Instrumentation

Description

An OBS instrumentation is an ensemble of instruments associated with specific channels constitute a physical unity that will be launched and recovered as a unit. While obsinfo is concerned only with the signal processing aspects of the instrumentation, an OBS instrumentation also includes the physical parts of the OBS frame, ballast elements, recovery devices, communication and power supply.

Channels in the instrumentation all have string labels, which are usually channel numbers. They must specify an orientation. Default chann properties can be specified with a label default. These properties are common to all channels unless overridden by attributes present in specific channels. For example, if a sensor X appears under the label default but a sensor Y appears under the label “2” then for channel 2 the selected sensor will be Y. If a preamplifier Z is specified under the label default and no preamplifier is specified under the label “2”, then channel 2 will have preamplifier Z. All attributes can be specified under the default label.

Python class:

Instrumentation

YAML / JSON label:

instrumentation: Contained in an instrumentation file

Corresponding StationXML structure

None: At the Station level StationXML documents the total number of channels and the selected number of channels. Both are equal in OBS and are calculated implicitly.

Object Hierarchy

Superclass

None

Subclasses

None

Relationships

Is used in a Station
Has one or several Channels
Has one or specifications defined in Equipment

Attributes

Name	Type	Required	Default	Equivalent StationXML	Remarks
equipment	Equipment	Y	None	None
channels	Array of Channel	Y	None	Channel
channel_modifications	Array of Channel	Y	None	Channel	See Advanced Topics for details

The attribute channel_modifications is used to modify the attributes of a channel. In particular, instruments are supposed to be a rather static database of components and their configurations, but occasionally it is necessary to change some of the attributes for particular campaigns.

Under this keyword the user can specify a complete hierarchy down to the filter level. Only the value(s) specified will be modified. So if a “leaf” value is changed, such as gain value, only the gain value for a particular stage will be changed. But if a complete sensor is specified, the whole component along with its stages and filters will be modified. For more details, see Advanced Topics.

JSON schema

https://www.gitlab.com/resif/obsinfo/-/tree/master/obsinfo/data/schemas/instrumentation.schema.json

https://www.gitlab.com/resif/obsinfo/-/tree/master/obsinfo/data/schemas/definitions.schema.json

Example

YAML code for instrumentation information file https://www.gitlab.com/resif/obsinfo/-/tree/master/obsinfo/_examples/Information_Files/instrumentation/BBOBS1_2012%2B.instrumentation_base.yaml with the channel_template and das_channels parts elided.

---
format_version: "0.110"
revision:
   date: "2019-12-19"
   authors:
       - {$ref: "authors/Wayne_Crawford.author.yaml#author"}
       - {$ref: "authors/Romuald_Daniel.author.yaml#author"}
instrumentation_base:
   operator: {$ref: "operators/INSU-IPGP.operator_info.yaml#operator_info"}
   equipment:
       model: "BBOBS1"
       type: "Broadband Ocean Bottom Seismometer"
       description: "LCHEAPO 2000 BBOBS 2012-present"
       manufacturer: "Scripps Inst. Oceanography - INSU"
       vendor: "Scripps Inst. Oceanography - UNSU"

   channels:
       default:
             ...

       "1":
             ...

       "2":
             ...

       "3":
             ...

       "4":
              ...