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WORLD METEOROLOGICAL ORGANIZATION
__________________
CIMO/MG-9/Doc. 5.1(2)
(3.III.2011)
_______
COMMISSION FOR INSTRUMENTS AND
METHODS OF OBSERVATION
ITEM: 5.1
CIMO MANAGEMENT GROUP
Ninth Session
Original: ENGLISH
Geneva, Switzerland
5 - 8 April 2011
CIMO GUIDE
Update of the Satellite Observations Chapter of the CIMO Guide
Summary and purpose of document
In response to an action agreed by the Expert Team on Satellite Systems at its fifth
meeting (ET-SAT-5, 26-29 April 2010) new material has been developed with the aim to
replace the current Chapter on Satellite Observations in the Guide to Meteorological
Instruments and Methods of Observation (CIMO Guide, Part II, Chapter 8), which dates
back to 1994.
Given the considerable development and diversification of space-based observation
capabilities over the past seventeen years, and the increasing importance of spacebased observation data for WMO Members, in particular for NWP, for severe weather
warning, for Nowcasting, for global climate and environment monitoring, the ET-SAT felt
the need to not only update the current Chapter 8 but to expand it substantially. In view
of the variety of physical variables that need to be addressed, it is furthermore
suggested that a new part (tentatively Part IV) of the CIMO Guide be entirely dedicated
to space-based observation. A preliminary draft has been developed and is being
submitted to ET-SAT Members for review. Its outline is attached, and the full draft
document
(163
pages)
is
available
for
download
at:
http://www.wmo.int/pages/prog/sat/meetings/documents/ET-SAT-6_Doc08-1-add.zip .
The objective is to introduce to the fundamental principles and the main features of
space-based observation. The document aims at raising the technical awareness of the
reader on satellite capabilities, explaining the advantages and limitations of spacebased observation, and helping WMO Members to consider the best use of these
capabilities as an increasingly important source of observation data. This contribution to
the CIMO Guide is meant to complement the Dossier on the Space-based Global
Observing System (often designated as the “GOS Dossier”), which provides a more
comprehensive inventory of current and planned satellites and instruments, as well as
an analysis of the capabilities and gaps in key observations. The GOS Dossier is
available for download ( ftp://ftp.wmo.int/Documents/PublicWeb/sat/DossierGOS/) and
is updated at least every year.
ACTION PROPOSED
-
-
The CIMO Management Group is invited:
to consider the proposal to dedicate a new Part of the CIMO Guide to satellite observation
to provide guidance to ET-SAT that will discuss this issue on 12-15 April 2011.
________________
CIMO/MG-9/Doc. 5.1(2), p. 2
Proposed Outline for a Future Part IV of the CIMO Guide
The full draft text (163 pages) is to be downloaded from:
http://www.wmo.int/pages/prog/sat/meetings/documents/ET-SAT-6_Doc08-1-add.zip
1
1.1
1.2
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.2.6
1.3
PREAMBLE
Historical perspective
Specific features of space-based remote sensing
Spatial and temporal coverage
Spatial integration
Indirect measurements
Calibration
Validation
Satellite lifecycle
Updated Programme information
2.
2.1
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.2
2.2.1
2.2.2
2.2.3
2.2.3.1
2.2.3.2
2.2.3.3
2.2.3.4
2.2.4
2.2.4.1
2.2.4.2
2.2.4.3
2.2.5
2.2.5.1
2.2.5.2
2.2.5.3
2.3
2.3.1
2.3.2
2.3.3
PRINCIPLES OF EARTH OBSERVATION FROM SPACE
Orbits and Earth viewing from space
Field of view from satellites and instruments - Instrument swath
Orbital period, geostationary orbit, observing cycle, repeat cycle
Orbital precession, sunsynchronous orbits, drifting orbits
Elliptical orbits
Launchers and injection into orbit - Services of the platform
Principles of remote sensing
The electromagnetic spectrum utilised for remote sensing
The basic laws of the interaction between e.m. radiation and matter
Observations in the atmospheric windows
Emerging radiation
Measurements in VIS+NIR+SWIR
Measurements in MWIR and TIR
Measurements in MW
Observations in absorption bands
The radiative transfer equation
Profiles retrieval
Limb sounding
Active sensing
Radio occultation
Radar
Lidar
Data circulation and processing
Data transmission
Data processing
Communication services
3.
