TRNG I HC BCH KHOA TP.HCMB MN A TIN HC

CHNG 0GiI THIU MN HC Mn hc cung cp cho sinh vin cc kin thc: H thng quy chiu trc a Vit Nam* Cng tc thit k li khng ch ta , cao nh nc p dng cc k thut o gc, o di, o cao chnh xc vo cng tc lp li khng ch Tnh ton s liu o c, bnh sai li khng ch ta , cao Tnh ton gi thnh xy dng li, t chc thi cng li khng ch

Chng 1: H QUY CHIU V LI TRC AH quy chiu: gc to v h trc c s to da vo c th biu din c tt c cc im trong khng gian.Li trc a l mt tp hp cc im c s xc nh to cao trong h quy chiu c chnh xc theo yu cu, c b tr vi mt ph hp trn phm vi lnh th ang xt Cc loi h quy chiu:H quy chiu vung gc khng gian X, Y, Z H quy chiu mt ellipsoid B,L,HH quy chiu mt bng x,y s dng ch yu cho mc ch thnh lp cc loi bn .*

Cch thc thnh lp h quy chiu v li trc a

o c mt li cc im to c s (h to ) bng cc th loi cng ngh t chnh xc cao nht v c mt theo yu cu.Xc nh c h quy chiu ph hp trn c s chnh l cc kt qu o h to cc im c s.Chnh l cc kt qu o h to cc im c s trong h quy chiu xc nh.H to cc im c s to thnh mt li im lm gc tng i vi xc nh cc im to khc quanh n.

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Kinh trc a LV trc a BCao trc a H

Quan h gia to trc a B, L v thin vn ,

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MI QUAN H GIA X,Y,Z V B,L,HTnh X,Y,Z t B,L,H

vi

Tnh B,L,H t X,Y,Z:Cng thc Bouring:

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Cng thc lp: s ln lp l n=7 th sai s tnh ton

Mt khc:

Phng trnh trn cha bin B trong c hai v, cho php s dng bin trung gian: i=1, 2, 3, 4nTrong :Tnh lp cho n khi :V B c xc nh l: cao trc a H c tnh theo cng thc:

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PHP CHIU HNH TR NGANGPhp chiu Gauss-Kruger

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bin dng php chiu Gauss-Kruger:

hoc

Php chiu UTM (Universal Tranverse Mercator)Hnh tr ct Ellipsoid => bin dng m v dng,Cng thc quan h gia Gauss-Kruger v UTM: *

CC H QUY CHIU TI VIT NAMThi Php thuc: Ellipsoid Clark, im gc ti H ni, php chiu Bonne v h thng im to ph trm ng dng;Min Nam VN t 1954-1975: h Indian 54 vi Ellipsoid Everest, im gc ti Ubon, Thailand , php chiu UTM v h thng im to ph trm Nam Vit Nam, h cao Mi Nai, H Tin;Min Bc t 1959 bt u xy dng h thng li Trc a v h quy chiu v kt thc nm 1972 => h HN-72 vi Ellipsoid Krasovski, im gc ti Punkovo chuyn v VN ti i thin vn Lng HN (thng qua im Ng Lnh Trung Quc), h cao Hn du, Hi phng HH = HM + 0.167 mT 1992-1994: nh v li Ellipsoid Krasovski ph hp Vit Nam.T 1996-2000: Xy dng h VN-2000 vI EllipsoidHe quy chieu toa o trac a la mot mat Ellipsoid kch thc do WGS-84 c nh v phu hp vi lanh tho Viet namvi cac tham so xac nh, iem goc toa N00 at tai Vien nghien cu a chnh, Tong cuc a chnh, ng Hoang Quoc Viet, Ha noi; php chiu UTM, h cao Hn du, Hi phng.

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MI QUAN H GIA CC H QUY CHIUQuan h ton hc gia hai h ta khng gian.Quan h ton hc gia hai h ta trc a. Quan h ton hc gia hai h to khng gian v thut ton xc nh tham s chuyn i.Thut ton xc nh cc tham s chuyn trn hai Ellipsoid khc nhau. Kho st chnh xc ca bi ton chuyn i khi thay ma trn xoay R y bng ma trn xoay rt gn.nh gi chnh xc ca cc tham s chuyn i.Quan h ton hc gia hai h toa phng.

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M HNH CHUYN I (X1i, Y1i, Z1i) X , Y , Z , x , y , z v S (X2i, Y2i, Z2i) (B1i ,L1i, H1i) X , Y , Z , x , y , z v S (B2i ,L2i, H2i)*

CNG THC BURSA -WOLF*

Khi cc gc xoay l nh: *

Nu tn ti gia s t l S th:*

CNG THC MOLODENSKIDng chun:*

Dng rt gn:Dng y :*

THUT TON XC NH THAM S CHUYN ICng thc Bursa-Wolf:*

Trng hp 7 tham s:*

Pi - trng s ca h phng trnh s hiu chnh : Lp h phng trnh chun : Gii h phng trnh chun ta c 7 tham s chuyn iX , Y , Z , x , y , z v S. *

NH GI CHNH XC CC THAM S CHUYN I TO Sai s trung phng trng s n v : Nghch o ma trn (ATPA): (ATPA)-1=Q. =>cc sai s ca 7 tham s chuyn i c xc nh: *

chnh xc to tnh chuyn*

XC NH THAM S CHUYN I TO THEO MOLODENSKIHm mc tiu:cc phng trnh s hiu chnh:*

Vi dB=B2-B1, dL=L2-L1,dH=H2-H1.Trng s ca h phng trnh s hiu chnh c xc nh:

Lp h phng trnh chun :

