space reflecto 2013
DESCRIPTION
Space Reflecto 2013. Simulations and exploitation of GNSS-R signals from a 60-meter lighthouse for applications in surface hydrology processes. Nicolas ROUSSEL Laurent LESTARQUIT. 04/05 novembre 2013. PhD advisers : Guillaume RAMILLIEN, Frédéric FRAPPART. Plan - PowerPoint PPT PresentationTRANSCRIPT
Simulations and exploitation of GNSS-R signals from a 60-meter lighthouse for applications in
surface hydrology processes
Space Reflecto 2013
Nicolas ROUSSELLaurent LESTARQUIT
PhD advisers: Guillaume RAMILLIEN, Frédéric FRAPPART
04/05 novembre 2013
2
PlanIntroduction Simulations Field measurements
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
4/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
PlanIntroduction Simulations Field measurements
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
34/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Ground configuration Embedded configuration
Direct/reflected signals correlation Position of the specular reflection point Altimetry Properties of the reflection surface
(roughness)
Source : Institut de Ciències de l’Espai (http://www.ice.csic.es)
IntroductionIntroduction Simulations Field measurements
44/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
- 60
m -
IntroductionIntroduction Simulations Field measurements
The Cordouan Lighthouse (45°35’11’’N ; 1°10’24’’O)
54/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
PlanIntroduction Simulations Field measurements
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
64/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Modeling the trajectories of GNSS electromagnetic waves that are reflected on the surface of the Earth, based on real ephemeris
Determine the potential of GNSS-R for mapping the characteristics of the reflecting surface
Explore different configurations of performing measurements and instrument installations:
variations in the reflectometer height, mask effects due to the terrain, satellites geometry, ...
Simulator development
SimulationsIntroduction Simulations Field measurements
74/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
84/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Determination of the position of the specular reflection points: 3 algorithms
- Approximation of the Earth into a local sphere
- Approximation of the Earth into a local ellipsoid
- DEM (Digital Elevation Model) integration
Correctness Computation speed
Gnu R
For further information : Simulations of direct and reflected waves trajectories for in situ GNSS-R experiments, submitted in Geosciences Model DevelopmentN. Roussel, F. Frappart, G. Ramillien, C. Desjardins, P. Gegout, F. Pérosanz, R. Biancale
SimulationsIntroduction Simulations Field measurements
94/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
SimulationsIntroduction Simulations Field measurements
Simulator outputs Simulations on the Cordouan lighthouse (45°35’11’’N ; 1°10’24’’O)
SimulationsIntroduction Simulations Field measurements
104/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Simulations over a week
SimulationsIntroduction Simulations Field measurements
114/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Simulations over a week
SimulationsIntroduction Simulations Field measurements
124/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
134/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
PlanIntroduction Simulations Field measurements
14
PlanIntroduction Simulations Field measurements
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
4/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
SILICOM Data-LoggerData Logger
records and time tags a wide choice of supported RF GNSS signals
makes possible the characterization of the reflected signal and the development of algorithms for processing the GNSS-R signals.
SILICOM Data-loggerIntroduction Simulations Field measurements
154/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
31st may 2013 campaignData Logger
to collect GNSS-R signals, receiving the direct signal via a RHCP zenith-looking antenna, and the reflected signal via a LHCP nadir-looking antenna
Approx. 25 min of acquisitions, 25 MHz, 8 bits
SILICOM Data-loggerIntroduction Simulations Field measurements
164/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Acquisition
1 ms Doppler : [-5000:1:5000] Hz
Detection of 6 satellites :
- PRN12- PRN15- PRN17- PRN24- PRN25- PRN26
In agreement with the simulations
SILICOM Data-loggerIntroduction Simulations Field measurements
174/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Acquisition
Reflected signalDirect signal
PRN15 exemple : detection of the initial doppler
SILICOM Data-loggerIntroduction Simulations Field measurements
184/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Acquisition
Reflected signalDirect signal
PRN15 exemple : detection of the initial delay
SILICOM Data-loggerIntroduction Simulations Field measurements
194/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Correlation functionReflected signalDirect signal
SILICOM Data-loggerIntroduction Simulations Field measurements
1 ms 1 ms
100 ms100 ms
204/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Correlation function
SILICOM Data-loggerIntroduction Simulations Field measurements
Reflected signalDirect signal
1 ms 1 ms
100 ms100 ms
214/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Delay-Doppler Maps
SILICOM Data-loggerIntroduction Simulations Field measurements
244/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Tracking
SILICOM Data-loggerIntroduction Simulations Field measurements
234/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
Differences between direct and reflected paths – C/A PRN12
Time (s)
Dis
tanc
e (m
)
𝛿d=2h𝑠𝑖𝑛(𝜖) : satellite elevation
Determination of the C/A pseudo-distance for both direct and reflected signals The difference between both gives the extra distance traveled by the reflected wave
Tracking
Direct signal
𝛿d=2h𝑠𝑖𝑛(ϵ ) With the elevation Satellite Num Receiver height h (m)PRN12 57,47
PRN15 60,47
PRN17 57,75
PRN24 61,98
PRN25 61,66
PRN26 59,46
Mean 59,80 ± 1,92
SILICOM Data-loggerIntroduction Simulations Field measurements
234/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
25
PlanIntroduction Simulations Field measurements
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
4/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
26
PlanIntroduction Simulations Field measurements
Introduction
Simulations
Field measurements
GNSS-based tide gauge system with SILICOM datalogger
Analysis of signal-to-noise ratio (SNR) series
4/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
phase difference between the direct signal and the reflected signal (multipath)
Direct signal amplitude
Multipath amplitude
x = sin θ :
SNR dataIntroduction Simulations Field measurements
Larson et al., GPS Sol., 2008
274/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
SNR dataIntroduction Simulations Field measurements
L2 SNR data
2nd order polynom
284/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
SNR dataIntroduction Simulations Field measurements
294/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
L2 SNR data
0 – 40° elevation filtration
SNR dataIntroduction Simulations Field measurements
L2 SNR data
304/5 November 2013 Space Reflecto – Nicolas ROUSSEL / Laurent LESTARQUIT
The whole 3 months time series is currently being analyzed in order to make the tide appear
Thanks for your attention !