Huongdan_GPSurvey2.35

8/2/2019 Huongdan_GPSurvey2.35

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cC BN B TNG THAM MU

pH NG TRC A - A hn h

- - - - -

H

ng dn s dngPhn mm GPSURVEY 2.35(Static prosessing)

(Dng cho loi my GPS Geoexplorer 3)

h NI 2-2004


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http://www.ebook.edu.vn 2

Ni dung rangI Ci t phn mm 3

I.1 Ci t Manager . . . . . . . . . . . . . . . . . . . . . . . . 3

I.2 Ci t Trimnet . . . . . . . . . . . . . . . . . . . . . . . . 3

I.3 Ci t Wave . . . . . . . . . . . . . . . . . . . . . . . . . 3

I.4 Nhy p. . . . . . . . . . . . . . . . . . . . . . . . . . . 3

II tnh khi lc cnh o gps 3

II.1 Chuyn File s liu thnh dng RINEX . . . . . . . . . . . . . . . 3

II.2 Khi ng phn mm . . . . . . . . . . . . . . . . . . . . . . 4

II.3 Cu trc hp thoi . . . . . . . . . . . . . . . . . . . . . . . 4

III Bnh sai li GPS . . . . . . . . . . . . . . . . . . . . . . . 11

III.1 Bnh sai mt phng li GPS . . . . . . . . . . . . . . . . . . . 11III.2 S dng m hnh geoid OSU91a v GEM-96 bnh sai li cao GPS . . 22

IV Bin tp kt qu . . . . . . . . . . . . . . . . . . . . . . . 27

V Phn ph lc . . . . . . . . . . . . . . . . . . . . . . . . 28


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I. Ci t phn mm

M th mc cha phn mm GPSurvey2.35, xut hin 5 th mc con: Manager,Trimnet, Wave, GPSurvey2.35 v BTKQ_GPS. Ci t 4 thmc con sau (Hnh 1):

1.1. Ci t Manager

- Nhy p Manager,

- Nhy p Install

1.2. Ci t Trimnet

- Nhy p Trimnet

- Nhy p Install

- Chn tt c cc Geoid Models, Hnh 1

1.3. Ci t Wave

Thao tc tng t nh khi ci t Manager1.4. Nhy p

Thmc con BTKQ_GPS dng bin tp kt qu bnh sai li GPS.

II. tnh khi lc cnh o gpsII.1. Chuyn File s liu thnh dng RINEX

S liu o c c lu gi di nhiu dng, ph thuc vo loi my GPS s dng. c th cp nht c vo cc phn mm khc nhau, phi chuyn chng vo dng chun:RINEX. i vi d liu o bng my Geoexplorer 3, dng phn mm GPS Pathfinder

chuyn (Data Convert).Khi ng GPS Pathfinder, vo ca s Utilities \ Other \ SSF To RENEX (bng 1), snhn c bng 2. Trong bng 2, s dng Browse (ca s Selected Files) gi File cnchuyn, Browse (ca s Output Folder) lu file chuyn. Nhn Enter () s xut hinbng 3.

D liu phi a vo bng 3 nh sau:

- Antenna maker (im t my):

+ Name: Tn im;

+ Number: S hiu im;

- Name (a ch):

+ Observer: Tn ngi o;

+ Agency: Tn c quan;

- Receivers (Loi my thu):

Bng 1 Bng 2

Bng 3


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- Type: Loi;

+ Number: S hiu;

+ Version: Phin bn;

- Antenna Position: V tr anten:

+ Height of bottom surface of Antenna above Maker ( cao anten t tm mc nvnh ca anten.

+ Eccentricity of Antenna center relative to Maker to the East ( lch t tm mc nvnh pha ng vnh anten).

+ Eccentricity of Antenna center relative to Maker to the North ( lch t tm mc nvnh pha Bc vnh anten).

thun tin cho vic tnh ton sau ny, nn a s hiu im trm o vo cc v trName, Number, Observer v Agency. V d:

+ Name: 199 (199 l s hiu im t my);

+ Number: 199;

+ Observer: 199;

+ Agency: 199;

+ Type: 42;

+ Number: 1;

+ Version: 1;

+ Height of bottom surface of Antenna above Maker: 1.45 m (1.45 l cao thng ngt tm mc n tm anten, c th tnh theo nh l Pitagor).

+ Eccentricity of Antenna center relative to Maker to the East: 0.0

+ Eccentricity of Antenna center relative to Maker to the North: 0.0

Xong nhn OK kt thc qu trnh chuyn i.

Lu : Mi ln ch chuyn 1 File, chuyn File tip theo, qu trnh trn c lp li.

II.2. Khi ng phn mm

T mn hnh Window, vo Start \ Programs \ GPSurvey \ GPSurvey 2.35, hoc nhy pvo trn mn hnh chnh ca Window, s xut hin hp thoi nhbng 4.

a. Util ities (Bng 5)

a.1. System Check: Lit k tt c cc Files c trong

phn mm GPSurvey c ci t.

a.2. Set System Defaults

Khi chn Set System Defaults, trn mn hnh s xut hin hp thoi (bng 6):

II.3. Cu trc hp thoi

Ti liu ny ch trnh by nhng kin thc linquan n tnh khi lc cnh v bnh sai li GPS. tm hiu thm v cc chc nng khc, c th thamkho trong cc ti liu hoc trc tip trong ca sHelp ca GPSurvey 2.35.

Bng 4

Bng 5


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Lu : Khi chn loi antenUnknown External, chiu cao ca anten phi c tnh vphng thng ng bng cch dng nh l Pitagor.

- Antenna Meas. Methot: Phng php o anten gm:

+ Measured to bottom of antenna mount (o n y ca vnh anten);

+ True Vertical (Chiu cao thng ng).

- Antenna Group: Nhm anten. Chn RINEX;

- Riceiver Type: Loi my thu. Chn Geo Explorer;

- Time Zone: VietNam (Khu vc tnh thi gian);- GMT Time Difference: lch thi gian a phng so vi gi quc t (7 gi).

Cc ca s Add Time Zone, Delete Time Zone cho php thm hoc xo mt khu vc tnhthi gian.

Khi chn xong nhn OK.

S dng Menu Utilities, khi to cc Project (d n) mi, cc thng s ci t s clu li. Nu ch dng mt loi my GPS thu d liu, ta khng cn chn li na. Cc thngs chn cng c th c a vo trong ca s Option ca New Project trong menu Project.

a.3. Antenna Editor (Bng 7)

Ca s ny cho php np cc thng s v anten.

- Uncorrected measurement methods: Phng php o chiu cao anten, cha c hiuchnh v chiu cao thng ng (Default RINEX Measured to Bottom of Antenna Mount). tnh cao thng ng vo ca s:

- Calculate (bng 8):

+ Units: n v o. Thng thng l mt (m).

- New Group: a nhm anten mi;

- Close: ng ca s.

MenuAntenna Editor dng tnh chiu cao thng ng ca anten khi bit loi antenthu tn hiu. Trng hp chn loi anten Unknown External th khng cn phi vo menu ny.

Bng 8

- Project Root Directory: Th mc gcca d n (ni ci t phn mm GPSurvey2.35);

- Antenna Type: Loi anten. Trng hp

dng loi anten khng xc nh th chnUnknown External (bng 6).

Bng 7

- Group: Nhm anten. Chn loi anten sdng thu tn hiu, v d: Compact Dome. Khichn xong, cc thng tin v nhm anten xut hin na bn phi ca s Antenna Editor phc v chovic kim tra.

+ Uncorrected: a gi tr chiu cao antencha hiu chnh;

+ Nhp chut vo True vertical s nhn cchiu cao thng ng.

Bng 6


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b. Project (Bng 9)

b.1. New: Khi cn to mt Project mi, vo ca s Project New. Trn mn hnh sxut hin bng 9. Cc thng s phi a vo:

Noter - Ghi chNu chn Options, nhng thng s c ci t trong Utilities \ Set System Default

vn c lu gi v khng cn t li (tr khi thay i loi my thu d liu).