Gii h phng trnh ta xc nh c 7 tham s cn xc nh. *

Quan h chnh xc gia X,Y,Z v B,L,H*

QUAN H TON HC GIA HAI H TA PHNG Bin i Affine: x2i = a1y1i +b1x1i+c1 y2i = a2y2i +b2x2i+c2Bin i Helmert: t p = mcos => q = msin

=> x2i =x0 + px1i - qy1i y2i = y0 +py1i +qx1i

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Xc nh h s ca php bin i AffineS lng im trng ti thiu: n=3;Khi n>3 th xc nh theo PP s bnh phng nh nht:t => Lp 2n phng trnh s hiu chnh dng sau: Hm mc tiu: *

Lp h phng trnh chun:

Gii h phng trnh chun, c cc h s *

Xc nh h s ca php bin i HelmertS lng im trng ti thiu: n=2;Khi n>2 th xc nh theo PP s bnh phng nh nht:t => Hm mc tiu: Lp 2n phng trnh s hiu chnh dng sau: *

Lp h phng trnh chun:

Gii h phng trnh chun, c cc h s *

Chng 2: THIT K LI TA Nguyn tc TK & XD li: Tng qut n chi tit, CX cao n CX thp.Thng xuyn cp nht, nng cao CX bng CN v KT o mi.Quy tc: mt im ph trm ton qucC 4 cp hng: I,II,II,IV Bo m CX: cp cao nht (hng I) gii quyt bi ton T c bn, cp thp nht (hng IV) o v t l 1:2000. SSTP tng h 7cm.

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Hang bac S (km) SSTP tng ho (cm)SSTP Tcanh yeu SSTP Tcanh ayIIIIIIIV20 ~ 30 7 ~ 20 5 ~ 82 ~ 5 + 7 + 7+ 7+ 71:200.000 1:150.0001:100.000 1:50.000 1:400.000 1:300.000 1:200.0001:200.000 +0.7 +1.0 +1.8 +2.5 2.5 3.5 7.0 9.0

hnh li*

Hnh dng ti u v mt im khng ch T Hnh dng ti u: Tam gic u (li tam gic); dui thng cnh u (li ng chuyn)Mt im khng ch ph thuc vo 3 yu t:Phng php o v bn : phng php trc tip i hI nhiu im KC hn phng php o v nh hng khngT l bn thnh lp: t l cng ln mt v s lng bc KC cng nhiu v ngc li.c im a hnh a vt khu o: a hnh a vt cng phc tp th mt im cng cao v ngc li. Mt im: o v t l 1/10000 cn phi c mt 1 im / 50 ~ 60km2 1/5000 1 im/ 20 ~ 30km2 1/2000 1 im/ 5 ~ 15km2

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Quan h gia t l o v vi mt im khi Tk li tam gic: T l B =1/M.1000

Chiu di cnh K/C ti thiu:

chnh xc yu cu i vi cc cp hng li TH s hn thua chnh xc k: l t s gia SSTP v tr im cp thp mthp vi SSTP v tr im cp cao k cn mcao:

gim nh hng SS s liu gc k2Sai s tng hp v tr im cp thp mTH:

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Gi tr c gi l t s nh hng ca SS im cp cao i vi v tr im cp thp .Gia h s hn thua k v t s nh hng e c mi quan h nht nh .

sai s v tr tng h gia hai im u l hp ca sai s phng v v di cnh ni gia hai im:

=> c th c tnh chnh xc o gc v cnh ca tng cp hng li

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c tnh chnh xc li to Nguyn l: SSTP M ca mt phn t li ph thuc vo SSTP trng s n v v trng s o ca phn t trong li

Cho nn m bo tr m khng ln hn chun qui nh , cn thit phi la chn mt trong hai bin php : Thay i P ,tc thay i cu hnh ca li. Thay i , tc thay i thit b o v phng php o .Thng thng ,khi thit k li quc gia th thit b o c coi l d kin c nh , ngi thit k ch cn cch thay i cu hnh t yu cu v chnh xc thng qua tiu chun trng s o ca li

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Cc phng php nh gi CX li to Phng php cht ch (ng dng PP bnh sai tham s):Lp h PT s hiu chnh:

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Lp ma trn trng s P, viTnh ma trn h s PT chun: Tnh ma trn trng s o: Tnh SSTP v tr im:

Tnh SSTP chiu di cnh v phng v => Lp hm s cnh v phng v tng ng:

Tnh SSTP ca hm s

Tnh SSTP v tr tng h:So snh cc sai s vi ch tiu tng cp hng. Nu nh hn th li t yu cu*

Phng php cht ch (ng dng PP bnh sai iu kin):Lp h PT iu kin: Lp ma trn trng s P, vi

Tnh ma trn h s PT chunLp hm s cnh v phng v tng ng

Tnh trng s o ca hm s:

Tnh SSTP ca hm s

Tnh SSTP v tr tng h:Nu tn ti SS s liu gc th: *

Cc PP nh gi CX li to (t.t.)Phng php gn ng:Li tam gic o gc, o cnh, giao hi (tham kho ti liu)Li ng chuyn:ng chuyn n, cnh u, dui thng treo:

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ng chuyn n, cnh u, dui thng ph hp:

ng chuyn n bt k treo:

ng chuyn n bt k ph hp:

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Nu im u C khng c SS th Nu im u C c SS Mg th

V SS khp ng chuyn = 2Mcuoi :SS khp tng i ng chuyn:

ng chuyn ph hp th im yu nht s nm gia tuyn. SSTP v tr im yu sau BS bng:

So snh 1/T v Myeu so vi ch tiu kt lun CX li TK

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c tnh chnh xc li ng chuynS dng PP thay th trng s tng ng v nhch dn:Tnh sai s tng tuyn=> trng s tuyn : Nu C ni 2 im nt th SSTP v tr im cui :Trng s ca tuyn:

