Passive Remote Sensing:
allocations, sensors,
measurements and
applications
[email protected]
NASA HQ Spectrum Management
REMOTE Office
SENSING WORKSHOP
Geneva, Switzerland 11 December 2007
Passive Sensing
Radio Regulation No. 1.183
(definition)
 Passive Sensor: A measuring
instrument in the earth explorationsatellite service or in the space
research service by means of which
information is obtained by reception
ofwaves
radio
waves
origin.
Radio
of natural
originof
arenatural
emissions from
the ground, air,

and water. All objects emit radio waves and the emissions convey
information about those objects.
Remote sensing is a layered
system
The complete remote sensing system
addresses societal concerns
Use of the Passive Bands
 Passive sensors are designed to receive and measure natural
emissions produced by the Earth’s surface and its atmosphere.
The frequency and strength of these natural emissions
characterize the type and status of many important
geophysical, which describe the status of the
Earth/Atmosphere/Oceans System:
 Earth surface parameters such as soil moisture, sea
surface temperature, ice extension and age, snow cover,
rainfall over land, etc ... ;
 Three-dimensional atmospheric parameters (low, medium,
and upper atmosphere) such as wind circulation,
temperature profiles, water vapour content and
concentration profiles of radiatively and chemically
important trace gazes (for instance O3, SO2 and ClO).
Use of the Passive Bands

Microwave observations at frequencies below 100 GHz enable
studies of the Earth’s surface and its atmosphere from spaceborne
instruments even in the presence of clouds, because clouds are
almost transparent at these frequencies. This "all-weather" observing
capability has been very important for EESS in achieving the
repetitive global coverage mandatory for meteorological,
climatological, and environmental monitoring and surveying.

The impressive progress made in recent years in weather analysis,
warning and forecasts, especially for dangerous weather phenomena
that affect all populations and economies is largely attributable to
the spaceborne observations and their assimilation in numerical
models.

Play a major role in the prediction and detection of disasters.
Use of the Passive Bands
Typical bands and their main application:
1400-1427
MHz: salinity (ocean), soil moisture (ground)
10.6-10.7 MHz: rain, snow, ice, sea state, ocean wind
23.6-24 GHz: total content of water vapour
31.3-31.5 GHz: the lowest cumulated effects due to
oxygen and water vapour in the vicinity of the 50 GHz
band. Optimum window channel to see the Earth’s
surface: reference for the other channels.
36-37 GHz: cloud liquid water, vegetation structure,
surface roughness
50.2-50.4 GHz: temperature profile
Passive Sensors observe
through the atmosphere
Sensitivity of Brightness Temperature to
Geophysical Parameters over Land
Surface
Tb
Pi
Surface roughness
Vegetation biomass
Cloud liquid water
Soil moisture
Integrated water vapour
5
10
15
20
Frequency (GHz)
25
30
35
40
Spectrum
Spectral Sensitivity to Environmental
Parameters: Ocean Scene
SALINITY
WIND SPEED
LIQUID CLOUDS
+
WATER VAPOUR
Tb
Pi
Frequency (GHz)
0
10
20
30
40
SEA SURFACE
TEMPERATURE
_
Aqua Instruments – AMSR-E





Advanced Microwave Scanning
Radiometer for EOS
12-Channels, 6 frequencies 6.9-89.0
GHz
dual-polarization
5.4-56 km
footprint at nadir
All weather
AMSR-E Products





Precipitation Rate
Cloud Water
Surface wind speed over oceans
Sea Surface Temperature
Ice, Snow and Soil Moisture
Aqua Instruments – AMSU/A
Advanced Microwave Sounding Unit
 15 Microwave Channels 15-90 GHz
 ~40 km footprint at nadir
 All-Weather

Global composite of brightness
temperature (K) From AMSU-A
Channel 3
Radiation Measurements to
Vertical Soundings