Sau khi to xong mt Project, trong thmc C \ GPSURVEY \ PROJECTS s c thmccon mang tn d n va to (v d HANOI). Trong th mc con ny cn c nhiu th mcc to ra trong qu trnh to Project, nhng cn quan tm n cc thmc sau:

C \ GPSURVEY \ PROJECTS \ GEOIDNET : Th mc cha kt qu tnh d thngtrng lc cho mt elippsoid xc nh theo mt m hnh trng lc xc nh;

C \ GPSURVEY \ PROJECTS \ NETADJ : Th mc cha kt qu bnh sai li GPS;

C \ GPSURVEY \ PROJECTS \ TRIMVEC : Th mc cha cc file tnh cnh *.ssf hoc*.sst.

c. Load ( c d liu)

Vo Menu Load, chn tip From RINEX File (bng 10), s nhn c bng 11:

- Chn Config, nhn c bng 12:

+ Interactive: Tng tc. La chn ny Load d liu nhanh, ng thi cho php xem vsa i cc thng tin v trm o.

+ Quick Edit / Batch Prompt: c nhanh, ging nh Batch Prompt.

Nn chn Interactive.

Bng 9

Project: Tn d n, v d: HANOI (nn t

tn d n vi nhiu nht 7 k t).Supervisor: Tn ngi lp d n (ngi

gim st).

b.2. Open: M mt Project (d n) c;

b.3. Modify: Sa mt Project;

b.4. Close: ng Project;

b.5. Delete: Xa mt Project;

b.6. Status: Tnh trng ca Project;

b.7. Exit: Ra khi Project;

Bng 11

Bng 12 c 2 ngn:- Ngn trn: Mode of Operation gm 4 la chn:

+ Batch Defer: c theo khi. La chn nyLoad rt lu;

+ Batch Prompt: c nhanh. La chn ny Loadd liu rt nhanh nhng khng kim tra c ccthng tin v trm o;

Bng 12

Bng 10


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- Ngn di - Cc thng tin v trm o. Dng Mouse nh du () v cc trng .

Khi xong nhn OK.

Quay tr li mn hnh bng 11.

+ Directories : Chn thmc cha File RINEX;

+ Drives: Chn a cha File RINEX;+ List Files of Type: Chn RINEX Files (.obs). Cc Files RINEX c trong th mc

c chn s xut hin ngn Files Found (bng 13).

C th chn tng file, mt nhm flies hoc chn tt c cc file.

+ Chn tng File: Dng Mouse nh du file cn chn, sau chn Add .

+ Chn Mt nhm Files: Gi phm Ctrl ng thi dng Mouse nh du cc Files cnchn, sau chn Add .

+ Chn tt c cc Files: Chn Add All.

Cc files c chn s c chuyn sang ngn Files Selected.

Nu chn nhm File no, th nh du file trong ngn Files Selected, sau chnRemove. Nu mun b tt c cc files trong Files Selected , chn Remove All.

Khi chn xong n Load Data. Xut hin mn hnh bng 14.

Trong bng 14 khng nh li File *.obs chn tng ng vi File *.nav. Nu File*.nav t ni khc, hoc c thay i g, phi chn li File *.nav tng ng. Xong chn OK.Lc ny bt u qu trnh Load d liu nhbng 15. Khi Load xong, xut hin bng 16.

Nhn OK, nhn c bng 17. Trong bng 17, cc thng s trong cc ca s c t

khi to lp Project. Ch cn ca s Receiver Type, chn Geo Explorer. Nhn OK s nhn cbng 18:

+ Name: a S hiu im;

+ Long Name: a S hiu im ca Name;

+ ID: a S hiu im ca Name.

Bng 13 Bng 14

Bng 15 Bng 16

Bng 17 Bng 18


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Khi chuyn i File sang dng RINEX, nu Name, Number, Observer, Agency chncng mt tn l S hiu im th trong bng 18 s hin ng tn l s hiu im (tn trm o)v khng cn phi a thm g vo bng ny.

Nhn OK s nhn c bng 19:

y thi gian hin trong bng khng nn thay i. C th i sau trong qu trnhtnh khi lc cnh.

- Antenna Information: Thng tin v anten:

+ Hight: cao Anten ( cao tnh v phng thng ng).

+ Type: Unknown External;

+ Method: Phng php o - True Vertical: Theo phng thng ng;+ Group: Nhm - RINEX.

Cc gi tr ny c lu gi khi lp Project, ch phi ch cao anten. Khi chuyni sang dng RINEX, cao anten ch lu gi n cm (2 ch s sau du phy). Nhng khitnh khi lc cnh, cao anten phi ly n mm. Xong nhn OK. Qu trnh ny c lp licho n khi Load xong tt c cc file trong ngn Files Selected.

d. Process (X l):Vo Process \ Baselines nhn c bng 20:

tnh khi lc cnh o GPS, phi chn t nht l 2 Files s liu. Nu tnh tt c cccnh, chn Add all, Nu tnh mt hoc mt s cnh, gi phm Ctrl v dng Mouse chncc files cha cnh cn tnh. Xong nhn Add. S liu ngn Files s c chuyn sang ngnSelected Files. Cn b trm o no th nh du tn file ca trm o bng Mouse v chnRemove. Nhn OK s bt u qu trnh chuyn ti d liu nhbng 21.

d.1. Menu Baseline (bng 22)

d1.1. File \ Load - Dng c d liu;

d.1.2. Edit+ Station Position Dng a ta khi tnh cho trm o. Ch s dng khi tnh

khi lc cnh cho li GPS Cp 0 hoc hng I.

+ Occupation List (bng 23). Dng sa d liu: Tn trm o, thi gian bt u vkt thc tnh cnh v cao anten. Cn sa trm no th dng Mouse nh du vo trm ,sau dng lnh Edit sa.

Bng 19

- Occupation Time (Local): Thi gian thu tn hiu camt Session:

+ Start: Thi gian bt u;

+ Stop: Thi gian kt thc.

Bng 20Bng 21

Bng 22 Bng 23


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d.1.3. Process (X l)

+ Setup. Chn Setup, nhn c bng 24:

- Static Baseline Generation:

All Baselines: Chn tnh tt c cc

cnh c th c trong mt session; Independent Set: Chn cc cnh khng lin kt vi nhau;

User defined: Cc cnh do ngi tnh chn.

- Process Times: Khong thi gian bt u v kt thc tnh chung cho cc cnh.

- Satellites: Nhng v tinh c nh du () l v tinh c thu tn hiu trongSession o (bng 25).

- Advanced Controls: iu khin ch nh (bng 26)

Xt cc lnh trong bng iu khin:

General (Tng quan): Cho php t ngng gc cao (Elevation mask), s bc lp tia trong qu trnh tnh cnh (Maximum iterations), thi gian ti a tn hiu b nhiu hoc bngt (Maximum fixable cycle slip) l nhng thng s c th thay i nng cao chnh xc khi tnh cnh.

Quality (Cht lng, bng 27):

1- Observation Editting (Chn tr o):+ Edit multiplier (Chn tng)

+ Level of confidence (Chn theo lp ring).

2- Ratio test (T s kim tra):

+ Ratio Cutoff (T s ngt)


3- Reference variance test (Kim tra quan h tng quan)


Ph

ng n 1- Bt buc phi chn. Cn ph

ng n 2- v 3- c th chn mt trong haihoc c hai. Trong 1- v 2- c th chn mt trong hai trng hp iu khin qu trnh tnhcnh.

Tu thuc vo yu cu cht lng cnh tnh chn cc gi tr ny cho ph hp. Xongnhn OK.

Quay li mn hnh bng 24. Nhn OK kt thc ci t cu hnh v quay v bng 22.

Lu : cc thng s trong bng 26 ch ci t mt ln cho ton b Project.

Chn Process \ Baselines. Qu trnh tnh cnh bt u (bng 28).

Bng 25 Bng 26

Bng 27

Bng 28 Bng 29


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Khi tnh cnh xong, trn mn hnh xut hin

thng bo: Processing Completed (bng 30).