Trng s im nt = tng trng s t cc hng:

SSTP v tr im nt:

Lp cho n khi gi tr SSTP ca cc im nt MNj khng i th dng.*

c tnh CX li ng chuyn (t.t.)SSTP v tr im cui ng chuyn ni t im cp cao n im nt Nj:

SSTP v tr im cui ng chuyn ni gia im nt Nk n im nt Nj:

p dng cng thc tnh SS khp tng i v SSTP v tr im yu ca ng chuyn:

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Quy trnh thit k lui to Gii thch yu cu , mc ch , ngha ca vic TK li.Thu thp v thng k cc ti liu trc a hin c trn khu o: li ta , cao v BH Thu thp v thng k cc ti liu v iu kin t nhin, kinh t x hi ca khu o.Xc nh c s ton hc, so lng cp hng li, s pht trin li.c tnh s lng im KC theo tng cp hng. (theo quy phm nu li pht trin theo quy phm. Nu li vt cp th phi tnh theo tng trng hp c th).Thit k li trn BH v nh s hiu im theo quy phm.nh gi chnh xc li thit k. Nu li khng m bo CX th thay i thit k t yu cu.c tnh gi thnh xy dng li.T chc thi cng xy dng li.

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Chng 3: THIT K LI CAO Cc h thng cao Sai s L thuyt, Bin php khc phc H cao chnh (Orthometric Height)H cao chun (Normal Height )H cao ng lc (Dynamic Height)Cu trc li cao quc giaNguyn tc xy dng li cao quc gia Dung sai trong thy chun chnh xcNi dung thit k li thy chun quc giaThit k s b Thit k k thut Cc loi mc thy chun

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Cc h thng cao Sai s l thuyt trong o cao hnh hc

Bin php khc phc: phi xy dng h thng cao khng ph thuc vo ng i tuyn thu chun, v cao phi l duy nht so vi im gc*

NGUYN L XY DNG H THNG CAOiu kin: cao cc im c xc nh khng ph thuc vo ung i cu tuyn thu chun. cao cn phi xc nh t cc d liu o trn b mt Tri t.Cc s hiu chnh khi o chnh cao cn phi nh sao cho c th b qua khi x l cc mng li cao cp thp hn.Vic la chn h cao phi tho iu kin tin li v d dng khi xc nh thnh phn ( hoc cao geoid) cao cc im phi l c nh khi so snh vi mt mt nc bin nc bin trung bnh.

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Chnh lch th nng, cao ng lcChnh lch th nng gia hai im OM

c gi l gi tr th nng gia hai im O v M.Cao o ng lc c xc nh

Tnh cht: Cao ng lc l c nh ti mi im trn mt mt ng th xc nh*

Cao chnh v gn ngCao gn ng:nh ngha:Cao gn ng l cao khng hiu chnh cc nh hng cu trng trng lc Tri t

Vi M : ga tr trng lc chun trung bnh trn tuyn CMCao chnhnh ngha: Cao chnh l cao tnh t mt Geoid n im xt nm trn b mt Tri t

Vi gMm : gi tr trng thc trung bnh trn tuyn CM

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Tnh cht: Khng ph thuc vo tuyn thu chunKhng th tnh chnh xc v thnh phn gm xc nh ph thuc vo cu trc Tri tCao Trc a c tnh theo cng thc:

Cao chun C s l thuyt:WO - WM = UO - UM2

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nh ngha: Cao chun l cao tnh t mt Quasigeoid n im xt nm trn b mt Tri tCong thc

Vi: Mm: Gi tr trung bnh trng lc chun trn tuyn CM2

Cao Trc a c tnh theo cng thc:

M: D thng cao ti im MCao Vignal: (dng cho Bc M) *

Cng thc tnh cao chun: (dng trong thc t)

Vi

Cng thc tnh chnh cao gia 2 im AM:

Chnh lch gia cao chnh v cao chun:

Chnh lch max < 2m ti nhng ni d thng trng lc max (500 mgal). Hu ht c gi tr vi cm.

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Cu trc li cao quc gia Nguyn tc xy dng li cao quc gia:Bo m chnh xc nghin cu bin ng ca lp v tri t:

Bo m chnh xc o v bn : Bo m chnh xc thi cng cc cng trnh xy dng Cu trc li cao nh nc*

THIT K LI CAO Tuyn T/C hng I v II c TK trn bn t l 1: 1000000 hoc 1: 500000. Ngoi ra, i vi tuyn hng I cn phi th hin cc im trng lc Tuyn T/C hng III v IV c TK trn bn t l 1: 200000 hoc 1:100000 Ni dung bn thuyt minh ca thit k:i.Mc ch ca thit k .ii.Thu thp v thng k cc ti liu trc a hin c trn khu o: cao v BH Thu thp v thng k cc ti liu v iu kin t nhin, kinh t x hi ca khu o.Cc phng n li, khi lng cng vic ca tng phng n .nh gi chnh xc li thit kiv.D kin t chc thc hin v d ton chi ph v chn phng n ti u .*

MT S LOI MC THU CHUNMc c bnMc gn vo , b tngMc tm thi*

Chng 4: Phng php o di in quang nh ngha mtCc phng php o di in quang:Phng php o xungPhng php o phasePhng php o tn sPhng php giao thoanh hng ca kh quyn n vn tc lan truyn ca sng in t v sng nh sngX l kt qu o di in quang*

nh ngha MTMT l di ca on thng bng 1/40000000 vng kinh tuyn qua Paris. (10-12-1799 )1 MT GC QUC T= 1553164,13 ca Cadium (1915)1 MT GC QUC T =1650763,73 ca Cripton 86 trong chn khng, nhn c t bc x ca cc nguyn t chuyn ng gia mc v . (1960)Vn tc c bn ca sng nh sng trong chn khng c xc nh l c =299792548 1,2 m/ s

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Cc phng php o di in quangphng trnh dao ng ca sng:

o thi gian (o xung):o phaseo tn s f,o bin A: c dng trong h thng VLBI (Very Long Baseline Interferrometry h thng giao thoa xc nh chiu di ca cnh c khong ln) hoc cc h thng kim nh chiu di bng phng php giao thoa.

