The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
MICROPROCESSOR IMPLEMENTATION OF AN ON-LINE OPTIMAL ESTIMATOR OF GUIDANCE STATES FOR A SHORT-RANGE HOMING SYSTEM
1
10
25465
10.21608/asat.1995.25465
EN
M. A.
Fahmy
Guidance Dept., M.T.C. Cairo, Egypt.
S. F.
Bahgat
Guidance Dept., M.T.C. Cairo, Egypt.
S.
Ghoniemy
Guidance Dept., M.T.C. Cairo, Egypt.
Journal Article
2019
01
20
An optimal online pp-based estimator for the guidance states of a short range homing system is presented, taking into account : the horning head measurement errors, autopilot measurement errors, launch initial heading errors, and wind disturbances. A powerful 16-bit microprocessor system is used. The obtained results illustrate the potential improvement of both the missdistance and normal acceleration as well as the overall system performance. Moreover, the system allows for further modifications through more powerful algorithms.
https://asat.journals.ekb.eg/article_25465_3acdfbb60a37ab47cde435f67a89fc80.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
AN APPROACH FOR THE EVALUATION OF RADIO-FUZE PERFORMANCE
11
27
25466
10.21608/asat.1995.25466
EN
M.
EL-LITHY
M.T.C , Cairo+
Ass. Prof. - Guidance Department, M.T.0 , Cairo.
Journal Article
2019
01
20
The problem of target destruction by anti-aircraft guided missiles is not solved only by using an accurate guidance system but also by using a highly-performant fuzing system. Aircrafts are characterized by high flying speeds and great maneuverability that make its destruction, using a guided missile, by a direct hitting is a very difficult mission. Therefore, the target destruction may be realized by a warhead (W.H) which is to be initiated properly according to the missile-target (ma) encounter conditions. Up to the moment, there has not been a distinct way for evaluation of a fuze performance (F.P) in a specific M/T encounter conditions. The present paper provides a graphical method for the evaluation of F.P . The proposed algorithm of such method is developed and the flowchart is included. The program of F.P calculation is elaborated. The results include the evaluation of radio fuze(R.F) performance in different encounter conditions which take into consideration the variation of missile speed, target speed, maneuverability and W.H characteristics. The proposed method and its algorithm are well-suited for further research towards the improvement of R.F performance.
https://asat.journals.ekb.eg/article_25466_5c6e82dddb651cad57181c1b1671033b.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
TOWARDS PERFORMANCE IMPROVEMENT FOR RADIO FUZES OF AA/C GUIDED MISSILES
29
46
25467
10.21608/asat.1995.25467
EN
A. A.
SALEH
M. Sc - M.T.0 , Cairo.
M.
EL-LITHY
Ass. Prof - Guidance Department, M.T.C , Cairo.
Journal Article
2019
01
20
The fuze is the equipment of the missile which is responsible for initiating the warhead (W.H) explosion. The performance of the fuze or its efficiency is measured by the probability of target destruction which it can achieve. To improve a fuze performance means to increase the probability of target destruction by that fuze. This may be realized by increasing the degree of identity between the fuze activation zone (F.A.Z) and the target destruction zone (T.D.Z). The matching process may be either an actual one by using radio fuze(R.F) with variable antenna beam pattern(A.B.P) or virtual one by delaying the W.H initiation. This delay is calculated according to the real missile-target (M/T) encounter conditions. The present paper deals with the analysis of methods for R.F performance improvement in the cases of R.F with variable A.B.P and that with fixed A.B.P. The paper provides a mathematical model which is used to determine the relative velocity modulus necessary for determination of the W.H initiation optimum time instant . In the case of R.F with variable A.B.P , the model determines the optimum tilting angle of the antenna beam with respect to the missile axis. For R.F with fixed A.B.P, the model determines the corresponding delay time that do matching between the F.A.Z and the T.D.Z for a specific encounter conditions. The improved performance is calculated for some specific encounter conditions and the results are evaluated. A performance improvement factor (P.I.F) is defined which value may reach 83.7%.
https://asat.journals.ekb.eg/article_25467_c94ceaed10423eeabe804c0421c2e648.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
CLOSED FORM SOLUTION FOR THE NUMERATOR POLYNOMIAL OF SAMPLED DATA SYSTEMS
47
55
25468
10.21608/asat.1995.25468
EN
G. M.
EL-BAYOUMI
Lecturer, Dpt. of Aerospace Engineering. Cairo University.
