acquisition.md

Acquisition Metadata

• The Acquisition metadata describes the acquisition parameters set by the user on a particular interrogator. While different interrogator vendors may implement various photonics design and algorithms which are not easily translatable across interrogators, the Acquisition metadata intends to capture the critical acquisition attributes that are commonly required to analyze and interpret the output time series or matrices. These attributes are carefully defined to be standardized across all interrogator systems.

• While the Acquisition metadata listed below should be self-sufficient for most purposes, the native headers provided by interrogator vendors can be preserved for expert users.

• Required fields (mark with an asterisk, and indicated in the tables below)
  acquisition_id* | interrogator_id* | acquisition_start_time* | acquisition_end_time* | acquisition_sample_rate* | acquisition_sample_rate_unit* | gauge_length* | gauge_length_unit* | unit_of_measure* | number_of_channels* | spatial_sampling_interval* | spatial_sampling_interval_unit*

• Optional fields
  pulse_rate | pulse_rate_unit | pulse_width | pulse_width_unit | comment

---

acquisition_id

attributeID	acquisition_id Required
Description	Unique identifier of the data acquisition, assigned by data provider. Identifier should have a maximum of 8 alphanumeric characters with no special characters (e.g., underscores, period, dash). One identifier per acquisition settings.
Required	True
Type	String
Style	Alphanumeric
Units or options	--
Example	A001

interrogator_id

attributeID	interrogator_id Required
Description	Unique identifier of the interrogator unit used in this data acquisition. The acquisition_id must nest within this interrogator_id.
Required	True
Type	String
Style	Alphanumeric
Units or options	--
Example	IU001

acquisition_start_time

attributeID	acquisition_start_time Required
Description	Start time of this data acquisition in UTC.
Required	True
Type	String
Style	ISO formatted datetime
Units or options	--
Example	2016-03-11T16:46:18.000Z

acquisition_end_time

attributeID	acquisition_end_time Required
Description	End time of this data acquisition in UTC. if data acquisition is still in operation, use a date in the future (e.g. 2999-01-01T00:00:00.000Z).
Required	True
Type	String
Style	ISO formatted datetime
Units or options	na
Example	2016-03-26T01:01:15.000Z

acquisition_sample_rate

attributeID	acquisition_sample_rate Required
Description	The rate at which the interrogator provides output data.
Required	True
Type	Integer
Style	na
Units or options	na
Example	1000

acquisition_sample_rate_unit

attributeID	acquisition_sample_rate_unit Required
Description	Unit of acquisition sample rate.
Required	True
Type	String
Style	Controlled vocabulary
Units or options	Hertz
Example	Hertz

gauge_length

attributeID	gauge_length Required
Description	The averaging length along the fiber for a measurement, determined at experiment setup and used during acquisition.
Required	True
Type	Float
Style	na
Units or options	na
Example	10

gauge_length_unit

attributeID	gauge_length_unit Required
Description	Unit of gauge length.
Required	True
Type	String
Style	Controlled vocabulary
Units or options	meter
Example	meter

unit_of_measure

attributeID	unit_of_measure Required
Description	Unit of measure of archived data set. This may be the same unit as the Interrogator Unit of Measure if the data are raw.
Required	True
Type	String
Style	Controlled vocabulary
Units or options	[count
Example	count

number_of_channels

attributeID	number_of_channels Required
Description	The total number of sampling points along the fiber as output from the interrogator, referred to as NumberOfLoci in PRODML.
Required	True
Type	Integer
Style	na
Units or options	na
Example	8720

spatial_sampling_interval

attributeID	spatial_sampling_interval Required
Description	The channel spacing, or offset, between channels.
Required	True
Type	Float
Style	na
Units or options	na
Example	1.000

spatial_sampling_interval_unit

attributeID	spatial_sampling_interval_unit Required
Description	Unit of spatial sampling interval.
Required	True
Type	String
Style	Controlled vocabulary
Units or options	meter
Example	meter

pulse_rate

attributeID	pulse_rate Optional
Description	Rate at which the interrogator unit interrogates the fiber sensor.
Required	False
Type	Float
Style	na
Units or options	--
Example	1000

pulse_rate_unit

attributeID	pulse_rate_unit Optional
Description	Unit of pulse rate.
Required	False
Type	String
Style	Controlled vocabulary
Units or options	Hertz
Example	Hertz

pulse_width

attributeID	pulse_width Optional
Description	Width of the pulse sent down the fiber in unit of time.
Required	False
Type	Float
Style	na
Units or options	--
Example	--

pulse_width_unit

attributeID	pulse_rate_unit Optional
Description	Unit of pulse width.
Required	False
Type	String
Style	Controlled vocabulary
Units or options	nanoseconds
Example	nanoseconds

comment

attributeID	comment Optional
Description	Additional comments.
Required	False
Type	String
Style	Free form text
Units or options	--
Example	na