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Cc phng php o di in quang Nguyn l:

Phng php o xungNguyn l: Da trn thi gian lan truyn xung (thng l cc xung di tn sng Radio v sng nh sng) t may pht n b phn x v tr li my thu. S nguyn l:

chnh xc: ph thuc vo b o thi gian, thng 10ns 1,5 mPhm vi ng dng: trong trc a v tinh, altimetry, radioaltimetry B o thi gianB pht xungB thuXung c sXung phn x*

Phng php o tn sNguyn l: Vic o khong cch da trn c s ng dng cc dao ng cu tn s sng iu bin tn s (FM)theo thi gian v s suy gim tn s t my pht n thit b phn x v ngc li.S o cau to:

Cng thc tnh:

Vi: F-tn s sng u bin f chnh lch tn s gia sng pht v sng phn x, ai lng cn o;F - tr s cc i ca sng iu bin FM; p h s loi iu bin; p=4 khi u bin tam gic v hnh sin; p=2 khi iu bin hnh rng cao chnh xc: Gii hn ca php o tn s: Khoang cch ti a o c tnh theo cng thcSai s hng s:

B m tn soB thuB phatu phatB phn xa*

Sai s o khong cch:

Phm vi ng dng:cac thit b o cao gn trn my bay, mot vi h thngnh v radio, Phng php o phase:Nguyn l: Vic o khong cch da trn vic xc nh lch phase (hieu phase) gia thi im pht sng t my pht v thi im thu sng phn x. (song ieu ho hnh sin)S cu to:

Cng thc tnh: T

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Suy ra:

S cu to:

Cc phng php o phase:Phng php tn s ngn (iu chnh tn s iu bin)Nguyn l: bin i m tn s sao cho f1>f2>>fm.Xt trng hp bin i hai tn s f1, f2 khi :

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f1, f2 c iu bin sao cho ? = 0, ?/2, ? cho ?N = {0,1/4,1/2...} v ghi nhn tr s N1,2=N1-N2. Khi :

f1 c iu bin sao cho ?N =0, ta c:

Mi thit b o khong cch theo phng php ny ch c th thay i cc tn s iu bin trong 1 khong ?f (di tn) nht nh.

Phng php kt hp tn s (c nh mt vi tn s)Nguyn l: Tng t nh phng php tn s ngn nhng thay v tm trc tip Ni th ta tm N1,2 khi :

Trong phng php ny, nu cc tn s fi (I=1..m) khng i v chm sng, chang hn chm 5 tn s, c t c nh cc gi tr sao cho tha iu kin: (*)*

Vi th vic xc nh D s t chnh xc cc mc n v ty khi dng cc cp tn s kt hp (f1,f2), (f1,f3), (f1,f4)V vy phng php ny cp1 tn l phng php kt hp tn s. Neu cac cp tn s ny tha iu kin (*) th D s xc nh c theo cng thc:

Nu c nh f1 sao cho th:

chnh xc ca phng php o Phase:T cng thc ca phng php o Phase (cng thc 2), theo l thuyt sai s , ta c:

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Phng php giao thoaPhng php ny thng c dng o khong cch ngn v c chnh xc cao nht. Nguyen ly: da trn vic quan st hin tng giao thoa cu hai (hoac nhiu hn )chm nh sng, tnh ra khong cch.

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Vn tc sng in t trong khng kh Vn tc sng in t trong khng kh ph thuc vo nhit , p sut, m khng kh, bc sng:h s khc x V H s khc x nh sng: (theo Barrell-Sears) i vi sng n (di sng nh sng):i vi chm sng nh sng : h s khc x K chun:

: tnh bng m

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i vi sng radio: *

H sT0 =288,16 K (t=150 C)P0 =760mmHgT0 =273,16 K (t=00 C)P0 =760mmHgA272,613287,583B1,52941,6134C0,013670,01442

cong ng truyn sng cong ny ph thuc vo loi sng v khong cch truyn. i vi sng radio th =25000 kmSng nh sng =50000 km*

Chng 5: DNG C V PHNG PHP O GC CHNH XCDng c o gc chnh xc: My kinh v chnh xc c m2.Cu to my kinh v chnh xc: ng knh (Vx30), bn ngang, bn ng, h thng c s (micrometer), h thng cn bng (ng thu di vi 10/2mm.C h thng chiu sng bn bng bng n cho php o gc vo ban mC h thng b tr bn ng.*

Quy tc c s c s vnh ngang hoc ng ca my Theodolite chnh xc, cn thit phi:Vi chnh micrometer chp hai vch ca hai u ng knh vnh . Da vo con tr vnh c s v pht, ng thi da vo con tr micrometer c s giy ln 1. Ph v trng thi i., chp vch mt ln Na, c s giy ln 2. Ly tng ca ,pht, giy ln 1 v giy ln 2 c s c cui cng

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Cc ngun sai s trong o gc chnh xcSai s ca b micrometer: i. Sai s chp vch l sai s o gc ny sinh do chp vch hnh nh hai na vnh khng chnh xc. Ngi ta kim nghim sai s chp vch bng phng php tr o kp. Thng thng sai s ny rt nh (di 0.3) v nh hng c tnh ngu nhin.ii. Sai s r (Jeu) l sai s c s micrometer trong hai trng hp quay thun v quay ngc khng ging nhau. khc phc sai s ny ngi ta thng qui nh trong mt ln o ch c dng nm xoay micrometer theo mt t th (xoay thun hoc nghch).iii. Sai s di micrometer (cn gi l REN) l sai s o gc ny sinh do di ca chu vi vnh giy micrometer khng ng nht vi di trung bnh ca 1/2 khong chia trn vnh v nh hng c tnh h thng ti kt qu o gc. Khi kim nghim, nu sai s ln (trn 0.5) th a v xng hiu chnh.iv. Sai s vch khc micrometer l sai s o gc ny sinh do khc vch trn vnh giy khng u. hn ch nh hng ca sai s ny, ngi ta dng bin php thay i s c xut pht ca micrometer gia cc ln o khc nhau khong (trong m l s ln o trn mt gc).

