the typhoon investigation using gnss-r interferometric ......experimental campaign in shenzhen...
TRANSCRIPT
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
The Typhoon Investigation using GNSS-RInterferometric Signals (TIGRIS)
F. Fabra1, W. Li2, M. Mart́ın-Neira3, S. Oliveras1, A. Rius1,W. Yang2, D. Yang2 and Estel Cardellach1
1Institute of Space Sciences ICE-CSIC/IEEC, Spain2School of Electronic and Information Engineering SEI, BeiHang University, China
3European Space Agency ESA-ESTEC, Netherlands
SPACE REFLECTO 20133rd Conf. on passive reflectometry using radiocom space signals
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Outline
1 Introduction
2 Experimental campaign in Shenzhen (China)
3 Preliminary results
4 Conclusions
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
FrameTyphoon remote sensing
Outline
1 Introduction
2 Experimental campaign in Shenzhen (China)
3 Preliminary results
4 Conclusions
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
FrameTyphoon remote sensing
The frame of this work
China-Europe Joint Initiative
National Remote Sensing Center of China (NRSCC), Ministry of Science andTechnology
School of Electronic and Information Engineering (SEI), BeiHang University
China Meteorological Administration (CMA)
European Space Agency (ESA)
Institute of Space Studies from Catalonia (IEEC)
+ Other institutions
TIGRIS experiment
Typhoon Investigation using GNSS-R Interferometric Signals
Main purpose: Research on GNSS-R towards remote sensing of typhoons
But also: Provide recommendations for a future GNSS-R space-based mission
Related work: aircraft experiments done by S.J. Katzberg and NASA’s CYGNSSmission
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
FrameTyphoon remote sensing
Typhoon remote sensing with GNSS-R
Basic idea...
Typhoons can be characterized by itsimpact over the sea surface
Remote sensing measurementsthrough intense rain fall (lowerattenuation at L-band) ⇒ betterunderstanding on typhoon’s air-seainteraction
Potential retrievals
Wind Speed (WS) ⇒ waveform’samplitude and area
Significant Wave Height (SWH) ⇒waveform’s leading edge andcoherence time
Sea Surface Level (SSL) anomalies(up to 1 m) ⇒ altimetry
Interferometric waveforms (all GPS codes) with different wind
speeds simulated by W. Li under PARIS IoD nadir geometry
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Outline
1 Introduction
2 Experimental campaign in Shenzhen (China)
3 Preliminary results
4 Conclusions
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Location: Xichong bay, South-East of China
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Scenario: Antennas installation in Shenzhen site
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Campaign: Instrumental setup
Antenna Inputs
RF Coaxial
N−Type Female
PS1234
IN
PSIN
12
PSIN
12
PSIN
12
Up−looking Low−gain Antenna
Up−looking High−gain Antenna
Down−looking High−gain Antenna
ANTENNA SYMBOLS
Nav
EthUSBPower
GOLD−RTR
Power
Eth
RF1
RF0
Power Supply Jack
PIRA
PSIn
12
IEEC’s Equipment
Link−3
Link−2
Link−1
Nav
Power Input
CEE 7/7 plug
AC 220V/50Hz
SEI’s Equipment
USB
USB
IN1
IN2
IN3
IN1
IN2
4−channel GPS IF signal collector
2−channel BeiDou IF signal collector
A4) RHCPA3) LHCP
A1) RHCP A2) RHCP
IN4
RHCP−U−H
RHCP−U−H
LHCP−D−H
LHCP−D−H
RHCP−D−H
RHCP−U−L
LHCP−D−H
LHCP−D−H
RHCP−U−L
RHCP−D−H
POWER SPLITTER (PS)
2, 3, 4 Outputs DC BLOCKED
IN Input DC THRU
1 Output DC THRUIEEC: Institut d’Estudis Espacials de Catalunya
SEI: School of Electronic and Information Engineering
INSTITUTIONS
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Campaign: IEEC’s GNSS-R Instrumentation
GOLD-RTR
GPS Open Loop Differential Real Time Receiver
GNSS-R dedicated hardware receiver (standard approach using GPS L1 C/Acode)
10 channels compute cross-correlations (waveforms) of 64 lags every millisecond
50 ns lagspacing ⇒∼ 15 meters
PIR
PARIS Interferometric Receiver
GNSS-R dedicated hardware receiver (direct cross-correlation)
1 waveform of 320 lags every millisecond
12.5 ns lagspacing ⇒∼ 3.75 meters
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Campaign: SEI’s GNSS-R Instrumentation
