Alaa El-Din Sayed Hafez

Optimum stealthy aircraft detection using a multistatic radar

Radar systems, based on Multistatic radar concept attracted a substantial attention in the recent years. The paper proposes system geometry for S-band Multistatic radar. This technique is used for detecting and tracking the small cross section area and stealthy aircrafts. The proposed geometrical structures are studied with different radars spacing to extend the detection coverage over the Monostatic radar used for air surveillance. The radar detection coverage is also studied with all possible stealthy aircraft paths to find the improvement achieved from using this type of radar. The simulation is done using Matlab program. The results show that the first system geometry with two transmitters and four receivers extends the detection coverage 80 Km for small aircraft and 62 Km for stealthy targets. The second system geometry with two transmitters and six receivers extends the detection coverage 85 Km for small targets and 69 Km for stealthy targets. The achieved SNR from these system geometries guarantee a high probability of detection for small and stealthy aircraft detection.

A simple 8-bit digital microcontroller implementation for chaotic sequence generation

This paper introduces a simple implementation of digital chaotic sequence generator. The implementation is based on using microcontroller ATMGA 16 to generate the chaotic map required for advanced encryption standard (AES) encryption scheme s-box and radar frequency agile control. The implemented circuit is simple, low cost and suitable for use with identification friend or foe (IFF) equipped with data encryption systems. The circuit also can changes the carrier frequency of the transmitted signal based on chaotic map, benefits a security and confidentiality to the radar waveform against Electronic Counter Measurement (ECM). The circuit generates 256 random sequences at different initial conditions and each of them has 256 sequences generated from different bifurcation parameters. The circuit is simulated under Matlab program environment and Proteus circuit simulation program. A security analysis for the implemented circuit is demonstrated. The results show the superiority of the circuit for generating the random sequences forming an efficient s-box for IFF system and radar frequency agility.

A new fuzzy CFAR processor for radar MTD systems

This paper proposes a new fuzzy constant false alarm processor (FCFAR) for radar MTD systems. The proposed amplitude processor decides the fixed threshold value for the CFAR using fuzzy logic controller according three input variables. First input is the fast threshold from fifty serially averaged range cells. The second is the slow threshold from concatenated 500 averaged range cells. The third input is the signal to noise ratio at the RF stage of the radar system. The proposed processor is simulated under Matlab program environment on 1 million range cells data in additive white Gaussian noise (AWGN) with non-homogeneous background clutter and from 5 to 30 dB signal to noise ratio (S/N). The results show the superiority of the proposed FCFAR than the traditional systems used during the last decade.

New radar pulse compression codes by particle swarm algorithm

In this paper, new optimized multilevel biphase pulse compression codes (MBPCC) with low peak side lobe (PSL) and mean side lobes (MSL) have been investigated. Amplitude and phase coding have been used during the optimization process. In previous studies, biphase codes were optimized using genetic algorithm (GA). The robustness of genetic algorithm in solving optimization problems degrades simultaneously as the code length increases. Particle swarm optimization (PSO) algorithm has been used with MBPCC to solve this problem. PSO algorithm has the merits of rapid convergence to the global optimum. Complete description of PSO implementation process has been clarified. Swarm intelligence boasts a number of advantages due to the use of mobile agents. Set of novel codes with optimum PSL ranging between -27.06 dB and -38.26 dB for codes of length 5 up to 45 has been introduced. Optimization results obtained using both PSO and GA has been compared. Comparative study shows both the optimality and superiority of PSO algorithm over GA for different code lengths. MBPCC have a precision of 103 (-30) dB, which can be feasibly implemented using digital attenuators at element level with optimum performance and hardware implementation facility.

A Developed ESPRIT Algorithm for DOA Estimation

Abstract A novel algorithm for estimating direction of arrival (DOAE) for target, which aspires to contribute to increase the estimation process accuracy and decrease the calculation costs, has been carried out. It has introduced time and space multiresolution in Estimation of Signal Parameter via Rotation Invariance Techniques (ESPRIT) method (TS-ESPRIT) to realize subspace approach that decreases errors caused by the model’s nonlinearity effect. The efficacy of the proposed algorithm is verified by using Monte Carlo simulation, the DOAE accuracy has evaluated by closed-form Cramér–Rao bound (CRB) which reveals that the proposed algorithm’s estimated results are better than those of the normal ESPRIT methods leading to the estimator performance enhancement.

Direction of Arrival estimation using novel ESPRIT method for localization and tracking radar systems

A novel concept for determining Direction of Arrival estimation (DOAE) of air target has been investigated. The methodology relies on the echo signal inducing a known spatially varying electric field. In Uniform Linear Array (ULA), the elevation angle is estimated by multiresolution ESPRIT (MRESPRIT) method. The efficacy of the proposed algorithm is verified by Monte Carlo simulation, DOAE accuracy is evaluated by closed-form Cramér-Rao bound (CRB). We use the MRESPRIT to decrease effectively the errors of estimation which caused by models nonlinearity. Our estimated results are better than those of the normal ESPRIT method [1]. Finally, the estimator performance has been enhanced by taking into account the nonlinearity effects.

A new phased MIMO radar partitioning schemes

The paper studies the performance of multiple input multiple output (MIMO) radar with collocated antennas called Phased MIMO radar. In this study, the transmit array will be partitioned into a number of sub-arrays that are allowed to overlap. Each sub-array transmits an orthogonal waveform to other sub-arrays. Compared to the phased-array radar, the use of MIMO radar with co-located antennas enables improving angular resolution, increasing the upper limit on the number of detectable targets, extending the array aperture. The tradeoff of this technique with different partitioning schemes is simulated using Matlab program environment for the corresponding beam pattern and signal-to-interference-plus-noise ratios (SINRs) expressions. The results demonstrate an important tradeoff performance between these different schemes.

A new hybrid security allocation steganography algorithm

Security, authentication, and identification are essential requirement for confidential data transmission. The will known methods of data encryption attain certain security levels, they make the encrypted data unreadable and unnatural this attracts some unintended observer attention. To search for a higher security approach, Steganography and Cryptography are two popular ways of sending vital information in a secret way. One hides the existence of the message and the other converts the message into an unreadable format. This paper, describes a method for integrating the advantages of Cryptography and Steganography together through image processing. The paper introduces a New Hybrid Security message Allocation Algorithm (NHSA) to achieve a higher level of security. The statistical evaluation of this system shows that, a higher PSNR and MSE are achieved comparing with the other systems.

A new hybrid fuzzy-decomposed full capacity Stego-system

The aim of this paper is to introduce a new hybrid fuzzy-decomposed Stego-system for embedding secret messages into gray scale image. Experiments and evaluation metric parameters show that the Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR), Correlation (COR) and Entropy computed by the proposed system are better than those generated by the previous existing system. Thus, a high level of imperceptibility and high level of overall security had been attained.

Optimum dynamic navigation ratio for launch vehicles using Genetic Algorithm

This paper is devoted to demonstrate a Genetic Algorithm optimization of a dynamic navigation ratio for launch vehicles target scenario. This optimization provides a bounded target interception under six degrees of freedom control and minimum-effort-miss distance to improve the intercepting accuracy of launch vehicles. This optimization is performed for two guidance laws, the proportional navigation and the differential geometry under influence of target heading, altitude and target maneuvering capabilities. The results show that the optimized dynamic navigation ratio achieves a significant improvement for the miss distance over the previous fixed navigation ratio. The maximum achieved improvement factor is 22 dB for the proportional navigation guidance and 21 dB for the differential geometry.