Journal Article
2019
01
20
A problem of continuing interest in control is the specification of sampling period that results in a system response with specified time domain characterestics such as minimum phase behaviour, overshoot and settling time. This paper presents a closed form solution for the numerator polynomial of sampled data systems. The coefficients of the numerator polynomial are given in terms of the residues and poles of the continuous time system, and the sampling period. A'so, numerical algorithm is proposed for determining reasonable sampling period for minimum phase behaviour.
https://asat.journals.ekb.eg/article_25468_8c12234ef24a1c97fbfaf122baf79751.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
2019
01
20
Influence of Adaptive Power System Stabilizer on the Transient and Dynamic Performance of a Multimachine System
57
65
25469
10.21608/asat.2019.25469
EN
F. A.
Khalifa
Ass. Prof, Dept. of Electrical Power and Energy, Military Technical
College, Cairo, Egypt.
W.
Sabry
Ass. Teacher, Dept., of Electrical Power and Energy, Military Technical
College, Cairo, Egypt.
Journal Article
2019
01
20
This paper presents a power system stabilizer (PSS) for improving the performance of a multimachine system when the system is subjected to different types of disturbances. An adaptive proportional-plus-derivative-plus-integral (PID) PSS is proposed in this paper. In this technique, the controller parameters (proportional, integral, and derivative gains) are not fixed but they are varying according to the system operating conditions. The derivative of power angle, error in output power, terminal voltage, and error in power angle are selected to be the input signals to the proposed stabilizer. A weighting factors are assigned to these signals to obtain the best performance characteristics of each machine. The obtained computer results from simulation study are compared with those of a conventional lead-lag stabilizer.
https://asat.journals.ekb.eg/article_25469_fed2cfd166341795fc0764acfde1dcf9.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
EVALUATION OF PERFORMANCE FOR AN AIR DEFENSE DUEL
67
74
25470
10.21608/asat.1995.25470
EN
A. H.
MAKARIOS
Associate Professor, Guidance Department, M.T.C., Cairo, Egypt.
Journal Article
2019
01
20
Simulation techniques are applied for the evaluation of possible outcomes of an air defense combat. A duel between an attacking aircraft [A/C] that uses air-to-ground missiles and a ground battalion [GB] of anti-aircraft guided missiles is investigated .The simulation model considers all the possible outcomes of the engagement and adaptsthe case of A/C destruction as the main concern of the air defense [GB] unit. Large number of runs of the simulation model program using Monte-Carlo sampling techniques are carried out for the evaluation of performance. Results obtained from the model confirm the practical experience related to similar cases. The model can be adopted for different types of guided missiles according to their capabilities and used for experimentation, prediction and sensitivity analysis .
https://asat.journals.ekb.eg/article_25470_d240ddab8992c8980a6e3af1fd962a86.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
DELAYED GUIDANCE FOR ROLLING MISSILES WITII BOOST-SUSTAIN PROPULSION MOTOR
75
87
25471
10.21608/asat.1995.25471
EN
M.
Medgawy
Graduate student, Algerian Military 'Technical College, Algeria.
Mohsen S.
Aly
instruc-tor, Guidance Department, Military Technical College, Cairo.
S.
Ghoniemy
Professor, Mili-tary Technical College, Cairo, Egypt.
