gi trca vtr ban u (hnh v) c mc u tin cao nht cho tt ccctin ch sc hin th;

3. Nu yu cu c tha mn th sang bc 6, nu yu cu khng tha mn v i=12 thsang bc 5;

4. Chn vtr mi i+1 (khi tn ang xt ln tn tin ch khc hay ln biu tng hay ln mp bn ). Trli bc 3.

5. Gim ln ca cc k t, trli bc 3 hay chnh bng tay;

6. Kt thc.

Ngoi ra cn mt sthut ton xl thng tin bn nh: thut ton lp bn chuyn; Thnh lp bn mt ; Tm kim i tng trn bn ; Tm ng i ngn nht; Cc biton vtnh ton trn bn (tnh din tch, chu vi, di).

CU HI N TP CHNG 21. M hnh dliu l g? Ni dung ca m hnh dliu?2. Trnh by ni dung m hnh dliu Spaghetti?3. Trnh by ni dung m hnh dliu Topology?4. So snh hai m hnh Spaghetti v Topology?5. Trnh by mt sthut ton xl thng tin bn .


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Chng 3

CHUN HO DLIU BNthun tin trong qun l v sdng cc loi bn chuyn ngnh, dliu bn cn

c xy dng thng nht v ng b. Qu trnh thng nht v ng bdliu theo cc chun nh trc c gi l chun ho dliu bn . Chng ny gii thiu nhng quy nh hinhnh, c p dng trong qu trnh xy dng cc loi bn cbn nht ca ngnh Ti nguynv Mi trng l Bn a chnh, Bn a hnh, Bn hin trng, quy hoch sdngt nc ta. T gip ngi c nm vng v p dng hiu qunhng quy nh gip choqu trnh xy dng bn c tin hnh nhanh chng v chnh xc.

Trong x hi hin i, cng nghthng tin c mt vai tr quan trng trong vic thu thp vqun l thng tin. qun l cc dliu c tnh khng gian (c vtr a l), ngi ta sdngH thng Thng tin a l (Geographical Information System - GIS) qun l. Mt trongnhng vn ln khi qun l, trao i thng tin l thng tin cn phi c chun ha. Chun hol cng vic l cn thit khi ngi dng GIS mun tch hp h thng ca mnh vi cc phn

cng khc, vi cc phn mm GIS khc nhau v cc ngun dliu khc nhau. Chun l cn thitkhi trao i dliu trn mng, to khnng truy nhp dliu sc phn bcc vtr a lkhc nhau, chia sdliu gia cc cquan, cng ty, gia cc Quc gia vi nhau.

Mc tiu ca BTN&MT l dng mt Hthng thng tin t ai thng nht ton quc. c th c mt CSDL a chnh thng nht tch hp t cc CSDL a chnh con ti cc STN&MT, BTN&MT phi c cc quy nh chung, cth.

Trong bt kmt CSDL c a vo sdng chung u phi tin hnh chun ho dliu. C nhvy vic khai thc dliu mi c thchia scho nhiu i tng sdng, vic hinchnh dliu tnhiu ngun mi m bo tnh thng nht. CSDL ti nguyn t ai c thitlp trn c s tp hp d liu thu thp t cc n v thuc BTN&MT v cc STN&MT.

Ngoi ra cn thm mt sdliu tcc ngun cc cquan iu tra cbn khc. Ngi sdng rt a dng tngnh a chnh ctrung ng v cc cp a phng, tcc cquan qun lNh nc, tcc bngnh khc, tcc tchc trong nc v ngoi nc, tcc i tng l cdn c nhu cu. Trong khung cnh nhvy vic chun ho d liu, h thng thit b, tchcqun l phi rt thng nht.

Hin nay tp hp dliu ca ngnh a chnh kh ln. Mt phn dng truyn thngtrn giy, mt phn dng snh trong nhiu nh dng (format) khc nhau, mt phn dng thng nht theo nh hng ca BTN&MT. Vn t ra l phi xem xt bin php nhchun v chun ho dliu nhthno thu c mt CSDL thng nht. Cc vn cn giiquyt nhsau:

- Xc nh chun dliu thng nht .

