gps data during sop1 sop2 d4b2
Download
Skip this Video
Download Presentation
GPS data during SOP1 & SOP2 (D4B2)

Loading in 2 Seconds...

play fullscreen
1 / 15

GPS data during SOP1 & SOP2 (D4B2) - PowerPoint PPT Presentation


  • 67 Views
  • Uploaded on

GPS data during SOP1 & SOP2 (D4B2). IODAMED meeting, 16 May 2014. Olivier Bock, LAREG IGN Pierre Bosser, ENSG IGN Contributions from : C. Champollion, E. Doerflinger (LDL) France R. Pacione (E-GEOS/ASI) Italy

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' GPS data during SOP1 & SOP2 (D4B2)' - sybill-jordan


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
gps data during sop1 sop2 d4b2
GPS data during SOP1 & SOP2(D4B2)

IODAMED meeting, 16 May 2014

Olivier Bock, LAREG IGN

Pierre Bosser, ENSG IGN

Contributions from:

  • C. Champollion, E. Doerflinger (LDL) France
  • R. Pacione (E-GEOS/ASI) Italy
  • J. A. Sanchez Sobrino (IGN-E), A. Seco (UPN), A. Botas (Logica), C. Sanchez Tugores (Sitibsa), L. García Pellicer (ARAGEA), Spain
  • M. Vasconcelos (DGT), Portugal
  • J. Jones, D. Offiler (UKMO), UK

IODAMED meeting, 16 May 2014

slide2

Outline

  • The operational GPS network and ZTD data flow (EGVAP -> assimilation in NWP models)
  • A reprocessed dataset for HYMEX SOP1+2
    • Screening of ZTD data
    • Conversion of ZTD to IWV
    • Comparison of GPS IWV to AROME WMED Op An

IODAMED meeting, 16 May 2014

e gvap eumetnet eig gps water vapour program

May 2012

E-GVAPEUMETNET EIG GPS Water Vapour Program
  • Aim: use NRT GNSS ZTD for operationalmeteorology.
  • EGVAP is a consortium of 13 National Weather Services working in close collaboration with11 National MappingAgencies.
  • GNSS network iscomposedof public & private stations and counts ~ 1500 sites.
  • GNSS rinex data are processed by 15 ACs in Near Real Time (NRT), i.e. latency < 1h45min.
  • NRT ZTD disseminated by UMKO on the GTS (BUFR files) and assimilatedin NWP models by UKMO, Meteo-France, DMI…

IODAMED meeting, 16 May 2014

slide4

ZTD GPS data input

AROME - France

10 000 values per 3h

15 GPS ACs with different sofware and processing procedures

=>

ZTD dataset is

inhomogeneous

IODAMED meeting, 16 May 2014

slide5

NRT ZTD data archived on hymex DB

  • NRT_EGVAP_SGN (IGN/SGN, France)
  • Network:
  • - RGP (France) + reference stations (321 sites)
  • Processing:
  • BerneseGPS software
  • Ultra-rapidIGS orbits, fixed positions, CO=10°, no gradients, ZTD values at HH+00, 15, 30, 45, 59’
  • NRT_EGVAP_IGE (IGN, Spain)
  • Network:
  • - Spain + Portugal + reference stations (288 sites)
  • Processing:
  • BerneseGPS software
  • Ultra-rapidIGS orbits, ZTD values: HH+00, 15, 30, 45, 59’
  • NRT_EGVAP_ASI + NRT_EGVAP_ASI1 (E-GEOS/ASI, Italy)
  • Network:
  • - Italy+ reference stations (164 sites)
  • Processing:
  • GIPSY-OASIS II software
  • Ultra-rapidJPL orbits, fixed positions, ZTD values HH+00, 15, 30, 45’

IODAMED meeting, 16 May 2014

slide6

Hymexdatabase

sedoo.fr

IODAMED meeting, 16 May 2014

slide7

Comparison of NRT ZTD data at common sites

ASI – SGN, 44 common sites, different software

Mean = -3 ± 5 mm

Std. = 7 mm

IGE – SGN, 50 common sites, same software

Std. = 7 mm

Mean = 0 ± 2 mm

IODAMED meeting, 16 May 2014

slide8

Reprocessed network

REPRO

EGVAP

Orphéon

SGN

IGE

HYMEX_FR

HYMEX_DE

15 networks

ASI

Sardinia

773 stations

(3 Analysis Centres)

