Browsing by Author "Efe, M."

Now showing 1 - 6 of 6

Open Access
1 mJ pulse bursts from a Yb-doped fiber amplifier
(Optical Society of America, 2012-07-01) Kalaycıoğlu, Hamit; Eldeniz, Y. B.; Akçalan, Önder; Yavaş, Seydi; Efe, M.; İlday, Fatih Ömer
We demonstrate burst-mode operation of a polarization-maintaining Yb-doped fiber amplifier capable of generating 60 μJ pulses within bursts of 11 pulses with extremely uniform energy distribution facilitated by a novel feedback mechanism shaping the seed of the burst-mode amplifier. The burst energy can be scaled up to 1 mJ, comprising 25 pulses with 40 μJ average individual energy. The amplifier is synchronously pulse pumped to minimize amplified spontaneous emission between the bursts. Pulse propagation is entirely in fiber and fiber-integrated components until the grating compressor, which allows for highly robust operation. The burst repetition rate is set to 1 kHz and spacing between individual pulses is 10 ns. The 40 μJ pulses are externally compressible to a full width at half-maximum of 600 fs. However, due to the substantial pedestal of the compressed pulses, the effective pulse duration is longer, estimated to be 1.2 ps.
Open Access
A complete framework of radar pulse detection and modulation classification for cognitive EW
(Institute of Electrical and Electronics Engineers Inc., 2019) Yar, Ersin; Kocamış, M. B.; Orduyılmaz, A.; Serin, M.; Efe, M.
In this paper, we consider automatic radar pulse detection and intra-pulse modulation classification for cognitive electronic warfare applications. In this manner, we introduce an end-to-end framework for detection and classification of radar pulses. Our approach is complete, i.e., we provide raw radar signal at the input side and produce categorical output at the output. We use short time Fourier transform to obtain time-frequency image of the signal. Hough transform is used to detect pulses in time-frequency images and pulses are represented with a single line. Then, convolutional neural networks are used for pulse classification. In experiments, we provide classification results at different SNR levels.
Open Access
Incorporating doppler velocity measurement for track initiation and maintenance
(IET, 2006) Kural, F.; Arıkan, F.; Arıkan, Orhan; Efe, M.
Performance of multiple target tracking algorithms in complex environments heavily relies on the success of track initiation and measurement-to-track association algorithms. Doppler velocity measurement is the major discriminant of clutter from the target of interest with relatively higher velocities. This work summarizes the analytical derivations and presents simulation results about track initiation and maintenance using Doppler velocity reports along with the 3D position measurements extracted by a phased array radar.
Open Access
Parçacık sürü Optimizasyonu ile Dağıtık Tespit
(IEEE, 2011-04) İnce, O.; Efe, M.; Arıkan, Orhan
Doğadan esinlenerek geliştirilen optimizasyon yöntemleri, kullanım kolaylıkları ve yüksek performansları nedeniyle pek çok farklı disiplinde kendilerine uygulama alanı bulmaktadırlar. Bu çalışmada, son yıllarda yoğun ilgi gören dağıtık tespit problemine, literatürde Parçacık Sürü Optimizasyonu olarak bilinen yöntem uygulanmıştır. Temel bir paralel dağıtık topoloji üzerinde denenen senaryolarda PSO'nun performansının doğruluk ve güvenilirlik ve hız açısından oldukça yüksek olduğu gözlenmiştir.
Open Access
Performance evaluation of the sequential track initiation schemes with 3D position and doppler velocity measurements
(Electromagnetics Academy, 2009) Kural, F.; Arikan, F.; Arıkan, Orhan; Efe, M.
This study investigates the effect of incorporating Doppler velocity measurements into the most commonly used sequential track initiation schemes, the rule and logic based schemes. The measurement set has been expanded from range and azimuth to include elevation and Doppler velocity. Unlike previous studies, elevation and Doppler measurements have also been included in the analytical evaluation of the false track initiation probability. Performance improvement obtained by employing Doppler measurements has been demonstrated through simulations in terms of false track initiation probability and true track initiation probability. Receiver Operating Characteristics and System Operating Characteristics have also been utilized in performance evaluation. Analytical derivations and simulations have revealed that using Doppler velocity measurements along with 3D position measurements while initiating tracks in clutter leads to significant decrease in false track initiation probability while providing an acceptable level of true track initiation probability. Simulation results have also shown that inclusion of Doppler measurements has reduced the required time for track initiation, resulting in faster track initiation.
Open Access
Performance evaluation of track association and maintenance for a MFPAR with doppler velocity measurements
(2010) Kural, F.; Arikan, F.; Arıkan, Orhan; Efe, M.
This study investigates the effects of incorporating Doppler velocity measurements directly into track association and maintenance parts for single and multiple target tracking unit in a multi function phased array radar (MFPAR). Since Doppler velocity is the major discriminant of clutter from a desired target, the measurement set has been expanded from range, azimuth and elevation angles to include Doppler velocity measurements. We have developed data association and maintenance part of a well known tracking method, Interacting Multiple Model Probabilistic Data Association.