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Cc ngun sai s trong o gc chnh xc Sai s h trc b ngm: H trc b ngm bao gm trc ngm (ng thng ni quang tm knh vt v giao im ca mng dy ch thp), trc quay ca ng knh v trc quay ca b ngm. i. Sai s trc ngm l sai s o gc ny sinh do trc ngm khng vung gc vi trc quay ca ng knh. Sai s ny c th loi tr bng phng php o gc theo hai v tr (thun v o) ca ng knh. ii. Sai s trc quay ca ng knh l sai s o gc ny sinh do trc quay ng knh khng vung gc vi trc quay ca b ngm. Bng bin php s dng hai v tr ca ng knh (thun v o) c th loi tr nh hng ca sai s ny. iii. Sai s trc quay ca b ngm: l sai s o gc ny sinh do trc quay ca b ngm khng trng vi phng dy di. Anh hng ca sai s trc quay b ngm c tnh h thng v khng th loi b bng bin php s dng hai v tr ca ng knh.

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Cc ngun sai s trong o gc chnh xc 3. Sai s vnh ngang:Theo yu cu thit k, tm ca vnh ngang phi trng vi tm quay ca my v gi tr vch khc ca vnh phi ng u mi v tr. i. Sai s lch tm ca b ngm v vnh ngang:C th khc phc nh hng ca hai sai s ny bng bin php c s hai u ng knh ca vnh . ii.Sai s vch khc ca vnh ngang l sai s cng ngh ch to vch khc vnh bao gm sai s chu k ngn v chu k di. C th gim thiu nh hng ca loi sai s ny bng bin php thay i s c xut pht.*

Cc yu t nh hung chnh xc o gci. nh hng ca khc x ngang: Gim di cnh tam gic xung di 30km. Trong li tam gic (c bit l chui ng ty) cn c mt s phng v Laplace. Cnh tam gic khng nn i gn mt ao h, sng ngi, bi ct, sn ni, vch tng. Chia 1/2 s ln o vo bui ngy v 1/2 vo s ln o vo bui m.ii. nh hng ca i lu khng kh:Nng tm ngm ln cao, cch xa mt t. o 2 bui: bui ngy ch o gc ngang 1-2 gi gia bui sng v 1-2 gi bui chiu. Bui m c th ko di t 1 gi sau mt tri ln n 1 gi trc mt tri mc *

Cc yu t nh hung chnh xc o gciii. nh hng ca chiu sng: Gn ng knh ph tr (kim tra gc xon) v thay i chiu quay ca b ngm gia hai Na ln o. Che d, lm lu bt cho my, sp sp thi gian o i xng vi thi im trung bnh.S dng b ngm vi sai v dng thit b chiu sng nhn to nh gng, n chiu sng. iv. nh hng ca thit b oSai s ko theo vnh : l sai s ny sinh do tc ng ca b ngm ln vnh thng qua lc ma st (khi quay). khc phc nh hng ca sai s ko theo vnh , trong sn xut thng s dng bin php duy tr hng quay thng nht ca b ngm trong mi Na ln o.ii.Sai s Jue ca c cn: l sai s ny sinh do c cn khng n nh. khc phc sai s ny khng nhng phi duy tr hng quay thng nht ca b my trong mi Na ln o v cn phi quay trc mt vi ln d ly trniii.Sai s xon ca b ngm: l sai s ny sinh do tnh ca ng knh khi tc ng lc quay c vi ng ca ng v b ngm khi ngm chun cc mc tiu trong mi Na ln o.

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Quy trnh tng qut ca cc PP o gc Dng hai v tr ng knh c s trn mt hng o khc phc sai s do trc ngm v trc quay ca ng knh. Xc nh gc nghing ca trc quay ng knh khi gc ng ca hng ngm V >10 khc phc sai s do trc quay ca b ngm.Thay i trt t ngm cc mc tiu gia hai Na ln o gim thiu sai s do chiu sng v hun nng khng trn ct tiu v thit b o.Duy tr chiu quay thng nht ca b ngm khi ngm chun cc mc tiu trong mi Na ln o gim thiu sai s ko theo ca vnh v sai s Jue ca c cn.Duy tr hng quay ca cc nm vi ng ca b ngm v nm vi ng ng knh theo mt chiu nht nh khi ngm chun mc tiu gim sai s xon ca b ngm v ng knh.*

Quy trnh tng qut ca cc PP o gcThay i s c hng ca mi ln o mt tr s gim thi sai s khc vch ca vnh v micrometer, c xc nh bi biu thc: trong : m l s ln o trn mt gc. t l gi tr khong chia nh nht ca vch khc vnh . d l gi tr di ca chu vi vnh Micrometer.Duy tr tiu c ca ng knh khng thay i trong mt ln o loi tr sai s do s bin ng ca trc ngm.Chn thi gian hp l trong cc bui ngy v m gim thiu sai s do khc x nh sng v i lu khng kh.

