Title: Overview of LIDARLADAR Systems
1Overview of LIDAR/LADAR Systems
2Space Based Systems
- Geoscience Laser Altimeter System (ICESat) (Jan
12, 2003 - Jan 15 earth pointing) - Mars Orbiter
- LITE aerosol Backscatter Lidar
- Vegetation Canopy Lidar (in stasis)
- SPARCLE EO-2 (Cancelled)
- Mars Polar Lander Lidar (spacecraft lost)
- Calipso (Oct 2004)
3Aircraft based Systemshttp//ltpwww.gsfc.nasa.gov
/eib/
- ER-2 Cloud Lidar System
- Large Aperture Scanning Airborne Lidar (LASAL)
- Laser Vegetation Imaging Sensor (LVIS)
- Scanning Lidar Imager of Canopies by Echo
Recovery (SLICER) - Raster Scanning Airborne Lidar (RASCAL)
- Water Vapor Raman Lidar
- Visible and Infrared Lidar (VIRL)
- MACAWS (retired)
4Govt Labs
- NASA JPL Lidar Group
- http//lidar.jpl.nasa.gov/
- NASA GSFC Cloud and Aerosol lidar Group
- http//virl.gsfc.nasa.gov/
- NASA LaRC Lidar Applications Group
- http//asd-www.larc.nasa.gov/lidar/lidar.html
- NOAA ETL Remote Sensing Division
- http//www.etl.noaa.gov/et2/
- Govt Systems
- CALYPSO (Oct 2004)
- Cloud-Aerosol Lidar and Infrared Pathfinder
Satellite Observations - http//www-calipso.larc.nasa.gov/calipso.html
5Govt Groups and SystemsNASA -
LRSBhttp//ltpwww.gsfc.nasa.gov/eib/
- NASAs Laser Remote Sensing Branch
- ground-based Scanning Raman Lidar
- Shuttle Laser Altimeter (SLA)
- Mars Orbiter Laser Altimeter (MOLA) for Mars
Global Surveyor Mission - Ongoing work
- Geoscience Laser Altimeter System (GLAS) for
ICESat - Mercury Laser Altimeter (MLA) for Messenger
Mission
- Also developing
- Airborne surface imaging lidar
- Airborne Raman Lidar
6Commercial
- ITRES - CASI and LIDAR integration
- http//www.itres.com/docs/casilidar.html
7Lidar Research
- University of Wisconsin Lidar Group
- http//lidar.ssec.wisc.edu/
- Purple Crow Lidar at the University of Western
Ontario - http//pcl.physics.uwo.ca/
8Literature
- Global tropospheric wind field
- summary for accurate global tropospheric wind
data needed for several key unresolved climate
questions - Baker et al. Bulletin of the Americal
Meteorological Society, 1995, Vol 76 pp. 869-888
9Additional Resources
- Bobs Introduction to Lidar - Exploring the
Atmosphere with Lidars - http//pcl.physics.uwo.ca/pclhtml/introlidar/intro
lidarf.html - www.lidar.com
- Lidar Tutorials
- http//www.ghcc.msfc.nasa.gov/sparcle/sparcle_tuto
rial.html - http//aesd.larc.nasa.gov/gl/tutorial/lidar/lidar_
mn.htm - NASA Remote Sensing
- http//spacelink.nasa.gov/NASA.Projects/Earth.Scie
nce/Atmosphere/Remote.Sensing/
10Lidar Specs Out There
- Transmitter
- Wavelength
- Pulse duration
- Pulse repetition rate
- Average power
- Frequency stability
- without I2 - locking
- with I2 - locking
- Receiver
- Telescope
- Type
- Diameter
- Focal length
- Filter bandwidth
- daytime/night time
- FOV
- daytime/night time
- Polarization rejection
11Lidar Specs to look for
- System name
- Detection
- DIAL, topographic, etc
- Laser type
- tunable CO2, OPO, NdYAG
- Wavelength
- Energy
- fpulse
- ?tpulse
- ??
- ?beam
12Things to look for
- Optomechanical design
- optics size, obscurations, etc
- Laser specs
- pulse length, period, power, coherence length,
polarization) - Scanning rates
- Altitudes
- Platform stability
- Pointing accuracy
- Noise
- Temporal MTF of range/time gate hardware
- rise times, decay times, etc
- How does range trigger work?
