Understanding the resource specific metadata elements for a Time Series

The metadata description for time series in HydroShare comes from the ODM2 information. The representation of Time Series in ODM2 is quite similar to Version 1.1 of ODM, which is used by the CUAHSI HIS. In general, you need to describe the location at which the data were measured or created (Site), what was observed (Variable), how the observations were created (Method), the level of processing or quality control the data have received (Processing Level), and then some additional information about the Time Series values like Units (Time Series Result). The following are descriptions of each of the individual Time Series resource specific metadata elements. You can see an example time series resource in HydroShare here: https://www.hydroshare.org/resource/1a25b11fa1354773b6edb9495e754f4e/

Site Information

Site code: A brief and unique code that identifies the site at which the data were collected (e.g., “USU-LBR-Mendon” or “10109000”).

Site name: A brief but descriptive name for the site (e.g., “Little Bear River at Mendon Road near Mendon, Utah”).

Elevation m: The elevation of the site in meters (e.g., 1345)

Elevation datum: The datum to which the site elevation is referenced (e.g., “NGVD29”)

Site type: A controlled vocabulary term that describes the type of data collection site (e.g., “Stream”)

WGS84 Latitude: The latitude coordinate of the site location using the WGS84 datum (e.g., 43.1111)

WGS84 Longitude: The longitude coordinate of the site location using the WGS84 datum (e.g., -111.2334)

Variable Information

Variable code: A brief and unique code that identifies the measured variable (e.g., “Temp”)

Variable name: A brief but descriptive name of the variable that was measured selected from a controlled vocabulary of variable names (e.g., “Temperature”)

Variable type: A term selected from a controlled vocabulary that describes the type of variable that was measured (e.g., “Water quality”).

No data value: A numeric value that is used to represent “NoData” values in the time series (e.g., -9999)

Variable definition: An optional, longer text description of the variable (e.g., “Water temperature”)

Speciation: A term describing the chemical speciation of the resulting data values. For most continuous time series from environmental sensors, this will be “Not Applicable”.

Method Information

Method code: A brief and unique code that identifies the method used to create the observations (e.g., “Hydrolab”)

Method name: A brief but descriptive name for the method used to create the observations (e.g., “Hydrolab MiniSonde 5”)

Method type: A term selected from a controlled vocabulary to describe the type of method used to create the observations. For sensor measurements use “Instrument deployment.”

Method description: A longer text description of the method (e.g., “Water temperature measured using a Hydrolab Multiparameter Sonde.”)

Method link: A URL link to a website that contains more information about or a detailed description of the method (e.g., “http://www.hydrolab.com”)

Processing Level Information

Processing level code: A brief and unique code that identifies the processing level of the observations (e.g., “QC1”)

Definition: A brief description of the processing level (e.g., “Quality Controlled Data”)

Explanation: A longer text description of the processing level that provides more detail about how the processing was done (e.g., “Data that have passed quality control processing.”)

Time Series Result Information

Units type: A term selected from a controlled vocabulary that describes the type of units used for the Time Series result values (e.g., “Temperature”)

Units name: A brief, but descriptive name of the units used for the Time Series result values (e.g., “Degrees Celsius”)

Units abbreviation: A text abbreviation for the units (e.g., “Deg. C”)

Status: A term selected from a controlled vocabulary to describe the status of the time series. Completed datasets use “Complete”. Where data collection is ongoing, use “Ongoing.”

Sample medium: A term selected from a controlled vocabulary to specify the environmental medium in which the observation was made (e.g., “Liquid aqueous”)

Value count: The total number of data values in the Time Series (e.g., 24205)

Aggregation statistic: An indication of whether the values are “Continuous” or represent recorded values of some statistic aggregated over a time interval (e.g., “Average”).

UTC Offset Information: The value of the UTCOffset for timestamp values accompanying your time series data.