- Xy dng quy trnh thng nht chuyn cc dliu cvdng chun nh;

- Xy dng quy trnh thng nht vthu thp dliu c c cc dliu chun.

3.1. CHUN HO BN A CHNHNi dung chun ho bn a chnh bao gm nhiu thnh phn. Mi thnh phn chun

ho thhin cho mt lnh vc lin quan n bn a chnh. Cthchun ho bn a chnhbao gm cc thnh phn sau:

- Chun vdliu bn (Cartography Data Standard)

- Chun vthhin bn (Cartographic Represetation Standard)

- Chun vkhun dng file (Data format and data exchange standard ).

- Chun ho vdliu m tCSDL (metadata) cho bn a chnh (Metadata Standard).


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3.1.1. Chun ho dli u bn a. La chn m hnh dliu

Cc i tng ca bn a chnh c m tbng cc m hnh dliu khng gian. Mhnh dliu khng gian (spatial data model) l mt m hnh ton hc m tcch biu din cci tng bn di dng s.

m tcc i tng bn , hin nay tn ti nhiu m hnh d liu khng gian khcnhau. Chun vm hnh dliu khng gian cho bn a chnh c xc nh da trn vicxem xt cc kha cnh sau :

- Tnh cht chvmt ton hc.

- Tnh phbin, c sdng rng ri trong cc csdliu bn Vit nam v thgii.

- Thhin c cc tnh cht mang tnh c th ca bn a chnh Vit nam.

c im ca bn a chnh l cu trc ca cc i tng n gin. i tng quan

trng nht cho lu trcng nhtra cu, x l sau ny l tha t. Nguyn tc la chn m hnhdliu cho csdliu bn a chnh l m hnh ny phi phn nh c i tng tha tvi y c im v tnh cht ca n.

Cc yu cu vqun l vi cc i tng ca bn a chnh :

ng ranh gii tha cn c qun l nhmt i tng thc sv c d liu thuctnh.

Tha t l mt i tng kiu vng c nh ngha bi cc ng ranh gii tha khpkn.

Thuc tnh quan trng nht ca tha t l din tch tha. Din tch tha sbsai lch khing ranh gii tha thhin bng i tng ng khng c din tch mt d trong thc t,

ng bny c chiu rng v c din tch. Nhvy ng ranh gii tha tha khi cn thit cnc gn thuc tnh l rng btha m bo khi tnh din tch tha c chnh xc.

ng ranh gii tha c th l tham gia vo ng bao ca tha t vi cc i tngkhc nhng giao thng, thuvn.

M hnh dliu phi m tc quan hkhng gian gia cc i tng tha t.

Quan hkhng gian gia cc tha t rt quan trng c bit l quan hknhau, tip gipnhau. Quan hknhau thhin khng chtrong CSDL Bn a chnh m cn thhin trongCSDL Hsa chnh di dng cc chsdng kcn. Quan hknhau cn l cn cphp lxc nh quyn sdng t ca chsdng.

Tha t l i tng bn chnh tham gia vo qu trnh bin ng t ai. Tha t c

thbin ng vmt hnh hc : bin dng, chia tha, tch tha hay bin ng vmt thuc tnhnhthay i vloi t, mc ch sdng, chsdng.v.v. Khi bin ng, nhng thay i trnmt tha snh hng n cc tha ln cn.

CSDL bn a chnh c c im l khi lng dliu rt ln, m hnh dliu c khnng ti u ho vlu tr.

Xut pht tnhng yu cu trn ca bn a chnh, m hnh d liu Vector Topology(Vector Topology Data Model) l m hnh ph hp nhtm tcc i tng bn a chnhtrong csdliu.

i vi cc i tng a hnh : im cao, ng bnh , khng cn thit phi dngm hnh scao DEM m tm chcoi chng nhnhng i tng im v ng c gn

gi trcao.


