1-02 Measurement unit (C) 1-03 Temporal extent (M) 1-04 Spatial extent (M) 2. Purpose of observation 2-01 Application area(s) (M) 2-02 Programmes/network affiliation (M) 3. Station/ platform 3-01 Region of origin of data (C) 3-04 Station/platform type (M) 3-05 Station/platform model (M) 3-02 Territory of origin of data (C) 3-08 Data communication method (O) 3-03 Station/platform name (M) 3-06 Station/platform unique identifier (M) 3-07 Geospatial location (M) 3-09 Stationoperating status (M) 4. Environment 4-04 Events at station/platform (O) 4-05 Site information (O) 4-01 Surface cover (C) 4-02 Surface cover classification scheme (C) 4-03 Topography or bathymetry (C) 4-06 Surface roughness (O) 4-07 Climate zone (O) 5. Instruments and methods of observation 5-01 Source of observation (M) 5-11 Maintenance party (O) 5-04 Instrument operating status (O) 5-02 Measurement/observing method (M) 5-12 Geospatial location (C) 5-06 Configuration of instrumentation (C) 5-03 Instrument specifications (C) 5-15 Exposure of instrument (C) 5-07 Instrument control schedule (C) 5-05 Vertical distance of sensor (C) 5-08 Instrument control result (C) 5-09 Instrument model and serial number (C) 5-10 Instrument routine maintenance (C) 5-13 Maintenance activity (O) 5-14 Status of observation (O) 6. Sampling 6-03 Sampling strategy (O) 6-05 Spatial sampling 6-01 Sampling procedures (O) 6-07 Diurnal base time (C) 6-02 Sample treatment (O)
6-08 Schedule of observation (M) 6-04 Sampling time period (M) 6-06 Temporal sampling interval (M) 7. Data processing and reporting 7-03 Temporal reporting period (M) 7-02 Processing/analysis centre (O) 7-01 Data processing methods and algorithms (O) 7-04 Spatial reporting interval (C) 7-06 Level of data (O) 7-05 Software/processor and version (O) 7-11 Reference datum (C) 7-09 Aggregation period (M) 7-07 Data format (M) 7-10 Reference time (M) 7-08 Version of data format (M) 7-12 Numerical resolution (O) 7-13 Latency (of reporting) (M) 8. Data Quality 8-01 Uncertainty of measurement (C) 8-02 Procedure used to estimate uncertainty (C) 8-03 Quality flag (M) 8-04 Quality flagging system (M) 8-05 Traceability (C) 9. Ownership and Data Policy 9-02 Data policy/use constraints (M) 9-01 Supervising organization (M) 10. Contact 10-01 Contact (nominated focal point) (M) Attachment to Appendix 2.4. Metadata Standard I. WIGOS An important aspect of WIGOS (WMO Integrated Global Observing System) implementation is ensuring maximum usefulness of WIGOS observations. Observations without metadata are of very limited use: it is only when accompanied by adequate metadata (data describing the data) that the full potential of the observations can be utilized. Two complementary types of metadata are required: discovery metadata and interpretation/ description or observational metadata. Discovery metadata facilitate data discovery, access and retrieval. They are WIS metadata and are specified and handled as part of WIS. Interpretation/description or observational metadata enable data values to be interpreted in context. They constitute WIGOS metadata and are the subject of this WIGOS standard for the interpretation metadata required for the effective utilization of observations from all WIGOS component observing systems by all users. The WMO Integrated Global Observing System metadata should describe the observed variable, the conditions under which it was observed, how it was measured, and how the data have been processed, in order to provide users with confidence that the data are appropriate for their application. The Global Climate Observing System(GCOS) Climate Monitoring Principle 2.2.1(c) (see Appendix 2.2) describes the relevance of metadata as
Figure 1. UML diagram specifying the WIGOS Metadata Standard (**: code tables expected; [0..1*]: optional or conditional elements. Conditional elements become mandatory if a given condition is met. Conditions are referenced in parentheses. Optional elements may be declared mandatory as part of profiling the standard for specific application areas; [1..*]: mandatory elements. These elements must be reported, and if no value is available, a nilReason must be reported, which indicates that the metadata is “unknown”, or “not available”). Table 2. Names and definition of elements An asterisk (*) denotes the element is required for the WMO Rolling Review of Requirements (RRR) process. A hash sign (#) denotes that it is acceptable to record a "mandatory" element with a of nilReason (that indicates that the metadata is either “unknown”, or “not applicable”, or “not available”). Category Id Name Definition MCO Phase Observed variable 1-01 Observed variable – measurand Variable intended to be measured or observed or derived, including the biogeophysical context M* 1 1-02 Measurement unit Real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared to express the ratio of the two quantities as a number [VIM3, 1.9] C* 1 1-03 Temporal extent Time period covered by a series of observations inclusive of the specified date-time indications (measurement history) M* 1 1-04 Spatial extent Typical georeferenced volume covered by the observations M* 1
