70 likes | 81 Views
Explore advantages and drawbacks of communication methods for manned VOS ships. Discussion on cost, systems, and benefits of binary compression in data reporting.
E N D
VOS data com. systems Manned VOS AWS systems PMO-3 workshop – Hamburg – 23-24 March 2006
Inmarsat-C (standard) Only manned VOS are concerned here • Advantages • GMDSS beacon of the ship is used (by almost manned VOS) • alphanumeric FM-13 SHIP messages reported from the ship (no processing needed ashore – important aspect for code 41) • Drawbacks • hight cost of transmission (1.00 €/report) • unfair share of the transmission costs (code 41) : a few NMSs pay communication costs for VOS recruited by others Remark : Some NMSs ask for a direct reception of the SHIP reports of their VOS fleetsThe « code 41 » procedure is then not used but communication costs remain high PMO-3 workshop – Hamburg – 23-24 March 2006
Inmarsat-C (standard) Only manned VOS are concerned here • Existence of bilateral arrangements • e.g. between DWD and Met Office ; DWD and KNMI • allow to reimburse communication costs (e.g. for German VOS) • E-SURFMAR compensations • 54 k€ in 2005, 59 k€ in 2006 • about 300,000 reports compensated in 2005 ; 315,000 in 2006 • about 0.18 €/report – to be compared to the real cost (~1.00 €/report) PMO-3 workshop – Hamburg – 23-24 March 2006
Inmarsat-C (standard) PMO-3 workshop – Hamburg – 23-24 March 2006
Alternative com. systems • For AWS • any system may be used since the AWS is fitted with its own transmitter • e.g. Argos, Globalstar, Inmarsat (Data Reporting), Iridium, Meteosat • For manned VOS using Turbowin for instance • - it seems difficult to report pure binary data through the GMDSS beacon • but it should be possible to report half-compressed data through this way (~0.40 €/report) • or to fit Turbowin laptops with an Iridium modem + antenna (0.08 €/report) Equipment (300-500€ laptop excluded) to be amortized • or to use the cheapest system used aboard by the crew to report ashore: (Globalstar, Iridium…) Remark : In any case, « code 41 » would be abandonnedbecause of the necessity to have data processing centres PMO-3 workshop – Hamburg – 23-24 March 2006
Binary compression Not linked reserved to Batos or Inmarsat only • Characteristics • a SHIP report tits in a 256-bits block (32 bytes) • rather looks like to an Argos compression than BUFR or compressions commonly used by computers • data received through e-mails • Advantages • reduces the communication costs (0.15 €/report for Inmarsat, 0.08 €/report for Iridium) • Drawbacks • needs a data processing centre to uncompress the data and then code them into GTS formats • to simplify the work, a ship is attached to a processing centre => data stream control possible = advantage PMO-3 workshop – Hamburg – 23-24 March 2006
Binary compression Each ship is attachedto a processing centre Monitoring and Metadat PMO-3 workshop – Hamburg – 23-24 March 2006