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Tuy nhin chng ta xem xt n 2 c im na ca CSDL bn a chnh :

CSDL bn a chnh l CSDL c cc dng ngi s dng rng ri v a dng: tnhng cquan trong BTN&MT n cc Bngnh khc thm ch n cnhng ngi dn bnhthng. Phn ln cc ngi dng u chcn hoc chc quyn tra cu nhng thng tin c

sn trong CSDL chkhng lin quan n xl thng tin.CSDL bn a chnh c tnh phn tn. Cc CSDL a chnh cho tng tnh c hnh

thnh v tp trung ti cc tnh. Trn trung ng chqun l cc thng tin c tnh vm. Cch tchc thng tin nhvy dn n phng thc truy nhp thng tin s qua mng cc b ti a

phng, trn mng din rng ca ngnh (INTRANET) hoc trn mng din rng cng cng(INTERNET). Giao din truy cp thng tin chyu sl WEB.

Vi 2 c im trn, m hnh dliu Topology khng thc sthch hp v trong m hnhny cc i tng vng ( tha t , ng, sng .v.v.) khng c m ttng minh. i vicng vic tra cu, thng tin cng tng minh cng tt v i vi dliu khi trao i trn mng,i tng cn trao i cng t thng tin phcng tt. gii quyt vn ny,M hnh dliu

vector Spaghetti (Spaghetti Data Model) tra thch hp hn c.Tnhng phn tch trn, chun vm hnh dliu bn a chnh c la chn nhsau:

- p dng c2 m hnh d liu TOPOLOGY v SPAGHETTI cho csdliu bn a chnh.

- Dliu trong csdliu chnh c m tbng m hnh VectorTopology. Dliu m tbng m hnh Spaghetii l dliu dn xut, c to ra t dliu m tbng m hnh Topology.

- Cc i tng c m tbng m hnh Topology c sdng cho cc ng dng ccbthuc vchuyn ngnh a chnh ca Sa chnh nhcp nht bn , xl bin ng t ai.

- Cc i tng m tbng m hnh Spaghetti c sdng cho cc ng dng vtra cuthng tin v cc ng dng phn phi thng tin trn INTRANET, INTERNET.

Hnh 3-1. M hnh dli u cho bn a chnhb.p dng chun m hnh dliu

Dliu lu trong csdliu phi m bo tnh Topology ca chng. Yu cu ny cxem xt n khi sho hay khi chnh sa bn a chnh s.

Sliu bn sphi c kim tra v sa li theo yu cu ca m hnh topology.

Ngnh a chnh

CSDL BCM hnh SpaghettiChuyn i

m hnh

Ngi dng cui

CSDL BCM hnh Topology

Bo tr, cp nht v xl dliu

Tra cu dliu Phn phi dliu


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- ng ranh gii tha to thnh ng bao tha lun m bo tnh khp kn tuyt i vto.

- Cc ng ranh gii tha khng c php giao nhau, phi lun ct nhau ti u hoccui ng ( ti im nt NODE)

- ng ranh gii tha cn phi c qun l nhmt i tng c lp v c thgn rng tha. Khi mt ng ranh gii c nhiu on c rng khc nhau cn thit phi tch rathnh cc ng i tng khc nhau.

- Cc i tng vng khp kn ( tha t) phi c m ttheo m hnh dliu Topology(m hnh c cu trc), khng m tcc cc i tng hnh hc dng vng (m hnh khng ccu trc). Tha t c xc nh bng danh sch cc ng ranh gii tha to nn ng baokhp kn v mt im nhn tha c trng cho tha t.

- Csdliu chnh ca bn a chnh phc vphn tch v xl sliu ( thc hinqu trnh bin ng ) phi c lu trv qun l bng cc phn mm m tdliu bng mhnh Topology nhv dnhFAMIS, ARCINFO, MGE.

