The distances Y. of each one of the SCP are measu-
red as follows: first by means of an instrument
(telemeter is the best alternative) and secondly -
photogrammetrically. The differences between the
double determined distances is AY., where "j" is
the number of SCP (in this case jl= I - IIl).
These differences give rise to corrections in the
distances of the CP which can be determined with
sufficient accuracy using the proportional depend-
ence between the distances and the horizontal pa-
parallax, i.e.
Pp.
A. ai rem ^t; (2)
1
1
where p, is the horizontal parallax of the respec-
tive SCP; P; is the horizontal parallax of the
CP.
The formulas (2) are used to determine corrections
(1).
After the photogrammetric determination, the spa-
cial photogrammetric co-ordinates X;, MIA of the
CP are corrected with the help of (1 and T. i.e.
X, = XX + Ax, ;
i 1 1
= : + °
X Y Ay, : (3)
27. = 725 4-A2..
1 d li
The transformational image co-ordinates x,, 7 z
are determined using (3). The differences between
them and the measured image co-ordinates are
AX = a + a, x, x + a,x, 2 + 442 + a,x 3
(4)
Az = i + cz. X + e zz + C4X + cz
The formulas (4) are figured out by means of the
principle of least squares and result in the coef-
ficients Ya” and "c".
The same formulas (4) are used also to receive the
corrections of the image co-ordinates of the exa-
minated points (EP),(Fig.l, points 1, 2, 3, ....).
The iterative method is applied. For the first ap-
proximation the measured values of x_ and z are
used. The iterations continue until the following
conditions are observed:
k+1 k <
AX, m AX, | = Mx ’
k+1 k <
| Az, - Az. 3 M. ; (5)
where and Ju, are apriori values; "n" is the
x
number Of the EP and "k" is the number of the
iterations.
The image transformational co-ordinates are recei-
ved using the calculated corrections and through
them - the spacial photogrammetric transformatio-
nal co-ordinates of the EP. These co-ordinates can
serve to calculate the geodetic co-ordinates or
the relative displacements as it is very often
done:
acl 5. oe:
AX = 2a An ?
= i = o
AY, = ln Y 3 (6)
i 0
A7, ® elds Far!
0 0 o ; ;
where X , Y , Z are the spacial photogrammetric
transformational co-ordinates of the EP at the ze-
i i i > ;
ro cycles X, Y? Z are similar co-ordinates at
the deformational cycle "i" ("i" depends on the fun-
ction of the structure and on its size and shape);
"n" is the number of EP.
3. PRACTICAL RESULTS.
The deformations of a reinforced reservoir ( size
28/14/5 m), which is supported by 45 pillars, are
examinated. Photographic parameters: f = 194.82 mm
(Photheo 19/1318, Carl Zeiss); B = 13.020 m; Y =
62.000 m.
Nineteen EP are observed in two cycles: a zero (an
emrty reservoir) and a deformational cycle (a full
reservoir). Geodetis measurements are used to get
the displacements: range (using the theodolite Theo
010A, Carl Zeiss) and levelling (using the level Ni
007, Carl Zeiss).
The photogrammetric displacements are compared to
the latter, which are accept as most probable.
In each cycle three photographs are taken and they
are measured with the help of Stekometer, Carl
Zeiss. Each of the points is measured three times.
In calculations a computer is used and software
respectively. The final results are given in
TABLE 1.
TABLE 1
o
Ne AX n^ X, €. AY u^ Ts E, |^ Z n^ ag €,
mm | mm | mm| mm | mm |mm mm | mm | mm
1 15 6 91-34 1-25 1-9 ]|- 9 | -3] -6
2 18 12 61-37 |-28 | -9 -13 | -4] -9
3 13 8 5]-29 ]-20 | -9 -13 mû | -9
4 8 5 31-14 |- 9 | -5 -7 -3] -4
5]-6|- 1 —-5 1-20 |-14 1-6 |-10 | -4 | -6
6 14 8 6 | -16 1-11 | -5 - 9 -4 | -5
7177 |-3 —-4 1-19 ]-11 1-8. | —11 -4 | -7
81-9 1-1 -8|-12|-61|-6 |-8]| -3] -5
917-7 1-2 -51-9]-5]-4 1-10 | -4 | -6
10 4 2 21-61-21-4 1-7 -4 1 -3
11 6 2 4|-5]|-1[|-4 [-10]| -4]| -6
12 6 3 31]-51-2]1]-3 ]-10] -4| -6
13 5 2 31-3 51-8 |-5 -3 | -2
14 7 2 5173 31-6 — 5 -3] -2
15 6 3 3I1-31—5 2 - 6 3 | -3
16 |- 2 6| -8/-31-6 3 = / -4 | -3
17 6 1 $1-7251-.21-3 -10 | -4 | -6
18 7 1 61-3 0[-3 1-9] -31.-6
19 7 1 6 1 ==3 01-3 1-8 | -3 -5
There AX h? AY h? AZ are photogrammetric dis-
placements; AX, AYP AZ are geodetic displace-
ments; €., £5 E, “are tPue errors of the photo-
grammetric displacements. The results of the exami-
nation of only one of the walls are shown, i.e. of
the wall with the biggest displacements.
The displacements of the EP are illustrated graphi-
cally in Fig.2.
Using the true errors the standard errors of the
displacements are calculated:
2
+ es + |/ 550
à
TAX = n = = 7519; 5.4 mm,
2
AE ES: ue te,
m Y n 19 . mm,