Journal Article
2019
01
20
The results of a 6-Degrees-of-freedom (6DOF) simulation model of a short-range homing missile are presented. The missile considered is roll-rate stabilized and is guided by proportional navigation law. The missile motor is of boost-sustain type. In this paper, the effect of the boost acceleration is analyzed. During the boost phase, it is found that the presence of a relatively large incidence angle increases the demanded missile maneuver to correct for the input errors to the guidance loop. Mathematical analysis shows that this large incidence angles couples a considerable amount of the boost acceleration to the lateral plane. This can be regarded as an input acceleration bias that increases the effort done by the guidance loop. In the sustain phase; however, the sustainer acceleration is low and this effect can be neglected. To reduce the demanded effort from the guidance loop, a • delayed guidance scheme is proposed. In this scheme, the guidance and control of the missile starts few moments after launch. The results obtained via numerical computations are in complete agreement with the theoretically obtained conclusions.
https://asat.journals.ekb.eg/article_25471_a90bc8f297909ec1563351a24352f6cd.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
MODELING AND EVALUATION OF INFRARED TRACKING SYSTEMS
89
99
25569
10.21608/asat.1995.25569
EN
Mohscn S.
A Y
Guidance Department, Military Technical College, Cairo, Egypt.
Journal Article
2019
01
22
The mathematical model of an infrared (IR) tracking system is developed. The system considered has a gyro-stabilized IR optical eye with rotating optical chopper. The dynamical equations of the gyro-mass assembly are derived. The equations that describe the signal processing in the electronic section of the system are obtained.Thus, the transfer functions that relates the precessional motion of the gyro assembly to the location of the IR-spot relative to the gyro spin axis are established. A physical simulation of the invloved system is then presented. A digital controller is employed to control the operation of the simulated tracking loop. The control is achieved via the parallel interface bus (HP-IB). The chopping action of the,tyro rotating reticle is physically simulated by placing an enlarged reticle in the front ,of an oscilloscope screen. The oscilloscope inputs are adjusted such that the oscilloscope,Spot traces a circle with angular frequency given by the gyro spinning speed. The electrimic part of the tracking system is inserted in the simulation loop. This hardware-in the loop procedure ensures that the simulation results are very close to reality. Via this simulation setup it is possible to develop and design the critical components of the system. In addition, the performance of the designed system can be tested. Simulation results show that the steady state tracking errors and the behavior of the tracking loop in: the transient period are affected by the IR spot intensity and size in the reticle plane.
https://asat.journals.ekb.eg/article_25569_268cb9ffeeac0c6d3db14d2405581ce8.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
ACCURATE CLOSED-FORM SOLUTION OF PROPORTIONAL NAVIGATION FOR MANEUVERING TARGETS
101
117
25570
10.21608/asat.1995.25570
EN
Wagih
Abd El-ghany
Col. Dr. Eng., Air Defence College.
Wahid
Kassem
Brig. Gen. Prof. Dr., M.T.C.
Journal Article
2019
01
22
We present in this paper a method of accurately solving the pure proportional navigation equations in closed form for maneuvering and nonmaneuvering targets. The method is based on a quasilinearization (QL) procedure. The explicit QL solutions presented here are shown to be a generalization of the classical linear (CL) solutions. This generalization results in an improvement in the estimation of missile lateral acceleration and enlarges the validity of the solutions to a wide range of engagement geometries and maneuver levels than is possible with the CL approach. The method outlined here is capable of generating explicit solutions for all trajectory angles, as well as the time of flight and lateral acceleration.
https://asat.journals.ekb.eg/article_25570_b4dd8f0ce32a4b5c508cab3e130b2484.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
IMPLEMENTATION OF BANDWIDTH BALANCING MECHANISM FOR DQDB NETWORK WITH MODIFIED PROTOCOL
119
129
25571
10.21608/asat.1995.25571
EN
Sayed Abd-El Hadi
Nouh
Computer & Systems Department
Faculty of Engineering, Al- Azhar University Cairo, EGYPT.
