CALIPSO LIDAR BROWSE IMAGES (PRODUCTION - STANDARD - Science Ready)
This site contains combined browse images of the CALIPSO lidar (CALIOP),
Infrared Imaging Radiometer (IIR),
and Wide Field Camera (WFC).
The CALIOP images primarily comprise the total 532 nm attenuated backscatter signal (the sum of the 532 nm parallel and perpendicular return signals),
the perpendicular 532 nm attenuated backscatter signal, and the total 1064 nm attenuated backscatter signal from CALIOP from the Level 1B products,
as well as masked information derived from the Level 2 products. A full tutorial of image content is provided
The lidar signal strength has been color coded such that blues correspond to molecular scattering and weak aerosol scattering, aerosols
generally show up as yellow/red/orange. Stronger cloud signals are plotted in gray scales, while weaker cloud returns are similar in strength
to strong aerosol returns and coded in yellows and reds.
The CALIOP 532 nm channels
do not recover instantaneously from very strong returns such as those from ocean and land surfaces. Instead, there is a decay which is
approximately exponential. Due to this effect, there is often apparent lidar return from beneath the surface. This effect is particularly
noticeable in Antarctica where frequent cloud-free atmospheres and a highly reflective surface result in surface signals which apparently
extend significantly below the true surface.
When the atmosphere is not clear, varying atmospheric attenuation will modulate the strength of the surface return and the magnitude
of the transient recovery. Return signals from very strongly scattering clouds can also produce this effect, although it is not always apparent.
The V4 browse images contain
overplots of CloudSat radar reflectivity and cloud mask data.
The CloudSat data, taken from the most recent version of the 2B-GEOPROF data products, are imposed on CALIPSO day and night browse images
from June 2006-April 2011, and then only daytime from November 2011 onward when CloudSat went to daylight data collection only. CALIPSO will
process and post these images as the CloudSat data becomes available.
Two versions of the standard CALIPSO browse images are currently supported. The Version 4.1 CALIOP products use the meteorological reanalysis
product MERRA-2 (Modern-Era Retrospective analysis for Research and Applications, Version 2) from GMAO, which introduces a 3-4-month delay in
generation and distribution of several CALIPSO products.
Users are encouraged to use the Version 4.1 CALIOP data products as these provide most up to date improvements since Version 3.
To account for this delay the standard Version 3.41 images will also be
posted, but should be treated as expedited products and should not be used in rigorous scientific studies. They
are generated 2 to 3 days from science data downlink, but will only be available for the last 6 months at a time.
DATA RELEASE IMAGE AVAILABILITY
Version 4.1 - Versions 4.10 and V4.11; June 13, 2006 thru Current
Version 3.4 - Version 3.41; sliding 6-month window
SELECT DATA RELEASE VERSION TO VIEW IMAGES
VERSION 4: V4.1
VERSION 3: V3.4
Last Updated: May 28, 2021