Sentinel-4 and -5
Status and Level-2 Products
Ben Veihelmann, Jörg Langen, Dirk Schüttemeyer, Paul Ingmann
ESA/ESTEC
OMI Science Team Meeting 18
March 2014, KNMI, De Bilt, The Netherlands
Overview
• Sentinel-4: mission implementation and Level-2 products
• Sentinel-5: mission implementation and Level-2 products
• AROMAT campaign: preparation of future validation
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 2
The Sentinel Missions
for Copernicus Atmosphere Services
GEOstationary (GEO)
Low Earth Orbit (LEO)
–
Hourly revisit time over Europe
–
Daily revisit time global coverage
–
Mainly air quality
–
Climate, air quality, ozone & UV
–
Diurnal cycle of tropospheric
composition
–
Tropospheric & stratospheric
composition
 Sentinel-4
 Sentinel-5
 Sentinel-5 Precursor
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 3
Sentinel-4/-5/-5P Mission
Implementation
Utilization of data from
Mission
Instrument
Sentinel-4
UVN spectrometer
Sentinel-5
Sentinel-5
Precursor
Imager
Infrared
sounder
Other
FCI (2)
IRS (1)
LI (2,*)
UVNS spectrometer (3)
VII
IAS (3)
3MI (3)
UVNS spectrometer
TROPOMI (4)
VIIRS (5)
CRIS (5,*)
OMPS (5,*)
(1)
on MTG sounder (GEO)
(2) on MTG imager (GEO)
(3) on MetOp-SG (LEO)
(4) on dedicated platform (LEO)
(5) on SNPP/JPSS (LEO)
(*) synergy on higher data level
(1)
MTG = Meteosat Third Generation
MetOp-SG = MetOp-Second Generation
SNPP = Suomi National Polar-orbiting Partnership
JPSS = Joint Polar Satellite System
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 4
(3)
UVN = Ultraviolet + Visible + Near infrared
FCI = Flexible Combined Imager
IRS = InfraRed Sounder
LI = Lightning Imager
UVNS = UVN + Short wave infrared
VII = Visible/Infrared Imager (MetImage)
IAS = Infrared Atmospheric Sounder (IASI-NG)
3MI = Multi-viewing, -channel, -polarisation Imager
TROPOMI = TROPOspheric Monitoring Instrument
VIIRS = Visible Infrared Imaging Radiometer Suite
CrIS = Cross-track Infrared Sounder
OMPS = Ozone Mapping Profiler Suite
Sentinel-4/UVN Instrument
East-West
Scan Range
Earth
View Port
External
MLI
Nadir Baffle
top Part
NIR FPA
NIR
Spectrograph
Telescope
Co-Registration
Compensator
TSA
Structure
Sun Calibration
View Port
UV-VIS
Spectrograph
UV-VIS FPA
Scanner
Base Plate
Kinematic
Mounts
Scanner Cover
Z
UV-VIS FEE
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 5
X
Courtesy Astrium
Calibration
Assembly
Sentinel-4/UVN Instrument
Characteristics
Radiometric accuracy 1.8% (315-500 nm), 2.3% elsewhere
Spectral
Band
range
[nm]
resolution
[nm]
sampling
ratio
Spectral features <0.05%
UV
305 - 400
0.5
3
Signal-to-Noise Ratio compliant
VIS
400 - 500
0.5
3
Spatial Sampling 8 km at 45˚N
NIR
750 - 775
0.12
3
Polarisation sensitivity <0.7%
UV-vis
Geographic Coverage Area (GCA) Europe + Sahara
NIR
Repeat Cycle 1 h over Reference Area (RA)
300
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 6
400
500
600
700
Wavelength (nm)
800
Sentinel-4 Level-2 Products
Application
Product
Air
Quality
Climate
O3 total & tropospheric column
X
X
O3 enhanced sensitivity to lower
X
X
troposphere
Comment
Surface
UV
Synergy with infrared data from IRS
NO2 total & trop. column
X
SO2 total column
X
Also for volcanic eruption monitoring
CHOCHO total column
X
By-product
CH2O total column
X
Aerosol extinction coeff. profile,
column optical depth / type / index
X
X
Cloud optical thickness, fraction,
altitude
Surface reflectance daily map
Who takes care of IRS alone products such as CO, HNO3?
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 7
Also for volcanic eruption monitoring
Also auxiliary for other S4 products
Synergy with imager data from FCI
X
Mainly auxiliary for other S4 products
Synergy with imager data from FCI
X
Mainly auxiliary for other S4 products
Sentinel-4 Level-2 Performance Estimate
(IUP, RAL, Noveltis)
Assumptions
•
polluted scenario at 50˚N, 15h local time
•
radiometric offset error small, spectral calibration successful
•
cloud fraction up to 20%
Tropospheric
column
O3 [%]
NO2 [%]
CH2O [%]
SO2 [%]
Error type
Ran.
Sys.
Ran.
Sys.
Ran.
Sys.
Ran.
Sys.
Instrument
3
3
7
3
13
3
5
10
Scene (clear)
9
20
10
21
7
27
12
20
Scene (cloudy)
9
22
11
26
9
34
19
36
Total (clear)
22
25
31
25
Total (cloudy)
24
29
37
42
10-25
15-25
20-50
20-50
User req.
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 8
 Valuable aerosol data from O2A band
in morning/afternoon expected
Boundary
Layer
Total
Column
Aerosol Optical Depth Noise Error
06h
09h
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 9
12h
15h
18h
R. Siddans, STFC Rutherford Appleton Laboratory
Assumptions: European background aerosol profile
User
requirement
Sentinel-4 Level-2 Performance Estimate
(IUP, RAL, Noveltis)
Sentinel-4 Level-2 Processor
Development Challenges
Tropospheric NO2 diurnal variation
Aerosol layer height
•
good precision and accuracy
•
from O2A band
•
avoid diurnal biases!
•
little heritage
•
 need to account for
•
spectroscopy
– surface anisotropy
•
pseudo-noise mitigation
– tropospheric profile
•
spectral calibration
– stratospheric sub-column
•
computational speed
– aerosol vertical distribution
– aerosol phase function
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 10
Aerosol & surface characteristics
•
joint retrieval from aggregated data
•
little heritage
•
processor architecture
•
computational speed
Sentinel-4 Level-2 Pre-development
SURMACED (BIRA, GC, LOA, IM)
GPGPU (LOA, Catalyst)
Objective
•
Aerosol & surface reflectance from temporally aggregated radiance
•
Application to real satellite measurements
•
Validation based on real measurement
Approach
GOCI on
COMS
•
SURMACED (finalised): GRASP algorithm, performance demonstrated for
favourable illumination conditions (summer), driver NO2 retrieval
•
GPGPU (ongoing): Proxy data from GOCI, reference from AERONET and
PARASOL
OMI STM 18 | KNMI De Bilt, NL | March
2014 | Slide 11
Bi-directional
Reflectance Factor, 440 nm, various surface types
Sentinel-4 Level-2 Pre-development
AEROPRO (KNMI)
Objectives
•
Aerosol layer height retrieval from O2A-band
•
Application to real satellite measurements
•
Validation based on collocated measurements
GOME-2 on
MetOp
Status
•
GOSAT (0.016 nm) + airborne lidar  finalised
•
GOME-2 (0.5 nm) + ground based lidar  almost finalised
•
poster Bram Sanders
CarbonExp Campaign 2011
Lidar on FAAM
Collocated
GOSAT target mode
airborne lidar
STM 18 | KNMI
CarbonExpOMI
Campaign
2011De Bilt, NL | March 2014 | Slide 12
TANSO on
GOSAT
CarbonExp Campaign 2011
Sentinel-4 Level-2 Processor Development
• ITT early 2014
• Build on heritage
• Challenges
• Consortium formation now!
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 13
Mission Elements: Sentinel–5
LEO Atmospheric Mission
Applications:
• air quality, climate forcing and
stratospheric ozone,
tropospheric chemistry
Instrumentation:
• UV-VIS-NIR-SWIR spectrometer
• Use of thermal IR sounder, cloud
imager and polarisation imager

