To address the high demand for continuous observations of ABL heights both at the European and regional scale, the ABL testbed has the objective to demonstrate the capabilities and limitations of existing measurements and processing tools to derive this variable continuously. The ABL testbed is evaluating and improving several steps of quality control and data harmonisation to obtain ABL heights from profiles observed by automatic lidars and ceilometers (ALC):
- Quality assurance to account for instrument-specific artefacts in the measurements such as the instrument-specific background or the incomplete optical overlap.
- Absolute calibration of the range-corrected signal to the variable of attenuated backscatter.
- Automatic layer detection through algorithms that are tailored to the quality of the input data (Kotthaus et al. 2020).
- Automatic quality screening of the derived layer heights to remove physically unreasonable discontinuities.
- Evaluation of layer heights through comparison to other methods, e.g. thermodynamic layer heights from radiosonde data or turbulence-derived layer heights from Doppler lidar observations.