Agreement over Time focuses on how the difference between the two datasets evolves over time. It provides key metrics commonly used to assess agreement between datasets, together with plots that visualise the differences at different time scales. These results help you review the data directly and identify patterns that may require further investigation.

Mean bias, annual bias, and monthly bias represent the average difference between the datasets over the available data period. They are calculated for the full dataset, per year, and per month, respectively.

The separation between all-sky conditions and data filtered as almost clear-sky provides additional detail. Keep in mind that these values only represent the available data and may be significantly affected by data gaps, abnormal values, and filtering criteria.

Caution: The metrics provided in this section only represent the apparent relationship between the datasets. They should not be used to judge sensor performance without careful review of the detailed results and further investigation into the causes of any mismatch.

Reference values are provided for convenience and give an approximate indication of what may generally be considered small deviations. For more accurate guidance, always consult a trusted advisor and consider the specific requirements of your application and measurement setup.

See more details on how to read Carpet Plots and the Understand the Absolute Irradiance Difference plot.

To complement the time-based comparison with an overall correlation view, see General Linearity.