GACP Projects
Form A: GACP ACCOMPLISHMENT REPORT
Name: Edward Uthe
INSTITUTION: SRI International
TITLE: Airborne Sensors Data Fusion: Aerosol/Cloud Properties
ABSTRACT:
Under project SUCCESS, SRI International (SRI) developed an angular scanning backscatter lidar for operation on the NASA DC-8 research aircraft and deployed the scanning lidar during the SUCCESS field campaign. The primary purpose of the lidar was to generate real-time displays of clouds and contrails above, ahead of, and below the DC-8 as a means to help position the aircraft for optimum cloud and contrail sampling by onboard in situ sensors, and to help extend the geometrical domain of the in situ sampling records. A large, relatively complex lidar database was collected and several data examples were processed to illustrate the value of the lidar data for interpreting other data records collected during SUCCESS. These data examples were used to develop a journal publication for a special SUCCESS Geophysical Research Letters issue. The data examples justified data analyses of a larger part of the DC-8 lidar database, and a proposal for this purpose was accepted by NASA/Atmospheric Effects of Aviation Program (AEAP) and is the objective of the current study.
GOALS:
The purpose of this study is to (1)
further develop computational and display methods
to best integrate DC-8 aircraft scanning lidar
displays of aerosol/cloud density distributions
with radiation and aerosol/cloud microphysical
measurements made onboard the aircraft, (2) apply
these methods to case study analyses of the
SUCCESS database in terms of aerosol/cloud
physical and radiative properties, and (3) present
results of the study in animated web site displays
available to the research community.
APPROACH/TASKS COMPLETED:
An angular scanning
lidar operated from an airborne platform can
provide unique information on aerosol/cloud
distributions surrounding the aircraft that effect
response of onboard radiometric and in situ
sensors and extend the spatial domain of
measurements made with these sensors. However,
integration of the lidar signatures into time
dependent three-dimensional views that can be
related to in situ sensor records collected along
flight path segments requires efficient use of
available computational and display methods. As a
first task, lidar fixed viewing angle backscatter
signatures were used to show that lidar and
onboard radiometric and microphysical sensor
records can be combined to provide enhanced
information on aerosol/cloud properties not
attainable by the individual sensors (GRL, Vol.
25, No. 9, pp. 1339-1342). Subsequent efforts
have been directed to generate polar plots that
correct lidar viewed aerosol/cloud distributions
for aircraft movement during lidar angular scans.
Animated displays have been generated that
propagates in situ sensor data records to
distances remote from the aircraft as a means to
relate the data records to lidar observed
aerosol/cloud distributions. Over 30 case studies
have been processed in movie format simulating
forward observed vertical aerosol/cloud properties
during aircraft flight. The movie formats can be
accessed at our web site www.rsed.sri.com/lidar.
FUTURE PLANS:
Studies are being continued on
airborne scanning lidar data computational and
display methods and their integration with onboard
radiometric and microphysical sensor records in
terms of aerosol/cloud properties. Additional
case studies will be processed. Tabulated
aerosol/cloud properties will be added to our web
site and a paper discussing case study analyses
will be prepared and submitted for publication.
RESULTS:
The approach and results of this study
are best viewed at web site www.rsed.sri.com/lidar
that presents (1) equipment configuration, (2)
fixed viewing angle data examples, (3) GRL
publication discussing fixed viewing angle results
(referred to above), (4) angular scan case studies
in movie format, and (5) data inventory and
availability.
Form C: FUTURE PLANS
We plan to complete our study of aerosol/cloud properties derived by combining the DC-8 scanning lidar data records with other onboard data collected during the SUCCESS project. Results will be posted on our web site www.rsed.sri.com/lidar, submitted for journal publication, and presented to GACP as appropriate.
Sincerely,
Ed Uthe
