ISO 19289:2015 空气质量 气象学 陆地上观察站选址分类

标准编号：ISO 19289:2015

中文名称：空气质量 气象学 陆地上观察站选址分类

英文名称：Air quality — Meteorology — Siting classifications for surface observing stations on land

发布日期：2015-03

标准范围

This International Standard indicates exposure rules for various sensors, but what should be done whenthese conditions are not fulfilled? There are sites that do not respect the recommended exposure rules.Consequently, a classification has been established to help determine the given site’s representativenesson a small scale (impact of the surrounding environment). Hence, a class 1 site can be considered as areference site. A class 5 site is a site where nearby obstacles create an inappropriate environment for ameteorological measurement that is intended to be representative of a wide area (at least tens of km2).The smaller the siting class, the higher the representativeness of the measurement for a wide area. In aperfect world, all sites would be in class 1 but the real world is not perfect and some compromises arenecessary. A site with a poor class number (large number) can still be valuable for a specific applicationneeding a measurement in this particular site, including its local obstacles.The classification process helps the actors and managers of a network to better take into considerationthe exposure rules and thus it often improves the siting. At least, the siting environment is known anddocumented in the metadata. It is obviously possible and recommended to fully document the site butthe risk is that a fully documented site might increase the complexity of the metadata, which wouldoften restrict their operational use. That is why this siting classification is defined to condense theinformation and facilitate the operational use of this metadata information.A site as a whole has no single classification number. Each parameter being measured at a site has itsown class and is sometimes different from the others. If a global classification of a site is required,the maximum value of the parameters’ classes can be used. The rating of each site should be reviewedperiodically as environmental circumstances can change over a period of time. A systematic yearlyvisual check is recommended: if some aspects of the environment have changed, a new classificationprocess is necessary. A complete update of the site classes should be done at least every five years.In this International Standard, the classification is (occasionally) completed with an estimateduncertainty due to siting, which has to be added in the uncertainty budget of the measurement. Thisestimation is coming from bibliographic studies and/or some comparative tests.The primary objective of this classification is to document the presence of obstacles close to themeasurement site. Therefore, natural relief of the landscape may not be taken into account, if far away(i.e. >1 km). A method to judge if the relief is representative of the surrounding area is the following:Does a move of the station by 500 m change the class obtained? If the answer is no, the relief is a naturalcharacteristic of the area and is not taken into account.Complex terrain or urban areas generally lead to high class numbers. In such cases, an additional flag “S” can be added to class numbers 4 or 5 to indicate specific environment or application (i.e. 4S).

标准预览图