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Development of Active Phased Array Weather Radar. Masakazu Wada. Comparison of Dual-Pol and Phased-array Radar. Parabolic radar. Phased Array Weather Radar. Concept on Phased-array Radar. About 2m. About 2m. Overview of Antenna. Overview of Antenna Scan. < Cost Performance > - PowerPoint PPT Presentation
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© 2012 Toshiba Corporation
Development of Active Phased Array Weather Radar
Masakazu Wada
2© 2011 Toshiba Corporation 2Development of Active Phased Array Weather Radar
Comparison of Dual-Pol and Phased-array Radar
Dual-Pol Radar
( parabolic antenna )PAWR
(phased array antenna)
Elevation: Mechanical
Azimuth: MechanicalScanning
Elevation: Electronic
Azimuth: Mechanical
About 20/ 5 to10 minutes
Elevation Number
/ Time Interval
About 100/ 10 to 30 seconds
Zh , Vh , Wh , Zdr , Kdp ,ρhv
Parameter Zh , Vh , Wh
Parabolic radar Phased Array Weather Radar
3© 2011 Toshiba Corporation 3Development of Active Phased Array Weather Radar
Concept on Phased-array RadarAbout 2mAbout 2m
Ab
ou
t 2m
Ab
ou
t 2m
< Antenna Scan >•1 degree of azimuth beam width by slotted antenna mechanically
•1 degree of elevation beam width by Antenna electronically
•Fan beam transmission•Multi-beams receiving by DBF
•3D fast observation with one rotation
< Cost Performance >•1-dimension Active Phased Array Antenna and DBF ( Digital Beam Forming)
•Maximize the Cost Performance•The same price range as compared to parabolic radar
Overview of AntennaOverview of Antenna Overview of Antenna ScanOverview of Antenna Scan
4© 2011 Toshiba Corporation 4Development of Active Phased Array Weather Radar
..…
Block Diagram
Digital Signal Processor•Pulse Compression•Calculate Radar Reflectivity Doppler Velocity Velocity Width
I/Q Data Accumulation(for study)
Tra
nsm
itter
an
d R
ece
iver
(24
line
s)
Re
ceive
r(9
6 lin
es)
……
……
…S
lotte
d W
ave
gu
ide
an
ten
na
(12
8
ele
me
nts)
Rx F
req
ue
ncy C
on
versio
n(1
28
line
s)
Tx Frequency
Conversion
……
……
D/A
Digital Seed
~A
/D a
nd
I/Q(1
28
line
s)
……
……
….
. DB
F
……
……
….
.
DBF output (16 beams)
No DBF output (128 I/Q data)
Use Gallium Nitride
on Tx Amp
5© 2011 Toshiba Corporation 5Development of Active Phased Array Weather Radar
Active Phased Array Antenna
Active Phased Array Antenna
2.2m
2.1m
6© 2011 Toshiba Corporation 6Development of Active Phased Array Weather Radar
Tx/Rx Unit
Include 8ch Tx/Rx Elements The system uses 3 units
Tx/RxCard
Condensercard
FrequencyConversion
Card
7© 2011 Toshiba Corporation 7Development of Active Phased Array Weather Radar
Receiving Unit
RxCard
FrequencyConversion
Card
Include 8ch Rx Elements The system uses 13 units
8© 2011 Toshiba Corporation 8Development of Active Phased Array Weather Radar
Frequency Conversion Card
9© 2011 Toshiba Corporation 9Development of Active Phased Array Weather Radar
A/D I/Q Unit
16ch A/D & I/Q The system uses 8 units
10© 2011 Toshiba Corporation 10Development of Active Phased Array Weather Radar
DBF Unit
The system uses DBF technique to calculate beam form from 128 I/Q data
11© 2011 Toshiba Corporation 11Development of Active Phased Array Weather Radar
Observation Mode
Prepare wide observation mode and fast obsevation mode
Specification
Maximum
Power Up to 430W
Frequency 9320 to 9445MHz, 5MHz step
Beam Width
(after DBF) About 1 degree
Mode Fast
Observation
Wide
Observation
Coverage 20㎞ 60㎞
Scan
Interval 10 seconds 30 seconds
Number of
Hit About 10 About 20
Number of
Elevation About 100 About 100
12© 2011 Toshiba Corporation 12
Phased-array Radar installed in Osaka Univ.