13Sort outTypes of LIDAR vs applications
- DIAL
- Elastic scattering
- Rayleigh scattering
- Fluorescence
- Raman
- Broadband lidar
- Doppler lidar
- Random Code Modulation
- http//www.etl.noaa.gov/et2/lidar
- Clouds, Aerosols, and Climate
- Water Vapor
- Marine Ecology
- Air Quality
- Mesoscale and Boundary Layer Processes
- Topographic
- Bathymetry
- Imaging Laser Altimetry
- http//www.geolas.com/Pages/laser.html
14Techniques of Laser Enviromental Sensingtaken
from Laser Remote Sensing Fundamentals and
Applications by Raymond M. Measures pgs (206-207)
- Rayleigh Scattering
- Mie Scattering
- Raman Scattering
- Resonance Scattering
- Fluorescence
- Absorption
- Differential absorption and scattering (DAS)
15Techniques of Laser Enviromental Sensingtaken
from Laser Remote Sensing Fundamentals and
Applications by Raymond M. Measures (pgs 206-207)
- Rayleigh Scattering
- Laser radiation elastically scattered from atoms
or molecules is observed with no change of
frequency
- Mie Scattering
- Laser radiation elastically scattered from small
particulates or aerosols (of size comparable to
wavelength of radiation) is observed with no
change in frequency
h?
h?
16Techniques of Laser Enviromental Sensingtaken
from Laser Remote Sensing Fundamentals and
Applications by Raymond M. Measures (pgs 206-207)
- Raman Scattering
- Laser radiation inelastically scattered from
molecules is observed with a frequency shift
characteristic of the molecule (h? - h? E)
- Resonance Scattering
- Laser radiation matched in frequency to that of
a specific atomic transition is scattered by a
large cross section and observed with no change
in frequency
17Techniques of Laser Enviromental Sensingtaken
from Laser Remote Sensing Fundamentals and
Applications by Raymond M. Measures (pgs 206-207)
- Fluorescence
- Laser radiation matched to a specific electronic
transition of atom or molecule suffers absorption
and subsequent emission at lower frequency
collision quenching can reduce effective cross
section of this process broadband emission is
observed with molecules
- Absorption
- Observe attenuation of laser beam when frequency
matched to the absorption band of given molecule
Excited level
Electronically excited vibrational levels
h?
Ground level
h?
h?
Ground level
18Techniques of Laser Enviromental Sensingtaken
from Laser Remote Sensing Fundamentals and
Applications by Raymond M. Measures (pg 207)
- Differential absorption and scattering (DAS)
- The differential attenuation of two laser beams
is evaluated from their backscattered signals
when the frequency of one beam is closely matched
to a given molecular transition while the others
frequency is somewhat detuned from the transition
Excited level
h?2
h?1
h?2
Ground level
19LITELidar In-space Technology Experiment Science
20ICESat(aka Laser Altimetry Mision)The Ice,
Cloud, and Elevation Satellite
- Launched Jan 12, 2003
- Jan 15, 2003 Earth pointing
- Measures
- ice sheet elevations
- changes in elevation through time
- height profiles of clouds and aerosols
- land elevations
- vegetation cover
- approximate sea thickness.
- Geoscience Laser Altimeter System (GLAS) - sole
instrument - Combinination surface lidar with dual wavelength
cloud and aerosol lidar
Images and info from http//icesat.gsfc.nasa.gov/
21ICESat(aka Laser Altimetry Mision)The Ice,
Cloud, and Elevation Satellite
- First laser-ranging instrument for continuous
global observations of Earth - Mission data will be distributed and archived by
the National Snow and Ice Data Center
- More detailed info
- ICESat FACT SHEET (.pdf)
- ICESat BROCHURE (.pdf)
- ICESat LITHO (.pdf)
- Environmental Assessment for ICESat (.pdf)
- National Environmental Policy Act (.pdf)
Images and info from http//icesat.gsfc.nasa.gov/
22ICESat(aka Laser Altimetry Mision)The Ice,
Cloud, and Elevation Satellite
- http//glas-scfweb.gsfc.nasa.gov/
- More detailed info
- ICESat FACT SHEET (.pdf)
- ICESat BROCHURE (.pdf)
- ICESat LITHO (.pdf)
- Environmental Assessment for ICESat (.pdf)
- National Environmental Policy Act (.pdf)
Images and info from http//icesat.gsfc.nasa.gov/