Journal Article
2019
01
22
A potential problem with DQDB network is the achievement of fair sharing of bandwidth in terms of the location of the access node. For the sake of compensating this unfairness, the IEEE 802.6 Standard recommends to utilize a Bandwidth Balancing (BWB) Mechanism. This paper deals with the implementation of BWB mechanism using the modified DQDB method. We focus on the behavior of this protocol when the network is Heavy load. The effect of BWB mechanism on the fairness problems suffered by a DQDB network with two stations for three different scenarios is investigated analytically through using a graph model which is based on the space time diagram. Simulation is used when the number of active stations is larger than two. Our results provide a deep insight into the equilibrium access of data channel by all the active stations. They also show that the station throughputs are independent on the state of the network when overload occurs.
https://asat.journals.ekb.eg/article_25571_6d178a6a5f2ef34df9d33a5bcc19a12e.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
NEURAL NETWORK IMPLEMENTATION OF BINARY TREES
131
139
25572
10.21608/asat.1995.25572
EN
Ismail A.
Farag
Dr., Department of Specialized Electrical Engineering, Military Technical College Cairo, Egypt.
Fawzy
Ibrahim
Dr., Department of Specialized Electrical Engineering, Military Technical College Cairo, Egypt.
Journal Article
2019
01
22
Multiple layer artificial neural network (ANN) structure is capable of implementing arbitrary input-output mappings. Similarly, hierarchical classifiers, more commonly known as decision trees, possess the capabilities of generating arbitrarily complex decision boundaries in an n-dimensional space. Given a decision tree, it is possible to restructure it as a multilayered neural network. The objective of this paper is to show how this mapping of decision trees into multilayer neural network structure can be exploited for the systematic design of a class of layered neural networks, called entropy nets, that have far fewer connections.
https://asat.journals.ekb.eg/article_25572_e779c1f47a6d1a0dfa89c1296e66f8b4.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
AIRCRAFT ACQUISITION AND OPERATION IN A TOTAL QUALITY ENVIRONMENT Part I: A Conceptual Framework and Approach
141
152
25573
10.21608/asat.1995.25573
EN
Mohamed M.
Elmaadawy
Major General, EAF.
Atef 0.
Sherif
Professor, Aeronautics Dept., Cairo University.
Journal Article
2019
01
22
A conceptual framework and an approach for handling the problem of aircraft acquisition and operation in a total quality environment are proposed in this part of the work. For this purpose, a typical acquisition process is described and the system operational and maintenance support requirements are summarized. The Aircraft Mission Support Process (AMSP) is analyzed at different levels of detail to identify the problem symptoms, causes, statement, problem solving approach and the design alternatives. This provides the necessary background and foundation for establishing a Logistic Engineering Model to support the decision making during aircraft acquisition and operation. Statistical Process Control (SPC) and process capability measures are utilized in the decision making process. To support this concept, the intended model is further developed to provide sampling experiments to pursue the required statistical analysis. This is done by using aircraft operational availability as the external performance indicator for the Aircraft Mission Support Process. Internal performance indicators are also considered. This approach can provide a mechanism for evaluation of different acquisition and/or operation options directed to continuous improvement of aircraft readiness and utilization. Part II of this work presents (AMSP) modeling and improvement procedure.
https://asat.journals.ekb.eg/article_25573_d342e334caea5e96a4108bb67231ab43.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
AIRCRAFT ACQUISITION AND OPERATION IN A TOTAL QUALITY ENVIRONMENT Part II: Process Modeling and Improvement
153
167
25574
10.21608/asat.1995.25574
EN
Atef 0.
Shenf
Professor, Aeronautics Dept., Cairo university.
Mohamed M.
Elmaadawy
Major General, EAF.