3.1
3.1.1
3.1.2
3.1.3
3.1.4
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.3
REMOTE SENSING INSTRUMENTS
Instruments basic characteristics
Scanning, swath, observing cycle
Spectral range: radiometers and spectrometers
Spatial resolution (IFOV, pixel, MTF)
Radiometric accuracy
Visible and Infrared imagers
Multi-purpose imaging VIS/IR radiometer
High resolution optical imager
Medium-resolution VIS/NIR spectro-radiometer
Multi-channel/direction/polarization radiometer
Infrared sounders
CIMO/MG-9/Doc. 5.1(2), p. 3
3.3.1
3.3.2
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.5
3.5.1
3.5.2
3.5.3
3.5.4
3.5.5
3.6
3.6.1
3.6.2
3.6.3
3.6.4
3.7
3.7.1
3.7.2
3.7.3
3.7.4
3.8
3.8.1
3.8.2
3.8.3
3.8.4
3.9
3.9.1
3.9.2
3.9.3
3.9.4
3.9.5
3.10
3.10.1
3.10.2
3.10.3
3.10.4
Narrow-band channel IR radiometer
Medium-resolution IR spectrometer
Microwave imagers and sounders
Multi-purpose imaging MW radiometer
Low-frequency MW radiometer
Non-scanning MW radiometer
Absorption-band MW radiometer/spectrometer
Spectrometers for atmospheric chemistry
High-resolution nadir-scanning SW spectrometer
High-resolution nadir-scanning IR spectrometer
Limb-scanning SW spectrometer
Limb-scanning IR spectrometer
Limb-scanning MW spectrometer
Special instruments
Broad-band radiometer
Solar irradiance monitor
Lightning imager
GNSS radio-occultation receiver
Radar
Radar altimeter
Radar scatterometer
Cloud and precipitation radar
Imaging radar (SAR)
Lidar
Backscatter lidar
Doppler lidar
Lidar altimeter
Differential Absorption Lidar (DIAL)
In-situ measurements at platform level
Gradiometer / accelerometer
Satellite-to-Satellite ranging system
Magnetometer
Electric field sensor
Space environment monitor
Navigation and positioning systems
Laser retroreflector
Radio-positioning system
GNSS receiver
Star tracker
4.
4.1
4.1.1
4.1.2
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.4
SATELLITE CONSTELLATIONS
Operational meteorological satellites
Satellite constellation in geostationary orbits
Specialised Atmospheric missions
Precipitation
Radio occultation
Atmospheric radiation
Atmospheric chemistry
Atmospheric dynamics
Missions to ocean and ice
Ocean topography
Ocean colour
Sea surface wind
Sea surface salinity
Waves
Land observation missions
CIMO/MG-9/Doc. 5.1(2), p. 4
4.4.1
4.4.2
4.4.3
4.5
4.5.1
4.5.2
4.6
4.6.1
4.6.2
4.6.2.1
4.6.2.2
4.6.2.3
Main operational or near-operational missions
The Disaster Monitoring Constellation
All-weather high-resolution monitoring (by SAR)
Missions to Solid Earth
Space geodesy
Earth’s interior
Missions to Space weather
Solar activity monitoring
Magnetosphere and ionosphere monitoring
Observation of the Magnetosphere
Observation of the Ionosphere
Space environment observation from operational meteorological satellites
5.
5.1
5.1.1
5.1.2
5.1.2.1
5.1.2.2
5.1.2.3
5.1.2.4
5.1.2.5
5.1.2.6
5.1.3
5.2
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
5.2.6
5.2.7
5.3
5.3.1
5.3.2
5.3.3
5.3.4
5.3.5
5.3.6
5.3.7
5.3.8
5.3.9
5.3.10
5.3.11
5.3.12
5.3.13
5.3.14
5.3.15
5.3.16
5.3.17
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.4.5
5.4.6
SPACE-BASED OBSERVATION OF GEOPHYSICAL VARIABLES
Introduction
Processing levels
Products quality
Atmospheric volumes (relevant to profiles)
The horizontal resolution (x)
The vertical resolution (z)
The observing cycle (t)
The accuracy (RMS)
The timeliness ()
Evaluation of satellite product quality
Basic atmospheric 3D and 2D variables
Atmospheric temperature
Specific humidity
Wind (horizontal)
Wind vector over the surface (horizontal)
Height of the top of the Planetary Boundary Layer
Height of the tropopause
Temperature of the tropopause
Cloud and Precipitation variables
