Presentation is loading. Please wait.

Presentation is loading. Please wait.

A lightweight, ultra-wideband polarimetric W-band radar with high resolution for environmental applications Richard Holliday, Matt Rhys-Roberts and Duncan.

Similar presentations

Presentation on theme: "A lightweight, ultra-wideband polarimetric W-band radar with high resolution for environmental applications Richard Holliday, Matt Rhys-Roberts and Duncan."— Presentation transcript:

1 A lightweight, ultra-wideband polarimetric W-band radar with high resolution for environmental applications Richard Holliday, Matt Rhys-Roberts and Duncan A. Wynn Q-par Angus Ltd Barons Cross Laboratories Leominster Herefordshire HR6 8RS UK Tel: +44(0) Fax: +44(0) EuRAD 2006 European Radar Conference Manchester, UK 14 th September 2006

2 Outline Background Review of suitable radar waveforms Ultra-wideband (UWB) and random signal radar Cross-ambiguity function analysis Outline description Transmitter Binary random phase coding RF spatial power combiner Antenna Processing Performance Applications Summary

3 Background A major threat to global stability is the change in the Earths climate Extremes of heat and drought, storms, wind, rain and more intense cold Unpredictable environmental behaviour - Temperature rises are likely to be non-uniform across the globe Uncertainty of the impact is incorporated into long-term national and international decision-making - reflected in environmental standards and targets including : - protection of people, homes and business from risk of flood - ensure availability of suitable water for drinking and bathing - prevention of destruction of natural habitats and extinction of animal species - There is a very wide breadth of environmental issues …..

4 Better understanding of the complex interaction between the Earths surface and atmosphere is essential Accurate descriptions of local and regional surface features and associated phenomena with timely monitoring are vital There are disadvantages associated with existing methods such as LIDAR and airborne/space-based SAR Millimetre wave radar offers an all-weather remote sensing solution with the benefits of compactness and high resolution - Electromagnetic compatibility and tolerance to EMI with reduced Size, Weight and Power (SWAP) are becoming more affordable Background

5 Review of radar waveforms: Uncoded CW Linear FMCW Pulse compression waveforms Phase shift / frequency shift coding Coherent pulse trains/pulsed Doppler Ultra wideband (UWB) and Random Signal Radar (RSR) Noise-like / chaotic waveforms Sine plus noise FMCW Noise FMCW Compound noise FMCW Dual-random quasi-CW Correlation RSR / spectrum analysis RSR / anti-correlation RSR random phase coded Random pulse radar Binary random phase coded

6 Binary random phase coded CW Time domain sequence of binary random phase coded CW f c =94 GHz, chip rate=3 GHz

7 Binary random phase coded CW Power spectrum of binary random phase coded CW (unfiltered) f c =94 GHz, chip rate=3 GHz

8 Cross-ambiguity function performance analysis : For a complex signal, where is the complex envelope The cross-ambiguity function is defined as where The time-reversed complex envelope for the output of a filter that is matched for a signal but receives the signal that is time-delayed with a frequency shift imposed upon it The time of arrival of the signal is considered to be unchanged by the frequency shift.

9 Cross-ambiguity function for binary random phase modulated waveform: 94 GHz carrier with 3 GHz chip rate Delay (ns) Doppler offset frequency (Hz) | (, )| Cross-ambiguity function performance analysis 0 Hz ns (-2.77 m) ns (2.77m) 0 ns 3.7 GHz

10 Cross-ambiguity function performance analysis Doppler offset frequency spectrum and cross correlation responses Mean square sidelobe level (MSSL) supports range sidelobe supppression > 20 dB rms Range (along) resolution (unprocessed) better than m Cross correlation (dB) Delay (ns) S(f) (dB) Doppler offset frequency (Hz) Mean square sidelobe level (MSSL) supports Doppler sidelobe suppression > 21 dB rms Velocity (radial) resolution better than m.s -1

