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421 Comments and analysis of results
From the results obtained, we can see that :
1 when (B) is a constant and (D) variable or
when (B) is variable and (D) constant the best
positional accuracy achieved was obtained from
a theodolite ,secondly from a camera and lastly
from a phototheodolite .
2 at certain ratios for (D/W) and (B/W),the
accuracy achieved from a camera mounted on a
theodolite(phototheodolite) is nearly equal to
the accuracy achieved from both the camera and
theodolite separately .
5. OBSERVATION SCONCLUDING
REMARKS AND RECOMMENDATIONS
1 With the developed formulae relating the
object space co-ordinate standard errors to the
system parameters (B,D,O,W and H) , it has been
illustrated that the standard errors obtained
from a given close range photogrammetric
system can be sufficiently estimated . lt is ,
therefore , possible to arrive at a decision as to
whether , using a given system , a certain
required accuracy is achievable or not . But
more importantly , the formulae provide a
convenient tool with which we can choose the
parameters and ,in turn , the components , of a
system which will yield the required accuracy
for a proposed project .
2 This study confirms that the highest accuracy
of object points for close range photogrammetry
could be obtained by using a theodolite.
3 Above certain ratios for (D/W) and (B/W) in
the normal and convergent cases of photography
the accuracy achieved from using a
phototheodolite will be nearly equal to the
accuracy achieved if we used the camera and the
theodolite separately. In this study since the
smallest difference in the accuracy achieved
between the phototheodlite and the camera
theodolite combination was 0.6 um in the
normal case of photography and was 0.10 um in
the convergent case of photography (O = 30°) , in
simple tasks when high accuracy is not required
and the time is significant , the use of the
phototheodolite is more satisfactory.
4 A more further study between the theodolite ,
the camera and the phototheodolite will be
needed with different types of theodolites ,
cameras and phototheodolites and for different
configurations.
References
Abdel - Aziz , Y.l, 1982. The accuracy of control
points for close range Photogrammetry.
International Archieves of photogrammetry ,
248): 1-11.
Mahmoud, A.A.E , 1989 . The application of close
range photogrammetry to the restoration of
architectural features. Ph. D. dissertation
,Department of Civil Engineering ,Zagazig
University , Egypt , 129 pages.
JABLE 1
The base distance B , the corresponding object distance D
that satisfies OXmt= ODmt and the values of 6Dmt at
different values of convergence angle @ .
Convergenc
Base Distance | Object Distance
Angle (2) B D Som?
(m) (m) (mim)
1 2 3 4
0.1W 0.295W 0.0200
0.2W 0.288W 0.0100
0.3W 0.110W 0.0046
0.4W 0.121W 0.0039
0.5W 0.223W 0.0042
0.6W 0.286W 0.0045
eo 0.7W 0.328W 0.0047
LS 0.8W 0.363W 0.0048
0.9W 0.335W 0.0044
1.0W 0.290W 0.0039
14W 0.247W 0.0037
1.2W 0.174W 0.0035
1.3W 0.122W 0.0034
1.4W 0.156W 0.0036
1.5W 0.178W 0.0038
0.1W 0.289W 0.0200
0.2W 0.281W 0.0102
0.3W 0.271W 0.0070
© 0.4W 0.256W 0.0054
Ce 0.5W 0.201W 0.0041
T 0.6W 0.266W 0.0045
0.7W 0.306W 0.0047
0.8W 0.251W 0.0040
0.9W 0.225W 0.0037
1.0W 0.196W 0.0036