Abstract
"Investigation of DME on the basis of j-correlation signal processing"
- Introduction
- 1. Theme urgency
- 2. Goal and tasks of the research
- 3. Circuit description DME
- Conclusion
- References
Introduction
Radar is a collection of methods and technical means intended for the detection of various objects in space, the measurement of their coordinates and motion parameters by receiving and analyzing the electromagnetic waves emitted or reradiated objects.
Radar as a scientific and technical direction in the radio was born 30–ies. The achievements of aviation technology made it necessary to develop new means of detection planes of high performance (range, accuracy). These funds were radar systems.
Getting information in radar surveillance is associated with a region of space. Technical means by which the radar surveillance is carried out, called radars (radar), and the observed objects – radar targets. Typical objectives include aircraft, missiles, ships, ground engineering structures [5].
Basic requirements for the radar pulse generators: high accuracy, speed of measurement must correspond to the number of simultaneously observable goals and their velocity; accepted method of measurement must meet the required resolution of the radar, the method of measurement must meet the applicable detection system. The last requirement is facilitated by the fact that the optimal filtering and correlation processing of signals not only contribute to the detection of weak signals, but also to improve the accuracy of measurements. Nevertheless, some differences exist: in order to combine the given probability of correct detection and false alarm, choose an interim threshold of detection, whereas the highest accuracy is obtained by fixing the peak optimally processed signal [7].
Radar gauges are classified according to the following criteria:
- Continuous measurement of current positions and velocities of targets, called the accompaniment (tracking) can be manual (semi–) or automatic. Measuring instruments used for this purpose are classified respectively as nesledyaschie or tracking.
- As the number of channels are divided into single–channel meters and multi–channel.
- By measuring the coordinate of the target parameter, or distinguish meters range, azimuth, elevation (height), the radial – Noah and the angular velocity.
- According to the method of measurement – is the amplitude, frequency, phase, Doppler, and other methods, depending on which option is the basis for signal measurements.
Figure 1 – Principle of operation of pulse radar
(animation: 9 frames, the number of cycles of repetition: infinite, 16 kilobytes)
1. Theme urgency
Correlation processing techniques are widely used in radar systems, however, radar stations, the use of these methods is limited. First of all, this is due to an adverse effect on the Doppler correlation function, since in this case the maximum of the correlation function R (z) at z=0 decreases and changes the course of the correlation function. Therefore, location of moving targets with the help of DF correlation is very difficult [6].
J–correlation method for measuring distance was first developed by Associate Professor at the "Radio Engineering and Information Security", Donetsk National Technical University, Professor Sorochan Anatoliy.
2. Goal of the research
The purpose of this paper is a statistical analysis based on the DME J–correlation signal processing, determination of its potential accuracy.
3. Circuit description DME
Figure 2. Block diagram of DME–based J–correlation signal processing
Ан. 1, Ан. 2 – the transmitting and receiving antennas, ЛТ – a linear path, УМ – Power Amplifier, КГ – quartz oscillator, РЛЗ – Calibrated–regulated delay line, СМ – mixer, Х1 – Х3 – the first – third multiplier, ЛЗ – delay line, ФНЧ – a filter lower frequencies, УПФ – a narrow–band bandpass filter, ГНЧ – low frequency oscillator, УЦО – digital signal processing device.
Conclusion
This master's paper is devoted to actual scientific study of the problem based on the DME j-correlation processing signalov.Provedenny analysis of DME shows the possibility of achieving high performance potential. Measurement accuracy depends on the input signal/noise ratio, signal parameters and device that implements the method.
This master's work is not completed yet. Final completion: December 2012. The full text of the work and materials on the topic can be obtained from the author or his head after this date.
References
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