The PON‐EMSO InSea (Initiatives in Supporting the consolidation and enhancement of the EMSO infrastructure and related Activities) project aims to upgrade the seafloor infrastructures of the EMSO Western Ionian Sea facility managed by INGV. The objective of the project is the permanent installation of several multiparametric seabed observatories, at a depth of about 2000 meters, powered by a submarine electro‐optical cable connected to a shore station located in the port of Catania and managed in collaboration
with INFN (Istituto Nazionale di Fisica Nucleare).
The infrastructure that powers the EMSO Western Ionian Sea facility is intended to provide the power to the instruments and the equipments of the facility, make available a network communication link used to acquire scientific data from the instruments and to monitor the infrastructure and distribute a common clock that allows to timestamp all data produced.
The GPS-derived reference clock is acquired onshore and distributed throughout the network by means of the Precision Time Protocol (PTP). Using commercial switches that implement the PTP in hardware, it is possible to propagate the reference time with an error of about +/-100ns. The use of PTP allows time to be distributed with a standard, reliable, internationally regulated protocol widely implemented in various commercial devices.
All the instruments and the equipment of the facility are nodes of an ethernet network and can be divided into three categories depending on their sampling frequency and synchronisation mechanism:
- Environmental and oceanographic instruments without synchronisation protocol, with sample frequency <10Hz and an RS232 communication protocol;
- Geophysics instruments that support PTP synchronisation protocol, sampled from few tens Hz to few kHz;
- High frequency hydrophones with proprietary synchronisation protocol and sample frequency>10kHz.
The technical report, “Sistema di sincronizzazione dei dati multiparametrici acquisiti dagli osservatori sottomarini cablati nella facility di EMSO Western Ionian Sea”, describes the constructional and functional characteristics of the Syncboard v1.0 synchronization board developed by INGV. The Syncboard v1.0 distributes the timing supplied by a GPS antenna, installed at the shore station, to those instruments of the submarine observatories that do not implement the PTP synchronization protocol.
For more details:
Giacomozzi E., Simeone F., Marinaro G., (2023). Sistema di sincronizzazione dei dati multiparametrici acquisiti dagli osservatori sottomarini cablati nella facility di EMSO Western Ionian Sea. Rapp. Tec. INGV, 471: 1-20, https://doi.org/10.13127/rpt/471
Or you can email to Emanuele Giacomozzi: emanuele.giacomozzi@ingv.it
Credits of the “Rapporti Tecnici”’s Figure: INGV
Figure 2: Syncoboard and hardware interfaces. Credits: Emanuele Giacomozzi (INGV)
Author: Aleassandra Giuntini (INGV)