Information Regarding PEM-West B Images

PEM-West B Field Experiment Description

Major PEM-West B Campaign References 



INFORMATION REGARDING PEM-West B IMAGES


The horizontal display interval of the full flight images depends on the length of the flight.
Both nadir and zenith data are imaged together.  In the aerosol images, a black trace appears at the
aircraft altitude. The ozone is interpolated from DIAL nadir/zenith to in-situ.  "Modeled" data is
only used to extrapolate the DIAL profiles to the ground.  Archival data has flag values to allow
identification of interpolated and extrapolated values. Only one color scale is used for the ozone images.
Only one color scale is used for the aerosol images. The vertical scale factor is consistent between images.
Aerosol data are reported as Atmospheric Scattering Ratios on a logarithmic scale.  Ozone data are reported
as mixing ratios (ppbv) on a linear scale.


       Resolution of the data are:






      VERTICAL RESOLUTION:



Vertical averaging interval
        Aerosol    30 meters
Ozone      300 meters (nadir)
600 meters (zenith)

Vertical display interval for averaged data
        Aerosol    30 meters
Ozone      30 meters




       HORIZONTAL RESOLUTION:



Horizontal averaging interval
        Aerosol    60 seconds, or approximately 14 kilometers
Ozone      300 seconds, or approximately 70 kilometers

Horizontal display interval for averaged data
        Aerosol    8 seconds or approximately 1850 meters
Ozone      either 3.5 or 7 seconds, or
approximately 800 or 1600 meters respectively,
except for whole flight images which vary,
averaging 21 seconds, or approximately 4900 meters




      Times on the images are Universal Time (UT).




The airborne DIAL data images are to be used as a reference to the digital data located in the  Langley Distributed Active Archive Center (DAAC).  The images (both aerosol and ozone) viewed on this WWW page are from a full resolution data set, whereas, the digital data archived at the DAAC are a sub-sampled data set (aerosol - 10 seconds/profile and ozone - 1 profile/minute).  If full resolution digital data are required, please contact the Lidar Applications Group.  Images are not to be published without permission from NASA.




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