Performance Analysis of the ATLID Lidar: A Multi-Parameter Statistical Approach Using L1 Data

Recognizing the need for a comprehensive lidar system performance analysis, we present a method for day-to-day assessment of the ATLID/EarthCARE lidar system. Unlike traditional calibration/validation methods involving in situ measurements or comparisons with ground-based, air- and space-borne instruments, our approach dispenses with the need for a second instrument. Instead, we focus on stability control checks using the atmosphere and surface as a 'reference,' assuming their properties remain constant during the lidar mission's lifetime. Leveraging L1 data flow, our method evaluates critical performance aspects, including the stability of ATLID channels, accuracy of cross-talk coefficients, and the consistency of day- and nighttime noise. Employing a clustering algorithm on scattering ratio histograms, we monitor radiation detection stability globally across diverse atmospheric scenarios. Defining 11 parameters related to surface reflection, stratospheric noise, and scattering ratio histograms, we showcase the feasibility of our approach using CALIOP L1 data. We also present results from our analysis of simulated ATLID data, demonstrating the sensitivity of the proposed quality control indicators to various experimental issues.