Journal Article
2019
01
22
In part I of this work, a conceptual framework and approach for handling the problem of aircraft acquisition and operation in a total quality environment was presented. Decisions related to aircraft acquisition or operation are usually based on predicting the expected performance of Aircraft Mission Support Process (AMSP). The objective of part II is to present the modeling approach and improvement procedure of this process. The model is developed such that it can provide sampling experiments required for the application of Statistical Process Control (SPC) and process capability measures. A process capability index is used to measure the capability of the process in providing the system user with the required level of performance. Aircraft operational availability is taken as the process external performance indicator (or quality characteristic). A simple analytical model is investigated to determine its adequacy for the intended statistical analysis. Simulation is adopted as the preferred approach to model the process. Different acquisition options for improvement are evaluated by changing the design, support, and/or operational characteristics of the acquired system. For each option it is possible to determine the benefit and the worth of the change. Results of application of this approach show its power in predicting the process future performance. The suggested model could also provide an interfacing mechanism between aircraft users and suppliers in support of their mutual decision making during aircraft acquisition or operation.
https://asat.journals.ekb.eg/article_25574_22922f88de6aacd5a22152805c92f5e5.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
Fast Calculation of the Modular Exponential Function in the RSA Cipher
169
178
25576
10.21608/asat.1995.25576
EN
AIN.
Elsherbiny
Graduate Student.
M. N.
Saleh
Faculty ofEnginerring, Ain Shams University.
A.
Elosmany
Military Technical College, Cairo.
S.
Elhabiby
Military Technical College, Cairo.
Journal Article
2019
01
22
Two different techniques are used to secure communication between military aircraft and control centers; the conventional secret key system and the public key system. In the public key system, the most famous technique is the RIVEST-SHAMIR-ADLEMAN (RSA) method. In the RSA system, the modular exponential function is used to encipher the plaintext message and to decipher the ciphertext message. The problem considered here is how to speed-up the calculation of the modular exponential function. An improved binary algorithm based on the binary redundant representa-lion (BRR) is proposed. This algorithm requires the minimum number of basic operations (modular multiplications) among all possible binary redundant representations. Compared to the binary algorithm, the proposed algorithm reduces the number of basic operations by 33%. Systolic array of Montgomery is used to decrease the needed number of operations in the calculations. Results show that the time needed to compute the modular multiplication became less than 50% of the original time needed to perform the same operation without using systolic array of Montgomery. The final results show that, the needed time to calculate the modular exponential function will decrease by 66% of the original time.
https://asat.journals.ekb.eg/article_25576_68444634e8a6c320eb8fa8e4eaf7a256.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
APPROACHES TO BREAK THE RSA ALGORITHM AND HOW TO COMBAT THEM
179
187
25577
10.21608/asat.1995.25577
EN
M. N.
Elsherbiny
Graduate Students.
M. N.
Saleh
Faculty of Engineering, Ain Shams University.
A.
Elosmany
Military Technical College.
S.
Elhabiby
Military Technical College.
Journal Article
2019
01
22
The public key cryptosystem is one of the protection systems used to secure communication between computer terminals. Since no technique exists to prove that an encryption scheme is secure, the only test available is to see whether anyone can think of a way to break it. This paper outlines a selection of attacks that have been used and explains some of the basic tools available to the cryptanalyst. We presented survey of a collection of protocols in which the level of security is not actually attained, not because of a failure of the encryption algorithm used, but rather because of shortcomings in the design of the protocol. Guidelines will be extracted from the analysis of these protocols. A czyptanalytic attack on the use of short RSA secret exponent is described. The attack makes use of an algorithm based on continued fractions that find the numerator and denominator of a fraction in a polynomial time when a closed enough estimate of the fraction is known. The public exponent e and the modulus n = pq can be used to create an estimate of a fraction.
https://asat.journals.ekb.eg/article_25577_e477c6e188a42d0dd412762e8814050c.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
Enhancement of TV Tracking Effeciency Using Deterministic and Statistical Automatic Control Predictors
189
203
25578
10.21608/asat.1995.25578
EN
Sayed Fadel
Bahgat
Dr., Guidance Department, M.T.C., Cairo, Egypt.