970 stations

(2 ACs, 21 networks)

IODAMED meeting, 16 May 2014

slide9

Reprocessed network

Homogenous reprocessing of 970 sites for period 1 Sep 2012 – 31 Mar 2013

  • Reprocessing by IGN/LAREG, France
  • Network: 823 sites
  • France : RGP (349 sites) + Orphéon (182 sites)
  • Temporary sites : Cévennes (8 sites, Géosci. Montpellier) and Corsica (5 sites, GFZ)
  • Spain: 14 regions (231 sites) + IGE national network (37 sites)
  • Portugal: RENEP (43 sites)
  • North Africa: UNAVCO (5 sites)
  • Processing:
  • GIPSY-OASIS II software
  • Final JPL orbits & clocks, ZTD + gradients every5’, VMF1, 30 h session
  • Reprocessing by e-GEOS/ASI, Italy
  • Network:
  • Italy: ASI1 + new stations (Sardinia) = 147 sites
  • Processing:
  • Idem repro_LAREG

IODAMED meeting, 16 May 2014

slide10

Comparisonof NRT to post-proc. data

IGE

Mean= 0.5 ± 3 mm

Std. = 8 mm

SGN

Mean= -0.1 ± 2 mm

Std. = 6mm

ASI

Mean= 0.8 ± 2 mm

Std. = 4 mm

IODAMED meeting, 16 May 2014

slide11

Screening of ZTD data

1st step

Analysis of formal error for ZTD, station height, and other processing output information

After

Before

mean

1 – 99 percentiles of ZTD formal error

Std.dev.

2nd step

Comparison of GPS ZTD data to ZTD data from a NWP model, rejection of data at ± 3 

IODAMED meeting, 16 May 2014

slide12

Conversion of ZTD to IWV

accurate to 0.006%

Surface pressure or NWP Analysis

accurate to 0.1-1 hPa

(0.01-0.1%)

accurate to 0.06%

accurate to 10-3 m s-2(0.01%)

Principle: IWV=K(Tm)*( ZTD – ZHD )

Requires auxiliairy data

accurate to 2.4 %

accurate to ±3 %

but k’2 = 0.047 * k3/Tm

Empirical model Tm = f(Ts) or NWP Analysis

Tm= 250 ± 20 K (8% variations)

IODAMED meeting, 16 May 2014

slide13

Uncertainty budget of GPS IWV

ZTD uncertainty + ZHD uncertainty + K(Tm) uncertainty

1 mm (0.06% k1 error)

+

1-2 mm (0.5-1 hPa Ps measurement error)

+

1-2 mm (interpolation error)

1-2% (k2 & k3 error)

+

1-2% (Tm error < 5K)

4-6 mm (IGS solution)

IWV=40 kg/m2

IWV=5 kg/m2

0.3-0.5 kg/m2

0.1-1.1 kg/m2

0.6-0.9 kg/m2

GPS IWV uncertainty:

bias≈ 0.2-0.8 kg/m2

random ≈ 0.2-1.5 kg/m2

slide14

Comparison of GPS IWV to AROME WMED

Mean= 1.5 kg m-2

Std.= 1.5 kg m-2

Slope = 0.96

Correl = 0.92

16 networks, 1 month (Sep 2012)

Auxiliairy data for IWV conversion: AROME WMED (surf + T) + emp. model Tm =f(Ts)

IODAMED meeting, 16 May 2014

slide15

Next steps

  • Finalise validation of reprocessed GPS ZTD dataset
    • ZTD data screening (improve method, 1st step)
    • ZTD to IWV conversion (assess auxiliairay datasets)
    • Validate GPS IWV data by comparison with other data (MWR…)
  • Assimilation of reprocessed GPS ZTD data
    • AROME WMED reanalysis
      • Prepare data (BUFR files) and assimilation system
      • Test impact of assimilation, case studies
    • Assimilation in research models
  • Monitoring of radiosonde humidity biases
  • Validation of simulations (case studies)
  • Process studies (HPE)

IODAMED meeting, 16 May 2014

ad