Sau khi file bn a chnh sa li xong, phi chy BUILD to Topology cho cc that v gn dliu thuc tnh cho ng ranh gii tha t, tha t.

- m tdliu bn , ngoi file hothhin ng nt bn cn phi c file mttopology ca cc i tng bn . V dnhfile DGN v file POL trong phn mm FAMIS.

- Qu trnh chnh l bin ng cho bn a chnh c thc hin trn csdliu cam hnh Topology.

c. Chun vni dung csdliu bn a chnh

Chun vni dung CSDL bn a chnh xc nh ni dung ca CSDL. Chun ny xcnh v m tnhng i tng bn lu trtrong csdliu, sphn loi, cch nhn dng,

Saing

0.20.3

Sai

0.2 0.3

ng

Sai Sai ng


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ni dung ngha ca tng loi i tng ny ng thi cng m tcthvquan hkhng gianvi cc i tng khc v dliu thuc tnh ca chng

Chun vni dung CSDL bn a chnh bao gm :

- Chun phn lp thng tin cc i tng bn

- Chun m t k thut ca cc i tng. Trong m t k thut, tng i tng trongCSDL c m trt chi tit, cthnhm, lp (level), chnh xc, cc quan hkhng gianv cc dliu thuc tnh. M tkthut cc i tng c sdng nhmt tp tra cu hngdn y nht cho cc dng ngi sdng tngi vo sliu cho n ngi tra cu, sdngdliu.

*Chu n vphn l p thng tin

Nguyn tc nh chun ni dung csdliu

Trc khi i vo m tmt bng phn lp thng tin ca bn a chnh cth, cn ara mt snguyn tc nht nh trong qu trnh xy dng chun ho cc lp thng tin. Sau y lmt snguyn tc chung khi nh chun vphn lp thng tin ca bn a chnh:

- Phn lp thng tin c ktha theo bng phn loi cc i tng bn trn bn achnh trong quy phm ca BTN&MT ban hnh.

- Cc i tng trong mt lp thng tin thuc vo mt loi i tng hnh hc duy nht:im (point), ng (polyline), hoc vng (polygon).

- Mi lp thng tin chthhin mt loi i tng (Object). Cc i tng c cng chungmt sc im tnh cht nht nh c gp thnh lp i tng (Object Class). Cc lp itng c gp li thnh cc nhm i tng (Category). Mi mt i tng c gn mt msthng nht. M ca kiu i tng gm .

- Mi mt lp thng tin c mt m duy nht.

- Trong mt nhm lp thng tin, m ca cc lp c nh slin tc.- Tn ca lp thng tin c t theo kiu vit tt sao cho ddng nhn bit c l lp

thng tin no.

Ni dung bng phn loi cc i tng trong CSDL bn a chnh

Sau y l bng phn loi cc i tng bn a chnh trong c sd liu. Cu trcbng gm cc ct:

- Phn nhm chnh

- Lp i tng

- i tng

- M a hnh: c nh s, phthuc vo loi i tng, v dng bnh cbn cm l 301, im thin vn c m l 112. mt si tng khng c m ny

- M: M c thhin bng k hiu chtheo tng nhm i tng. V dcc i tngtrong phn nhm chnh a hnh c m l DH ( DH1, DH2,)

- Chslp trong Microstation: Chslevel trong phn mm Microstation c gn chomi loi i tng.

- Dliu thuc tnh: m tcc dliu thuc tnh ca i tng lu trong csdliu.

- Quan hgia cc i tng: m tquan hvkhng gian, thuc tnh vi cc i tngkhc.


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p dng chun bng phn lp thng tin

- Xc nh ng cc i tng trn bn a chnh giy tng ng bn a chnh s.Trong bng phn loi cc i tng trn, ct sthttrong quy phm l tham chiu gia cc itng ca bn a chnh giy v bn a chnh s.