Journal Article
2019
01
22
The tracking process is simply the continuous determination of the target coordinates. The tracking of moving objects in noisy conditions is very complex. The use of spatial band-pass filters (window) reduces the effect of all objects lying outside this window. The crossing object is a moving object flying across the window at the same time with intended target. So, the tracking system may be confused and become unable to recognize the correct target after separation. If the system is designed to have the ability to predict the new target center relative position, the window will be located at the predicted center, which is assumed to be very close to the real position. As a result, the system performance to track maneuvering targets will be improved. This paper introduces the use of different kinds of predictors to overcome the two main problems of tracking process (crossing moving targets and target maneuver). Simulation results show that the use of statistical predictors gives useful performance in a large class of tracking problems, but it increases the system complexity due to the need to compute the mean and variance of the target pixels inside the window.
https://asat.journals.ekb.eg/article_25578_207368f1afa7359790f24e22e96b8367.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
A NOVAL APPROACH TO SPEECH ENHANCEMENT USING ADAPTIVE MULTI-BAND LOGARITHMIC ENVELOPE EXPANSION TECHNIQUE
205
216
25580
10.21608/asat.1995.25580
EN
S. F.
Bahgat
Guidance Department, M.T.C., Cairo, Egypt.
A.
Rohim
Guidance Department, M.T.C., Cairo, Egypt.
S.
Ghoniemy
Guidance Department, M.T.C., Cairo, Egypt.
Journal Article
2019
01
22
The speech enhancement problem covers a broad spectrum of constraints, applications and issues. The principal application areas of speech enhancement are noise reduction for human listening, preprocessing for recognition systems and preprocessing for linear predictive coding. This paper introduces a modified technique based on Multi-band envelope expansion technique called adaptive multi-band logarithmic envelope expansion technique. In this technique a threshold level varying according to the change of input signal-to-noise ratio is used, and the nonlinear function used to expand the envelope is a logarithmic function. In addition, the use of non-uniform frequency spacing gives better enhancement since the majority of filters are concentrated in the actual speech band ( up to 1.5 KHz ) with few filters in the remaining band 1.5 up to 4 KHz ). The simulation results show that the new technique gives a high dynamic range of input signal-to-noise ratio ( up to - 8db ), and a high improvement factor. The intelligibility of the proposed technique is considered as a subject for further investigation.
https://asat.journals.ekb.eg/article_25580_8236bb9bd9869c58a59b3303aeffe604.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
A Study of Distributed Control In Cellular Radio Networks
217
225
25582
10.21608/asat.1995.25582
EN
Yahia Z.
Mohaseb
Graduate student , Communications Department.
Ismail A.
Farag
Dr., Staff Member, Computers Department.
Emad A.
Fahmy
Dr., Chairman of Communications Department, Military Technical College; Cairo, Egypt.
Journal Article
2019
01
22
The increased processing load experienced in centralized controlled cellular systems of the first and second generation is discussed. The necessity of distributed control is established, and solutions utilizing the concept of distributed control are surveyed. A discussion of a proposed new structure for cellular networks is presented, followed by the appropriate multiple access scheme to be used in such networks.
https://asat.journals.ekb.eg/article_25582_2f838d9835feede04945bf8e3693b62d.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
Development of Multi-Channel IR Seekers Utilizing Binary Diffraction Optics
227
235
25586
10.21608/asat.1995.25586
EN
Magdy Z.
Mohamed
Dr. Magdy Zahab Mohamed is the chief of Electrooptics and
Radar research section, the Technical Research Center of the armed forces.
A. A.
Abdelaziz
Dr. A. A. Abdelaziz is the chief of Guidance research section, the Technical Research Center of the armed forces.