Chn OK kt thc.

d.2. Xem kt qu

Chn Options \ Detailed Output (bng 29). Nhn c bng 31:

- Station Tracking summary: Tm lc thng tin trm o (ph lc 3). Thng thng chchn menu ny nh gi cht lng thu tn hiu tng cc v tinh v quyt nh xem nnloi b v tinh no v khong thi gian tt nht tnh cho mt session;

- Combined tracking summary: Tm lc thng tin lin kt trm o (ph lc 4);

- Continuous kinematic quality: Cht lng x l ng;

- Residuals: Phn tha (Ph lc 5)

Cn c vo ch tiu nh gi cht lng cnh o (bng 32) xem xt cnh tnh thay cha. Nu cnh cha t th phi chn s v tinh phi loi khi qu trnh tnh ton, thigian tnh ph hp v ngng gc cao v tinh X l cnh bng cch chn v tinh, thi giantnh ph hp hon ton ph thuc vo kinh nghim ca ngi tnh. Nu tnh ton cn thnri m vn khng t th phi o li. C th t Setup Reference Variance 30.

Ch tiu nh gi cht lng cnh GPS Bng 32

Chiu di cnh Solution Rms Ratio Reference Variance

10 km L1 fixed 0.02+(0.004xS) 3.0 0.95

10 20 km L1 fixed 0.03+(0.003xS) 3.0 0.95

20 30 km L1 fixed 0.04+(0.002xS) 3.0 0.95

> 30 km L1 fload 0.04+0.001xS) 2.8 0.95

Khi cc ch tiu cnh GPS t, chn:

File \ Save ghi kt qu tnh ton (bng 33).

Kt qu tnh cnh c lu trong thmc:

C \ GPSURVEY \ PROJECTS \ TRIMVEC.

Trong mt Project, c th tnh ring tng cnh, chung cho 1 session, hoc chung cho ccng trnh. Cng c th to cc Project ring cho tng session hoc tng khu vc ca mtcng trnh.

e. View

Chn View \ Network Map (bng 34) s nhn c bng 35.

Bng 35 cha nhiu menu con nhm phc v cho vic tham kho cc thng tin v cnho. y ch nu cch tnh khp hnh bng Closure, cc chc nng khc bn c t tm hiu.

Bng 31

La chn kt qu cn xem bng cch nh du() vo trc cc

- Summary: Tm tt kt qu (ph lc 1);

- Phase ambiguities: Tr nhp nhng ca phaphch sng mang;

- Processor controls: Kim tra qu trnh s l(ph lc 2);

Bng 30

Bng 33


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Khi chn Baselines \ Closure, trn mn hnh xut hin s tnh cnh v hai bng con:Baseline v Closure. Di chut trn cnh no ca s tnh th cnh i sang mu . Nhpchut phi ln cnh mu , cnh i sang mu xanh l cy, ng thi trn bng Baseline xuthin cc thng tin v cnh c chn gm: Cnh o t s hiu n s hiu, chiu dicnh, phng v, chnh cao, Ratio, Variance Mun bit thm thng tin nhp chut voMore cui mn hnh. Trn bng Closure c cc sai s v ta , tng chiu di cc cnhc chn v tng sai s (bng 36). Nu cc cnh c chn to thnh tam gic (hoc a gic)khp kn th tng sai s tr thnh sai s khp hnh.

Cc hnh khp c sai s t ch tiu, c nh cc sai s ny li bng cch nhp chutvo Lock Validate Update. khp mt hnh mi, nhp chut vo Reset v qu trnh tnhkhp hnh c lp li. ghi kt qu khp hnh chn File \ Save Closure Log.

III. bnh sai li GPSSau khi tnh khi lc cnh xong, tin hnh bnh sai li GPS bng phn mm GPSurvey.

Bnh sai li GPS bng Geomatic Offic cng rt thun tin v quy trnh khng khc sovi bnh sai bng GPSurvey 2.35. Tuy nhin kt qu ca bnh sai bng Geomatic Offic cvit di dng Web nn rt kh khn bin tp thnh qu. Trong khi cha c chng trnhbin tp kt qu ca Geomatic Offic, Phng Trc a - a hnh son tho hng dn bnh saibng GPSurvey 2.35.

III.1. Bnh sai mt phng li GPS

Nu tt c cc cnh c tnh trong mt Project th kt qu tnh cnh c lu trong thmc C \ GPSURVEY \ PROJECTS \ TRIMVEC. Cn tnh cnh trong cc Project khc nhauth Load (c) d liu vo th mc ny bng cch:

Vo Load \ From SSF Solution File (bng 37), s nhn c (bng 38):

Trc khi chn cc cnh xy dng li, nhp chut vo ca s Config, nhn oc(bng 39):

Mode of Operation (Phng php ngi x l chn):

Bng 37 Bng 38

Bng 34

Bng 35

Bng 36

- Nn chn tng sai s < 5 ppm (tng ng1/200.000);

- Cc cnh c o 2 ln th cn c vo ktqu khp hnh chn gi tr chnh xc nht.


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Cch tt nht nn chn phng php Interactive.

Station ID - Tn trm t my:

- Strip underscores from Station ID - B qua cc trm my m tn im c gch di;

- Strip leading zeros from Stations ID - B qua cc trm my m khng c tn im;

- Use Station ID is name if missing - S dng cc im m tn trm my t sai.

Khi tnh ton bnh sai cn t du () vo cc trng hp ca Station ID.

Station Name - Tn trm my:

nh du nhc () vo Create Station Name if it Not does Exist - t tn im trm mynu cha c.

Sau khi t Config thch hp, vo th mc Trimvec Load d liu (Bng 40):

Kt thc vic chuyn d liu nhn Load Data hoc OK. Trn mn hnh xut hin ca scho tng cnh (bng 41):

y cho php ta kim tra li cc ch tiu v cnh cng nh li gii tt nht c chn.- Station Information:

S hiu im hai u cnh. C th thay i tn im bng cch vo ca s Edit.- Baseline Information:

Nu mun xem thm thng tin th vo ca s More, cn mun chn li gii khc - voSolution Type.

Bng 39

- Batch Defer: X l ton li mt cch chm ri,chc chn;

- Batch Prompt: X l ton li ngay lp tc;

- Interactive: X l ton li c tc ng ln nhau;

- Quick Edit / Batch Prompt: Ging nh BatchPrompt.

C th Load tng cnh (file) hoc mt s cnh,bng cch nhn Shipt + bm chut vo cc cnh cnchn, sau nhp chut vo ca s Add. Nu chntt c cc cnh th nhp chut vo ca s Add All.

Nu mun b cnh no th nh du vo cnh v s dng ca s Remove chuyn tr li.

Bng 40

Nu ng chn Interactive th nhn OK, cnchn cc ch khc th thay i du () trc BatchDefer hay Batch Prompt, sau nhn OK.

Mn hnh xut hin (bng 42): Bng 41

Bng 42

Khi kim tra xong tt c cc thng s vcnh th nhn OK.

Qu trnh ny tip tc cho n khi Load xongtt c cc cnh.

Cch tt nht l cho chng trnh t chnli gii cho cc cnh.


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Khi load xong d liu Vo Adujst \ Network s nhn c bng 43:

MAIN MENU GPS NETWORK MODULE

Build Network from Trimvec Directory

View Contents of Trimvec Directory

View Vectors

Summarize Network

Edit Network

Network Adjstmemt

Save GPS Network to Disk

View Map of GPS Vectors

View Trimvec File

ESC = EXIT = MOVE Enter = SELECT F1 = HELP

Dng phm mi tn ln hoc xung a vch sng vo vo ca s cn chn, sau nEnter (). Ln lt xt tng ca s trong bng 44:

+ Build Network from Trimvec Directory: Khi vo Build Network from Trimvec Directorynhn c hnh o ni vi tt c cc cnh c chn a vo bnh sai. n ESC quay v ca s mn hnh nhbng 44. Khi bng 44 c dng nhbng 45.

MAIN MENU GPS NETWORK MODULE

Build Network from Trimvec Directory

View Contents of Trimvec Directory

View Vectors

Summarize Network

Edit NetworkNetwork Adjstmemt

Save GPS Network to Disk

View Map of GPS Vectors

View Trimvec File

ESC = EXIT = MOVE Enter = SELECT F1 = HELP

S khc bit duy nht y l phn mn hnh con STATUS. Khi li c xcnh vi Datum: WGS-84, s gii php tnh cnh, s cnh, s lng vector v s trm my.

