CALIPSO Lidar Calibration Algorithms. Part I: Nighttime 532-nm Parallel Channel and 532-nm Perpendicular Channel
Open Access
- 1 October 2009
- journal article
- Published by American Meteorological Society in Journal of Atmospheric and Oceanic Technology
- Vol. 26 (10), 2015-2033
- https://doi.org/10.1175/2009jtecha1242.1
Abstract
The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission was launched in April 2006 and has continuously acquired collocated multisensor observations of the spatial and optical properties of clouds and aerosols in the earth’s atmosphere. The primary payload aboard CALIPSO is the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), which makes range-resolved measurements of elastic backscatter at 532 and 1064 nm and linear depolarization ratios at 532 nm. CALIOP measurements are important in reducing uncertainties that currently limit understanding of the global climate system, and it is essential that these measurements be accurately calibrated. This work describes the procedures used to calibrate the 532-nm measurements acquired during the nighttime portions of the CALIPSO orbits. Accurate nighttime calibration of the 532-nm parallel-channel data is fundamental to the success of the CALIOP measurement scheme, because the nighttime calibration is used to infer calibration across the day side of the orbits and all other channels are calibrated relative to the 532-nm parallel channel. The theoretical basis of the molecular normalization technique as applied to space-based lidar measurements is reviewed, and a comprehensive overview of the calibration algorithm implementation is provided. Also included is a description of a data filtering procedure that detects and removes spurious high-energy events that would otherwise introduce large errors into the calibration. Error estimates are derived and comparisons are made to validation data acquired by the NASA airborne high–spectral resolution lidar. Similar analyses are also presented for the 532-nm perpendicular-channel calibration technique.Keywords
This publication has 16 references indexed in Scilit:
- CALIPSO Lidar Description and Performance AssessmentJournal of Atmospheric and Oceanic Technology, 2009
- Airborne High Spectral Resolution Lidar for profiling aerosol optical propertiesApplied Optics, 2008
- Airborne validation of spatial properties measured by the CALIPSO lidarPublished by American Geophysical Union (AGU) ,2007
- Estimating random errors due to shot noise in backscatter lidar observationsApplied Optics, 2006
- Calibration Technique for Polarization-Sensitive LidarsJournal of Atmospheric and Oceanic Technology, 2006
- GOMOS on Envisat: an overviewAdvances in Space Research, 2004
- Spaceborne lidar calibration from cirrus and molecular backscatter returnsIEEE Transactions on Geoscience and Remote Sensing, 2002
- Comparison of various linear depolarization parameters measured by lidarApplied Optics, 1999
- Rayleigh-scattering calculations for the terrestrial atmosphereApplied Optics, 1995
- Methodology for error analysis and simulation of lidar aerosol measurementsApplied Optics, 1979