|0.1||Streamlined and cleaned up draft||2013-12-06|
|0.5||Fixed typos and minor editing for Milestone 1.0||2014-08-31|
|Jeff de La Beaujardière||Author||NOAA/NESDIS/Technology Planning and Integration Office|
|Derrick Snowden||Contributor||U.S. IOOS Office|
|Carmel Ortiz||Contributor||U.S. IOOS Office|
|Alex Birger||Contributor||U.S. IOOS Office|
|Anna Milan||Contributor||NOAA National Geophysical Data Center (NGDC)|
For the sake of illustration, we first provide examples of identifiers in use by IOOS. Later sections of this document constitute the actual specification of those identifiers. In the case of conflict or ambiguity, the specification sections take precedence over these examples.
|WMO buoy 42001||
|Wave sensor on WMO buoy 42001||
|CO-OPS station cb0102||
|Active water level sensors within CO-OPS network of stations||
|Water level sensor at CO-OPS station 8454000||
|Nortek Acoustic Doppler Profiler sensor that is measuring water currents and/or waves and is mounted on the CO-OPS cb0201 station||
General Identifier Convention
Use of Uniform Resource Names
An IOOS identifier is a Uniform Resource Name (URN). URNs are commonly used as identifiers in the Internet’s information architecture. An introductory description of URNs may be found on Wikipedia. Some of the material in this section is based on definitions and restrictions established by Internet Engineering Task Force (IETF) Request for Comments (RFC) 2141.
All URNs assigned by IOOS begin with the string
urn:ioos:, followed by one or more fields also separated
by colons (
:). The initial
urn: indicates that the identifier is a URN. The following
indicates that the URN is in the IOOS namespace.
NOTE: IOOS intended to formally register the ioos namespace with IANA, but has not done it yet (2010-12-22) has not.
The additional fields may only include letters and numbers (A-Z, a-z, 0-9) and the following characters: ( ) + , - . = @ ; $ _ ! *
Special characters not in the foregoing list must be represented using hexadecimal encoding as %xx, where xx represents a two-digit hex value. The use of such characters in IOOS URNs is not recommended.
IOOS URNs are considered to be case-insensitive. Example:
urn:ioos:abc refer to the same thing.
This is more restrictive than, but permitted by, IETF RFC 2141. The fields in IOOS URNs are customarily lower-case
but may appear in uppercase or mixed-case.
The general pattern for IOOS asset identifiers is
which consists of the following fields delimited by
urn:ioosa fixed string indicating this is an IOOS URN;
asset_typea variable indicating the type of asset being identified;
authorityan abbreviation or name for the organization that assigned the label;
labelthe number or label that was assigned by the authority to the asset;
componentan optional field naming a specific component.
The following sections explain in details the use of all variable fields. Ideally these fields will be populated with values from community governed controlled vocabularies. While this is not mandated by this specification, some candidate vocabularies are suggested in the following sections.
asset_type field indicates the type of asset to which this identifier applies. The following values
asset_type are recognized by IOOS:
- A fixed installation or nominally-constant position where measurements are performed. Examples include: a
water-level gauge mounted on a pier; a moored buoy that moves within a known watch radius of the nominal
mooring location; an OceanSITES deep-water monitoring location; a site at which water quality samples are taken.
componentfield may be added to the URN to identify a specific sensor located at the station. If
componentfield is omitted, the URN identifies station itself.
- A network of stations defined above.
- A device associated with the station that measures one or more observed quantities at or adjacent to the
station location. Examples include: a water-level sensor; a temperature sensor; an anemometer; a current meter.
A sensor identifier URN includes the
labelfields of the station, and a
componentfield to distinguish it from other sensors at the same station. Note that
labelfor sensor is different from
- A visual observation, measurement or collecting samples by a human observer performed at a station or from a ship for a follow-up analyzes in the laboratory. Example: a quarterly visit to a known location to collect water for chemical analysis; an assessment by a diver of the species present in a particular location, etc.
asset_type values may be added by IOOS as needed. Candidate controlled vocabularies that may
be adopted as the valid values in the
asset_type field are:
authority field indicates the organization that assigned the label for this asset. There is no fixed
set of values, because additional authorities may become relevant as new observing systems are connected to IOOS.
However, the same abbreviation or name should be used for all instances of a particular authority. These
abbreviations are case insensitive. The following values for
authority are currently used in IOOS:
- World Meteorological Association.
- Center for Operational Oceanographic Products and Services (COOPS) in the National Ocean Service (NOS) of the U.S. National Oceanic and Atmospheric Administration (NOAA).
- U.S. Army Corps of Engineers.
- Florida International University.
- Temporary service instance using for test.
Candidate controlled vocabularies that may be adopted as valid values for the
authority field include:
- GCMD Keywords
- Data Centers: http://gcmdservices.gsfc.nasa.gov/static/kms/providers/providers.csv
- Projects: http://gcmdservices.gsfc.nasa.gov/static/kms/projects/projects.csv
label is a number or string assigned by the Authority to the asset. Allowed values are defined by the
particular authority. The only restrictions are that (a) the characters used must not conflict with the URN
specification (see section 2.1) and (b) labels in the scope of a given authority must be unique.
label value varies between station and sensor URNs.
component field is used to distinguish between different assets associated with the same parent asset.
For example, a buoy may have multiple sensors attached to it, and each sensor will have an identifier that includes
the label for the buoy and the label for the sensor. The component label must be unique for each
Convention for Specific Asset Types
The pattern for IOOS platform identifiers is
Platform identifiers do not include a
The pattern for IOOS sensor identifiers may be either
Depending on the option, sensor is identified either by its
label_sensor, or by a station
which provides a name for the sensor. The specific names are at the discretion of the organization operating the sensor
or the service to access data from the sensor. The
label_sensor values may vary for the same
sensor, and may reflect the make and model of the sensor (e.g.,
SONTEK-ADP-419), the phenomenon observed by that
salinity), or an arbitrary label used by the organization (e.g.,
A1). The name may not include
characters not allowed in Section 3.1.
Currently, IOOS Convention does not regulate asset versioning; therefore, no requirements have been established for the version number report. It is strongly recommended to avoid referring to any version number at all in asset’s URN.
A survey identifier URN includes the
label fields of the station or a ship, and a
field to distinguish it from other surveys at the same station or ship:
For visual observation purpose, the
component fields may also indicate either
(1) the general observing protocol or (2) the specific type of observation.
General observing protocol
If visual estimates are made according to some established observing protocol, then the
authority field may contain
a reference to the document that describes the protocol. For example, if observation was made by the
NWS Observing Handbook No. 1 (2004),
then the survey identifier will look as follows:
If a simple reference to the document is sufficient to avoid any need for additional interpretation, it is acceptable to identify the survey with just the URL of the document describing the observing protocol, laboratory procedures, etc. In the case of the NWS Observing Handbook, for example, the following URL may play a role of the survey ID:
Specific type of observation
The survey identifier may include the type of observation made by the human. For example, in the NWS Handbook, Chapter 2,
page 2-7 says that “iw” is the “wind speed indicator”, and that it has values 0, 1, 3, 4 depending on how the wind speed
was estimated or measured, with “3” being “wind speed estimated in knots.” For such an observation, the survey identifier
may use the observation code instead of
or in a more verbose manner:
Similarly, from p.2-76, sea surface temperature measurement can be identified as