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How to decipher a Reference Designator

The OOI maintains over 800 instruments, spread throughout 7 Research Arrays in the Atlantic and Pacific oceans. Keeping track of all of these instruments is a complex challenge, and so the Marine and Cyber engineering teams developed a special coding system to uniquely identify each instrument and it’s place in the OOI infrastructure.

These codes are called Reference Designators, and they are used to help organize the data that is collected by the OOI. The Glossary includes definitions for each infrastructure element.

You can use Reference Designators to search for data in the Data Portal (though on some screens you may have to toggle them on). They are also used in the Raw Data and Cruise Data archives to organize the data.

If you know the codes for the instruments you use most often, it can make it a lot easier to find the data you’re looking for in the various archives, so here is a quick primer.

Reference Designators for instruments are 27 characters long, and look like the following example:


To interpret this code, you can break it down as follows:

CP – Array

The first two characters denote the Research Array that the instrument is deployed at. The 7 arrays are:

  • CP – Coastal Pioneer
  • CE – Coastal Endurance
  • GA – Global Argentine Basin
  • GI – Global Irminger Sea
  • GS – Global Southern Ocean
  • GP – Global Station Papa
  • RS – Cabled Array

CP01CNSM – Site

The first 8 characters (including the two Array characters) represent the Site, or Platform the instrument is deployed on. In this case it’s the Coastal Pioneer Central Surface Mooring.

For uncabled, non-mobile sites, this typically identifies a specific mooring at a stationary location. For cabled sites, this represents the parent underwater node location that a number of smaller nodes with instruments are plugged into. Mobile assets, like gliders, are grouped into a single platform that follows the form XX05MOAS, where XX is the research array.

To translate these codes, you can check out this full list of OOI Sites

CP01CNSM-MFD35 – Node

The first 14 characters define the Node that a specific instrument is plugged into. For this example, it’s the Seafloor Multi-Function Node (MFN) on the Coastal Pioneer Central Surface Mooring.

For the Cabled Array, secondary nodes are typically in different locations than the primary node (i.e. the Platform) to which they are connected.

For mobile assets, each node actually corresponds to a unique glider or AUV. So if you’re interested in all the data from a single glider, you can just look it up by it’s Node, though keep in mind that gliders may be tasked with different missions each time they are deployed. Also, when a glider is deployed in a different array, it is given a new Reference Designator to keep the datasets from each array separate.

For moorings, the Node is typically a controller computer & communications box, but the code can also indicate where on the mooring the Node is located. This can tell you whether a Node is on the surface buoy, mooring riser, profiler, or a multi-function node on the seafloor. Nodes that start with “SB” indicate instruments located on the Surface Buoy, while RIC and RID are nodes located on the near surface instrument frame (7 or 12 m depth for coastal and global moorings, respectively). All other “RI” codes are nodes on the mooring riser (the cable that connects the buoy to the anchor on a mooring). For profilers, WFP indicates a wire-following profiler, SF is the cabled shallow profiler, SC and PC are nodes on the cabled shallow profiler 200 m platform, and DP indicates a deep profiler.

04 – Port

The two numerical digits following the Node code indicates the port on the Node that the instrument is plugged into.

VELPTA – Instrument Class/Series

The unique instrument code is the last 9 characters of the full Reference Designator, but the most useful parts are the six characters immediately following the dash which specify the Instrument Class and Series. In this case, it is a Single Point Velocity Meter, Series A.

To translate these codes, please check out the list of Instrument Class Codes.

CP01CNSM-MFD35-04-VELPTA000 – Instrument / Full Reference Designator

Now we have the full Reference Designator (including the site/node prefix and the port number “-04-” that the instrument is plugged into) for an instrument that is deployed in the OOI.

Note, that Reference Designators are tied to the “design” location for an instrument. This means that individual instruments (with their own serial numbers) are assigned to the same Reference Designator for the same location when they are swapped out between deployments. This, you can use a Reference Designator to retrieve multiple years of data for the same location, no matter how many actual instruments or deployments there have been.