ISO 28902-4:2026 PDF

Overview

ISO 28902-4:2026 addresses the use of ground-based particle backscatter lidar to remotely sense meteorological parameters critical for air quality and atmospheric studies. Developed by the International Organization for Standardization (ISO), this standard is part of the broader ISO 28902 series on environmental meteorology and remote sensing. It specifically provides a framework for determining vertical, height-resolved profiles of atmospheric backscattering using active optical (lidar) measurements. These measurements enable the derivation of essential atmospheric features such as cloud bases, boundaries of optically thin clouds, internal structures of aerosol layers, and particle characteristics up to several kilometers above ground level.

Key Topics

• Lidar Principle and Measurement: Uses laser pulses directed into the atmosphere and measures backscattered light to analyze atmospheric conditions. The distance to scattering particles is calculated using travel time of the light, providing height-resolved data.

• Derived Atmospheric Parameters: Enables determination of:

  • Cloud base height and penetration depth
  • Upper and lower boundaries of atmospheric layers (e.g., boundary layer, mixing layer)
  • Attenuated backscatter of particles
  • Particle backscatter and extinction coefficients (with relevant assumptions)
  • Particle size (Ångström exponent, colour ratio) and shape classification (linear depolarisation ratio) through multi-wavelength and depolarisation lidar techniques

• System Components: Describes essential lidar system elements, including lasers, transmitting and receiving optics, detectors, filters, data acquisition systems, and support infrastructure. Addresses mono- and multi-wavelength, as well as polarization-sensitive (depolarisation) systems.

• Measurement Planning and Uncertainty: Covers best practices for planning lidar measurements, safety considerations, instrument adjustment, maintenance, and uncertainty estimation associated with collected data.

Applications

Particle backscatter lidar, as standardized in ISO 28902-4:2026, is essential in a range of atmospheric and environmental applications:

• Air Quality Monitoring:

  • Provides vertical profiling of the atmospheric boundary layer, helping to assess pollutant dispersion and stratification.
  • Supports identification and tracking of particle layers such as dust, smoke, or pollution events.

• Aviation Safety:

  • Enables accurate detection of cloud base heights and visibility range, supporting real-time decision-making for air traffic and airport operations.
  • Offers measurements in support of the requirements found in ISO 28902-1 for visual range assessments.

• Weather Forecasting and Climate Modeling:

  • Supplies crucial input for models by providing high-resolution data on cloud properties, atmospheric layering, and aerosol distribution.
  • Enhances understanding of phenomena such as mixing layers and temperature inversions.

• Particle Transport Studies:

  • Useful for monitoring movement of volcanic ash, desert dust, and other aerosol events, thus informing public health advisories and mitigating transportation disruption.

• Satellite Remote Sensing Validation:

  • Lidar observations are used to validate and calibrate satellite-derived atmospheric data.

Related Standards

For organizations integrating particle backscatter lidar systems within their monitoring networks, the following related ISO standards should be considered:

• ISO 28902-1: Ground-based remote sensing of visual range by lidar
• ISO 28902-2: Ground-based remote sensing of wind by heterodyne pulsed Doppler lidar
• ISO 28902-3: Ground-based remote sensing of wind by continuous-wave Doppler lidar
• ISO 19926-1: Weather radar system performance for frequencies between 2 GHz - 10 GHz
• VDI 4210-1: Differential absorption lidar (DIAL) for gaseous air pollution measurement (the DIAL technique is referenced but not covered in detail in ISO 28902-4)

Practical Value

Adhering to ISO 28902-4:2026 ensures:

• Consistent and reliable generation of lidar-based meteorological data.
• Improved comparability of results across international studies and regulatory monitoring.
• Safe and effective operation of instrumentation under varying atmospheric and site conditions.
• High value for air quality agencies, meteorological services, climate researchers, and industries requiring validated atmospheric profiling tools.

By following this standard, users can enhance the accuracy, repeatability, and utility of ground-based lidar observations, supporting robust air quality management and environmental decision-making.