PARSAX An Informal Look at Radar Technology and Applications within TU Delft

22Oct/100

IEEE Proceedings Special issue on “Sensor Network Applications”

The Special Issue on "Sensor Network Applications" of the Proceedings of the IEEEThanks to the Wireless Sensor Networks Blog, I have found the information about recently published Special Issue on "Sensor Network Applications" of the Proceedings of the IEEE. It is already available on IEEExplore. There are eleven articles on the current state of the art in sensor network research, including articles on technologies that are enabling sensor networks, and articles on the applications of sensor networks. The guest editors: Neal Patwari, Mingyan Liu, and Andreas Terzis. It can be interesting to read this issue in connection to our activity in the STARS project.

16Oct/100

Microwave Sense

The lecture with such title has been given by Professor DSc. Olexander Yarovyi (also known as Alexander Yarovoy, there is some ambiguities with his name transliteration from russian/ukrainian cyrillic into western spelling) yesterday during his official inauguration as the TU Delft full professor and the chairman of the Microwave Technology and Systems for Radar (MTSR) group at  the Department of Telecommunications of the Faculty of Electrical Engineering, Mathematics, and Computer Science (EEMCS) at Delft University of Technology. The one-hour lecture is available on-line  (you need to have Silverlight Player in your browser).

Microwave Sense

The PARSAX radar has been mentioned in the lecture many times - as the instrument already providing interesting for application data and as the platform for future research projects in the field of radar technology, waveform agility and adaptivity.

14Oct/100

PARSAX radar in “A short course on radar meteorology” – Video

The lecture "A short course on radar meteorology" has been given by Tobias Otto in the frame of TU Delft's Challent program (http://challent.tudelft.nl). It provided to the Bachelour students from different faculties a simple introduction into the radar technology field with the main focus on radar meteorology. The lecture covered such topics as the radar principle, how the information about observed object encoded in scattered microwaves, the brief introduction into the radar equation for a point target with further explanations how to make a step from a point target to atmospheric volume targets, the definition of such important radar measurable as the reflectivity, how the reflectivity measured with radar is connected to the rain rate, and what additional information can be extracted from the polarimetric weather radar observations. The lecture has been illustrated with real radar data about clouds and precipitations, which were measured with TU Delft radars: TARA, IDRA, and PARSAX.

PARSAX radar in "A short course on radar meteorology"

Click on the picture to see the video-lecture on-line (you need to have Silverlight Player in your browser).

10Oct/100

Envelope-tracking technology can double efficiency of RF power amplifiers

This information, which can be interesting for further radar technology development, came from last MathWorks News & Notes.

Power amplifiers (PAs) ensure that the source radio frequency (RF) signal, such as a DVB, 3G, LTE, or 4G signal, is powerful enough for transmission. Because PAs use a fixed supply voltage, they draw maximum power whatever the amplitude of the signal, making them notoriously inefficient for amplitude modulated RF signals.

Envelope-tracking technology can double a PA’s efficiency from 30% to 60% or more by dynamically modulating the amplifier’s supply voltage according to the RF signal passing through the device.

Nujira’s High Accuracy Tracking (HAT™) technology, the first practical implementation of envelope tracking, is being used or evaluated for cellular infrastructure and terminals, broadcast transmitters, military communications and other applications. It is featured in three product lines: Coolteq.L for mobile handsets, Coolteq.h for cellular base stations, and Coolteq.u for DVB transmitters. We used MathWorks tools across the entire development life cycle of these product lines, from research, through modulator design, to verification and automated testing.

 

Envelope-tracking technology
Figure 1. Left: Power amplifiers with a fixed supply voltage.
Right: Supply voltage modulated using envelope tracking. 

Conventional PAs waste as much as 80% of the energy they consume as dissipated heat. The PAs in a cellular base station, for example, account for half the total power consumed.

Although it was first described more than 60 years ago, envelope tracking has not been applied commercially until recently, largely due to the difficulty of implementing a power supply modulator that meets the efficiency, bandwidth, and noise requirements of wideband signals such as multicarrier WCDMA, WiMAX, or DVB.