Cloud detection (mask)
Cloud top temperature
Cloud top height
Cloud type
Cloud cover
Cloud base height
Cloud optical thickness
Cloud liquid water
Cloud drop effective radius
Cloud ice
Cloud ice effective radius
Freezing level height in clouds
Melting layer depth in clouds
Precipitation (liquid or solid)
Precipitation rate at surface (liquid or solid)
Accumulated precipitation (over 24 hours)
Lightning detection
Aerosol and Radiation
Aerosol optical thickness
Aerosol concentration
Aerosol effective radius
Aerosol type
Volcanic ash
Downward solar irradiance at TOA
CIMO/MG-9/Doc. 5.1(2), p. 5
5.4.7
5.4.8
5.4.9
5.4.10
5.4.11
5.4.12
5.4.13
5.4.14
5.4.15
5.4.16
5.4.17
5.4.18
5.5
5.5.1
5.5.2
5.5.3
5.5.4
5.5.5
5.5.6
5.5.7
5.5.8
5.5.9
5.5.10
5.5.11
5.5.12
5.5.13
5.5.14
5.5.15
5.5.16
5.6
5.6.1
5.6.2
5.6.3
5.6.4
5.6.5
5.6.6
5.6.7
5.6.8
5.6.9
5.6.10
5.6.11
5.6.12
5.6.13
5.6.14
5.6.15
5.6.16
5.6.17
5.6.18
5.6.19
5.7
5.7.1
5.7.2
5.7.3
5.7.4
5.7.5
5.7.6
5.7.7
Upward spectral radiance at TOA
Upward long-wave irradiance at TOA
Upward short-wave irradiance at TOA
Short-wave cloud reflectance
Downward LW irradiance at Earth’s surface
Downward SW irradiance at Earth’s surface
Earth’s surface albedo
Earth’s surface SW bi-directional reflectance
Upward long-wave irradiance at Earth’s surface
Long-wave Earth surface emissivity
Photosynthetically Active Radiation (PAR)
Fraction of Absorbed Photosynthetically Active Radiation (FAPAR)
Ocean and sea ice
Ocean chlorophyll concentration
Colour Dissolved Organic Matter (CDOM)
Ocean suspended sediments concentration
Ocean Diffuse Attenuation Coefficient (DAC)
Oil spill cover
Sea surface temperature
Sea surface salinity
Ocean dynamic topography
Coastal sea level (tide)
Significant wave height
Dominant wave direction
Dominant wave period
Wave directional energy frequency spectrum
Sea-ice cover
Sea-ice thickness
Sea-ice type
Land surface (including snow)
Land surface temperature
Soil moisture at surface
Soil moisture (in the roots region)
Fraction of vegetated land
Vegetation type
Leaf Area Index (LAI)
Normalised Difference Vegetation Index (NDVI)
Fire fractional cover
Fire temperature
Fire radiative power
Snow detection (mask)
Snow status (wet/dry)
Snow cover
Snow water equivalent
Soil type
Land cover
Land surface topography
Glacier cover
Glacier topography
Solid Earth and Space Weather
Geoid
Crustal plates positioning
Crustal motion (horizontal and vertical)
Gravity field
Gravity gradients
Total Electron Content (TEC)
Electron density
CIMO/MG-9/Doc. 5.1(2), p. 6
5.8
5.8.1
5.8.2
5.8.3
5.8.4
5.8.5
5.8.6
5.8.7
5.8.8
5.8.9
5.8.10
5.8.11
5.8.12
5.8.13
5.8.14
5.8.15
5.8.16
5.8.17
5.8.18
5.8.19
5.8.20
5.8.21
5.8.22
5.8.23
5.8.24
5.8.25
5.8.26
Atmospheric chemistry
O3
BrO
C2H2
C2H6
CFC-11
CFC-12
CH2O
CH4
ClO
ClONO2
CO
CO2
COS
H2O
HCl
HDO
HNO3
N2O
N2O5
NO
NO2
OH
PAN
PSC occurrence
SF6
SO2
6.
6.1
6.1.1
6.1.2
6.1.3
6.1.4
6.1.5
6.1.6
6.1.7
6.1.8
CALIBRATION AND VALIDATION
Instrument calibration
Factors affecting calibration
Pre-flight calibration
On-board calibration
Vicarious calibration
Inter-calibration by Simultaneous Nadir Observations
Bias adjustment of long-term data records
Traceability of space-based measurement
Using calibration information
6.2
6.2.1
6.2.2
6.2.3
6.2.4
6.2.5
Validation of satellite-based products
Factors to be accounted for in validation
Requirements for ground-truth measurements
Continuous statistics
Dichotomous statistics
Impact studies
7.
7.1
7.1.1
7.1.2
7.1.3
7.2
7.2.1
7.2.2
7.2.3
CROSS-CUTTING ISSUES
Data access
Direct broadcast
Rebroadcast
Availability of data servers
Use of the frequency spectrum
Passive MW radiometry
Active MW sensing
Communications
REFERENCES
ACRONYMS