Journal Article
2019
01
22
New generations of infrared (IR) seekers adopt two or more detectors to define corresponding spectral lines of the target signature. An optical system composed of ordinary optical components (lenses and mirrors) are implemented to focus different incident spectral lines on the corresponding detectors. These ordinary optical components have diffraction losses of considerable amplitude which adds to their heavy weight, manufacturing complexity, and high production expenses. To overcome these drawbacks, a thin film Fresnel zone plate (FZP) lens is proposed to substitute the ordinary optical components in separating and focusing different spectral lines. The technology of FZP lenses is quite compatible with recent fabrication techniques. In the present paper, a theoretical analysis and numerical calculations are given to verify the achievements of the proposed FZP in decreasing the diffraction losses, focusing the incident radiation, and enhancing the performance of the detector. The focusing and spectroscopic characteristics of the FZP are studied with varying the wavelength.
https://asat.journals.ekb.eg/article_25586_1075670d8197e4e980a6187becec1049.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
2019
01
22
REDUCTION OF MUTUAL COUPLING IN A MULTI- BAND MICROSTRIP WINDOW ELEMENT
237
244
25587
10.21608/asat.2019.25587
EN
A. A.
Abdelaziz
working with the Technical Research Center of the armed forces, Cairo, Egypt.
Magdy Z.
Mohamed
working with the Technical Research Center of the armed forces, Cairo, Egypt.
Journal Article
2019
01
22
Mutual coupling between two circular window elements has been reported in various papers and the results indicate that mutual coupling level is greater for the window patch antennas than for the normal patches due to cylindrical waves which are trapped by the metal of the low frequency element and these cylindrical waves are added to the radiative waves to increase the mutual coupling level. Since mutual coupling between antenna elements in an array can be problematical, some techniques will be presented in this paper to reduce the mutual coupling between elements in a multi-band window element depending on the phase cancellation between the radiative and the trapped waves.
https://asat.journals.ekb.eg/article_25587_bc4f5f248bec6f6afa65a357e236ec3a.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
2019
01
22
Automatic TV Image Tracking Using Advanced Positive Frame Difference Predicted Window Technique.
245
258
25588
10.21608/asat.2019.25588
EN
S. F.
Bahgat
Guidance Department, M.T.C., Cairo, Egypt.
O.
EI-Mowafy
Guidance Department, M.T.C., Cairo, Egypt.
S.
Glioniemy
Guidance Department, M.T.C., Cairo, Egypt.
Journal Article
2019
01
22
TV image tracking is a subject of increasing interest due to the progress of the new technologies and fabrication of high resolution long range cameras and fast microprocessors. A new technique for TV image tracking; advanced predicted window technique (APWT), is proposed. In this technique the tracking window is positioned at an advanced (predicted) position of the target moving center in a noisy background. In addition, the advanced positive frame difference predicted window technique (APFDWT) is presented, and its mathematical formulation ( including separation of moving target from noisy background, extraction of dominant features of moving target, and selection of target to be tracked ) is derived. The proposed system has the ability to identify and track close distinct targets flying in noisy stationary ambient-ground. The evaluation of target center, orientation angle, and velocity parameters are introduced to improve the tracking process.<br />The proposed system overcomes most of the disadvantages of the traditional TV tracking systems such as : initial manual location of the window around the selected target, initial adjustment of the window size, tracking failure due to the movement of other targets across the window, and the increased processig time due to the use of micro image processors in case of multi-target tracking. Simulation results show that the proposed tracking system is more stable and reliable .
https://asat.journals.ekb.eg/article_25588_5e80bbc58f5d6d651231488f949671ba.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
THIN-FILM MULTILAYER OPTICAL FILTERS; SENSIIVITY ANALYSIS
259
268
25589
10.21608/asat.1995.25589
EN
S. M.S.
SAAD
Assistant Professor, Dept. of optoelectronics, Military Technical College, Cairo, Egypt .