“a depression within plains of very low depth” 4-04 Events at observing facility Description of human action or natural event at the station or in the vicinity that may influence the observation NOTE 1: This information may be frequently changing (for example ocean debris impacting buoys). NOTE 2: The start and end time/date of the event should be included 4-04 or free textor an URL O (Phase 2) 4-05 Site information Non-formalized information about the location and its surroundings at which an observation is made and that may influence it NOTE: In hydrology, description and dating of activities occurring in the basin that can affect the observed discharge, e.g., construction of a regulation structure upstream of the gauging location that significantly affects the hydrological regime, inter-basin diversion of water into or from the basin upstream of the gauging location, significant change in consumptive use, surface cover or land use. EXAMPLES: maps, plans, photographs, descriptions and other unique site information that is difficult to express in words or that cannot easily be quantified. Free text and/or URL(s) O (Phase 2) 4-06 Surface roughness The Terrain classification in terms of aerodynamic roughness length NOTE: The Terrain classification (Davenport and Wieringa) as mentioned in WMO-No. 8, 2008, Updated 2010, to Chapter 5 4-06 O (Phase 3) 4-07 Climate zone The Köppen climate classification of the region where the observing facility is located The Köppen-Geiger climate classification scheme divides climates into five main groups (A, B, C, D, E), each having several types and subtypes. 4-07 O (Phase 3)
(iv) Ship: Visual Obs Height: 22.0 m a.s.l.; (v) Weather Radar: Warruwi AU 24.3 m above ground surface (see 7-07); (vi) Transmissometer 2.55 above runway surface; (vii)Depth of buoy relative to lowest astronomical tide; (viii)Pressure sensor: vertical distance above mean sea level. 5-06 Configuration of instrumentation Description of any shielding or of the instrumentation or auxiliary equipment needed to make the observation or to reduce the impact of extraneous influences on the observation NOTE: An URL could be provided in case of space-based observations. EXAMPLES(for surface-based observations): Shelter, temperature control, etc. Internal volume: [m3] Aspirated: [Natural/forced/na] Aspiration rate: m3s-1 Shielding from: [radiation/precipitation/ wind/etc.] C# (Phase 3) 5-07 Instrument control schedule Description of schedule for calibrations or verification of instrument NOTE: For space-based observations, it applies only to major changes; For very frequent changes on parameters, a specific link to external source should be provided. EXAMPLE: Every year on first week of February C 3)
6-08 Schedule of observation Schedule of observation EXAMPLES: profiling observations are available from Zurich airport between 0600 and 1200 local time; Radio-sondes are collected at a particular station from January to August on weekdays at 0000z and 1200z. Free text M (Phase 1) {6-05, 6-06, 6-07, 6-08} A nil Reason = ”not applicable” is acceptable for space-based observations. 7: Specifies how raw data are transferred into the observed variables and reported to the Id Name Definition Note or example Code table ItemMCO 7-01 Data processing methods and algorithms A description of the processing used to generate the observation and list of algorithms utilized to derive the resultant value NOTE: In hydrology, this would be the equation(s) defining the rating curve and any shifts or corrections applied to the data or the curve. EXAMPLE: Radiation correction and calculation of geo-potential height for soundings. Free text or an URL O (Phase 3) 7-02 center Center at the observation is processed. EXAMPLES: Chemical analysis, processing center, National Hydrological Service office. O (Phase 2)
7-13 Latency (of reporting) The typical time between completion of the observation or collection of the datum and when the datum is reported (i) For satellite data, the “observation” (e.g. a complete image) can take 20 minutes to generate. Hence the latency would be the time between the completion of the image collection, and when it is available. Typically this can be 2–3 minutes. Some satellite products such as SST can take about 10 minutes of processing until it is available; (ii) A radar volumetric scan can take 6–10 minutes (in Australia), so the latency would be the time between the completion of the scan and when the data is locally available. In Australia, this varies between a few seconds to several minutes depending on delays in data communications; (iii) AWS data may have a latency of 1–20 seconds (or considerably more in some places) between the completion of the observation and arrival of the data at a central archive. M 3) 1 Provided as part of the WIS metadata records Conditions: {7-04}: mandatory for remote sensing observations and mobile platforms in general {7-11}: mandatory for stations/platforms that report a derived observation value that depends on a local datum 8: Specifies the data quality and traceability of the observation Id Name Definition Note or example Code ItemMCO 8-01 Uncertainty of measurement Non-negative parameter, associated with the result of a measurement, that characterizes the dispersion of NOTE 1:
EUMETSAT, ESA, NOAA, NASA, CMA, RapidEye, ISRO 9-02 Data policy/use constraints Details relating to the use and limitations surrounding data imposed by the supervising organization NOTE: Only one single use constraint with a value taken from WMO_DataLicenseCode is allowed to ensure unambiguity (WMO, 2013b, p. 51) 9-02 M* (Phase 1) 10: Specifies where information about an observation or dataset can be obtained. Id Name Definition Note or example Code Table ItemMCO 10-01 Contact (Nominated Focal Point) Principal contact (Nominated Focal Point, FP) for resource NOTE: The FP would be able to provide data users with information regarding individual observing platforms and their observations. EXAMPLES: Programme or Network Manager, e.g. E-AMDAR Technical Coordinator (TC) has responsibility for data quality of several airlines’ fleets, has information on aircraft type/software/known errors etc. M (Phase 1)