CALIPSO Lidar Description and Performance Assessment

TLDR

This paper supplies background material for a series of CALIOP algorithm papers to appear in the Journal of Atmospheric and Oceanic Technology. It briefly describes the design and performance of CALIOP, a three‑channel elastic backscatter lidar aboard the CALIPSO satellite. After more than two years on orbit, CALIOP continues to deliver excellent performance in laser energy, signal‑to‑noise, polarization sensitivity, and long‑term stability, though short‑term calibration shifts, radiation‑induced detector and laser effects, and slow 532‑nm channel recovery require special treatment but do not significantly compromise the high‑quality level‑2 data products.

Abstract

Abstract This paper provides background material for a collection of Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) algorithm papers that are to be published in the Journal of Atmospheric and Oceanic Technology. It provides a brief description of the design and performance of CALIOP, a three-channel elastic backscatter lidar on the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. After more than 2 yr of on-orbit operation, CALIOP performance continues to be excellent in the key areas of laser energy, signal-to-noise ratio, polarization sensitivity, and overall long-term stability, and the instrument continues to produce high-quality data products. There are, however, some areas where performance has been less than ideal. These include short-term changes in the calibration coefficients at both wavelengths as the satellite passes between dark and sunlight, some radiation-induced effects on both the detectors and the laser when passing through the South Atlantic Anomaly, and slow transient recovery on the 532-nm channels. Although these issues require some special treatment in data analysis, they do not seriously detract from the overall quality of the level 2 data products.