تحليل الشبكات في أنظمة المعلومات الجغرافية ...
تمثل الشبكة مجموعة من الخطوط والنقاط التي تمثل الكائنات الجغرافية المتصلة مع بعضها البعض والتي من خلالها تتحرك الموارد (سيارات , مياه , كهرباء , غاز....الخ)
1- أنظمة تدفق موجهة
يتحرك التدفق من المصا
در إلى المصارف
الموارد لا تملك القدرة على اتخاذ قرارات المسير
(على سبيل المثال، نظام النهر)
2- أنظمة تدفق غير موجهة
النظام لا يتحكم بشكل كامل بعملية التدفق
الموارد تملك القدرة على اتخاذ قرارات المسير الخاصة بها
(على سبيل المثال، نظام السير)
The contribution of relative light particles and relative neutrinos in the cosmic
Omega-density parameter (W) was separately calculated based on the data of Wilkinson
Microwave Anisotropy Probe. Also it has been shown that the effect of the relativ
e
particles circulating in the universe in Omega-density parameter is roughly equivalent to
the effect of the Big Bang neutrinos in this parameter and the universe will remain in the
vicinity of the critical situation.
With substantial development in the field of surveying instruments, and the
emergence of various and different generations of Theodolites which are used to measure
horizontal directions and angles, it is urgent to develop the methods of assessing a
nd
determining the accuracy of measurements using these instruments. This is achieved by
taking into consideration all the internal and external factors affecting the measurement
system. The research team studied the famous error equation (Colcord equation) of
horizontal directions and tested it using a several equipments of theodolites and targets on
a 250 m long, 5-sections base-line. The team concluded that there was a need to develop
Colcord equation by taking into consideration the factors involved mainly by Colcord
equation (positioning error, initial sitting error, reading error) in addition to the type of
target and the distance of the line of-sight. The proposed equation was tested in practice,
which proved that expected errors of measurements were close to their actual values. This
could be adopted to estimate the root mean square error (r. m. s. e.) of measurements of
horizontal directions.
This paper presents the monitoring horizontal and vertical displacements of railway
which heavy cranes run on using special geodetic techniques for the purpose provaiding
rialway stability and safe working cranes on it. To quaranty that heavy crane
s work safly, a
rialway should be just horizontal– a small error of milimeters leveling is allowed according
to working conditions for cranes. A rialway shoud also maintain its spaces to facilitate the
crane motion on it. Monitoring railway vertical displacements involve measuring the
relative vertical displacements of target points that are distributed along the railway in two
cases: static and dynamic. vertical displacements determined by precise leveling which are
performed using digital high accuracy level. The precise leveling measurments of target
points have been connected to stable benchmark that are located in surrounding terrain of
railway for purpose of further studies. In this paper the alignment method was used to
monitoring the railway horizontal displacements using digital rulers and total station
provided by a prism fixed forcely on the railway. This is done by measuring the small bias
angles of the targat points which are distributed along the railway. This research has
illustrated the efficiency of alignment method in order to calculate the horizontal
displacements of railway axis.
The research aims to complete the study of the theory and operation of networks
geodesic associated marine beach, whether horizontal or vertical, with display rods and
devices used in completion of topographic survey of networks in both land and ma
rine
parts.
In theoretical part it was addressed to specific shapes networks geodesic which
distinguish maritime works beach that takes the form of the morphological characteristics
of the natural land of each building proposed network, and the numerical characteristics of
each building proposed networks.
In the practical part the results of measurements and amendments was presented to
some forms of executed geodesic beach networks for several forms of works: (topographic
raise achievements within the existing and investor basin in order to establish a slider,
completion of the cadastral beach works in order to determine distortions in the existing
pier, clean the shipyard of silt and sediment.
Software has been reviewed to assist in completing marine works, utmost to obtain
the final marine charts.
The research concluded that specific proposals on vertical geodetic networks studies,
and identify the various parts of software related to marine works and ways to take
advantage of them.
The research aims to complete the theoretical, analytical and practical study for
elevation networks in some medium and small dams in the coastal region of the Syrian
Arab Republic, In terms of the configuration of network, strength of network and
measured
elements, And instruments that must be used to obtain the required accuracy, and efficient
of the mathematical model used, The design and implementation of monitoring and control
points in the used network and propose appropriate solutions. During the research was
done on two independent programs , The first relates to simulated measurements in the
elevation network specific elements, The second for adding program to software is the
famous engineering drawing (land development) to enable the user for adjusting elevation
networks without going out of the graphical program.
The research concluded that specific proposals on elevation geodetic networks
studied, and to show the efficiency of all programs designed within Land development
software and modeling the elevation measurements.
Precise point positioning technique uses recursive algorithms to solve the navigation
problem. In fact, traditional least square method doesn’t meet the requiredassessments of
processing speed, and quality in different geodetic and surveying applic
ations,due tobig
amount of output processing data provided by global navigation satellite systems.
Extended Kalman filter is considered as optimal solution approach of the navigation
problem. This filter requiresthe knowledge of measurements, its observational models, and
physical state for estimation problem like: (receiver dynamic, received signals characters,
and suitable estimation of its initial conditions).
Research refers to a mathematical suggestion, which reduce the negative effect of
convergence time at EKF initial conditions. This work also shows how a position
estimation accuracy affected by the suggested modification of using EKF in PPP, and
supporting the use ofthis modification in position estimation field, in spite of increasing
processing time.
GPS technology considers the essential tool for establishing geodetic networks.
Static method of GPS is used often in observing geodetic network points. Establishing
geodetic networks using GPS requires accuracy, consistency and economency.
This p
aper discusses influence of observation mode and number of GPS receivers in
accuracy of calculating of coordinates of points. Coordinates of network points are
clculated using tow and three GPS receivers and with diferent methods like radial, traverse,
network.
Comparison between coordinates for network points obtained by several cases is
performed. The differences between coordinates indicate accuracy of network method in
calculating coordinates when three or more receivers are avlible. When tow receivers are
avilable the radial method is the best in accuracy and consistency.
The research aims to study the effect of weather (humidity - pressure - temperature) on
the linear measurements between geodesic network points through the introduction of
these factors directly on the Total station devices settings and get distanc
es patched for that
network has been based geodesic point (conducting field measurements necessary) within
easy reach of the design requirements of the device ideal conditions in the study area
(Trjano) in the province of Latakia, which we will adopt in the later stages to monitor
landslides and thus all measurement cycles will be compare basic measurement cycle
taking into account changes in ambient weather conditions in each measurement cycle for
the reference measurement cycle.
The research aims to study the possibility of using nondirect
leveling to the paths of the earth to find the heights of ground
traverses observatories within the works of the first phase of the
topographic survey rather than direct leveling.