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Chng 6: DNG C V PHNG PHP O CHNH CAO CHNH XCDng c o cao chnh xc: My thu chun, mia invar;Cc ngun sai s trong o cao chnh xc;Phng php o cao hng I, II;Phng php o cao I, II vut chng ngi vt;nh hng ca SS ngu nhin v h thng n o cao chnh xc: b Lalleman;Tnh ton khi lc o cao hng I, II;Bnh sai li cao hng I, II.

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Bnh sai li cao hng I,II Trng s o ca tuyn thy chun: Theo SS h thng v SS ngu nhin (hng I) hoc chn theo chiu di L, s trm my n (hng II tr xung)

Phng php bnh sai: Bnh sai tham s; Bnh sai iu kin; Bnh sai iu kin km n s b sung; Bnh sai tham s km iu kin.V d*

Chng 7: NG DNG CNG NGH GPS VO XY DNG LI KHNG CH TO GiI thiu v h thng nh v ton cu GPS;ng dng GPS vo lp li khng ch to ;Thit k li khng ch to o bng GPS;nh gi chnh xc li thit k;Quy trnh o c ngoi thc a;X l s liu o GPS;Bnh sai, ghp ni vi li to mt t.

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H THNG NH V TON CUc thit k v pht trin t nm 1973 bi B Quc phng MNm 1978, phng nhng v tinh u tin.H thng nh v ton cu GPS c 3 b phn: B phn khng gian. B phn iu khin. B phn s dng.

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B phn khng gian Gm 32 v tinh lm vic v d phng c t ln 6 qu o nghing 550 so vi mt xch o (Block II).Mi qu o l mt vng trn vi cao danh ngha l 20183 km (so vi mc nc bin trung bnh)Chu k v tinh 12h

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B phn khng gianBo m c yu cu l bt k lc no cng, bt k u trn tri t cng nhn thy c t nht 4 v tinhTrn mi v tinh trang b 4 ng h nguyn t cesium (l loi ng h cc k chnh xc 10-12). ng h sn sinh ra dao ng c s c tn s fo = 10.23 MHz C 2 m o: M C /A c tn s 1,023 MHz = fo/10 v c chiu di 1 msecM P c tn s 10,23 MHz = fo v c chiu di 266, 4 ngy 2 m o c iu bin bi 2 sng mang L1 = 1575.42 MHz (m P v C/A) v L2 = 1227.60 MHz (ch c m P)C 2 sng mang L1, L2 iu bin bng cc thng tin o hng bao gm: Ephemeride ca v tinh thi gian, s hiu chnh cho ng h v tinh, tnh trng ca h thng v tinh vv

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B phn khng gian Mi v tinh c trng lng 930 Kg v c tui th 7.5 nm. Nu v tinh no hng u c thay th ngay bo m tnh cht ch cu trc ca h thng Cc nhim v ch yu ca v tinh GPS:-Nhn v lu gi lch v tinh mi c gi ln t trm iu khin- Thc hin cc php x l c chn lc trn v tinh bng cc b vi x l t trn v tinh - Duy tr kh nng chnh xc cao ca thi gian bng hai ng h nguyn t Cesium v 2 ng h hng ngc Rubidium- Thay i qu o bay ca v tinh theo s iu khin ca trm mt t -Truyn thng tin v tn hiu trn 2 tn s L1 v L2 rt n nh v nht qun

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B phn iu khin mt tMc ch ca h thng iu khin l hin th s hot ng ca cc v tinh, xc nh qu o ca chng, x tr cc ng h nguyn t, truyn cc thng tin cn ph bin ln cc v tinh, cp nht 3 ln/ ngy*

B phn ngi s dngB phn ngi s dng bao gm tt c mi ngi s dng qun s v dn s Phn loi my thu: c 4 nhm my thu GPS nh sau: Nhm 1: My thu ch x l duy nht m C /A trn tn s L1. Nhm 2: My thu x l m C /A v phase sng mang L1 thng gi tt l my thu 1 tn s. Nhm 3: My thu x l m C /A v phase sng mang L1, L2 thng gi tt l my thu 2 tn s Nhm 4: My thu x l m Y v 2 phase sng mang L1, L2 ch c qun i M v ng minh mi c *

CC K THUT O GPSCu trc m

K thut o m (code)Phase sng mang

K thut o phase = -(f/c). f.(dt-dT) (f/c)(-dion + dtrop)*

CC PHNG PHP O GPSPhng php tuyt iPhng php tng i*

NH V TNH V NG*

X L TC THI V HU K*

CC NGUN SAI S TRONG NH V GPSSai s do h thng:Sai s ca ng h trn v tinh v trong my thuSai s qu o ca v tinh

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CC NGUN SAI S TRONG NH V GPSSai s do mi trngSai s do tng i lu v tng in ly:

Sai s do hin tng a ng truyn

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CC NGUN SAI S TRONG NH V GPSSai s do cu hnh v tinh: c th hin bng cc yu t suy gim c th hin bng cc yu t suy gim chnh xc DOP (Dilution Of Precision) = DOP o Cc loi tr s DOP: - VDOP.o : l suy gim chnh xc trong cao .- HDOP.o : l l suy gim chnh xc mt phng 2D.- PDOP.o : l l suy gim chnh xc v tr khng gian 3D.- TDOP.o : l suy gim chnh xc trong thi gian.- HTDOP.o : l suy gim chnh xc v tr mt phng v thi gian.GDOP.o : l suy gim chnh xc khng gian 3D v thi gian *

