الفهرس 
introdationOnly 14 pages are availabe for public view
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Abstract
The economic development of any country requires comprehensive and
modem geodetic control networks. The geodetic control networks, in
classical geodesy, provide a basis for mapping, cadastral applications and
large engineering projects. The recent applications of geodetic control
networks require a very high accuracy for the network coordinates. The
first order geodetic horizontal control networks of Egypt consists of two
main networks; network 1 and network 2. Network I has been adjusted by
ESA, using a non-rigorous adjustment . However, no final adjustment has
been done by ESA for network 2, where its provisional c0<1rdinates are
only available. During the past few decades, several previous solutions tor the
Egyptian horizontal geodetic networks have been performed, either in two
or three dimensions. However, these adjustments neglected, totally or
partially, the role of the geoid on the adjusted coordinates. Also, no
simultaneous adjustment for both networks l and 2 on the Egyptian Datum
(EGD30) has been performed before. Consequently, it can be seen that, the
accuracy of the existing c.oordinates of the Egyptian geodetic networks, will
not be sufficient for precise geodetic applications. Therefore, the rigorous
adjustment for the Egyptian horizontal control networks 1 and 2, is
essential fur recent scientific and precise purposes. In addition, the choice
of the geodetic datum will cause corresponding changes in the resulting
geodetic coordinates, which are computed relative to it. On the other hand,
GPS measurements require existing regional control networks to be
adjusted on the GPS datum, which is known as WGS84 _ The main goal of this thesis is to perform different simultaneous
rigorous adjustment solutions for the Egyptian horizontal geodetic control
networks, with the geoid effects on the reduced observations to the
reference ellipsoid being taken into account, referring to different geodetic
datums, using the currently available personal computers. The first
geodetic datum is the Egyptian geodetic datum (EGD30) , which is based
on He!mert ellipsoid (1906). The second datum is the WGS84, which is
the datum of the GPS observations. For this purpose, a software package was developed by the author, using FORTRA.~ 77 language, with
Microsoft FORTRAN compiler version 5.1. This program was designed
to perform the rigorous simultaneous least squares adjustment of l.arg:e
horizontal control networks, using the parametric approach, in terms of
the two dimensional geodetic latitude and longitude. The main
programming consideration was stipulated, such that the storage
requirements for all consecutive different steps ofthe :;olution, are kept
to a minimum in the memory of the used personal computer. By using the
developed version of the software, which runs under Windows, and using
any AT-IBM personal computers or their compatibles with extended
memory over 8 Meager Ram., the software is capable of adjusting a
horizontal network with more than 450 unknown stations. The obtained results indicated that the non rigorous adjustment
in sections, and the neglect of geoid effects in reducing observations to
the ellipsoid, as used by ESA, cause undesirable distortions in the
network point positions, as well as distortions in both scale and
orientations of network sides, that exceed the allowable limits specified
for first order geodetic work, and can not be neglected in precise
geodetic applications. In addition, including both networks I and 2 into
the same simultaneous combined adjustments, relative to EGD30 or
WGS84, improves the positional accuracy of network 1 stations more
than that of network 2 stations, when compared to the cases of adjusting
networks I and 2 individually by itself. On the other hand, the
simultaneous adjustment of network I alone, network 2 alone, and both
networks 1 and 2 combined together, relative to WGS84 datum,
possesses a higher point positional accuracy, than the corresponding
adjusted coordinates relative to the Egyptian regional geodetic datum
EGDJO. This can be attnbuted to the higher reliability of both the used
geoid model and datum initial fixed point in case of WGS84.
Consequently, the rigorous simultaneous adjustment of the entire
Egyptian networks, with the geoid information being taken into acwunt, is recorrunended to be perlbrmed, relative to WGS84 global datum, with
station 0 I at Helwan taken as the initial fixed point.