Development of Active Phased Array Weather Radar
Active Phased Array Antenna
Left: Radar Processor
Right: Radar Controller
Active Phased Array Weather Radar installed in Osaka Univ.
13© 2011 Toshiba Corporation 13Development of Active Phased Array Weather Radar
Conclusion
• Active Phased-array Weather Radar is able to generate 3D data without any gap in the period of 10 to 30seconds, in order to capture cumulonimbus quickly.
• We have installed Active Phased-array Radar on Osaka urban area and are evaluating it now.
• To protect safety of critically significant infrastructure such as urban area and Airport from disaster, Toshiba propose multiple observation using dual-pol solid-state radar and 1D phased-array radar.
This research is supported by the National Institute of Information and Communications Technology, Japan.
14© 2011 Toshiba Corporation 14
Toshiba’s Presentations in the ExhibitionToshiba’s Presentations in the ExhibitionExhibitor Booth
<No. 5005>
Right in front of main entrance
15© 2011 Toshiba Corporation 15Development of Active Phased Array Weather Radar
16© 2011 Toshiba Corporation 16Development of Active Phased Array Weather Radar
Measurement ( Anechoic Chamber )
We have one of the largest Chamber in Eastern Japan.
17© 2011 Toshiba Corporation 17Development of Active Phased Array Weather Radar
NSI Receiver
-40
-30
-20
-10
0
10
-80 -60 -40 -20 0 20 40 60 80
Am
plitud
e [d
B]
Azimuth [deg]
-40
-30
-20
-10
0
10
-80 -60 -40 -20 0 20 40 60 80
Am
plitu
de [
dB]
Elevation [deg]
Near field dataAmplitude Phase
Azimuth
Elevation
Calculated far field pattern
18© 2011 Toshiba Corporation 18Development of Active Phased Array Weather Radar
Antenna Pattern ( Azimuth)
Mechanical Beam Forming by Slot Antenna
Antenna Pattern (Azimuth)
- 50
- 40
- 30
- 20
- 10
0
- 80 - 60 - 40 - 20 0 20 40 60 80
Azimuth [deg]
Am
plitu
de[d
B]
< Beam Width >1degree or less<Side lobe>-23dB or less
19© 2011 Toshiba Corporation 19Development of Active Phased Array Weather Radar
Transmission and Receiving Pattern ( Elevation)
Transmission and Reception (Multi Beam) Pattern
- 50
- 40
- 30
- 20
- 10
0
- 45 - 30 - 15 0 15 30 45
Elevation[deg]
Am
plitu
de[d
B]
TX_8element Rx_EL0deg Rx_EL1deg Rx_EL2deg Rx_EL3deg Rx_EL4degRx_EL5deg Rx_EL- 1deg Rx_EL- 2deg Rx_EL- 3deg Rx_EL- 4deg Rx_EL- 5deg
1 transmission beam and receiving multi beam by DBFElectronic Scan EL 0deg to 90 deg
< Beam Width >1degree (Rx)<Side lobe>-10dB or less (Tx)-23dB or less (Rx)
20© 2011 Toshiba Corporation 20
Forecast of potential
Developing stage
Developing stage Maturation Decline stage
Decline stage
Strong rainfallStrong rainfall
Forcast at this Forcast at this
Vertical Integrated Liquid (VIL) and by the vertical distribution of precipitation, it is possible to predict the precipitation may fall to the ground
in the near future
Life cycle of Cumulonimbus
21© 2011 Toshiba Corporation 2110/20/2011Development of Active Phased Array Weather Radar
Transmission power can be reduced compared with conventional radar systems on a detection-range basis.
>> Reduction in operating voltage of the transmitter circuits>> Downsizing of the transmitter>> Suppression of the level of interference wave, etc.
Klystron Solid-state Pulse Compression Radar
TransmittedWaveform
Peak power can be minimized
without lowering the average power
time t
Am
plif
ier
Frequency
Del
ay ti
me
Chirp modulation ( Frequency modulation )1) add the frequency modulation on the transmission pulse 2) transmit this linear FM pulse3) put the received signal through the time delay filter 4) collect the divided frequency power in the received pulse
1) 2) 3) 4)
Pulse Compression TechniquePulse Compression Technique