Surface observation at fixed land stations (such as RBSN stations) report a standard set of physical variables. The report is known as a SYNOP after the traditional alphanumeric code form that was originally used to exchange them (FM12 SYNOP). They shuld now be exchanged in FM94 BUFR using templates that were derived from the reporting requirements for FM12 SYNOP.

explanations

metadata identifier

In case the data is disseminated as GTS bulletins, the identifier should be based on TTAAii CCCC string. In the example below, the bulletin ISMC01 RJTD has the identifier urn:x-wmo:md:int.wmo.wis::ISMC01RJTD.

See MDG_Spec1 for the regulation in general.

contact (of metadata)

The element gmd:contact is contact about the metadata record itself. It is supposed to be the WIS centre that submits the metadata. For synoptic observation that is supposed to be the NC (National Centre) of the country.

See MDG_Contact about the inside of contact.

title

The gmd:title element is the title of the dataset by which the dataset is cited. For GTS bulletins, in addition to the general guideline given in MDG_DO, it is recommended to include the heading TTAAii CCCC.

The example below ISMC01 RJTD - Surface synoptic reports at main synoptic hours for RBSN stations in Japan contains three out of four elements of good title in the guideline: what, when, and where. The creator of the dataset (who) may not relevant if the data is collected from more than one organizations. Rather the programme (RBSN) was chosen for clarification of who is working for the data.

abstract

The abstract element is more detailed description of the dataset.

In addtion to the general guideline given in MDG_DO, it is recommended to include WMO station identifiers and the names of the stations for fixed surface observations.

point of contact (of dataset)

The element gmd:identificationInfo/*/gmd:pointOfContact is contact about the content of the dataset. That may be different from the metadata contact, if the report is disseminated by an organization different from the NC.

resourceFormat and distributionFormat

TT-ApMD recommended that the elements resourceFormat and distributionFormat should have same contents. See also MDG_DIS.

For alphanumeric reports, the name and the version of MD_Format are FM 12 SYNOP and XII Ext. respectively. For BUFR Edition 4, the name and the version are FM 94 BUFR and XIV.

place keywords

Recommendation: station identifier 5-digit, name of station, and country name.

theme keywords (WMO_CategoryCode)

Mandatory. At least one keyword must be chonsen from common codelist WMO_CategoryCode.

theme keywords (physical quantities)

There have long been an idea that the WIS metadata for observation data should contain keywords representing physical quantity of the observation. Unfortunately the authors are not in the position to recommend a standard list of keywords.

resourceConstraints

As shown in example below, three types of keywords must be chosen:

• data policy such as WMOEssential
• GTS priority like GTSPriority2
• distribution area like globalDistribution

See MDG_Access for more general regulations and guidelines.

characterSet

For Alphanumeric bulletins (i.e. FM 12 SYNOP), the data character set (identificationInfo/*/characterSet) should be usAscii. The code usAscii is the closest approximate of CCITT IA5 (the difference never matters for WMO Codes).

For BUFR reporting, the concept characterSet does not apply: it should be omitted or empty with nilReason=inapplicable.

topicCategory

At least one of ISO topic category list must be chosen: that is mandatory ISO requirement.

bounding box

Ranges of latitude and longitude must be indicated. That is WIS requirement.

Please note that "done is better than perfect". The bounding box is useful because any kinds of geospatial data have in common. So impreciseness is built-in virtue, not problem. Don't worry about preciseness - it has no use to spend too much time about 0.01 degree digit, discussing geodetic datums, or dreaming about polygon or multipoint extensions. Even if you don't know exact city of the observing station or if it is moving frequently, that's no problem. Simply fill the bounding box of rough maximum possible range of lat/longs.

distributor

For GTS bulletins, the WIS metadata does not have to indicate the distributor or location (URL) of data, since each GISC must provide the link automatically. But it is still useful to indicate the location if there are any.

There can be several distributers. If there are many URLs to access the data operated by different WIS centres (for example NC, RTH, and GISC), each should be described under corresponding distributor.

See MDG_DIS for details of structure.

example

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