+ View Contents of Trimvec Directory: xem cc files cha vector cnh;

+ View Vectors: Dng kim tra cc gii php tnh cnh cng nh

cht l

ng ca cccnh c tnh. Khi vo View Vectors s nhn c bng 46:

y l cc Modules cho php bnh sai mt liGPS. Ln lt xt cc Modules ny theo tin trnh bnhsai li GPS.

Nhy p chut vo s nhn c bng lnhca GPS Network Module (bng 44)

STATUS

Network HANOIDatum UNKNOWN0 Solutions0 Baselines0 Unique Vector0 StationsPrinter OFFPlotter OFF

Bng 44

Bng 45

Bng 43

STATUSNetwork HANOIDatum WGS-845 Solutions5 Baselines

5 Unique Vector4 StationsPrinter OFFPlotter OFF


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Bng 46GPS NETWORK MODULE

Choose Trimvec Solutions to view

View from Solutions # 1

to Solutions # 5 = MOVE Enter = SELECTESC = EXIT F1 = HELP

Trimvec File 00000196.WAV Version W 2.35

Session 345c Solution # 1 Vector # 1 of 1 single baseline WGS-84

From Station GPS1 to Station N00 Time Dec 11 02:35:00 2003

latitude N 21 03' 17.026740" N 21 02' 00.659187" =0.0005mlongitude E 105 53' 18.447820" E 105 53' 55.733570" =0.0005mheight -16.9833m -18.1622m =0.0037m

normal azimuth= 155 22' 25.262678" = 0.0405" Ratio=9.3ellipsoid distance= 2583.635765m = 0.0005m Reject %= 1delta height= -1.1788m = 0.0037m

ESC = EXIT = SCROOL F1 = HELP+ Summarize Network: a vch sng v Summarize Network v nhn (),c bng 48:

SUMMARY VIEWS OF GPS VECTORS GPS NETWORK MODULE

Session Names -- short list

Session Names -- long listStation Names -- short l ist

Station Names -- long l ist

Apparently Duplicated Stations

Redundant Vectors

Global Network Closures

Duplicated Trimvec Files Not Read

Defective Trimvec Files Not Read

ESC=EXIT =MOVE Enter=SELECT F1=HELPTrong bng 48:

- Session Names -- short list: Xem Session Names vi tn rt gn, v d 354c - 354 lngy Julian, c l ln o th 3 theo vn abc.

- Session Names -- long list: Xem Session Names vi tn y , gm Session Names, sgii php (Solution), tn files cha Vector GPS v im u v im cui ca mi Vector;

- Station Names -- short list: Xem tn cc trm o;

- Station Names -- long list: Xem Station Names vi tn y , gm Station Names, sgii php, o t im () n im (), thuc Session () v tn files cha cc Vector GPSny;

- Apparently Duplicated Stations: Xem cc trm o c b trng tn hay khng?

- Redundant Vectors: Xem c Vector tha khng?

C th chn xem mt, mt nhm giiphp vector hay tt c cc vectors c trongli bng cch chn t Solutions # m n

Solutions # n, vi m n v m,n nguyn d

ng.Mi mt gii php cnh cho ta mt bng chacc tham s vector c chn nhbng 47:

Bng 47

Bng 48

STATUS

Network HANOIDatum WGS-845 Solutions5 Baselines5 Unique Vector4 StationsPrinter OFFPlotter OFF


15/32


- Global Network Closures: Kim tra khp ton li GPS. Phn ny s trnh by trongphn bin tp kt qu bnh sai li GPS.

- Duplicated Trimvec Files Not Read: Khng c (Load) cc files trng tn;

- Defective Trimvec Files Not Read: Khng c (Load) cc files khng t cht lng.

+ Edit Network (bng 49):Bng 49

EDIT GPS VECTORS GPS NETWORK MODULE

Delete Trimvec Solution

Add Trimvec Solution

FIX/FLT/TRP Substitution

Change Session Names

Change Station Names

Edit Single Vector

ESC=EXIT =MOVE Enter=SELECT F1=HELP

- Delete Trimvec Solution: Xo mt hay nhiu Vector trong li bng cch chn t giiphp # n gii php # (Bng 50).

- Add Trimvec Solution: Thm mt hay nhiu gii php (cnh) , vi iu kin trong thmc C \ GPSURVEY \ PROJECTS \ TRIMVEC vn cn nhng cnh cha c c (LOAD)khi xy dng li GPS.

- FIX/FLT/TRP Substitution: Cho php thay i tnh cht ca li gii ca tng Vector, vd t FIX FLT, t FIX TRP

- Change Session Names: Cho php thay i tn ca tng Session;

- Change Station Names: Cho php thay i tn ca tng Station;- Edit Single Vector: Cho php thay i tn ca tng Session, Station cng nh to u

v cui ca mi Vector.Bng 50

EDIT GPS VECTORS GPS NETWORK MODULE

+ Network Adjustment: Khi chn Network Adjustment xut hin bng 51, nhc bn c ghili ton b kt qu tnh ton bnh sai li GPS hay khng? Tr li (Y) hoc (N) bng cch nphm Space.

Bng 51

EXIT GPS NETWORK MODULE

DO YOU WANT TO SAVE THE NETWORK TO DISKBEFORE EXIT?

Y

(ESC returns to Main Menu)

STATUSNetwork HANOIDatum WGS-845 Solutions5 Baselines5 Unique Vector4 StationsPrinter OFFPlotter OFF


16/32


Sau nhn phm (), lp tc xut hin bng 52:

Xt cc ca s ca bng 49 theo ng cc bc bnh sai li GPS:Bng 52

MAIN MENU NETWORK ADJUSTMENT MODULE

Displays

Adjustment Menu

Change Coordinate System

Datum Definition

Computation Utilities

Data Base Connection

Save Network to Disk

GPS Network Module

Terrestrial Network Module

ESC=EXIT =MOVE Enter=SELECT F1=HELP- Datum Definition: Vo ca s Datum Definition xut hin bng 53:

Bng 53


Khi s dng GPSurvey 2.35a ln u, ta ch c cc Elippsoid c ci t sn xem cbao nhiu Elippsoid, bn chn View Known Datums, xa mt Elippsoid, chn DeleteDatum, cn thm mt Elippsoid, chn Add New Datum (bng 54).

Bng 54

DATUM NAME SEMI-MAJOR AXIS SEMI-MINOR AXIS 1/f

WGS-84 6378137.0000 6356752.3100 298.25722356300

WGS-72 6378135.0000 6356750.5200 298.26000000000

NAD-83 6378137.0000 6356752.3100 298.25722210100

NAD-27 6378206.4000 6356583.8000 294.97869820000nassau 6378137.0000 6356752.3140 298.25722014343

corva 6378206.4000 6356583.8000 294.97869821390

Krasov 6378245.0000 6356863.0188 298.30000000000

-

F1 = HELP ENTER = ADD DATUM EDIT KEYS

Ch cn thm tn, gi tr bn trc ln a v dt (phn mm t tnh bn trc nh b),hoc tn, bn trc ln v bn trc nh (phn mm t tnh gi tr 1/f) ca Elippsoid l ta ci

t thm c mt Elippsoid vo phn mm bnh sai li GPS.

Network STATUSDatum: WGS-84System: GeographicZone: GlobalsLinear Unit: Meter

Computations: Computed4 Stations5 Observatiens

5 GPS0 Terrestrials0 Geoid

Printer OFFPloter OFF


17/32


S dng phn mm GPSuvey 2.35a t ln 2 tr i, khi cn mt Elippsoid c th, vo cas Change Datum trong bng 53 v a vch sng vo Elippsoid cn chn, sau nhn

- Change Coordinate System: Trong bng 52, chn Change Coordinate System s nhnc bng 55:

Bng 55

CHOOSE COORDINATE SYSTEM NETWORK ADJUSTMENT MODULE

Geographic

User-defined Transverse Mercator

User-defined Lambert

User-defined Oblique Mercator

Universal Transverse Mercator

NAD-83 State Plane Coordinates

NAD-27 State Plane Coordinates

User-defined Projection Library

Exit

Ca s ny cho php chn cc h thng ta . Xt mt s h thng chuyn dng:

+ Geographic: H thng ta a l;

+ User-defined Transverse Mercator: H thng ta Transverse Mercator do ngi s

dng nh ngha. Khi chn User-defined Transverse Mercator s nhn c bng 56:

Cc tham s trong bng 56 c thay th cho ph hp vi h ta bn ang s dng.V d, trong h ta Gauss, kinh tuyn trc 105 00 00 sau khi a cc gi tr ny vobng 56 s nhn c bng 57.