NH HNG CU HNH V TINHPDOP

c im ca vic thit k li GPSPh thuc vo s lng my o. C n my o ng thi th c n-1 ng y c lp;Ph thuc vo s ng y c lp cn o;Lu tnh thng hng tng cp im d dng pht trin li cp thp hn; chnh xc ca li thit k ph thuc vo cu hnh, thit b, thi gian o, cu hnh v tinh;Cn phi lp lch o chi tit cn c theo v tr a l, ngy gi o sao cho PDOP 5.Chn im phi thng thong, tn hiu t v tinh n my thu l cc i;*

Thit k li khng ch to o bng GPSThu thp v thng k cc ti liu trc a hin c trn khu o: li ta (cp 0, hng I, II, cao v BH) Xc nh hnh li: hnh tam gic, a gic theo ch tiu ca cc cp hng quy phm;nh gi chnh xc li thit k: theo cc ng y => lp m hnh nh gi SS => SSTP v tr im, SSTP tng i cnh, SSTP phng v cnh trong khng gian;Chuyn v mt tham chiu (Ellipsoid VN2000, mt phng chiu UTM);So snh ch tiu trong quy phm => kt lun v li thit k.*

hnh liDng tam gicDng ng chuynDng kt hp

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c tnh chnh xc li TKChn n s l to KG ca cc im TK: Tr o l cc baseline vector: Phng trnh s hiu chnh tr o:

Lp ma trn h s A, vi cc h s +1, -1, 0Lp ma trn trng s P, vi cc h s vi c ly t SS do thit b o trn khong cch trung bnh ca tng cp hng. V d:mi: tnh theo s gia to *

c tnh chnh xc li TKDng ma trn P:*

c tnh chnh xc li TKLp ma trn chun tc N: Tnh ma trn trng s o:Tnh SSTP v tr im i trong khng gian:

Tnh SSTP v tr mt bng im

SSTP vi tri mt bng: vi *

c tnh chnh xc li TKSai s trung phng cnh Sij v phng v Aij

Hm trng s cnh

Hoc

SSTP vi tri tng h:

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QUY TRNH O C NGAI THC ALp lch o GPS: Chn thi im PDOP < 5, s lng v tinh >4;T chc ca o (section): Theo s lng ng y, s my thu, s im lp mi; Thi gian thu tn hiu: ph thuc vo cp KC, thit b; khang thu tn hiu (epoch): 15-30s;

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X L KT QUDownload d liuX l tng ng y n c lpnh gi chnh xc tr o trc bnh saiBnh sai li t do trong h WGS84Chuyn tan b kt qu bnh sai v h ta a phng da trn cc im trng (ti thiu 2 im)Xut kt qu theo h a phng (BLH, x,y,H)

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Chng 8: BNH SAI LI TO Tnh ton s bBnh sai li to nh gi chnh xc tr bnh sai*

Tnh ton s bKim tra s liu o;Tnh quy tm mc v tiu.Hiu chnh cc tr o mt t v mt Ellipsoid v mt phng chiu (tham kho gio trnh TCC): Chuyn cung php thun nghch v ng trc a; Hiu chnh tr o hng, thin nh t mt t v mt Ellipsoid tham chiu; Tnh s d mt cu;Hiu chnh tr o khong cch t mt t v Ellipsoid mt tham chiu;Chuyn ton b tr o t mt Ellipsoid tham chiu v mp chiu Gauss (hoc UTM)i vi li hng thp (hng III, IV, /c cp 1, 2): c th bo qua 2 s h/c 1, 2*

Tnh ton s bTnh to s b cc im trong liTnh SS khp v gc phng v, v to . Cc SS khp ny phi nh hn hn sai tng cp hng. Nu khng t th phi tin hnh o li. nh gi chnh xc tr o hng, cnh trc bnh sai.i vi tam gic o gc: p dng cng thc Ferrero:

: SS khp gc tng tam gic; n: s tam gic trong mng liSS khp gii hn v phng v:

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Tnh ton s bHn sai ca cc s hng t do phng trnh iu kin cc v iu kin cnh:

Vi: n- s gc tham gia tnh chuyn phng v; k- s gc tham gia vo PT K cc hoc cnh; - SSTP phng v cnh gc; - SSTP logarith chiu di cnh gc; - gia s logarith sin gc khi gc thay i 1.

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Tnh ton s bi vi li ng chuynSSTP o gc:Li c khng c im nt, N vng khp v ng ph hp:

Vi: - SS khp gc c th i.Li c K im nt, N c:

Trng hp c dui thng: tnh theo sai s khp hng ngang

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Tnh ton s bi vi li ng chuynSSTP o cnh:Tnh theo kt qu o kp;Tnh theo sai s khp hng dc c dui thngSai s khp hng dc ng chuyn th i:

Sai s trung phng o chiu di cnh:

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Bnh sai li ta Li c lp: li c s lng SLG = s lng SLG ti thiu.S lng SLG ph thuc vo loi li:Li tam gic o gc: 4 (to 1 im, phng v v chiu di 1 cnh hoc to 2 im);Li ng chuyn: 3 (to 1 im v phng v 1 cnh); Li tam gic o cnh: 3 (to 1 im v phng v 1 cnh); Li cao: 1 (Cao 1 im)Li ph thuc: li c s lng SLG > s lng SLG ti thiu.

