STERE( "TRIANGULATION 
© e TT = 
Tz f 
As 
| ST | i 
| : 
| Iz — = I 
I L T 9 
sr2 \ 
} a T 
{ | —+g 
t + : "i 
| ^ 
sT.3 4 en 
| 
i — 
p I 
| 
ST 4 | 
Fa T > ld 
\@ d, e + 
| 7 à + 1 
sT 5 | 
| 
i e = €} 
FrG. 2 
Strips after approximate 
tion 
| 
| 
| approximately transformed coordinates can 
be compared for erroneous data. Furthermore, 
| the coordinate differences on tie points com- 
mon to adjacent strips can also be examined 
for consistency of pattern. Note Figure 2. 
The strips are now divided into segments 
of at least two models (possibly more) with 
tie points in the corner of each segment gen- 
erally common to three adjoining segments. 
Note Figure 3. 
The next step is to simultaneously adjust 
these segments to the best fit with respect to 
each other and the geodetic control within the 
project area; that is, they should be adjusted 
in such a way that the residual errors on con- 
trol and the residual differences between seg- 
ments will be as small as possible. These con- 
Segment (jk) 
  
sraphical representation of 
one segment 
ADJUSTMENTS BY “UNIVAC” 9 
ditions are represented mathematically by 
the following equations: 
l. For geodetic control points: 
(X E AXGO) — xo — Ve) 
Tr : : (S) 
(V HAY). Va > V,, ) 
where 
(X9, YD) are the geodetic coordinates of 
. . i 
Control point (7) 
(XD, yo 
are the approximate coordi- 
nates for control point (7) resulting from 15 
the first transformation {Ss 
(AX'9, AYO) are the secondary corrections 
to be applied to the approximate coor- 
dinates 
(7.02. V!) are the residual errors on con- 
trol points (1, 2 3... n) 
2. For tie points on corners of segments: 
> (7) > (1) > (1) ; (2) 14) 
(À wt + AX ax ) — (À i+ + AX) = Vg, (pl) 
(6) 
(J 9 + AYj) — (1 ak dA Vj a) = VO. (j +1k)y 
where 
(1) (à 
(Xi Yu) are the approximate coor- 
dinates for tie point (7) on segment 7, k 
resulting from the first transformation 
(2) (4) 
(AXj, AYjg) are the secondary correc- 
tions to be applied to the approximate 
coordinates 
1) (2) 
V Gk) 410m Vititiky are the residual 
errors in X and Y between tie points 
(X ix Y ix) | 
Seinen (X nl Y ei 
(ik) Segment 
(j,k+1) 
(X (YA Roe V ise] 
Segment 
Kl) 
Graphical representation of 
four adjacent segments 
Fic. 3 
Archives 5 
-