Bng 56 Bng 57

- Adjustment Menu:

Trong bng 52, chn Adjustment Menu, nhn c bng 58:Bng 58


USER-DEFINED TRANSVERSE MERCATOR PROJECTION

Name of projection: HANOI

Central meridian: E 10550'19.000000"

Scale along central meridian: 0.999997169673

False northing for origin: 200000.0000

False easting for origin: 300000.0000


USER-DEFINED TRANSVERSE MERCATOR PROJECTION

Name of projection: HANOI

Central meridian: E 10500'00"

Scale along central meridian: 1.000000000000

False northing for origin: 0.0

False easting for origin: 500000.0000



18/32


Xt cc trng hp ca bng 58:

+ Coordinate Fix Status: Dng FIX ta , cao cc im gc:

- Trong h ta Geographic (bng 59):Bng 59

COORDINATE EDITING FIELDPT# NAME LATITUDE / LONGITUDE ELL(H)/ORTH(h) FIX NWN

GPS1 N 2103'17.026740" -16.9833 - - - - YXH-

E 10553'18.447820" 0.0000

N00 N 2102'00.659187" -18.1622 YXH-

E 10553'55.733570" 0.0000

TG41 N 2057'51.863245" -20.4659 YXH-

E 10547'43.035732" 0.0000

TG51 N 2104'54.690554" -16.4174 YXH-

E 10546'42.963767" 0.0000

ESC=EXIT ENTER=SAVE TAB=CURSOR PgUp PgDn (ALT) F2-F5=(SET) CLEAR FIX

Gi th c im gc ta TG51, TG41 v v gc cao N00 vi gi tr ta , caocho trong bng 60:

Bng 60

Stt SH B L X(m) Y(m) H(m) h(m) Lo

1 TG41 21 04' 54.690554" 105 46' 42.963767" 2319397.145 582675.684 31.874 5.143 1052 TG51 21 04' 54.690554" 105 46' 42.963767" 2332393.239 580876.851 ---

3 N00 33.947 6.868

Sau khi a cc gi tr ny vo bng 56, nhn c bng 61:Bng 61

COORDINATE EDITING FIELD

PT# NAME LATITUDE / LONGITUDE ELL(H)/ORTH(h) FIX NWN

1 GPS1 N 2103'17.026740" -16.9833 - - - YXH-

E 10553'18.447820" 0.0000

2 N00 N 2102'00.659187" 33.9470 H YXH-

E 10553'55.733570" 0.00003 TG41 N 2057'52.339590" 31.8740 XYH YXH-

E 10547'41.872796" 0.0000

4 TG51 N 2104'55.146187" -16.4174 XY YXH-

E 10546'41.801617" 0.0000

ESC=EXIT ENTER=SAVE ,TAB=CURSOR PgUp PgDn (ALT)F2-F5=(SET)CLEAR FIX

+ Cng cc gi tr ta , cao ca bng 60, trong h ta User-defined TransverseMercator, nhn c (bng 62):


19/32


Bng 62

COORDINATE EDITING FIELDPT# NAME NORTH/EAST ELL(H)/ORTH(h) FIX KNWN

1 GPS1 2329435.1640 -16.9833 - - - YXH-

592343.9137 0.0000

2 N00 2327092.2637 33.9470 H YXH-

593433.7069 0.0000

3 TG41 2319397.1450 31.8740 XYH YXH-

582675.6840 0.0000

4 TG51 2332393.2390 -16.4174 XY YXH-

580876.8510 0.0000

ESC=EXIT ENTER=SAVE ,TAB=CURSOR PgUp PgDn (ALT)F2-F5=(SET)CLEAR FIX

Nh vy, c th FIX ta , cao, hoc ch ta , hoc ch cao ca mt im. Saukhi a cc gi tr ta , cao ca cc im gc xong, nhn () ra khi bng 62. Tr limn hnh bng 58, vo ca s Weighting Strategy (chn trng s), nhn c bng 63:

Bng 63


Vo ca s GPS Observations, nhn c bng 64, chn tip Scalar, s c bng 65:

Bng 64 Bng 65

WEIGHTING STRATEGY

Scalar

Summation

Station Weighting

ESC=Exit

Cc ch v cch la chn trong bng 65 gm (bng 66):Bng 66

Current strategy: all gps solutions Current value set Default

each gps solution Alternativevar comp group User-Defined

WEIGHTING STRATEGY -- SCALING NETWORK ADJUSTMENT MODULE

Current strategy: all gps solutions Current value set: alternative

SOL # SCALAR SOL # SCALAR SOL # SCALAR1 113.582 0.603 67.664 187.305 157.87

F1 = HELP ENTER = A CCEPT VALUES PGUP/PGDN


20/32


- Chn cho ton li c chung trng s vi 3 phng php:

a. All GPS Solution (Chung cho ton li): Vi 3 cch chn trng s nh sau:

+ Default: Phn mm t chn trng s lun bng 1.0;

+ Alternative: Phn mm t chn trng s ty theo tnh cht ca tng li;

+ User-Defined: Trng s do ngi tnh ton chn.b. Each GPS Solution (Cho tng cnh trong li):

+ Default: Phn mm t chn trng s lun bng 1.0;

+ Alternative: Phn mm t chn trng s ty theo chiu di ca tng cnh trong li;

+ User-Defined: Trng s do ngi tnh ton chn.

c. Var Comp Group: Phng php dng ma trn tng quan. Chn Default, Alternative,User-Defined ging nhmc b.

Trng s ng mt vai tr rt quan trng trong vic bnh sai li trc a. La chn trngs ph hp s lm tng chnh xc ca li. i vi cc li yu cu chnh xc thp, c

th s dng cc tr

ng hp sau (bng 67): Bng 67


each gps solution Alternative

HocBng 68


each gps solution Alternative

i vi li yu cu chnh xc cao hn (t a chnh c s tr xung), bt buc phichn nh trong bng 68.

Bng 69

Current strategy: each gps solution Current value set alternative

Khi tnh bnh sai li trc a tng ng hng II, hng I hoc li GPS cp 0 nh nc,

trng s s c ngi tnh chn t c chnh xc ph hp vi yu cu ca cc cphng li. La chn trng s ph hp cho tng cp hng li l mt vic kh v tn nhiu thigian, cng sc.

Quay v ca s ca bng 58. Chn Special Controls, c bng 70. Chn tip Global

Adjustment Controls, nhn c bng 71.Bng 70



21/32


Trong bng 71, cc thng s c ci t sn. y lu hai loi thng s sau:

+ Compute horizontal adjustment: Y - Ch tnh bnh sai ta

+ Compute vertical adjustment: Y - Ch tnh bnh sai cao.

Tu thuc vo la chn (Y) hoc (N) c th ch tnh bnh sai ta , hoc ch tnh bnh

sai cao hoc tnh bnh sai c ta v cao. Bng 71

GLOBAL ADJUSTMENT CONTROLS NETWORK ADJUSTMENT MODULE

Display adjustment screen graphics Y

Write ellipse displays to disk files Y

Write histogram display to disk file Y

Display covariant terms Y

Direct all adjustment text displays to printer N

Write plotter file for network map N

Write plotter file for ellipses N

Compute horizontal adjustment Y

Compute vertical adjustment YUse reduced column profile if possible N

Model all heights on ellipsoid (one-height mode) N

Restrict covariant terms display to observed lines N

'Save to Disk?' prompt before exit Y

Univariate sigma scalar: 1.0000

Bivariate sigma scalar: 1.0000

Maximum number of adjustment iterations: 10

Tolerance on residuals to end iterations: 1.0e-005

Last-ditch tolerance on residuals : 5.0e-003

F1=HELP ENTER=ACCEPT VALUES ESC=EXIT F5=SAVE NEW SYSTEM DEFAULTS

Sau quay v ca s ca bng 58 v chn Adjust Network () bnh sai li.Qu trnh bnh sai kt thc, chn ca s DISPLAY xem kt qu. Vo Display, vo tip

Adjustment Results nhn c bng 72:

- Observation Closures:Sai s cc tr o trong li gm: Sai s phng v, sai s chnh caov sai s khong cch;

-Statistical Summary: Ch tiu nh gi kt qu bnh sai.