- Cc i tng ng chtham gia vo mt lp thng tin. Nhvy i vi cc ng nttham gia vo nhiu hn mt loi i tng, i hi phi c tch ra thnh cc lp khc nhautng ng vi lp thng tin m n m t. iu ny thng xy ra i vi cc i tng nh:

+ ng a gii hnh chnh chy theo a vt.

+ Cc ng gii hn hthng giao thng ng thi l ranh gii tha.

+ Cc ng gii hn hthng thuvn, ng thi l ranh gii tha.

- Cc ng nt khi tham gia vo 2 i tng phi c sao chp thnh 2 ng trngkht nhau vmt to, mi mt ng tham gia vo 1 loi i tng khc nhau, lu cc levelkhc nhau, mu sc, k hiu c thkhc nhau.

- Cc i tng trong bn a chnh sc lu theo ng quy nh trong bng phnlp. Cc i tng bn trong csdliu phi tun th:

+ Nm ng level hoc layer theo quy nh.

+ Tun theo cc k hiu v kiu ng v mu sc c quy nh

+ Gn dliu thuc tnh cho cc i tng c thuc tnh.

- Cn xy dng b cng c trn cc phn mm s ho hin i nh MicroStation chongi sdng, trnh cc sai st, lm ln.

Ni dung ca bn a chnh c quy nh trong Quy phm thnh lp bn a chnhv tp K hiu bn a chnh.

Chun vni dung CSDL bn a chnh xc nh ni dung ca CSDL. Chun ny m tnhng i tng no c lu trtrong csdliu, sphn loi, cch nhn dng, ni dung ngha ca tng loi i tng ny ng thi cng m tcthvquan hgia cc i tng vdliu thuc tnh ca chng.

* Chun vchi tit kthut

Phn chi tit kthut ca csdliu m trt chi tit tng i tng trong csdliubn a chnh. Mi mt i tng c m ttrn mt trang. Phn ny l ti liu chnh ngi dng csdliu bn a chnh c mt cch hiu su sc, r rng v ton din vcci tng trong csdliu.

Cu trc ca trang m ti tng c thhin bng 3-1


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Hnh 3-2. Phn lp thng tin trn bn a chnh s

Tha

Tha

Ng

ng iPh

Ph

Knh

Ng

Rnh

Tha

Tha

ng i

Rnh

Rnh

BN A CHNH TRN GIY

BN A CHNH SL U TRONG CS D LI U

THA T GIAO THNG

38


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39

Bng 3-1. Cu trc ca trang m t i tng

3.1.2. Chun vth hi n i tng bn Chun ho vthhin bn (Cartographic Represetation Standard)nhm chun ho

cch trnh by cc i tng bn strn cc thit bdng shoc cc vt liu lu trdnganalog nhgiy, phim. Trong csdliu, bn skhng chthun tu l mt ssao chpli ca bn giy. Trn bn giy, cc i tng bn c thhin bng ngn ngc

bit, gi l ngn ngbn v c xem xt nhmt hthng k hiu c trng ring. Khichuyn sang di dng bn s, ngn ngbn vn ng mt vai tr quan trng cho vic

thhin cc i tng bn analog qua cc thit bra nhmy in, my v. Chun v th

Danh mc cc i tng

Ngy thnh lp ti liu

Nhm i tng M nhm Tn phn nhm chnh

Lp i tng M lp Tn lp i tng

nh ngha

nh ngha tn ca i tng c m t

M i tng Phin bn C gi trt ngy

M i tng Shiu phin bn Ngy bt u chun c gi tr

M t

M tc im, tnh cht v cc c tnh vkthut ca i tng.Phn nh trong cs d li u

Phn nh tnh y ca i tng trong ton bcsdliu.i tng c thc phn nh y hoc chc phn nh ti mt vng hay trong nhng mtiu kin c bit no .