BeiDou IF signal collector
Dual-front-end for both direct and reflected signals
16.367 MHz sampling rate (18.75 meters resolution in delay)
Configurable to BeiDou, GPS and GALILEO
GPS IF signal collector
Quad-front-end channels
16.3667 MHz sampling rate
GNSS-R software receiver in post-processing
Computes waveforms using standard or interferometric approaches
Compatible with both Beidou B1 and GPS L1 band signals
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
ScenarioInstrumentationCollected data
Collected data during typhoons
Relevant aspects
Campaign’s duration: from end of July until end of September 2013
Two typhoons and one tropical storm were monitored!
An additional (but simpler) setup collected data from Yangjiang station
Name Classification Min. pressure Dates DistanceJEBI Strong Tropical Storm 985 mbar 31-July/3-Aug 470 km
UTOR Super Typhoon (cat. 4) 925 mbar 9-Aug/15-Aug 270 kmUSAGI Super Typhoon (cat. 5) 910 mbar 16-Sept/23-Sept 100 km
Preliminary results given next
Altimetric retrievals from GOLD-RTR around UTOR and USAGI
Scatterometric measurements from BeiDou IF signal collector around JEBI andUTOR
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Outline
1 Introduction
2 Experimental campaign in Shenzhen (China)
3 Preliminary results
4 Conclusions
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results
Main aspects
Results from IEEC’s GOLD-RTR
High gain antennas should avoiddirect signal contamination
However, we try to removewaveforms with presence ofresidual direct signal
Estimated coherence time of100 msec ⇒ 100 sec ofincoherent integration tominimize speckle (120 sec forpractical purposes)
Two periods analyzed: aroundUTOR and USAGI
245.44˚W 245.43˚W 22.47˚N
22.48˚N
5.00
10.00
15.00
20.00
25.00
30.00
Ele
vatio
n [
de
g]
Specular points over the ocean surface from
GPS tracks during 14th Aug
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: specular delay
Main aspects
Position of waveform’s peakpower (instead of maximum offirst derivative)
Related to altimetry
Low elevation angles magnifyaltimetric errors duringdelay-height inversion
Only values obtained forelevations > 25◦ are considered
20
40
60
80
100
120
Alti
metr
ic d
ela
y [m
]
5 10 15 20 25 30
Elevation [deg]
2 H sin(elevation)
−40
−20
0
20
He
igh
t re
sid
ua
l [m
]
5 10 15 20 25 30
Elevation [deg]
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: specular delay
−2.0
−1.5
−1.0
−0.5
0.0
0.5
1.0
1.5
2.0
Est
ima
ted
SS
L [m
]
00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00August 13 August 14 August 15 August 16 August 17 August 18
UTOR’s landfall
−2.0
−1.5
−1.0
−0.5
0.0
0.5
1.0
1.5
2.0
Est
ima
ted
SS
L [m
]
00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00September 18 September 19 September 20 September 21 September 22 September 23
USAGI’s landfall
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: specular delay (OSU Tide model)
−2.0
−1.5
−1.0
−0.5
0.0
0.5
1.0
1.5
2.0
Est
ima
ted
SS
L [m
]
00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00August 13 August 14 August 15 August 16 August 17 August 18
UTOR’s landfall
−2.0
−1.5
−1.0
−0.5
0.0
0.5
1.0
1.5
2.0
Est
ima
ted
SS
L [m
]
00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00September 18 September 19 September 20 September 21 September 22 September 23
USAGI’s landfall
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: specular delay (tide-corrected)
−2.0
−1.5
−1.0
−0.5
0.0
0.5
1.0
1.5
2.0
Est
ima
ted
SS
L [m
]
00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00August 13 August 14 August 15 August 16 August 17 August 18
UTOR’s landfall
−2.0
−1.5
−1.0
−0.5
0.0
0.5
1.0
1.5
2.0
Est
ima
ted
SS
L [m
]
00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00 06 12 18 00September 18 September 19 September 20 September 21 September 22 September 23
USAGI’s landfall
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Discussion
First impressions
Altimetric retrievals showmoderate agreement with tides,but errors are larger thanexpected
Altimetric errors showtrack-evolution ⇒ multipatheffect due to direct signalcontamination!