Network Reference Factor: Yu t quan h li. Nu kt qu bnh sai tt th gi trny phi bng 1.0 hoc 1.0;

Chi-Square Test ( = 95 %) = Pass. Nu kt qu bnh sai tt th gi tr ny phi =PASS.

Bng 72



22/32


Nu kt qu tnh cnh tt m cc gi tr ny cha t th tip tc qu trnh bnh sai(Adjust Network () cho n khi cc gi tr trn c tho mn.

- Coordinate Adjustment:Ta , cao v sai s ca chng sau bnh sai

- Observation Adjustment:Tr o, s hiu chnh, tr o sau bnh sai v cc sai sai s tngng;

- Largest Standardized Residuals:Tr o, s hiu chnh, tr o sau bnh sai v cc sai sai stng ng;

- Covariant Values:Phng v, sai s phng v; chnh cao, sai s chnh cao; cnh , sai so cnh v sai s tng i o cnh.

Khi kt qu bnh sai chp nhn c, quay v mn hnh bng 49, vo ca sComputation Utilities, vo tip ca s Long Format Point-Point Inverse s xut hin bng 73.Trong bng 73, thay cc gi tr t n ,(v d xem bng 74) xut pht t mt im (ttnht l t 1 im gc) nhn c bng tng hp thnh qu bnh sai bng tn file Scratch.filtrong thmc WINDOW \ TEMP v kt thc qu trnh tnh ton bnh sai.

Bng 73

INVERSE TEMPLATE NETWORK ADJUSTMENT MODULE

FROM TO

TG41 N GPS1 N

N00 N N00 N

GPS1 N TG41 N

TG51 N TG51 N

F1 = HELP ENTER = ACCEPT VALUES PGUP/PGDN

Bng 74

INVERSE TEMPLATE NETWORK ADJUSTMENT MODULE

FROM TO

GPS1 Y GPS1 N

N00 N N00 Y

TG41 N TG41 Y

TG51 N TG51 Y

F1 = HELP ENTER = ACCEPT VALUES PGUP/PGDN

III.2. S dng m hnh geoid OSU91a v GEM-96 bnh sai li cao GPS

S dng GPS o ni cao l mt vic hon ton c th nu chng ta xy dngc mt mng li trng lc v mt v t chnh xc cao. Tuy nhin, xy dngmng li trng lc l mt vic kh khn, gian kh v tn nhiu tin bc v thi gian. Trongkhi cha lm c vic , chng ta hy tn dng nhng thnh qu ca th gii phc vcho mc ch ca mnh: S dng m hnh geoid OSU91a hay GEM-96 o ni gn ng cao bng GPS.

M hnh geoid OSU91a: M hnh trng trng lc tri t OSU91a c thit lp trn cs s liu trng lc o mt t bng cc phng php khc nhau, kt hp vi s liu v tinh.

S dng cng thc Stock vi chui iu ho cu c pht trin ti bc n=m=176 vi 63.886


23/32


h s. M hnh geoid OSU91a c kch thc 30 x 30 vi chnh xc cao Geoid ti ntli l 2.0 2.5 m.

M hnh Geoid quc t GEM-96: Trn c s m hnh trng trng lc tri t OSU91a,b sung v chnh xc ha li d liu xy dng m hnh Geoid quc t GEM-96, vi chuiiu ha cu c pht trin ti bc n=m=360 v 130.676 h s. M hnh Geoid quc t

GEM-96 c kch thc li 15 x 15 vi chnh xc cao ti nt li 0.5 1.0m.Cn lu rng hin nay ch yu s dng m hnh GEM-96 tnh cao bng GPS, tuy

nhin trong mt s trng hp v mt s khu vc m hnh geoid OSU91a li cho kt qu tthn.

y nu phng php s dng phn mm GPSurvey 2.35 tnh bnh sai cao.Vo ca s Network Adjustment Module (t bng 40), chn:

- Datum: WGS-84;

- Coordinate System: Geographic

- Fix 1 im bt k (c ta X, Y v cao H) v vo ca s Adjust Network bnh

sai li GPS.Lu :im cn chn FIX to , cao khng nht thit phi l im gc. To ,

cao FIX l cc gi tr c sn, c GPS xc nh. Nu im FIX trng vi im gcth cng khng a gi tr ta v cao chnh xc ca im vo tnh ton.

Sau khi bnh sai xong, quay tr li mn hnh bng 52. Vo ca s Terrestrial NetworkModule, c bng 75:

Bng 75


Tr li Y + , nhn c mn hnh nh bng 76. Ti bng 76, vo ca s GeoidModule, nhn c bng 77:

Bng 76

MAIN MENU TERRESTRIAL OBSERVATIONS MODULE

Observations

Station Coordinates

Computation Utilities

Datum Definition

Coordinate System

Network Maps

Save Network to Disk

Network Adjustment Module

Geoid Module


Network STATUSName: HANOIDatum: WGS-84System: GeographicZone: GlobalsLinear Unit: Meter

Computations: Unraduced4 Stations0 Observatiens



24/32


Bng 77MAIN MENU GEOID MODULE

Displays

Estimate Geoid Heights

Load Geoid Model

Import New Geoid Model

Delete Geoid Model

Terrestrial Observations Module

Exit


Trong bng 77 chn Load Geoid Model(la chn m hnh Geoid),c bng 78:Bng 78

Chn WW15MGH (File cha d liu trng lc ca GEM-96), chng trnh s quay limn hnh bng77 . Tip tc chn Estimate Geoid Heights(c lng cao Geoid), cbng 79, gm:

- Creat e Display Grid: Hin th v tr im o GPS v to li Geoid cng cao ticc mt li;

- Creat e DCO File: To file cha cao Geoid ti cc im o GPS;- Creat e Net work Point List ing: Tnh cao Geoid ti cc im o GPS;- Export Gridded Model: Xut d liu thnh File cha cao Geoid ti cc im o GPS.Nhvy cc bc phi thao tc y l:

Bng 79

+ Vo ca s Create Display Grid, c s v tr im o GPS, Chn Enter (), cbngGrid Deffinition, chn Enter (), c bngGeoid Hights from WW15MGH( cao Geoid caGEM-96).

+ Vo ca s Creat e DCO File; + ()+ Vo ca s Create Network Point Listing + ();

STATUSProject:HANOINumber of Known Models: 4Current Model ID Number: 4Current Model:Geoid90 WestSystem:Geographic

4 Stations


This geoid model does not cover projectarea. Choose a new model.


25/32


+ Vo ca s Export Gridded Model + ().

Quay tr li mn hnh bng 77, chn Terrestrial Observations Module, quay v mn hnhbng 76. Tip tc chn Observations, c bng 80:

Bng 80

OBSERVATIONS MENU TERRESTRIAL OBSERVATIONS MODULE

Data EntryView Observations

Modify ObservationsDelete Observations

Default Observation Parameters

Terrestrial Observations ModuleAccess DCO Files

EXIT

Trong bng 80, chn Default Observation Parameters, c bng 81:Bng 81

DEFAULT OBSERVATION PARAMETERS TERRESTRIAL OBSERVATION MODULE

Min imu m St a n d a r d Er r o r

Ab so l u t e Pr o p o r t io n a l (ppm)Re j e c t l imit

Agles 0.00 2.50Directions 1.00 2.50Azimuths 1.00 2.50

EDM Distances 0.0050 5.0000 0.0200

Microwave Distances 0.0100 10.0000 0.0500

Tape Distances 0.0010 10.0000 0.0300Stadia Distances 0.3000 10 000.0000 1.0000

One-way vertical Agles 10.00 30.00Reciprocal vertical Agles 5.00 20.00

Delta Elevations 0.0030 20.0000 0.0050

Delta Geoid Heights 0.1000

Observed Geoid Heights 1.0000

Current Linear Units: Meter (1.000000 / 1.000000) x Meter

Compute Orthometric Height Corrections: no

Compute Correlations For Geoid Model no

Write Data Entry Log no

F1 = He l p En t e r = Ac c ep t Va l ues F5 = Save New Sys t em De f au l t s

Bng ny nu cc thng s li trng lc dng tnh cao GPS. Tnh cao GPS lmt vic rt kh, cn rt nhiu t hp kin thc: t thit k, o c n tnh ton v am hiutng tn v m hnh trng lc c p dng Ti liu ny mi chdng li mc hngdn s dng phn mm. lm vic ny trong bng 81, ch cn thay i nh sau (Bng 82):

