Figure 101. Prototype exchange set structure Determine what naming conventions, if any must apply to individual components of the exchange set - dataset files, exchange sets, and support files. Naming conventions are generally not needed for message-based or service modes of data delivery, but a unique identifier will generally be needed for each message or service transaction. Dataset updates General considerations for updates Define the conditions and mechanisms for data updates. specifically: update cycles how frequently data must be updated, whether updates are issued on a regular – cycle, as-needed, or a combination of both; how long each dataset is and how to validity periods will be indicated mechanisms for cancellation, replacement, and reissue of datasets metadata for updates of updates whether the data product requires incremental, whole-dataset replacement, – irregular, or cumulative updates. Criteria for determining when datasets must be replaced by new datasets, superseded, reissued, updated, and cancelled. Format-specific update considerations ISO 8211 Part 10a describes update mechanisms for ISO 8211 datasets. Each specification must – define the structure of update datasets. GML: Replacement of whole objects is the recommended method, but there are XML specifications that allow update of individual attributes. (Details are currently in a working paper, GML Datasets” - “Updating TSM5-4.11.) HDF5: Feature (coverage) can be updated in its entirety or in part (the update can be a sub-grid). Supporting information Describe how any auxiliary content is delivered either with or as an adjunct to data. S-100 provides for files’ to be included in exchange sets. Support files can be graphic or text information files ‘support referenced by dataset objects, or other files such as dictionaries and catalogues (including feature or portrayal catalogues). Define allowed file formats and naming conventions for support files. Note that since feature and portrayal catalogues are shared by all datasets conforming to a specific version of a product specification, it will generally be more efficient to deliver feature and portrayal catalogues once rather than with every exchange set. Possible methods of such special deliveries have not been standardized yet and are left to product specification developers, but may include special exchange sets distributed through the usual channels or a centralized means such as publication on a
Figure 101. Prototype exchange set structure Determine what naming conventions, if any must apply to individual components of the exchange set - dataset files, exchange sets, and support files. Naming conventions are generally not needed for message-based or service modes of data delivery, but a unique identifier will generally be needed for each message or service transaction. Dataset updates General considerations for updates Define the conditions and mechanisms for data updates. specifically: update cycles – how frequently data must be updated, whether updates are issued on a regular cycle, as-needed, or a combination of both; how long each dataset is and how to validity periods will be indicated mechanisms for cancellation, replacement, and reissue of datasets metadata for updates of updates – whether the data product requires incremental, whole-dataset replacement, irregular, or cumulative updates. Criteria for determining when datasets must be replaced by new datasets, superseded, reissued, updated, and cancelled. Format-specific update considerations ISO 8211 – Part 10a describes update mechanisms for ISO 8211 datasets. Each specification must define the structure of update datasets. GML: Replacement of whole objects is the recommended method, but there are XML specifications that allow update of individual attributes. (Details are currently in a working paper, “Updating GML Datasets” - TSM5-4.11.) HDF5: Feature (coverage) can be updated in its entirety or in part (the update can be a sub-grid). Supporting information Describe how any auxiliary content is delivered either with or as an adjunct to data. S-100 provides for ‘support files’ to be included in exchange sets. Support files can be graphic or text information files referenced by dataset objects, or other files such as dictionaries and catalogues (including feature or portrayal catalogues). Define allowed file formats and naming conventions for support files. Note that since feature and portrayal catalogues are shared by all datasets conforming to a specific version of a product specification, it will generally be more efficient to deliver feature and portrayal catalogues once rather than with every exchange set. Possible methods of such special deliveries have not been standardized yet and are left to product specification developers, but may include special exchange sets distributed through the usual channels or a centralized means such as publication on a
DQWG13-10A2_Guidance%20for%20PS%20Developers%20Part%20B%20-%20Execution%2020171231.docx