Pulsed radar measurements and related equipment
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Doctoral thesis (article-based)
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Author
Date
2009
Department
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Degree programme
Language
en
Pages
Verkkokirja (7002 KB, 72 s.)
Series
TKK dissertations,
155
Abstract
The purpose of this thesis has been to develop novel methods for pulsed radar measurements, creating practical tools for verifying the operation of a modern pulsed radar, and to build working prototypes suitable for field use. Very little information has been published in the radar field perhaps due to the military nature of many research projects. Methods and equipment are typically researched by different armed forces. In this thesis, some tools for frequency, power and waveform measurements are presented. Even the most modern commercial measuring instruments, however, are not capable of measuring a pulsed radar signal, mostly due to the short (even tens of nanoseconds) pulse length. The limitations of conventional measuring devices are discussed in the overview part of the thesis and also in Publications II and IV. The first publication demonstrates a radar calibration system, based on a fiber-optic delay line. The idea to use an optical delay line for such a purpose is not new, but an operational setup has not been published previously. The calibrator provides a convenient method to use the radar's own signal for calibration. The optical link makes it possible to use long delays, even tens of microseconds, without significant signal attenuation. Furthermore, two frequency measurement methods for short-term stability evaluation are presented. Both are based on a phase detector. The first setup has better frequency uncertainty, even 1.6 Hz, with a sampling speed of 10 000 s-1. The other setup is used to detect frequency differences: A deviation of 200 kHz in the carrier frequency could be detected when the pulse length was 200 ns. This system outperforms the first one when short pulses are evaluated. The phase detector based setup itself is old and familiar technology, but the idea to use it in this application is one thing new. Finally, two new instrumentation radars are also presented. They are used to measure the effects that terrain, weather, vegetation and seasonal changes have on radar clutter or signal propagation. A significant effort has been made by other scientists in developing mathematical models to be able to simulate the effects mentioned, but so far the only reliable method for creating clutter models is to collect data with a real radar. Such instrumentation radars have probably been developed earlier, but until now they have not been published.Description
Keywords
pulsed radar, radio frequency, power, frequency, waveform
Other note
Parts
- [Publication 1]: Mikko Puranen, Petri Kärhä, and Pekka Eskelinen. 2005. Fiber-optic radar calibration. IEEE Aerospace and Electronic Systems Magazine, volume 20, number 9, pages 30-33. © 2005 IEEE. By permission.
- [Publication 2]: M. Puranen and P. Eskelinen. 2006. Measurement of short-term frequency stability of controlled oscillators. In: Proceedings of the 20th European Frequency and Time Forum (EFTF 2006). Braunschweig, Germany. 27-30 March 2006, pages 76-79. © 2006 by authors.
- [Publication 3]: Mikko Puranen and Pekka Eskelinen. 2007. Improved methods for frequency measurement of short radar pulses. In: Proceedings of the 21st European Frequency and Time Forum (EFTF 2007). Geneva, Switzerland. 29 May - 1 June 2007, pages 970-973. © 2007 IEEE. By permission.
- [Publication 4]: Mikko Puranen, Pekka Eskelinen, and Jukka Ruoskanen. 2008. Practical uncertainty of pulse power measurements in Ka-band RCS instrumentation. IEEE Antennas and Propagation Magazine, volume 50, number 4, pages 120-125. © 2008 IEEE. By permission.
- [Publication 5]: Mikko Puranen, Pekka Eskelinen, Jukka Ruoskanen, and Heikki Heikkilä. 2006. Simple 3D millimetre clutter scanner for field measurements. In: Proceedings of the International Radar Symposium (IRS 2006). Krakow, Poland. 24-26 May 2006, pages 339-342. © 2006 Warsaw University of Technology, Institute of Electronic Systems. By permission.
- [Publication 6]: Mikko Puranen and Pekka Eskelinen. 2008. A short-pulse Ka-band instrumentation radar for foliage attenuation measurements. Review of Scientific Instruments, volume 79, number 11, 106106, 3 pages. © 2008 American Institute of Physics. By permission.
