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IHOP 2002 GPS/H20 Water Vapor Investigations with Ground-Based GPS. Contributions. GPS/H20 France: J. Van Baelen, J-P. Aubagnac, CNRM, Toulouse O. Bock, J. Tarniewicz, SA, Paris A. Walpersdorf, LGIT, Grenoble E. Doerflinger, F. Masson, LDL, Montpellier - PowerPoint PPT Presentation
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
1
IHOP 2002 GPS/H20
Water Vapor Investigations with Ground-Based GPS
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
2
Contributions
GPS/H20 France: J. Van Baelen, J-P. Aubagnac, CNRM, Toulouse
O. Bock, J. Tarniewicz, SA, Paris
A. Walpersdorf, LGIT, Grenoble
E. Doerflinger, F. Masson, LDL, Montpellier
Field Deployment: J. Van Baelen, E. Doerflinger, J-P. Aubagnac, Ph. Collard, O. Bock
OK Mesonet: J. Basara, OU / OKmesonet team
UCAR/GST: J. Braun
IHOP/DATA BASE: JOSS, NOAA/FSL, ARM/SGP
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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GPS derived IWV
HH
dzzNdzznZTD 6101
ZWDZHDZTD
HPZHD H733 108.22cos1066.21102768.2
4221.1610719.31051.461 55 mT
HH
m dzzTzedzzTzeT 2 sGPSm TKT 72.02.70
HHH
dzzTzedzzTzedzzTzezpZTD 56 10719.37.6462.7710
ZWDIWV
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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IHOP objectives for GPS/H20 teams
Methodology Aspects Mapping functions and antenna modeling errors,
Low elevation angles and slant tropospheric delays
Tomographic inversion algorithms, constraints and resolution,
Effect of WV heterogeneity on precise positionning,
Spatial and temporal correlations in ZTD’s and STD’s and covariance matrix determination
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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IHOP objectives for GPS/H20 teams
Scientific Objectives GPS water vapor retrieval validation,
Study of spatial and temporal variability and dynamics of IWV,
Study of WV convergence as CI precursor,
3-D water vapor distribution through tomography both local (L1 with few L2 constraints) and synoptic,
Data assimilation (slant delays),
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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Field Deployment: Objectives vs Logistics
Légende:
• Parc INSU
• SuomiNet
• NOAA/FSL
• ARM/CART
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
7
GPS deployment at OKmesonet sites
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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E p o c h s w / O b se rv a tio n s (ma x :
1 7 2 7 9 )
0
2 0 0 0 0
I O P d a y s ( 1 3 3 - 1 7 6 )
B L
A C
B R
E C
B U
R B
G U
T H
M E
D F
O IL
T
IHOP 2002 : GPS deployment and observation statistics
Observations
0
20000
40000
60000
80000
100000
120000
140000
160000
180000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
IOP days (133-176)
BLAC
BREC
BURB
GUTH
MEDF
OILT
REDR
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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E p o c h s w / O b se rv a tio n s (ma x :
1 7 2 7 9 )
0
2 0 0 0 0
I O P d a y s ( 1 3 3 - 1 7 6 )
B L
A C
B R
E C
B U
R B
G U
T H
M E
D F
O IL
T
IHOP 2002 : GPS deployment and observation statistics
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
1 2 3 4 5 6 7
BLAC BREC BURB GUTH MEDF OILT REDR
Summary per Station
EPS
OBS
DEL
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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GPS Data Analysis Status
Use of GAMIT / GLOBK software package Implemented at CNRM late fall 2002.
First pass analysis Preliminary work on the 11-12 June case (!),
10° cut off angle, 30 seconds epochs, Saastamoinen hydrostatic model, Dry and wet Niel mapping functions, Three-hourly ZTD calculations and a single
gradient per day, All stations non-constrained.
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
11
GPS Data Analysis Status
Next step Kalman filter to positionning and precise
calculation of (half-)hourly ZTD’s,
Automated processing for entire campaign,
Determination of IWV for all stations of interest to IHOP,
Results provided to IHOP Data Base in final form.
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
12
GPS Analysis Stations
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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Preliminary Results:
June 11-12 Case Study
ZTD and IWV Comparisons: NOAA half-hourly ZTD’s from IHOP D.B. French processed data (GAMIT) UCAR/GST processed data (Bernese)
Combined results: NOAA + French stations IWV’s UCAR/GST – French stations ZTD’s
Field Differences
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
18
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
20
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
21
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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IHOP Data Base [JOSS] Imagery
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
24
French GPS Station ZTD’s
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
25
GPS vs Radiosondes ZTD’s
J. Van Baelen IHOP Workshop, Boulder, CO 24-26 March 2003
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AIRS Campaign at CNRM (Fall ’02)
Comparison IWV
GPS - Radiosondes
27IHOP Workshop, Boulder, CO 24-26 March 2003
J. Van Baelen
Conclusions
First results of GAMIT single pass processed French GPS data consistent with other results,
Addition of French GPS stations seems to provide finer resolution to the central area of interest in the 11-12 June case,
In this case, higher humidity contents shown,
However, all solutions appear sensitive to single station ‘peculiar’ values => data or artifact ?
28IHOP Workshop, Boulder, CO 24-26 March 2003
J. Van Baelen
Ongoing WorkComplete processing of French GPS stations and others of the IHOP area with GAMIT soon to be available with (half-)hourly ZTD’s and gradients,
Methodology and Scientific studies to be undertaken following the topics specified,
Each topic is under the principal interest of various members of the French GPS/H2O teams, all of them are ready to collaborate and share their expertise with interested parties,
Contact [email protected] or the corresponding team directly