Journal Article
2019
01
22
Thin-film multilayer optical filters play an important role in many aeronautic applications. The selection of a specific wavelength signal is very important for aircraft communication, guidance and control. Aerial imaging and reconnaissance require optical filters to reject background radiation. The performance of optical filters is affected by many parameters: The materials' indices of refraction, the layers' thicknesses and the anges of incidence are the most important parameters. During production, these parameters have tolerances within which they can be produced. Here, a sensitivity study is done to show the effect of these parameters on the filter performance. The study covered single-layer, two-layer and three-layer filters. For all the investigated filters neither a variation of up to 5% of the indices of refraction and the thickness of layers nor angles of incidence up to 100 showed considerable effect on both the peak transmission and the shape of transmission curve. The sensitivity analysis helps greatly in studying the mutual relationship between the filter performance and the tolerance of its parameters.
https://asat.journals.ekb.eg/article_25589_0fd297ce49a81d0abaa2f291ee946ed8.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
A Spoken Language Interface For PC Control
269
277
25590
10.21608/asat.1995.25590
EN
Moatacsem M.
Abd Allah
Eng., Graduate Student; Computers Department.
Ismail Abd El-Ghaffar
Farag
Dr., Staff Members; Computers Department.
Matar Ali
Matar
Prof. Dr., Department of Avionics, Military Technical College, Cairo, Egypt.
Journal Article
2019
01
22
This paper presents a study and implementation of a spoken language PC interface as an interactive man-machine communication facility that allows the voice control of IBM compatible PCs. This incorporates an acquisition subsystem, preprocessing and LPC-based feature extraction subsystem as well as a DTW pattern-matching and classification subsystem. The System is implemented using personal computer PC/AT-486 with 50 MHz processor speed. This results in recognition rate for a such specified system amounting from 92% to 98% for single candidate and third candidate choices respectively. The system works in near real time operations as it takes about 25 seconds to recognize the uttered command. The integrated system compares well to the commercially available counterparts.
https://asat.journals.ekb.eg/article_25590_fc3ea46d9fbef66f9774be89ef3a609d.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
DESIGN PROCEDURE FOR TUNABLE NARROW-BAND DIGITAL FILTERS
279
286
25591
10.21608/asat.1995.25591
EN
Fawzy
Ibrahim
Dr., Department of specialized Electrical Engineering Military Technical College Cairo. Egypt.
Journal Article
2019
01
22
A new design technique is presented for narrow-band digital notch filters .The transversal filters have linear phase and their design is based on minimization of the integrated error energy over designated approximation bands. The optimal design is formulated as a constrained quadratic programming problem. A closed-from expression for the filter coefficients is presented. The notch frequency and null depth are the tunable parameters and the tuning process is described. It is shown that tuning the filter requires a relatively minimal number of operations, a matrix-vector multiply is required to change the filter coefficients. Several examples are included which show the effectiveness of the proposed design technique.
https://asat.journals.ekb.eg/article_25591_643c4013bf0af87931d0274088522d02.pdf
The Military Technical College
International Conference on Aerospace Sciences and Aviation Technology
2090-0678
6
ASAT CONFERENCE 2 — 4 May 1995, CAIRO
1995
05
01
ADAPTIVE ARRAY SUPERRESOLUTION :CONTROL-LOOP NOISE
287
301
25592
10.21608/asat.1995.25592
EN
Mostafa A.
Bahie-Eldin
Assoc. Prof. in Communication Dept., MTC, Cairo, EGYPT.
Journal Article
2019
01
22
In recent years, considerable effort has been spent in developing high adaptive array superresolution techniques. This paper presents a perturbation expansion method named "two-variable technique" to derive an expression for the output power of the adaptive null-steering antenna array considering the statistical weight fluctuations. This array utilizes Howells-Applebaum type adaptive weight. Thus, in turn, the paper presents the difference between the assumed and actual adaptive array signal processing response of different high resolution techniques. These techniques are based on maximum-likelihood method, adaptive-angular response, and thermal noise algorithm. By evaluating the model performance with different signal-to-noise ratios, number of antennas, and different signal arrival angles for selected test cases, we gain insights into the sensitivity of the signal estimation problem to model uncertainty.
https://asat.journals.ekb.eg/article_25592_29de2d16353f341d3023df59884620b3.pdf