Low Cost Radar and Sonar using Open Source Hardware and Software Lance Williams Radar Remote Sensing...
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Transcript of Low Cost Radar and Sonar using Open Source Hardware and Software Lance Williams Radar Remote Sensing...
Low Cost Radar and Sonar using Open Source Hardware and Software
Lance Williams
Radar Remote Sensing Group
University of Cape Town
Slide 2 © CSIR 2006 www.csir.co.za
Project Goal
• To create a Radar/Sonar application using the USRP and GNU Radio, and examine its effectiveness as a monostatic and netted Radar/Sonar node.
Slide 3 © CSIR 2006 www.csir.co.za
Outline
• Project Concept
• The Universal Software Radio Peripheral (USRP)
• The USRP Basic Layout
• Test Application Overview
• Implementation (FPGA)
• Results
• Further Development
• Conclusion
Slide 4 © CSIR 2006 www.csir.co.za
Project Concept: Reducing Cost
• There is increasing demand on telecom networks for more capability and coverage.
• More specialized DSP chips performing mixing, filteringand analog to digital conversion.
• Performance lost can possibly be regained by using
alternative radar types, configurations and processingtechniques.
Slide 5 © CSIR 2006 www.csir.co.za
Project Concept: Recovering Performance
• Netted radar may recover performance lost by using non-ideal components.
• Synchronized nodes show an improvement in certain performance metrics over a monostatic system.
• Netted radar: counter stealth, more robust tracking, more information for target classification.
• Cheaper nodes make larger, better performing netted radars more viable.
Slide 6 © CSIR 2006 www.csir.co.za
Project Concept: Open Source Hardware and Software
• Universal Software Radio Peripheral: A software definedradio hardware solution. A single hardware interface tomany different RF channel types. Re-configurabilityenables applications like FM radio, TV, GPS, Radar andSonar.
• GNU Radio: A flexible open source software application building frame-work that serves for developing small scale RF software systems, quick prototyping, and for educational purposes
Slide 7 © CSIR 2006 www.csir.co.za
The Universal Software Radio Peripheral
• usb 2.0 via Cypress FX2
• Altera Cyclone FPGA
• 4 14 bit DAC's capable of 128 M samples/sec
• 4 12 bit ADC's capable of 64 M samples/sec
• Interchangeable daughterboard front-ends.
Slide 8 © CSIR 2006 www.csir.co.za
The USRP Basic Layout
FPGA
ReceiveDaughterboard
Transmit Daughterboard
Transmit Daughterboard
ReceiveDaughterboard
ADC
ADC
ADC
ADC
DAC
DAC
DAC
DAC
Cypress FX2usb
controller
Slide 9 © CSIR 2006 www.csir.co.za
Daughterboard Functionality
● Basic RX, 0.1-300 MHz receive
● Basic TX, 0.1-200 MHz transmit
● LFRX, DC-30 MHz receive
● LFTX, DC-30 MHz transmit
● TVRX, 50-860 MHz receive
● DBSRX, 800-2400 MHz receive
● RFX1800, 1500-2100 MHz
Transceiver
● RFX2400, 2250-2900 MHz
Transceiver
Slide 10 © CSIR 2006 www.csir.co.za
Test Application Overview
• SONAR system using ultrasonic tranducers
• Emits chirp signals centred at 40 kHz
• 2 kHz bandwidth
• 1 millisecond pulse lengths (Variable)
• 16 ms pulse repetition interval (Variable)
Slide 11 © CSIR 2006 www.csir.co.za
Implementation (FPGA)
RamControlmodule
PRI counter
TX Chain module
Delay counter Window counter
RX Chain moduleRX
Buffermodule
TXBuffer
module
enable
enable
enable
enable
Slide 12 © CSIR 2006 www.csir.co.za
Results (1)
Fed back output showing the USRP capturing the transmitted pulse
Slide 13 © CSIR 2006 www.csir.co.za
Results (2)
Raw received data showing the PRI
triggered marker samples
Slide 14 © CSIR 2006 www.csir.co.za
Results (3)
Echo recorded from a stationary object
Echo spectrum
Slide 15 © CSIR 2006 www.csir.co.za
Further Development (1)
• Development of a USRP and GNU Radio based active radar prototype
Target
USRP with transceiver board, front end, and host computer
Slide 16 © CSIR 2006 www.csir.co.za
Further Development (2)
• Development of a small scale netted radar prototype
using the USRP and GNU radios existing support for
IP interconnectivity and distributed clocks.
Target
Slide 17 © CSIR 2006 www.csir.co.za
Further Development (3)
• Development of a passive coherent location
prototype using the USRP TV receiver daughterboard
FM / TV transmitter
Slide 18 © CSIR 2006 www.csir.co.za
Conclusion
• USRP modifications have proved successful.
• The system design within the USRP has been kept flexible in order to create radar application with little firmware modification.
• The GNU Radio software has been used to produce a basic front-end and perform data gathering.
• The standard USRP contains features that will be needed for netted Radar/Sonar prototypes.
Slide 19 © CSIR 2006 www.csir.co.za
References
1) GNU Radio – GNU FSF Project. 15 November 2006 [accessed online at http://www.gnu.org/software/gnuradio/ on 4 December 2006]
2) Ettus Research LLC. 20 November 2006 [accessed online at http://www.ettus.com/ on 4 December 2006]