Visibility measurement
Guide No. 8 links to methods for observing meteorological variables, including visibility in Volume I, Chapter 9.
Open primary resource ↗Keep good references
within reach.
Primary sources for atmospheric observations, optical definitions, physical constants, calibration and analysis. The separate patent register records relevant granted claims and their limits.
Primary resources
Measurement uncertainty and calibration
Handbook guidance on calibration, repeatability, reproducibility, measurement stability and uncertainty analysis.
Open primary resource ↗Analysis of paired observations
Explains paired comparisons, differences within pairs and the paired-sample t statistic.
Open primary resource ↗Fundamental physical constants
Searchable recommended values of fundamental physical constants, with uncertainties and related reference material.
Open primary resource ↗Global surface observations
Hourly and synoptic station observations, including visibility, temperature, dew point, wind and cloud observations where reported.
Open primary resource ↗Atmospheric Radiation Measurement data
Search atmospheric observations and derived data products by measurement, site or campaign, with product documentation and data-quality information.
An ARM account is required for data downloads.
Open primary resource ↗ACTRIS Cloudnet data and documentation
Cloud remote-sensing observations, processing documentation and an API for finding data and metadata.
Open primary resource ↗Mie scattering model documentation
Python documentation and examples for calculating extinction, scattering and absorption by spherical particles.
Open primary resource ↗Keep the data’s context. Retain station and instrument metadata, quality flags, missing-value conventions and the exact product version. A dataset or model’s inclusion here is not an institutional endorsement of weatherhill.