Next step: to retrieve altimetryfrom more robust phaseobservables (experience fromprevious campaigns)
−2
−2
−1
−0
0
0
1
2
2
Est
ima
ted
SS
L [m
]
00 06 12 18 00August 14
5
10
15
20
25
30
Ele
vatio
n [d
eg
]
−30
−25
−20
−15
−10
−5
0
5
10
Est
ima
ted
SS
L [m
]
00 06 12 18 00August 14
5
10
15
20
25
30
Ele
vatio
n [d
eg
]
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Scatterometric results
Main aspects
Results from SEI’s BeiDou IFsignal collector
BeiDou GEO #1 and #4satellites are monitored ⇒ stablegeometry and sharperauto-correlation function (2.046Mchips)
Off-specular reflections ⇒spatial filtering of antennafootprint and coastline
Two observables are analyzed:Area of the waveform andcoherence time
Two periods processed: aroundJEBI and UTOR
Specular points from BeiDou GEO #1 and #4
satellites
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Area of the power waveform (JEBI)
Area of the power waveform
Expected to be sensitive to the sea surface wind
speeds (proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Area of the power waveform (JEBI)
Area of the power waveform
Expected to be sensitive to the sea surface wind
speeds (proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Area of the power waveform (JEBI)
Area of the power waveform
Expected to be sensitive to the sea surface wind speeds (proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Area of the power waveform (UTOR)
Area of the power waveform
Expected to be sensitive to the sea surface wind
speeds (proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Coherence time (JEBI)
Coherence time
Expected to be sensitive to the Significant Wave Height (inversely proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Coherence time (JEBI)
Coherence time
Expected to be sensitive to the Significant Wave Height (inversely proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Coherence time (UTOR)
Coherence time
Expected to be sensitive to the Significant Wave Height (inversely proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Altimetric resultsScatterometric results
Altimetric results: Coherence time (UTOR)
Coherence time
Expected to be sensitive to the Significant Wave Height (inversely proportional)
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Outline
1 Introduction
2 Experimental campaign in Shenzhen (China)
3 Preliminary results
4 Conclusions
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).
IntroductionExperimental campaign in Shenzhen (China)
Preliminary resultsConclusions
Conclusions
Altimetric results
Moderate agreement with tides, but errors are larger than expected due todirect signal contamination
Preliminary results still have room for improvement!
More robust phase observables might overcome these limitations
Scatterometric results
Good correlation with the in-situ wind speed and SWH measurements
Off-specular reflections (spatial filtering of antenna footprint and coastline)benefit coastal applications
BeiDou GEO satellites provide good opportunities for sea state measurement
On-going analysis
Phase-based and polarimetric measurements, GPS interferometric signals...
Combined analysis is required to enable a proper typhoon characterization
Fran Fabra, ICE-CSIC/IEEC SPACE REFLECTO. Nov 5th, 2013. Brest (France).