11 Optically activated waveguide-based millimetre wave phase modulator with sub-nanosecond switching speed Transmitter: Binary random phase modulator Modulator RF input 3 GHz Constant amplitude RF phase modulated output < 0.3 ns Binary random phase modulator A, B and C are amplitude constants Performance Millimetre wave (W-band) Wide tunable bandwidth GHz Wide instantaneous bandwidth > 4 GHz High switching speed > 3 GHz Linear passive RF component Low insertion loss (< 0.5 dB) High RF power handling (typ. > 1w mean) Millimetre waveguide compatible are phase constants

12 Transmitter: RF spatial power combiner overmoded waveguidesecond harmonic graded gap Gunn GaAs diode array fundamental mode waveguide array Input 90 – 98 GHz >100 mW Output 90 – 98 GHz >500 mW

13 Antenna W-band scalar feed Modular 3-axis positioner Twin 0.75 m diameter reflectors with Cassegrain sub-reflectors spun Aluminium and precision machine-finished circularly symmetric scalar feed with WR-10 waveguide transition plane polarisation - Tx (V, H, arbitrary polarisation planes) - Rx (simultaneous orthogonal polarisation planes) GHz RF bandwidth (tunable) Radiation characteristics at 94 GHz Instantaneous RF bandwidth > 4 GHz Co-polar directive gain > 54 dBi 3 dB beamwidth 0.2 degrees Mean-square sidelobe level (MSSL) better than –19 dB Cross-polar response better than 30 dB RF isolation >50 dBEfficiency > 55 %

14 Processing

15 6-channel analogue to digital converter National Semiconductor ADC08D Attitude Heading Reference Watson Industries AHRS Global Positioning System Garmin GPS Modular 3-axis antenna positioner USB serial port Sony Vaio lap-top PC PCG-GRT896HP Graphical User Interface

16 Performance : Signal to noise power ratio vs range 7ms dwell time1s dwell time

17 Applications - Environmental Surface mapping of local land and water levels - observation and measurement of surface and near-surface water movements - measured water ripples can be resolved to infer flow rates, rates of change, flow direction and location of below-surface features Management of water resources -drainage and irrigation planning Flood defence planning - Definition of flood plane areas - Monitoring 24 hour / 7 day with automatic triggering upon user-specified events to provide warning of flood escalation - Effective and timely deployment of limited and valuable defences/barriers - Planning, design and effective deployment of flood defence resources and structures such as bridge constructions, sandbags etc

18 Applications - Environmental Pollution detection, localisation and monitoring - pollution in the form of particulate debris or paints,oils causing changes of water surface characteristics Bathymetry - measurement of water current flow vectors (depth, water magnitude, direction, flow rate and water surface topology) for monitoring and prediction in rivers, estuaries and inland waterways Agricultural crop monitoring Fish farming –salmon / trout fishing / deployment of fish spawn Monitoring of iceberg / bergy bits and glacier movements Traffic monitoring (speed, classification, traffic density, direction)

19 Summary Specifically designed for environmental applications An UWB polarimetric millimetre wave 94 GHz radar that uses binary random phase coding to provide a lightweight, all-weather remote measurement capability with high resolution is under development by Q-par Angus Ltd Simplified radar architecture – readily extended to other applications via plug and play High performance at relatively low cost by exploiting COTS components Completed radar will be demonstrated operating in a proof-of-concept surface mapping mode in a representative environment later in 2006

20 Acknowledgements UK DTI Advantage West Midlands UK Natural Environment Research Council University of Worcester Dr John Fagg (Head of Dept. of Geography, Applied Sciences and Archaeology) e2V Technologies Ltd Nigel Priestley and Martin Westmoreland University of Birmingham Prof. Peter Hall and Dr Edward Hoare

21 Thank you Any questions ?

Download ppt "A lightweight, ultra-wideband polarimetric W-band radar with high resolution for environmental applications Richard Holliday, Matt Rhys-Roberts and Duncan."

Similar presentations

Ads by Google