AIRSAMSUAHSB Data Subsetting and Visualization Services at GES DAAC

1
AIRS/AMSU-A/HSB Data Subsetting and Visualization
Services at GES DAAC
Sunmi Cho, Jason Li, Donglian Sun, Jianchun Qin
and Carrie Phelps, Code 902, NASA Goddard Space
Flight Center, Greenbelt, Maryland, 20771
AIRS Online Channel/Variable Subsetter
AIRS Data Services at GES DAAC
AIRS Visualization Tools
The AIRS Data Support Team at GES DAAC is
developing tools to read, visualize, analyze and
reformat AIRS/AMSU-A/HSB data as well as
researching and enhancing various existing
software packages to designed to handle the
HDF-EOS data format (the AIRS standard format).
This poster describes the AIRS data subsetting
procedure and visualization tools available at
the AIRS Data Support web page at GES DAAC.
The AIRS/AMSU-A/HSB products contain
radiance/brightness temperatures from 2401
channels (AIRS IR 2378, VIS 4, AMSU-A15, HSB
4) and various geophysical atmospheric
variables. AIRS online subsetter allows one to
download subset of data for only desired channels
and variables. Graphical and text-formatted
channel/variable selection feature enables user
to specify criteria more efficiently.
AIRS Data Support Team has also developed IDL-
based tools for AIRS/AMSU/HSB/VIS Level-1B data
visualization. The tools can be classified into
two categories a granule-level visualizer and a
multiple-granule stitching tool.   The
granule-level visualizer inverts brightness
temperature from observed radiance (if needed)
and allows users to scale the data automatically
to achieve optimal use of the IDL color scale.
Also provided on the image is a miniature global
map to indicate the geographic location of the
granule and flight direction of the spacecraft.
Furthermore, the visualizer adopts a single
pseudo satellite projection to minimize image
distortion anywhere on the globe.                
Step 1 Select data product, temporal range and
subset type
Channel or/and variable subset can be performed
for both Level1B and Level2 Data products that
are available online
Step 2 Select variables and range of channel
(wavelength)
The list of variables for specified product is
provided. It include geophysical parameters,
navigational variables, such as, latitude,
longitude, time, scan angle, etc, and QA flags.
One can select channels using following
options. 1. Type multiple ranges of channel or
wavelength.2. Select channels from the complete
list of channels (frequencies).3. If  browser is
Java capable, one can specify range of wavelength
using atmospheric transmission graph to select
AIRS IR channels.
A visible image of Super Typhoon Fengshen on July
20, 2002, is pictured to the left. This false
color composite is produced using AIRS Vis/NIR
band 1 (blue), 2 (green) and 3 (red) with spatial
resolution of 2.3km x 2.3km at nadir.  
The corresponding brightness temperature image of
the Super Typhoon Fengshen in the AIRS 11 ?m
thermal band is pictured to the right. Fengshen
reached Category 5 hurricane status, the most
severe hurricane status, on the previous day with
sustained winds at 145 knots (167 miles per
hour).
Step 3 Review and submit criteria for subsetting
Selected criteria will be displayed including
complete list of input files, channels, and
variables. Estimated output volume is provided
and input files can be de-selected at this step.
The multiple-granule stitching tool is useful for
obtaining regional or global views of
AIRS/AMSU-A/HSB measurements on particular day.
In order to get a consistent picture, brightness
temperatures are mapped onto a fixed color scale.
Finally, like the granule-level visualizer, it
allows users to pick any band.  
Information on AIRS data and data analysis tools
can be found at AIRS data support informational
web site that provides access to various
technical online documents, such as readmes,
users data product guides, instrument guides,
images from AIRS/AMSU-A/HSB data, product search
and ordering interfaces, HDF-EOS format
information, format conversion software, online
data analysis tools, other AIRS related web links
and more. Other data support services provided by
the ADDST are assist with data mining, helpdesk
for user questions on data and information, data
ordering, and educational resources.
Step 4 View sample image from the subsetted file
For Level1B products, sample images created by
AIRS QuickLook are provided for a specific
channel prior to downloading data. Global map is
also provided along with image to show geographic
coverage of the granule and flight direction of
the spacecraft.
Granule-level AIRS 11 ?m brightness temperature
images are stitched together and mapped onto a
Hammer-Aitoff equal area projection to the left.
Only the day-time granules are plotted in this
global composite.
Step 5 Download the subsetted data file and
metadata file
Click on the provided link to download your
subsetted file.
For further information on GES DAAC data product
support and services for the AIRS and related
data sets, please contact the AIRS Data Support
Team at atmdyn-dst_at_daac.gsfc.nasa.gov.
http//daac.gsfc.nasa.gov/atmodyn/airs/