Phn nh hnh hc cao chnh xc Level

Kiu i tng hnh hc dngphn nh i tng (im,ng, vng, m t)

C/khngc gi trcao

chnh xc casliu cm, dm, m

Level lu tritng trong file

DGN

chnh xc hnh hcChra chnh xc ca i tng vmt hnh hc, chnh xc phthuc vo dliu ban u v cc phng php dng sho i tng

M t c u trcM tm hnh dliu p dng m tv lu tri tng trong csdliu.Trong trng hp mt i tng c m tbng nhiu m hnh dliu khc nhau,

phn ny cng nu r trng hp no th sdng m hnh dliu no v l do.Phn ny cng M tcc mi quan hkhng gian ca i tng vi cc i tngkhc.

Phng php thu thpM tcc phng php c thc sdng thu thp dliu ca i tng vocsdliu.


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hin bn cn phi c da trn cc quy nh vk hiu v cch thhin bn trong quyphm.

a. Chun ho thhin cc i tng bn di dng s

Ni dung chun ho thhin bn di dng sbao gm :

- Chun ho vthvin k hiu (Symbol Library): Mi mt i tng kiu im tngng vi mt kiu k hiu nht nh trong thvin. Hnh dng k hiu c thit kda theoquy phm quy nh. File k hiu dng im do BTi nguyn v Mi trng ban hnh kmtheo phn mm Famis l file KIHIEUDC.CELL

- Chun ho v th vin kiu ng (Line Style Library): mi mt i tng kiung tng ng vi mt kiu ng nht nh trong thvin. Hnh dng kiu ng cthit k da theo quy phm quy nh. File k hiu dng ng do BTi nguyn v Mitrng ban hnh km theo phn mm Famis l File DUONGDC.RSC

- Chun ho vthvin mu t (Pattern Library): mi mt i tng kiu vng tngng vi mt mu t nht nh trong thvin. Hnh dng mu t c thit kda theo quy

phm quy nh.- Chun ho v th vin kiu font ch (Font Library): mi mt i tng kiu ch

tng ng vi mt font chv kch thc chnht nh trong thvin. Cc font trong thvin dng bfont chun ABC ca Ban cng nghthng tin quc gia. i vi mt sfont chcn phi to thm, cc font ny vn tun theo m chun ca bABC. File thvin phng chdo BTN&MT ban hnh km theo phn mm Famis l File VNFONT.RSC

- Chun ho vcc lp thng tin i vi tng ni dung bn chuyn khc nhauc thhin trong chc nng chn lp thng tinca phn mm Famis

b. Chun ho thhin cc i tng bn di dng analog

Ni dung chun ho thhin bn di dng analog bao gm :

- Chun vni dung cc lp thng tin c hin ththeo mi chuyn . V d bn a hnh, bn a chnh, bn hin trng sdng t.

- Chun vthtin ra cc lp thng tin (mc u tin khi in ra ). V d: thtin trongbn a chnh l : thuvn, giao thng, ranh gii tha.

- Chun vcch hin thcc lp thng tin. V d: Khi in bn a chnh, nu ranhgii tha trng vi ng mp nc th khng in ra. Khi in bn a hnh, nu ng ranhgii hnh chnh trng vi a vt, hin thranh gii theo tng on v2 pha ca a vt.

* Chun vni dung cc loi bn chuyn

Vnguyn tc, ngi sdng c thly bt cmt tp hp cc lp thng tin bt kt

csdliu to thnh bn chuyn cho ring mnh. Tuy nhin lm c iu ny,ngi sdng phi hiu rt r ni dung ca csdliu v c ton quyn vtruy nhp dliu. Khng phi ngi sdng cng c c hiu bit nhvy v tnh bo mt dliu khngcao. V vy, chun vcc loi bn chuyn nhm a ra mt sbn chuyn chungnht c ni dung c xc nh. Chun ny sc hon thin dn qua qu trnh khai thcthng tin. Sau y l mt sbn chuyn ly ra tcsdliu bn a chnh :

- Bn a chnh.

- Bn hin trng sdng t.

- Bn quy hoch th.

- Cc s, hstha t.

8/13/2

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