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Surface pressure PROVOR/ARVOR floats Coriolis DAC V. Thierry DMQC 4 – Toulouse – September 2009. downtime. uptime. A. D. C. B. telemetry period. Surface pressure for PROVOR/ARVOR floats. Psurf is measured just before the float dives
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Surface pressure PROVOR/ARVOR floatsCoriolis DACV. ThierryDMQC 4 – Toulouse – September 2009
downtime uptime A D C B telemetry period Surface pressure for PROVOR/ARVOR floats • Psurf is measured just before the float dives • The Psurf value is taken into account for the next cycle and for the next profile (in general 10 days later) • Psurf is simply substracted from the pressure measurements for CTF and CTS2 PROVOR floats • A reset of the pressure sensor is done with the “RESETOFFSET” command of the SBE41CP sensor for the CTS3 PROVOR and ARVOR floats
Surface pressure for PROVOR/ARVOR floats • Data are then truncated (-0.3 → 0; 0.6 → 0 ) and transmitted with a 1 dbar resolution for the CTF, CTS3, CTS3 et ARVOR • With an Iridium transmission and for CTS3 deployed since June 2009, the data are transmitted with a 1cbar resolution Those differences are significant when dealing with the microleak problem.
PROVOR – CTS2 • Psurf measurements (1cbar resolution) subtracted to the pressure measurements • No reset of the pressure sensor • 8% of the CTS2 affected by the micrloeak problem • The floats affected by the microleak problem have not been re-considered in D mode but the drift is corrected at each cycle
PROVOR CTS3 Surface pressure offset relative to the previous profile • Reset of the pressure sensor before each dive (RESETOFFSET command) • Transmission of a relative offset with a 1 dbar resolution • Statistics: • 140 floats with Psurf = 0 • 6 floats with Psurf = ± 1 dbar • 2 floats with |Psurf | > 1 dbar • Unknown percentage of the floats concerned by the microleak problem
PROVOR CTS3 Cumulative surface pressure offset • Reset of the pressure sensor before each dive (RESETOFFSET command) • Transmission of a relative offset with a 1 dbar resolution • Statistics: • 140 floats with Psurf = 0 • 6 floats with Psurf = ± 1 dbar • 1 floats with |Psurf | > 1 dbar • Unknown percentage of the floats concerned by the microleak problem
PROVOR CTS3 – cbar transmission CTS3 Iridium • Reset of the pressure sensor before each dive (RESETOFFSET command) • Transmission of a relative offset with a 1 cbar resolution • 73 % of the floats concerned by the microleak problem
PROVOR CTS3 – cbar transmission CTS3 Iridium • Reset of the pressure sensor before each dive (RESETOFFSET command) • Transmission of a relative offset with a 1 cbar resolution • 73 % of the floats concerned by the microleak problem