AIRS and AMSU data combined to create
vertical soundings of temperature and
humidity
Air and/or water vapor at various heights
(pressures) contribute to the total radiation
measurement viewed from space.
The contribution peaks at different pressures
for different wavelengths
Improve Accuracy of Severe
Weather Warnings
Microwave Imagery and
Sounding products
improve prediction of
precipitation, surface
wind speed and direction
Increase in hurricane
landfall forecast skill
saves an estimated $1
million per mile of
coastline that does not
have to be evacuated
Improved observations
yield improved early
warnings, which in turn
mitigate the devastating
effects of floods
through disaster
planning and response
Disaster Management
EARTH SYSTEM MODELS
• Earthquake: MMI, Quakesim
DECISION SUPPORT TOOLS
• Hurricane: HURRSIM
• Flood: SLOSH, WAVEwatch,
STWAVE, HURSURGE
• HAZUS-MH (Hazards U.S. Multi Hazard)
• Land: GPS Network, SBEACH
• Earthquake
prediction
• Building Cost Models: ATC-13
• Floods
• Building Structure Models:
EPEDAT
• Hurricane &
Typhoons
• Disaster Recovery/
Mitigation
• Land use decision
• Potential economic loss
*Supported Non-NASA Model
• Estimation of direct
damage, induced
damage, direct losses,
and indirect losses
Data
EARTH OBSERVATORIES
• Land: Landsat, SRTM, GPS,
SCIGN, Terra, Aqua
• Ocean: QuickSCAT, Seawinds,
IceSAT, GOES, POES, SSMI,
JASON, TOPEX/POSEIDON
• Atmosphere: TRMM, GOES,
POES, GPM, NPP, NPOESS
*Future Mission
• Land Surface
Topography
• Global
Precipitation
• Ocean Surface
Winds
• Surface
Deformation
• Motions of the
Earth’s Interior
• Accurate risk prediction
to communities
• Loss estimates of
buildings, essential
facilities, transportation
& utility lifelines, and
population
• Social impacts
VALUE & BENEFITS
• Identify/ Prioritize
high-risk
communities
• Reduction in lives
lost
• Reduction in damage
cost
• Anticipate the scope
of disaster-related
damage
• Improve disaster
response
• Community Planning
Disaster Related Remote Sensing
Applications




Weather Prediction: a key input to numerical weather
prediction models used globally for weather forecasting.
(Microwave(passive))
Global Warming: concentrations and distributions of
atmospheric gases, sea and land ice thickness and change,
and ozone measurements are key components to studying
and prediction of global warming. (Microwave(passive),
Infrared)
Severe Weather Events: the prediction of severe weather
events requires accurate measurements of rain rates in
storms over the oceans which is only possible with remote
sensing satellites. (Microwave(passive))
Forest Fires: detection of fires through smoke by their
microwave radiation. (Infrared)
Key Applications (continued)




