1 UWB RADAR IMAGING SYSTEM WITH TWO- ELEMENT RECEIVING ARRAY ANTENNA A.O. Boryssenko 1) & D.H. Schaubert 2) University of Massachusetts Amherst MA 01003 USA 1) [email protected] 2) [email protected] In Cooperation with Diascarb & Ratio (both in Kiev, Ukraine)
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
UWB RADAR IMAGING SYSTEM WITH TWO-ELEMENT RECEIVING ARRAY ANTENNA
A.O. Boryssenko1) & D.H. Schaubert2)
University of MassachusettsAmherst MA 01003 USA
1)[email protected])[email protected]
In Cooperation with Diascarb & Ratio (both in Kiev, Ukraine)
2
Highlights
UWB Radar Trough-Wall Vision
Advances in Hardware and Antennas
Matlab for Radar Control and Processing
2D Scene Imaging with UWB Array (Time-Domain Focusing)
Radar Scene Imaging in 1D & 2D in Matlab
3
General Idea Behind Operational Principle – 1A-Scan Presentation of the Received Data
Operational scene
Signal: without background compensation
Signal: with background compensation
Basic UWBR Hardware
Notebook:-Control-Processing-Imaging
Tx, Rx &Antennas On Tripod
4
2-Rx 1-Rx Trough-Wall Vision UWB Radar - 1
Windows compatible sound card for DAC & Serial (RS231) port for control
Stereoacoustic = Stereo-Imaging
UWBR Hardware
5
Novel UWB Antenna:: Geometrical MoM Model & Simulated Input Impedance
Nice 50-Ω bandwidth !Direct termination to 50-Ω coax – no balun!
6
Novel UWB Antenna:: Simulated Radiation Pattern in 0.50-3.00 GHz
0.50 1.00 1.5 GHz
2.00 2.50 3.00 GHz
E-plane
H-planeGood gain and front-to-back ratio !
7
2 Byte Command Word (through serial port)CONTROL.COM_PORT=1; % 1 / 2CONTROL.Start=1; %1 CONTROL.GM=4; % <3 digit> Maximum gain factor for AGC 0...7CONTROL.G0=0; % <3 digit> Initial gain factor 0...7CONTROL.RESERVE_HIGH=1;…
Controlling of ADC for Sound Card through Matlab
ADC.SamplePerScan=700; %722;ADC.ScanShift=-100/2;ADC.NumberOfScans=10;ADC.SampleRate=44100;ADC.BitsPerSample=16;….
Processing Specifications for Signal Processing in Matlab
PROCESS.AmplitudeNorm=1;PROCESS.ScanStack=1;PROCESS.BckgRemove='NO'; %'YES'/'NO'PROCESS.SkipScans=50;…Image Plot Options …
• Radar Hardware Control• Start / Stop• Range / Range Window• Time-Varying Gain, etc.
Data AcquisitionScattered Waveforms are downconverted
from UHF/Microwave 0.5-3.0 GHz to Audio Frequencies ~ 0.5-3.0 kHz that can be digitized using a standard compute audio card (very chip and good ADC!)
Signal Processing &Data ImagingA lot of such options in Matlab but a number of smart tricks is required to perform this in nearly “real-time” mode
Radar Control, Signal Processing and Data Imaging Using Matlab
1-D A-Scan (oscilloscope mode)2-D B-Scan (wavelets, dense,..)2-D Stereoscopic View
For this prototype all control/processing/imaging software is written in Matlab !
8
1-D (A-Scan) Imaging = Oscilloscope Mode
Regular Mode
Background Removing ModeAll is quite
A target is moving & becomes visible
TargetTx-Rx Direct Coupling
A target is invisible
?
9
2-D (B-Scan) Imaging = Stacked Waveforms
Background Removing ModeRegular Mode
A target is movingA target is stationary
Imaging Technique similar to thoseUsed for Ground Penetrating Radars (GPR)
10
2D Scene Imaging in Matlab: “Stereoscopic” View – Time-Domain Focusing
∫ ⋅⋅=TW
ijijji dttststWI )()()( ,2,1,
))2(10()( ,)2(1),2(1 cDcDtSts jiij −−=1. Equalize time delay to focus on a image “pixel”
2. Compute inter-channel windowed correlation
Ranging and Angular Tracking Image Pixel Map
A Naive Time-Domain Focusing Technique:
11
2D Scene Stereoscopic Imaging: How it woks?
Simulated Measured
Target Mark
The target mark is widespread in azimuth = More sophisticated time-domain beam-forming is required !E.g., a similar problem is solved in stereoacousticBut Matlab cannot handle this in real time
12
Rx-1
Rx-2
2D Scene Stereoscopic Imaging: Why is the Target Mark so Wide Spread?
Because of a small base, viz. the distance between Tx & Rx, the signals in the Rx channels are slightly mutually shifted in time that causes the wide spread mark.
13
Directions of Potential Future Efforts
More Elements in UWB Arrays
Two-Plane & Dual-Polarization Image focusing,
More sophisticated Time-Domain Focusing Techniques
Fast DSP Signal Processing
Fast ADC instead of slow Sound Card
Antenna Adaptations to Media Interfaces
Tracking and Recognition of Complex Scenes
… Feedbacks and Propositions are very welcome
Related Documents