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Bnh sai li to Phng php bnh sai iu kin:Trc quan, s lng n s t, c th chia nhm gii, nh gi c chnh xc trc bnh sai;Kh lp trnh, nh gi chnh xc kh khn (vn tnh trng s hm tr o)Phng php bnh sai tham s:D lp trnh, khng quan tm n cu hnh li; d dng nh gi chnh xc hm tr o (to , cnh, phng v)S lng n s lnPhng php bnh sai iu kin km tham s b sung:Thch hp cho li ng chuyn, c th nh gi trc tip cc n s b sung

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Bnh sai li tam gic o gc theo PP iu kinCc cng thc c bn:H phng trnh s hiu chnh: Trng s ca tr o:Lp h phng trnh chun:Gii h phng trnh chun:Tnh s hiu chnh:Tnh SSTP TSV:Tnh trng s o ca hm s:

nh gi chnh xc:*

Bnh sai li tam gic o gc theo PP iu kinCc dng phng trnh iu kin:iu kin hnh:

iu kin vng:iu kin cc: T 1 cnh bt k, dng cc gc bnh sai tnh chuyn sang cc cnh khc, khp v cnh ban u, th tr cnh tnh bng cnh xut pht.iu kin cnh: T 1 cnh gc, dng cc gc o sau bnh sai tnh chuyn v cnh gc khc, th tr cnh tnh bng cnh gc.iu kin gc c nh:iu kin gc phng v:

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Bnh sai li tam gic o gc theo PP iu kinCc dng phng trnh iu kin:iu kin to : T to im gc, thng qua cc tr gc bnh sai, tnh chuyn to im gc khc th tr tnh = tr gc:

Xc nh s lng phng trnh iu kin:Li ph thuc:vi N: s gc o; P: tng s im; Q: tng s im gcLi c lp: *

Bnh sai ng chuyn theo PP iu kinS lng phng trnh iu kin: 3Dng phng trnh iu kin:iu kin phng v:

iu kin to : *

Bnh sai ng chuyn theo PP iu kinPhng trnh s hiu chnh:

Trng s ca tr o:o gc:

o cnh:

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Bnh sai ng chuyn theo PP iu kin (t.t)Ma trn h phng trnh s hiu chnh B:

Ma trn trng s P v sai s khp W:

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Bnh sai ng chuyn theo PP iu kinLp h phng trnh chun:Gii h phng trnh chun:Tnh s hiu chnh: Tnh SSTP trng s n v sau bnh sai: Tnh tr bnh sai: Tnh to sau bnh sai:

nh gi chnh xc tr bnh sai:

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Bnh sai ng chuyn theo PP iu kinTrng hp bnh sai s b v gc:

Phng trnh s hiu chnh:

Tnh tr bnh sai:

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Bnh sai ng chuyn theo PP iu kin gim nh hng ss tnh ton, ta dng h to trng tm:

To cc im trong h to trng tm:

Phng trnh s hiu chnh:

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Bnh sai li ng chuyn theo PP iu kinS lng phng trnh iu kin (PTK):

vi : P- s vng khp kn; Q1 - s hng c phng v chnh xc; Q2 - s im gc. Trong :

Phng php lp PTK: mi ng chuyn c lp 3 PTK (1 PTK phng v, 2 PTK to )Lp, gii h PT chun, tnh s hiu chnh v nh gi chnh xc hm tr bnh sai: tng t bnh sai ng chuyn n.*

Bnh sai li ng chuyn bng pp tham sDng phng trnh s hiu chnh:

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Bnh sai li ng chuyn bng pp tham sLp h phng trnh s hiu chnh: (****)

Trng s ca tr o:o gc:

o cnh: Lp h pt chun:Gii h pt chun:Tr bnh sai: SSTP trng s n v: *

Bnh sai li ng chuyn bng pp tham sSstp cc n s:Sstp v tr im: Sstp hm tr o:Tr phng v :Tr o cnh :*

Quy trnh bnh sai li ng chuyn theo pp tham sT cc tr o gc, cnh tnh to s b tt c cc im trong mng li.Lp h pt s hiu chnh gc, hng, cnh theo tng tr o.Lp ma trn trng s PLp h pt chun theo dng (****).Gii h pt chun.Tnh to cc im sau bnh sai.nh gi chnh xc tr bnh sai.

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Bnh sai li ng chuyn theo PP iu kin km tham s b sung t vn : C nhiu tuyn ng thi tham gia vo cc PTK => khng hiu qu cho tnh ton.a thm vo cc n s ph gm to cc im nt v phng v mt cnh xut pht t cc im nt.Phng php lp h PT s hiu chnh km n ph:t cc n s ph ti cc im nt ; n ph ca phng v x, y n ph ca to im nt;Dng PT s hiu chnh km n s ph: (*), (**) *

Bnh sai li ng chuyn theo PP iu kin km tham s b sungDng PT s hiu chnh km n s ph: (h to trng tm)

Nu ng chuyn gi u ln 2 nt th c 6 n s ph.Nu gi u ln 1 im gc v 1 nt th c 3 n s ph.Trng hp ng chuyn xut pht t cc im gc th cc n ph = 0. Khi h phng trnh s hiu chnh s c dng nh bnh sai iu kin. *

Bnh sai li ng chuyn theo PP iu kin km tham s b sungt: Br,n ma trn h s pt s hiu chnh ca tr o; Cr,t ma trn h s pt s hiu chnh ca n s ph; t=3u (u s nt)- s n s ph. Xt,1 ma trn n s ph;Khi phng trnh s hiu chnh tng qut c dng:

Lp h pt chun: (***) *

Bnh sai li ng chuyn theo PP iu kin km tham s b sungGii h pt chun c K v X => V => tr bnh sai v to cc im sau bnh sai.

chnh xc cc n s ph:

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Quy trnh bnh sai li ng chuyn theo pp iu kin km tham s b sungTnh to s b cc im nt , phng v s b cc cnh t cc im nt (mi nt mt cnh) theo cc tr o gc cnh bng pp trung bnh trng s.Mi ng chuyn lp 3 pt s hiu chnh km tham s b sung theo dng (*) hoc (**).Lp ma trn trng s PLp h pt chun theo dng (***).Gii h pt chun.Tnh s hiu chnh gc, cnh v to , phng v ti nt.Tnh to cc im sau bnh sai.nh gi chnh xc tr bnh sai.

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