Nujira’s envelope tracking technology can double the efficiency of PAs and dramatically reduce power dissipation, which lowers energy bills and substantially reduces the amount of cooling required (Figure 1). It also enables higher device output power, allowing broadcasters to extend the range of existing broadcasting towers. Lastly, the wide-band operation of Nujira’s technology enables broadcasters to use fewer PA designs to cover their target broadcast spectrum.

Full information can be found using the link to MathWorks web-page or PDF file

 

9Oct/100

Radars in AMS Journals: September 2010

Journal of the Atmospheric Sciences, Volume 67, Issue 9 (September 2010)

  • Jameson, A. R., A. B. Kostinski, 2010: Direct Observations of Coherent Backscatter of Radar Waves in Precipitation. J. Atmos. Sci., 67, 3000–3005. - link
  • Hudson, James G., Stephen Noble, Vandana Jha, 2010: Comparisons of CCN with Supercooled Clouds. J. Atmos. Sci., 67, 3006–3018.- link
  • Suzuki, Kentaroh, Takashi Y. Nakajima, Graeme L. Stephens, 2010: Particle Growth and Drop Collection Efficiency of Warm Clouds as Inferred from Joint CloudSat and MODIS Observations. J. Atmos. Sci., 67, 3019–3032. - link

Journal of Applied Meteorology and Climatology, Volume 49, Issue 9 (September 2010)

  • Jameson, A. R., 2010: On the Temporal Characteristics of Radar Coherent Structures in Snow and Rain. J. Appl. Meteor. Climatol., 49, 1891–1893. - link
  • Dominique Bouniol, Alain Protat, Julien Delanoë, Jacques Pelon, Jean-Marcel Piriou, François Bouyssel, Adrian M. Tompkins, Damian R. Wilson, Yohann Morille, Martial Haeffelin, Ewan J. O’Connor, Robin J. Hogan, Anthony J. Illingworth, David P. Donovan, Henk Klein-Baltink, 2010: Using Continuous Ground-Based Radar and Lidar Measurements for Evaluating the Representation of Clouds in Four Operational Models. J. Appl. Meteor. Climatol., 49, 1971–1991. - link

Monthly Weather Review, Volume 138, Issue 9 (September 2010)

  • Journal of Atmospheric and Oceanic TechnologyLorsolo, Sylvie, Jun A. Zhang, Frank Marks, John Gamache, 2010: Estimation and Mapping of Hurricane Turbulent Energy Using Airborne Doppler Measurements. Mon. Wea. Rev., 138, 3656–3670. - link

Journal of Atmospheric and Oceanic Technology, Volume 27, Issue 9 (September 2010)

  • Bharadwaj, Nitin, V. Chandrasekar, Francesc Junyent, 2010: Signal Processing System for the CASA Integrated Project I Radars. J. Atmos. Oceanic Technol., 27, 1440–1460. - link
  • Torres, Sebastián, Richard Passarelli, Alan Siggia, Pentti Karhunen, 2010: Alternating Dual-Pulse, Dual-Frequency Techniques for Range and Velocity Ambiguity Mitigation on Weather Radars. J. Atmos. Oceanic Technol., 27, 1461–1475. - link
  • Giangrande, Scott E., Edward P. Luke, Pavlos Kollias, 2010: Automated Retrievals of Precipitation Parameters Using Non-Rayleigh Scattering at 95 GHz. J. Atmos. Oceanic Technol., 27, 1490–1503.- link
  • Käsler, Yvonne, Stephan Rahm, Rudolf Simmet, Martin Kühn, 2010: Wake Measurements of a Multi-MW Wind Turbine with Coherent Long-Range Pulsed Doppler Wind Lidar. J. Atmos. Oceanic Technol., 27, 1529–1532. - link
  • Root, B., T-Y. Yu, M. Yeary, M. B. Richman, 2010: The Added Value of Surface Data to Radar-Derived Rainfall-Rate Estimation Using an Artificial Neural Network. J. Atmos. Oceanic Technol., 27, 1547–1554.- link
  • Kowalewski, Stefan, Gerhard Peters, 2010: Analysis of Z–R Relations Based on LDR Signatures within the Melting Layer. J. Atmos. Oceanic Technol., 27, 1555–1561.- link