Bng 82

Compute Orthometric Height Corrections: Yes

Compute Correlations For Geoid Model Yes

Write Data Entry Log Yes

OBSERVATION STATUS0 Angles0 Directions0 Azimuths0 Distances0 Vertical Angles0 Delta Orthometric Heights0 Delta Geoid Heights0 Observed Geoid Heights


26/32


Chn Enter quay v bng 80. Trong bng 80 chn tip Access DCO Files chp nhncc thng s trng lc la chn vnhn c bng 83:

Bng 83

OBSERVATIONS MENU TERRESTRIAL OBSERVATIONS MODULE

Trong bng 83, chn Load Observations from File, sau dng lnh Exit quay v bng80, chn tip Exit quay v bng 76. Trong bng 76, chn Computation Utilities nhn cbng 84:

Bng 84

COMPUTATION UTILITIES TERRESTRIAL OBSERVATIONS MODULE

Compute Network COMPUTATIONS STATUTS

Observations:4 Unreduced0 Reduced

Known Coordinates:8 Horizontal5 Vertical

Unknown Coordinates:

0 Horizontal3 Vertical

Fixed Coordinates:

Display Observation Closures

Display Coordinate Computations

Clear Network Computations

Disable/Enable Observations

Point Inverses

Pt-Pt AnglesRecopute Single Point

Exit

ESC=Exit = Move Enter=Select F1,F2=Help

2 Horizontal2 Vertical

Chn Compute Network + ()v quay v bng 76. Trong bng 76, chn Save Network toDisk + (ESC), sau chn Network Adjustment Module s xut hin bng 85:

Bng 85

MAIN MENU TERRESTRIAL OBSERVATIONS MODULE

Tr li Y (dng phm Space) + () v quay v bng 45. Trong bng 45, chn NetworkAdjstmemt s xut hin bng 86 v la chn cc tham s ca bng 86 nh sau (bng 87):


27/32


Bng 86 Bng 87

LOAD NETWORK ADJUSTMENT MODULE

Curent Adjustment Network: load

GPS Network: Do not load

Terrestrial Network: Do not loadF1=Help ESC=Return to Control Module

S nhn c bng 52. Qu trnh bnh sai li ta , cao GPS s c tip tc tbng 52 n bng 74. S khc bit v gi tr ca mt s bng trong qu trnh bnh sai ln nyl do s tham gia ca m hnh trng lc s dng v cao ca cc im gc c FIXbng cao trc a. cao trc a ca im gc cao c tnh bng cng thc:

+= hH ,Trong : H - cao trc a ;

h - cao thy chun;

- D thng trng lc (ly t File Network.txt thuc th mc C \ GPSURVEY \ PROJECTS \ GEOIDNET \GMOD vi s hiu im tng ng vi s hiuca im gc cao).

Lu rng trc khi ra khi chng trnh, phi ghi s liu bnh sai li vo my tnh,bng cch g Y vo cu hi: DO YOU WANT TO SAVE THE NETWORK TO DISK BEFORE EXIT? .

VI. Bin tp kt quKt qu tnh cao Elippsoid c lu trong file Network.txt thuc th mc C \

GPSURVEY \ PROJECTS \ HANOI \ GEOIDNET \GMOD. Copy Network.txt vo th mc

cha kt qu bnh sai li GPS (C \ GPSURVEY \ PROJECTS \ HANOI \ NETADJ) v thchin quy trnh bin tp thnh qu bnh sai nh sau (theo chng trnh ca Tin s Nguyn VnVn, Trng Phng Trc a - a hnh ):

1. Copy file KQ_GPS.EXE vo GPSURVEY \ PROJECTS \ NETADJ

2. Tnh khp hnh cho tt c cc tam gic c th c trong s o ni v ghi kt quthnh File Khep.log;

3. Vo Utilities \ Project Report (bng 88) c bng 89. Trong bng 89, nh du ()vo Detailed Baseline Summary v Summary, ghi tn File ( v tr Title) l Canh.txt v nhpchut vo Text File

Bng 88 Bng 89

4. Copy File Scratch.fil trong th mc WINDOW \ TEMP vo GPSURVEY \ PROJECTS\ NETADJ;

5. Chy chng trnh KQ_GPS.EXE:

Chng trnh KQ_GPS.EXE gm 2 ch :- bin tp kt qu tnh cnh GPS, a bin s 1;

LOAD NETWORK ADJUSTMENT MODULE

Curent Adjustment Network: Do not load

GPS Network: load

Terrestrial Network: loadF1=Help ESC=Return to Control Module


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- bin tp kt qu tnh ton bnh sai li GPS thnh cc bng, a bin s 2.

Nu kt qu c bin tp trong mt thmc ring, cn c cc File sau:Bng 90

Stt Thmc bin tp Thmc cha File

1 KQ_GPS.EXE a CD ROOM2 Khep.log GPSURVEY \ PROJECTS \HANOI3 Canh.txt GPSURVEY \ PROJECTS \HANOI4 Network.txt GPSURVEY \ PROJECTS \ HANOI \ GEOIDNET \GMOD5 Closures.log GPSURVEY \ PROJECTS \ HANOI \ NETADJ6 Coords.log GPSURVEY \ PROJECTS \ HANOI \ NETADJ7 Covar.log GPSURVEY \ PROJECTS \ HANOI \ NETADJ8 Observs.log GPSURVEY \ PROJECTS \ HANOI \ NETADJ9 Scratch.fil WINDOW \ TEMP

nhn c ta , cao ca li GPS trong cc h thng ta khc (HANOI-72,WGS-84), vn tin hnh theo cch trnh by, sau dng chng trnh CIDALA vDMAVCT20 chuyn ta , cao vo h thng cn tnh.

V. Phn Ph Lc

Ph l c 1 - Summar y - Tm tt kt quFrom

Station

To

Station

Solution

Type

Slope Distance

(meters)

Ratio Reference

Variance

From Ant. Ht

meas. meters

To Ant. Ht.

meas. meters1100 1095 L1 fixed 7336.825 24.5 0.203 1.190 1.450

Ph l c 2 - Pr ocessor cont r ol s : Kim tra qu trnh s lProcessor Controls:[General]Process start time: 3/3/04 02:38:00 GPS (1260 268680)Process stop time: 3/3/04 05:02:10 GPS (1260 277330)Elevation mask: 15 degreesMaximum iterations: 10Maximum fixable cycle slip: 600 seconds

Ephemeris: BroadcastResiduals: EnabledAntenna phase correction: Enabled

[Observables]L1 phase EnabledL1 C/A code Enabled

[Static Network]Baseline generation: All baselinesMin baseline observation time 600 seconds

[Quality]Observation editing: Edit multiplier 3.5

Ratio test: Cutoff 1.5Reference variance test: Level of confidence 0.950


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[Tropo Correction]Model: HopfieldEstimated zenith delay interval: 2 hoursUse observed mets: Enabled

[Iono Correction] Ambiguity Pass Final PassCorrection: Broadcast Model Broadcast ModelApplied to: Static, Kinematic Static, KinematicApplication threshold: 10 kilometers 5 kilometers

[Final Solution]Final solution type: L1 Fixed

[Satellites]Disabled:

Ph l c 3 - St at ion Tr acking s ummar y: Tm lc thng tin trm o

Ph l c 4 - Combined t r acking summar y: Tm lc thng tin lin kt trm o

Ph l c 5 - Residual s : Phn tha


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VI. Thit k, o c v tnh bnh sai li GPS

VI.1. Li GPS

Li GPS l dng li trc a khng gian v thc cht li lin kt cc im trn mt t

thng qua cc im bit ta khng gian: cc v tinh. Tr o trong l

i GPS chnh l cckhong cch t cc im quan st n cc v tinh. Li GPS c o theo phng php tngi xc nh cnh gia cc im trn mt t. u im ca li GPS l khng cn thnghng gia cc im trn mt t m ch cn c thng thong trn bu tri my thu cth thu c tn hiu t cc v tinh mt cch thun li.

