DPFS_Manual_Appendix-II-1
MINIMUM STANDARDS FOR QUALITY CONTROL OF DATA FOR USE IN THE GDPFS (BOTH REAL-TIME AND NON-REAL-TIME)
INTRODUCTION
1. According to the WWW plan the Commission for Basic Systems was required to develop minimum standards for quality control of data in the GDPFS. The Plan for Monitoring the Operation of the WWW, developed by CBS (as presently published in the Manual on the GTS, WMO–No. 386, Attachment I-5), also includes reference to the fact that minimum standards should be defined in the Manual on the GDPFS.
OBJECTIVES
2. The objectives of the GDPFS quality control are:
(a) To ensure the best possible quality of the data which are used in the real-time operations of the GDPFS;
(b) In non-real time, to protect and improve the quality and integrity of data destined for storage and retrieval within the GDPFS;
(c) To provide the basis for feedback of information on errors and questionable data to the source of the data.
BASIC COMPONENTS
3. The minimum standards for quality control of data apply to all WWW centres: NMCs, RSMCs, WMCs. They include quality control at various stages of processing. They apply to both real-time and non-real-time processing and should lead to various records of quality-control actions.
ASPECTS OF IMPLEMENTATION
4. Quality-control standards may be introduced progressively at a GDPFS centre using a modular approach. The general priorities for implementation of the minimum standards under the modular concept concern quality control of data, according to:
(a) Sources (e.g. stations);
(b) Type (e.g. SYNOP, TEMP);
(c) Time (e.g. 00 UTC, 12 UTC);
(d) Parameters and characteristics (e.g. pressure, wind, temperature, amount of precipitation).
5. WMCs having multiple responsibilities as an RSMC and/or an NMC, and RSMCs also having a responsibility as an NMC, should assume the minimum standards pertinent to all levels at which the centre operates.
6. Table I of this Appendix lists the minimum standards for real-time and non-real-time quality control at NMCs, RSMCs and WMCs. Where applicable, regional associations and national Meteorological Services will set up similar quality-control standards for data exchanges only at regional or national levels.
RESPONSIBILITIES
7. General principles for the application and administration of GDPFS minimum standards for quality control of data are given in the following paragraphs.
8. The basic responsibilities for implementing minimum standards for quality control of the GDPFS rest with Members.
9. An essential part of the quality-control plan includes an exchange of information about data deficiencies between GDPFS centres and observation points in order to resolve those deficiencies and minimize their recurrence.
10. The frequency with which information is exchanged in order to improve the quality of data and products should correspond to the frequency with which monitoring reports are exchanged. These are given in the Plan for Monitoring the Operation of the WWW, as given in Attachment II.7, in particular, paragraph 22.
11. The minimum standards specify which data are to be quality-controlled and how often. The detailed methods for performing the quality control are left to the Members to develop, but should conform to the minimum standards.*
* Methods for real-time and non-real-time quality control are given in the Guide on the Global Data-processing System (WMO–No. 305).
MINIMUM STANDARDS FOR PROCESSED DATA
14. Minimum standards for quality control of processed data should include:
The geographic area (zone) of responsibility for application of the minimum standards will correspond to that undertaken by each WWW centre for data processing and forecasting, as laid down in Attachment III.2.
ADVANCED STANDARDS
12. The primary purpose of quality control is to detect data deficiencies and to attempt to correct them in real time. Thus, the WWW centres should perform quality-control operations as these are developed and as their technical capabilities allow. Centres which have high-speed computers can apply standards for quality control which are far beyond the minimum standards. These advanced standards should involve more real-time quality control, including correcting or flagging of more reports, parameters and levels than listed in Table I. The WWW Guides give information on methods for more advanced quality control.*
13. It is also the responsibility of automated centres to perform nearly continuous inspection and quality control of processing programmes that enable computers to identify, decode, process and array data properly.
MINIMUM STANDARDS FOR PROCESSED DATA
14. Minimum standards for quality control of processed data should include:
(a) Standards for presentation of processed data as they are given in Appendix II-4;
(b) Spatial and temporal coherence in the meteorological structure of the product (that is, no impossible or contradictory atmospheric states).
- Methods for real-time and non-real-time quality control are given in the Guide on the Global Data-processing System (WMO–No. 305).