OMS-tab

An dedicated format to capture metadata of columns in a dataset of (soil) observations, measurement and samples.

The format describes columns of one or more related tables, assuming that some columns contain obervation data, either field observations or laboratory measurements on samples.

For each column the following properties can be capured

Name	Description	Required	Default	Example
table_name	(File)name of the table	true	-	Field_obs
column_label	Name of the column, if empty assumes table has no column names, and uses columns in numeric order	false	-	Speed (m/s)
column_type	Value type of the column	-	string	numeric
column_format	The format of a date or numeric field, it can also be used to split a string in two or more fields, in that case the column is included multiple times in the metadata, 1 row for each string part	false	-	%Y-%m-%d
concept_type	The class for which this is a property	false	Sample	Observation, Site, Plot, Profile, Layer, Sample
concept	The nature of the property	false	-	Calcium content
concept_uri	A URI describing the concept	true	-	https://w3id.org/eusoilvoc/calcium-content
unit_symbol	the unit in which the value is written	false	-	m/s
unit_uri	the uri of the unit	true	-	http://qudt.org/vocab/unit/CentiM3
quantity_kind_uri	The quantity kind of the unit	false	-	Weight
method	the observation method used	false	-	The mass of the soil sample after oven-drying at 105 °C until constant weight, representing the dry mass of soil, measured in grams.
method_uri	A uri of the method	false	-	https://w3id.org/eusoilvoc/proc-calcium-extr
description	A description of the column	false		This column contains the measured length of the sample
primary_key	Indicates if this column is a primary key	false	false	true

Serialisations

The file can be serialised as CSV or as json-ld.

CSV

In a CSV encoding, each row describes a single column of a table.

Example:

table_name	column_label	column_type	column_format	concept_type	concept	concept_uri	unit_symbol	unit_uri	quantity_kind_uri	method	description
laos_data.csv	sample_ID	string		Feature of Interest							A unique identifier assigned to each soil sample, constructed to ensure traceability.
laos_data.csv	sample_name	string		Feature of Interest							A unique identifier for each soil sample, combining field number, replicate number, depth interval, and location.
laos_data.csv	ID_field	string		Attribute							Identifier representing the specific field from which the soil sample was collected.
laos_data.csv	ID_profile	string		Attribute							Identifier indicating the within-field replicate number for the soil sample.
laos_data.csv	ID_depth	string		Attribute							Identifier denoting the depth interval from which the soil sample was taken, with A for 0–5 cm and B for 15–20 cm.
laos_data.csv	ID_location	string		Attribute							Identifier representing the administrative location where the soil sample was collected, with ATP for Attapeu and KHA for Khammouane.
laos_data.csv	depth	string		Depth Upper	soil depth	http://w3id.org/glosis/model/common/soilDepthProperty					The soil depth interval from the surface over which the soil sample was collected, measured in centimeters.
laos_data.csv	landuse	codelist		Attribute	land use type	Tab-LandCoverTypes					The category of land use under which the soil sample was collected, such as rice, cassava, gardens, or non-cultivated.
laos_data.csv	volum_cylinder_cm3	integer		Observed Property	sample volume	https://data.geoscience.earth/ncl/ISO11074v2025/3.409	cm³	http://qudt.org/vocab/unit/CentiM3	http://qudt.org/vocab/quantitykind/Volume	ENVO – soil sampling device (ENVO:00002792)	The volume of the soil sampling cylinder used to collect an undisturbed soil sample, measured in cubic centimeters.
laos_data.csv	wet_mass_soil_g	float		Observed Property	soil water content	http://aims.fao.org/aos/agrovoc/c_7208	g	http://qudt.org/vocab/unit/GM	http://qudt.org/vocab/quantitykind/Mass		The mass of the soil sample immediately after collection, including water content, measured in grams.
laos_data.csv	dry_mass_soil_g	float		Observed Property	soil sample	http://opendata.inrae.fr/thesaurusINRAE/c_17874	g	http://qudt.org/vocab/unit/GM	http://qudt.org/vocab/quantitykind/Mass		The mass of the soil sample after oven-drying at 105 °C until constant weight, representing the dry mass of soil, measured in grams.
laos_data.csv	bulk_density	float		Observed Property	bulk density	https://data.geoscience.earth/ncl/ISO11074v2025/3.62	g/cm³	http://qudt.org/vocab/unit/GM-PER-CentiM3	http://qudt.org/vocab/quantitykind/MassDensity	ENVO – soil bulk density (ENVO:09200004)	The dry mass of soil per unit volume, including pore space, measured using a soil sampling cylinder and expressed in grams per cubic centimeter.
laos_data.csv	water_content	integer		Observed Property	soil water content	http://aims.fao.org/aos/agrovoc/c_7208	g/g	http://qudt.org/vocab/unit/GM-PER-GM	http://qudt.org/vocab/quantitykind/MassRatio	ENVO – soil gravimetric water content	The mass of water in the soil per unit dry mass of soil, expressed as a percentage by weight.
laos_data.csv	collection_date	date	%Y-%m	Phenomenon Time							The date on which the soil sampling occurred, formatted as YYYY-MM.
laos_data.csv	latitude	float		Latitude (Y)							The latitude of the geographic location where the soil sample was collected, expressed in decimal degrees (WGS84).
laos_data.csv	longitude	float		Longitude (X)							The longitude of the geographic location where the soil sample was collected, expressed in decimal degrees (WGS84).
laos_data.csv	elevation	integer		Elevation (Z)							The elevation of the location where the soil sample was collected, measured relative to sea level in meters.
laos_data.csv	location	string		Attribute	location	schema:location					The administrative province where the soil sample was collected.
laos_data.csv	country	string		Attribute	Country	schema:Country					The country in which the soil sample was collected, represented by the ISO country code LA for Laos.

JSON-ld

The json-ld encoding contains an array of table and column objects which are described using a flavour of CSV-W, extended to support observation metadata. Ambition for this implementation of CSV-W is not to enable full CSW-W interoperability, but to describe the columns in full detail. In a second automated step the OMS-tab metadata will be converted to RML to provide full SSN/SOSA interoperability.

Example:

{
  "@context": "http://www.w3.org/ns/csvw",
  "tables": [{
    "url": "signal.ID_7036_SIGNAL_SITE_POINTS.csv",
    "tableSchema": {
      "columns": [{
          "name": "OBJECTID",
          "titles": "OBJECTID",
          "datatype": "decimal",
          "propertyUrl": "http://schema.org/identifier"
          "@type": "sosa:FeatureOfInterest"
          "@id": "https://example.com#{OBJECTID}"
        },
        {
          "titles": "Latitude",
          "datatype": "decimal",
          "propertyUrl": "https://schema.org/latitude",
          "about": "https://example.com#{OBJECTID}"
        },
        {
          "titles": "Longitude",
          "datatype": "decimal",
          "propertyUrl": "https://schema.org/longitude",
          "about": "https://example.com#{OBJECTID}"
        },
        {
          "titles": "ECEC (DC/m)",
          "name": "ecec",
          "datatype": "decimal",
          "propertyUrl": "http://w3id.org/glosis/model/codelists/properties/electricalConductivity",
          "schema:measurementTechnique": "https://w3id.org/eusoilvoc",
          "schema:unitCode": "http://qudt.org/schema/qudt/DeciS-PER-M",
          "@type": "sosa:Observation",
          "@id": "https://example.com#{OBJECTID}/ecec"
        }
      ]
    }
  }]
}