An inventory of collocated and nearly-collocated CGPS stations and tide gauges

Plan : Background Survey results (September 2002) CGPS@TG data availability Outlooks

Guy Wöppelmann, CLDG - Université La Rochelle

Rationale for an inventory of CGPS@TG

Survey Survey started in Autumn 1999 To identify existing and planned GPS stations close to tide

gauges around the world (up to ~10 km) Initiative supported by various groups : M.Bevis (IGS/PSMSL),

C.Boucher (IERS/IGS), C.Bruyninx (EUREF) and P. Woodworth (GLOSS/PSMSL)

Motivations to get an up-to-date idea about CGPS positioning of TG status,

operational and potential (planned or not locally tied yet) to provide a starting point for discussions (what might be

worth to include in international projects, recommendations...)

“to update the list of GPS receivers at tide gauge sites at regular intervals” (GLOSS-GE action item, Hawaii 2001)

Results of the survey

Reported CGPS@TG has increased from 129 to 152 since last progress report in 2001.

There are still 6 planned stations in 2002, although not exactly the same as in 2001 ...

Progress Report is available at :http://www.sonel.org/stations/cgps/surv_update.html

GLOSS CGPS@TG stations (1)

GLOSS CGPS@TG stations (2)

Distance separating CGPS and TG

CGPS@TG, a vague concept... as collocation as well...

CGPS data availability

CGPS data availability - TIGA DC (1)

CGPS data availability - TIGA DC (2)

All data on-line. Easy and simple access by anonymous FTP (ftp.sonel.org)

DORIS@TG

CONCLUSIONS - OUTLOOKS

Data availability and access 1/3 (46 out of 152) of CGPS data at TG seem not available yet Access to off-line ancient IGS tracking data ? New available stations (UK, New-Zealand, South-America,

Turkey...) May TIGA DC duplicate sea level data (Coherence, Back-up...) ? Standard for sea-level data files (action within GLOSS) ?

Local ties A crucial point... Detailed survey ? Action within TIGA (TOS forms) ?

Continuously updated survey Dynamic tables (browse and search facilities into database) On-line form to fill up or E-mail (gwoppelm@univ-lr.fr)

Survey Form

Accessible through the on-line Progress Report

http://www.sonel.org/stations/cgps/surv_update.html

RONIM tide gauge network(18 operational stations, April 2002)

La Rochelle

MORS HT 200

Acoustic and Radar

Sensors