Management of Natural Resources: measurements of
biomass, deforestation, and water resources through
systematic environmental monitoring. (Microwave
(passive), Infrared, Optical)
Volcanoes: used to detect volcanic activity even before
eruptions and to track and predict the volcanic fallout
effects. (Optical, Microwave (active), Infrared, SubM)
Shipping: used to track sea ice, ice floes, and ocean storms
to steer ships out of harm’s way. (Optical, MW(active))
Long Range Climate Forecasts: study of global atmospheric
and oceanic events such as El Niño requires sea surface
temperature, ocean winds, ocean wave height, and many
other components used in the prediction of long range
weather forecasting and climatic trends. (Microwave
(active/passive))
Remote Sensing Report
– ITU-D SG 2 Question 22/2 “Utilization of ICT for
disaster management, resources, and active and
passive space-based sensing systems as they apply
to disaster and emergency relief situations”
• Work Item 2: Identification and examination of active
and passive sensing system applications for their
potential effect in enhancing disaster mitigation.
Version 1 of the Report is complete and
available upon request from the presenter.
THANK YOU!
Thomas vonDeak
NASA HQ Spectrum Management Office
(VIEWS EXPRESSED ARE THOSE OF THE PRESENTER
AND DO NOT NECESSARILY REFLECT THOSE OF NASA.)
National Aeronautics and Space Administration
Global Passive Sensor Systems
AQUARIUS
Aquarius is a focused satellite mission to measure global Sea Surface Sainity. Aquarius
will resolve missing physical processes that link the water cycle, the climate, and the
ocean.
AQUA
Aqua, collects information on the Earth’s water cycle. The AMSR-E instrument observes
atmospheric, lad, oceanic, and cryospheric parameters, including precipitation, sea surface
temperatures, ice concentrations, snow water equivalent, surface wetness, wind speed,
atmospheric cloud water, and water vapor. The AMSU instrument is a 15-channel
microwave sounder designed primarily to obtain temperature profiles in the upper
atmosphere (especially the stratosphere) and to provide a cloud-filtering capability for
tropospheric temperature observations.
CORIOLIS
Coriolis is a 3-year meteorological science mission to demonstrate the viability of using
polarimetry to measure ocean surface wind speed and direction from space, and to
demonstrate predictions of geomagnetic disturbances through continuous observation of
Coronal Mass Ejections. It’s WinSat instrument is a passive polarimetric microwave
radiometer developed as a risk reduction item in the development of the planned
production Conial Microwave Imager Sounder.
DMSP
The Defense Meteorological Satellite Program (DMSP) monitors the meteorological,
oceanographic, and solar-terrestrial physics environments. The SSM/I instrument is a
seven-channel, four frequency, linearly-polarize, passive microwave radiometric system
whose data is sued to obtain synoptic maps of critical atmospheric, oceanographic and
selected land parameters on a global scale. The SSM/T instrument is a five channel, total
power microwave radiometer designed to provide global monitoring of the concentration of
water vapor in the atmosphere under all sky conditions.
www.nasa.gov
National Aeronautics and Space Administration
Global Passive Sensor Systems
GCOM
JAXA’s Global Change Observation Missions (GCOM) will carry the AMSR2
instrument which is an upgraded version of the AMSR-E instrument on NASA’s
AQUA mission.
JASON
Jason-1 is the first satellite in a series designed to ensure continued observation of the
oceans for several decades. The JASON-1 Microwave Radiometer (JMR) is a passive
sensor which acquires measurements via three separate frequency channels to
determine the path delay of the altimeter’s radar signal due to atmospheric water vapor.
MEGHATROPIQUE
Megha-Tropique is designed to investigate the contribution of the water cycle to
climate dynamics specifically in the tropical regions. Its Microwave Analysis and
Detection of Rain and Atmospheric Structures (MADRAS) passive sensor measures
cloud, precipitation and upper atmospheric ice parameters.
METEOR-M-1
The overall objective of the Meteor-M-1 mission are to provide operational
meteorological services. The objective of MTVZA is to monitor ocean and land
surfaces as well as global atmospheric parameters such as temperature and water vapor
profiles and to obtain sea surface wind profiles.
METOP
MetOp promises to provide outstanding data sets to advance the filed of meteorology,
which will ultimately improve the accuracy of weather forecasting and our
understanding of climate change. AMSU-A and AMSU-B passively measure+C17
scene radiance which is used in conjunction with an infrared sounder to calculate the
global atmospheric temperature and humidity profiles.
www.nasa.gov
National Aeronautics and Space Administration
Global Passive Sensor Systems
NOAA (=GOES)
The NOAA satellites, more commonly known as the geostationary operational
environmental satellites (GOES), are used for short-range warning and
“nowcasting” and use a form of the AMSU sensor found on NASA’s AQUA
satellite.
NPP & NPOES
National Polar-Orbiting Operational Environmental Satellite System (NPOESS)
and its Preparatory Project (NPP) collects and distributes remotely-sensed land,
ocean, and atmospheric data to the meteorological and global climate change
communities. The Advanced Technology Microwave Sounder (ATMS)
passively collects atmospheric data to permit the calculation of temperature and
moisture profiles at high (~daily) temporal resolution.
OKEAN-1
The OKEAN series of satellites provide oceanagraphic monitoring including
measurements of arctic ice.
Sentinel-3
ESA’s Sentinel-3 satellite will be dedicated to providing operational
oceanographic services.
SMOS
ESA’s Soil Moisture and Ocean Salinity (SMOS) mission has been designed to
observe soil moisture over the Earth’s landmasses and salinity over the oceans.
TRMM
The Tropical Rainfall Measuring Mission (TRMM) is a mission designed to
monitor and study tropical rainfall. The TRMM Microwave Imager (TMI) is a
passive microwave sensor designed to provide quantitative rainfall information
over a wide swath under the TRMM satellite.
www.nasa.gov
National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit Three: Understanding … climate variability and change.
www.nasa.gov
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National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit Eight: Improving… terrestrial, coastal, and marine ecosystems..
www.nasa.gov
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National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit Eight: Improving… terrestrial, coastal, and marine ecosystems..
www.nasa.gov
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National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit Three: Understanding … climate variability and change.
www.nasa.gov
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National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit One: Reducing loss of life and property … from disasters..
Prediction
www.nasa.gov
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National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit One: Reducing loss of life and property … from disasters..
Prediction
www.nasa.gov
33
National Aeronautics and Space Administration
Capabilities of Space-Based Sensing
Societal Benefit One: Reducing loss of life and property … from disasters..
Prediction, Disaster Event Assessment, Monitoring
www.nasa.gov
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