AQD - Assessment Types Submitted None Data Dictionary Vocabularies Eionet Data Dictionary Fixed random measurements Member States may apply random measurements instead of continuous measurements for benzene, lead and particulate matter if they can demonstrate to the Commission that the uncertainty, including the uncertainty due to random sampling, meets the quality objective of 25 % and the time coverage is still larger than the minimum time coverage for indicative measurements. Random sampling must be evenly distributed over the year in order to avoid skewing of results. The uncertainty due to random sampling may be determined by the procedure laid down in ISO 11222 (2002) ‘Air Quality — Determination of the Uncertainty of the Time Average of Air Quality Measurements’. If random measurements are used to assess the requirements of the PM10 limit value, the 90,4 percentile (to be lower than or equal to 50 μg/m3) should be evaluated instead of the number of exceedances, which is highly influenced by data coverage. Valid Data Dictionary Vocabularies Eionet Data Dictionary AQD - Assessment Types Fixed measurement ‘fixed measurements’ shall mean measurements taken at fixed sites, either continuously or by random sampling, to determine the levels in accordance with the relevant data quality objectives; Legal reference: Decision 2011/850/EU - ANNEX II - (D) Information on the assessment methods , (ii) "Fixed measurement Information" describes the information to be made available by the Member States (mandatory or voluntary). Valid Data Dictionary Vocabularies Eionet Data Dictionary AQD - Assessment Types Indicative measurement ‘indicative measurements’ shall mean measurements which meet data quality objectives that are less strict than those required for fixed measurements; Legal reference: Decision 2011/850/EU, Article 9, paragraph 4 and Annex II D (iii) Valid Data Dictionary Vocabularies Eionet Data Dictionary AQD - Assessment Types Modelling Legal reference : Decision 2011/850/EU, Article 9, paragraph 5 and Annex II D (iv) Valid Data Dictionary Vocabularies Eionet Data Dictionary AQD - Assessment Types Objective estimation Legal reference: Decision 2011/850/EU, Article 9, paragraph 6 and Annex II D (v) “Objective estimation techniques” will be interpreted as mathematical methods to calculate concentrations from values measured at other locations and/or times, based on scientific knowledge of the concentration distribution. One example is linear interpolation based on a justified assumption that the concentration pattern is sufficiently smooth. Another example is a dispersion model that has been adjusted to reproduce concentrations measured within its domain. More information is available at: http://ec.europa.eu/environment/air/pdf/guidanceunderairquality.pdf Valid Data Dictionary Vocabularies Eionet Data Dictionary AQD - Assessment Types Other measurement “other measurement” shall mean measurements that do not meet the Air Quality Directives’ requirements for fixed or indicative measurements, but can be provided on the basis of exchange of information. For example, measurements from short measurement campaigns or measurements with lower quality. Valid Data Dictionary Vocabularies Eionet Data Dictionary AQD - Assessment Types