ISO/TC 146/SC 5/WG 6 - Lidar

This document specifies the requirements and performance test procedures for monostatic heterodyne continuous-wave (CW) Doppler lidar techniques and presents their advantages and limitations. The term "Doppler lidar" used in this document applies solely to monostatic heterodyne CW lidar systems retrieving wind measurements from the scattering of laser light by aerosols in the atmosphere. Performances and limits are described based on standard atmospheric conditions. This document describes the determination of the line-of-sight wind velocity (radial wind velocity). NOTE Derivation of wind vector from individual line-of-sight measurements is not described in this document since it is highly specific to a particular wind lidar configuration. One example of the retrieval of the wind vector can be found in ISO 28902-2:2017, Annex B. This document does not address the retrieval of the wind vector. This document can be used for the following application areas: — meteorological briefing for e.g. aviation, airport safety, marine applications, oil platforms; — wind power production, e.g. site assessment, power curve determination; — routine measurements of wind profiles at meteorological stations; — air pollution dispersion monitoring; — industrial risk management (direct data monitoring or by assimilation into micro-scale flow models); — exchange processes (greenhouse gas emissions). This document can be used by manufacturers of monostatic CW Doppler wind lidars as well as bodies testing and certifying their conformity. This document also provides recommendations for users to make adequate use of these instruments.

ISO 28902-2:2017 specifies the requirements and performance test procedures for heterodyne pulsed Doppler lidar techniques and presents their advantages and limitations. The term "Doppler lidar" used in this document applies solely to heterodyne pulsed lidar systems retrieving wind measurements from the scattering of laser light onto aerosols in the atmosphere. A description of performances and limits are described based on standard atmospheric conditions. This document describes the determination of the line-of-sight wind velocity (radial wind velocity). NOTE Derivation of wind vector from individual line-of-sight measurements is not described in this document since it is highly specific to a particular wind lidar configuration. One example of the retrieval of the wind vector can be found in Annex B. ISO 28902-2:2017 does not address the retrieval of the wind vector. ISO 28902-2:2017 may be used for the following application areas: - meteorological briefing for, e.g. aviation, airport safety, marine applications and oil platforms; - wind power production, e.g. site assessment and power curve determination; - routine measurements of wind profiles at meteorological stations; - air pollution dispersion monitoring; - industrial risk management (direct data monitoring or by assimilation into micro-scale flow models); - exchange processes (greenhouse gas emissions). ISO 28902-2:2017 addresses manufacturers of heterodyne pulsed Doppler wind lidars, as well as bodies testing and certifying their conformity. Also, this document provides recommendations for the users to make adequate use of these instruments.

This part of ISO 28902 mainly specifies the requirements in order to perform visual range lidar measurements for the determination of direction-dependent meteorological optical range (MOR). The term "visual-range lidar" is used in this part of ISO 28902 to apply to the lidar systems making visual-range measurements, commonly referred to as "visibility measurements". Due to physical approximations, quantitative determination is limited to a meteorological optical range of between 30 m and 2 000 m. For this range, this part of ISO 28902 specifies the performance of visual-range lidar systems utilizing the method of range‑integrated visual-range measurements based on light extinction. The following parameters can be calculated based on the directiondependent meteorological optical range: a) horizontal visual range; b) vertical visual range; c) slant visual range. NOTE The measures for visibility are strongly related to the historical definitions of visibility, which are related to human observers. The lidar technique extends the definitions to various conditions, such as daylight and night-time conditions. In addition, this measurement principle enables the user to retrieve information on cloud base height, boundary layer depth, fog banks and aerosol profiles due to the signal attenuation by water vapour and/or aerosols. Examples of these applications are given in Annex C. This part of ISO 28902 can be applied in the following areas: — meteorological stations; — airports; — harbours; — waterways; — roads and motorways; — automotive; — oil platforms.