Airborne Laser Polarization Sensor (ALPS) Experiment During the Forest Ecosystem Dynamics - Multisensor Airborne Campaign
Entry ID: FEDMAC_ALPS

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Summary
Abstract: Forest Ecosystem Dynamics Multisensor Airborne Campaign (FED MAC):
Airborne Laser Polarization Experiment

The Biospheric Sciences Branch (formerly Earth Resources Branch)
within the Laboratory for Terrestrial Physics at NASA's Goddard Space
Flight Center and associated University investigators are involved in
a research program entitled Forest Ecosystem Dynamics (FED) which is
fundamentally concerned with vegetation change of forest ecosystems at
local to regional spatial scales (100 to 10,000 meters) and temporal
scales ranging from monthly to decadal periods (10 to 100 years). The
nature and extent of the impacts of these changes, as well as the
feedbacks to global climate, may be addressed through modeling the
interactions of the vegetation, soil, and energy components of the
boreal ecosystem.

A new remote sensing instrument, the Airborne Laser Polarization
Sensor (ALPS), mounted on a helicopter, was used to make multispectral
radiometric and polarization measurements of the Earth's surface using
a polarized laser light source. The ALPS system consists of a pulsed,
polarized laser source, an optical receiver package, a video camera and
recorder, and data acquisition and analysis hardware and software. The
choice of laser wavelengths is limited to frequencies from the
ultraviolet to the near-infrared by the photo-cathode response of the
selected photo multiplier tube (PMT) detectors. Twelve PMTs were used
corresponding to the 12 channels of data: Channels 1,2,3,4,9 & 10 have
1090 nm bandpass filters. The reminder are for 532 nm. Channels 9 and
11 have no polarization filters.

For each wavelength, polarization filters are mounted in front of each
PMT at angles relative to the transmitted polarization. A pulsed (7 ns)
Nd:YAG laser is employed. It operates in the infrared at 1060 nm and
the visible at 532 nm. The 532 nm green wavelength can be seen near
the center of the TV screen as it hits the surface in most cases. This
is used for ground truth correlation. The spot is about 20 cm in
diameter from 100 meters altitude.

In these data for ALPS Experiment for the FED MAC 90, the file
tabulation refers to data files taken on September 9 and 11. A
standard VHS video tape is available (the master tapes are recorded at
the SP speed on Super-VHS). The first half of this tape is from a
camera coaxial with the laser transmission. Time on the tape
correspond to file times while oral comments on the tape supplement
the general comments. The second half of the tape consists primarily
of site descriptive narration on the ground and some pictures of the
helicopter setup.

The FED Home Page is at: "http://forest.gsfc.nasa.gov/".

Geographic Coverage
 N: 45.0 S: 45.0  E: -68.0  W: -68.0

Data Set Citation
Dataset Originator/Creator: James Kalshoven
Dataset Title: Airborne Laser Polarization Experiment
Dataset Series Name: FED MAC Home Page
Dataset Release Place: NASA/GSFC
Dataset Publisher: NASA/GSFC
Data Presentation Form: ASCII Tables


Temporal Coverage
Start Date: 1990-09-09
Stop Date: 1990-09-11


Location Keywords
CONTINENT > NORTH AMERICA
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MAINE


Science Keywords
SPECTRAL/ENGINEERING >INFRARED WAVELENGTHS >REFLECTED INFRARED    [Definition]
SPECTRAL/ENGINEERING >INFRARED WAVELENGTHS >SENSOR COUNTS    [Definition]
SPECTRAL/ENGINEERING >RADAR >RADAR BACKSCATTER    [Definition]
SPECTRAL/ENGINEERING >VISIBLE WAVELENGTHS >SENSOR COUNTS    [Definition]


ISO Topic Category
IMAGERY/BASE MAPS/EARTH COVER


Platform
AIRCRAFT    [Information]
HELICOPTER    [Information]


Instrument
ALPS >Airborne Laser Polarization Sensor    [Information]
LASERS >Light Amplification by Stimulated Emission of Radiation    [Information]


Project
FED MAC >Forest Ecosystem Dynamics Multisensor Airborne Campaign    [Information]


Keywords
ASHPHALT
BOG
FED MAC
FOREST CANOPY
HEMLOCK
SPHAGNUM
SPRUCE


Data Set Progress
COMPLETE


Originating Center
NASA/GSFC/FED


Data Center
Forest Ecosystem Dynamics Project, Biospheric Sciences Branch, Hydrospheric and Biospheric Sciences Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA    [Information]
Data Center URL: http://forest.gsfc.nasa.gov/

Data Center Personnel
Name: BRUCE COOK
Email: bruce.cook at nasa.gov
Contact Address:
NASA
Goddard Space Flight Center
Mailstop 614.4
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA



Distribution
Distribution_Media: WWW
Distribution_Format: ASCII
Fees: Free


Personnel
JAMES E. KALSHOVEN
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Email: james.e.kalshoven at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Mailstop 400.0
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA


TYLER B. STEVENS
Role: DIF AUTHOR
Phone: (301) 614-6898
Fax: 301-614-5268
Email: Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA


Publications/References
Walthall, C.L., M. Kim, D.L. Williams, B.W. Meeson, P.A. Agbu,
J.A. Newcomer, and E.L. Levine, 1993. Data sets for modeling: a
retrospective collection of bidirectional reflectance and forest
ecosystem dynamics multisensor aircraft campaign data sets. Remote
Sensing of Environment; 46:340-346.

Kalshoven, J.E., and P.W. Dabney. 1993. Remote sensing of the Earth's
surface with an airborne polarized laser. IEEE Transactions on
Geoscience and Remote Sensing; 31:438-446.

Creation and Review Dates
Last DIF Revision Date: 2011-05-05

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