Li GPS l mt trong nhng phng php xy dng li ta , khi thit k li cnnm vng cc quy nh k thut trong cc quy phm hin hnh thit k li GPS tho mncc yu cu v chnh xc cc yu t ca li trc a n m nhim v thc hin c ccquy nh k thut ring ca cng ngh o GPS.

VI.2. Thit k li GPS

Li khng ch GPS c xy dng phc v cho cc mc ch khc nhau ca thc t.Ty thuc vo chnh xc xc nh cp hng li, xy dng quy trnh o c v tnh toncho ph hp. Tuy nhin, d cp hng no th li GPS cng c thit k da trn ccnguyn tc chung sau:

- hnh li: Thit k theo cc kha tam gic, t gic hoc ti a l ng gic.

- Xut pht t cc im gc phi c t nht 3 hng n cc im trong li. Trng hpc bit kh khn (nh li khng ch cu, hm) c th ch c 2 hng. Tuy nhin trongtrng hp ny phi rt ch n quy trnh o c (thi gian o, chn v tinh) v tnh ton.

- Cc im gc phi c phn b u trong ton li. Khong cch t gc n gc phthuc vo cp hng li v theo quy nh ca quy phm. Tt nht l cc im gc phi c

khng ch cc bin ca l

i.- S chnh lch v di gia cc cnh v ln ca cc gc khng nn vut qu quynh ca li truyn thng.

VI.3. Chn im GPS

im GPS l im ta , khi chn cn tho mn cc yu cu chn im mt phng nichung, ng thi cn tho mn cc yu cu sau:

- Trong phm vi gc ng 15o t im t my ti bu tri (gc ngng) khng cchng ngi vt nh tn cy, nh cao tng

- im GPS cn chn cch xa i pht sng 500 mt v xa

ng in cao th 50 mt trnh nhiu;

- Li GPS xy dng mi cn c t nht 2 im ta Nh nc cp cao hn v 2 im cao thy chun ri u trn khu o tnh chuyn ta WGS-84 v ta Nh nc vchuyn cao trc a v cao thy chun.

- V nguyn tc, gia cc im GPS khng cn thng hng nhng thun tin chovic pht trin xung li cp thp, cc im GPS nn cn nhng cp thng hng.

- Cc im nn chn ni n nh v a hnh, d dng i li, tm kim nhng phi bo vlu di.

- Nn chn nhng khu vc c kh nng o dn thy chun hnh hc.

- Khi chn cn lu ti s lin kt gia cc mng li c v mng li mi.


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VI.4. Lp phng n b tr v thi cng li

T gc o li, c th coi li GPS l li o cnh tng ng. Cc cnh ni gia 2im c chnh xc biu th bng cng thc:

222Dba +=

Trong :

- D - chiu di cnh;

- a - sai s c nh;

- b - sai s bin i trong sai s c trng ca my thu.

Thng thng mi loi my c cch thit k ring, nhng trong thc t khi b tr liGPS cng ging nh cc loi li khc v im gc khi tnh mt phng, cao Nh nc; vs lin kt vi cc li c, v chn mc

Li phi c thit k to thnh cc vng khp kn hoc dng ng chuyn ph hpgia cc im cp cao. S lng im cp cao ph thuc vo tnh hnh thc t, nhng ni

chung mi khu o khng t hn 2 im khi tnh.Khi thit k phi tn dng cc im trong h thng im c c trong khu o.

Khi o GPS xy dng li ta thng o theo phng php o tnh, o tng inn t nht phi c 2 my thu tr ln ng thi thu tn hiu v tinh (session). Hai my o trongmt session to thnh 1 cnh o. Cng nhiu my o ng thi th s lng cnh cng ln vtt nhin iu kin kim tra cng nhiu.

VI.5. Lp k hoch o

T thi gian d nh o, v tr a l khu o, lch v tinh gn ng v cc tham s lachn nh suy gim chnh xc v tr im PDOP, gc ngng, s lng v tinh thu ctrong mt session vi phn mm km theo my ta bit c cc khong thi gian thu tnhiu tt nht trong ngy. lp lch thng ly ta trung tm khu o. Trong mt s trnghp khu o tri di (chnh l giao thng) th nn ly ta hai u khu o lp lch, sau ly gi tr trung bnh kt qu.

Thi gian thu tn hiu ti mi im ph thuc vo phng php o, khong cch o v chnh xc cn t c.

T cc khong thi gian o tt nht ngi ta lp ra k hoch di chuyn my hp l m bo cht lng o v thc hin c phng n b tr v thi cng li.

VI.6. Kim tra cht lng o cnh

Tu theo chiu di cnh m kim tra cc ch tiu chnh xc o cnh RMS, suy

gim chnh xc hnh hc GDOP, t s RATIO ca cc cnh. Khi cc quy nh trn vt qu1,5 ln ngi ta xc nh li cc tham s chn lc nh nng cao gc ngng, chn s v tinhkho tnh li cc cnh. Nu tnh li m ch tiu khng t th phi o li.

Tu chiu di cnh m chn li gii thch hp, thng cnh ngn hn 10 km nn chn ligii Fixed, cnh di chn li gii Float (sai phn bc 2 hoc 3).

Da vo kt qu tnh cnh vi cc s gia ta x, y, z ca cc cnh ngi ta tnh sais khp ta ca cc vng khp v tnh sai s khp tng i. Nu cc ch tiu k thut nyt yu cu th chun b tnh ton bnh sai bng cch chuyn tr o v mt quy chiu.

Cc ch tiu nh gi chnh xc cng tu thuc vo chc nng o v cu to my vphn mm tnh ton x l s liu.

Vic kim tra phi tin hnh ngay ti thc a tt nht l sau hng ngy i o v.


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Tnh khi lc cnh o GPS quyt nh cht lng ca li. V vy i hi ngi tnhphi rt cn thn trong tng giai on tnh. i vi tng Session, ngi tnh nn lp bng theo di kt qu trong ton b giai on tnh nh sau:

Stt Ngy Ses SH Ant.o Ant.tnh Tg o Tg tnh S o ni c im Ghi ch

1234 1.345 1.3445678 1.456 1.455

8765 1.567 1.566

1 13/8 1

4321 1.678 1.677

11h20

13h42

11h30

13h30

B SV15, 27B ngcho

1234 -8765

2

VII.3.6. Bnh sai kt qu o

Thng thng, km theo my thu c phn mm bnh sai kt qu o v nh gi chnh

xc cc yu t ca li v tnh chuyn ta , cao v h ta s dng. Cc phn mmthng dng Vit Nam: fillnet, Trimvec, GPsurvey, Trimle Geomatic..v.v. Mi phn mmu c nhng u nhc im ca n, nhng ni chung cc phn mm ra i sau tt hn v baoqut hn.

Chng trnh bnh sai thng thc hin qua 3 giai on:

- Kt ni tt c cc vect vo mt li thng nht;

- Bnh sai cc vect v hiu chnh vo cc thnh phn ca li;

- Tnh ton v chuyn i cc loi ta v cao im;

Trc tin bnh sai t do mng li mt phng trong h ta WGS-84, pht hin cc sais th, loi b nhng vect c sai s ln. Cc phn mm x l s liu GPS u cho php bnhsai li theo phng php s bnh phng nh nht. Kt qu bnh sai cho nhng thng tin tnghp v cht lng li.

Tnh ton cao trong li GPS kh phc tp v cao o trong GPS l cao c tnhton hc (ellipsoid), trong khi cao thy chun chng ta thng dng l cao mang tnhvt l (geoid), v vy mun tnh chnh xc cao thy chun cn phi c m hnh Geoidchun. nhng vng chnh lch gia ellipsoid v geoid nh hoc l bin ng u th chnh xc cao bng GPS c th t ti dm. Hin nay trong iu kin tt ta c th xc nh cao GPS tng ng hng IV Nh nc

khc phc nhng sai st trong tnh ton v bnh sai nht thit phi c mt imgc mt phng v cao Nh nc. Cc im gc phi phn b u trn khu o.

Documents

Huongdan_GPSurvey2.35