UV-Visible (270-500nm)

NIR (685-775nm)

SWIR (1590–1675nm; 2305-2385nm)

Spectrometers with spectral resolutions between 0.25 nm and 1.0 nm

Spatial sampling with 50 (T)/15 (G) km < 300nm and 15 (T)/5(G) km > 300 nm

Global daily coverage

Sun-synchronous Low Earth Orbit platform at 824 km mean altitude

Embarked on EPS-SG, operated by EUMETSAT
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 14
Possible Level-2 Products from
Sentinel-5 UVNS
species
priority applications
O3 vertical profile
O3 total column
1
1
SO, AQ, CL
SO
NO2 total & trop. col.
1
AQ
CH4 total column
1
CL
CO total column
SO2 total column
HCHO total col.
BrO total column
H2O total column
CHOCHO total col.
1
1
1
2
2
2
AQ, CL
AQ
AQ
SO
AQ, CL
AQ
CO2 total column
(1)
CL
species
Cloud
optical
fraction, height
priority applications
depth,
1
(2)
auxiliary
Aerosol absorption index
Aerosol optical depth,
2
1/2 (3)
AQ, CL
AQ, CL
Aerosol vertical profile
1/2
AQ, CL
type
Surface reflectance
Vegetation fluorescence
SO
AQ
CL
=
=
=
(2)
2
auxiliary
science
stratospheric ozone
air quality
climate
Only observed in strongly polluted areas (volcanic eruptions, major power plants)
(2) Priority 1 not as geophysical product itself, but for use in correcting retrievals of other products
(3) Priority 2 for instrument development; priority 1 for Level-2 product development
(1)
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 15
Possible Sentinel-5-relevant Level-2 Products
from other instruments on Metop-SG
IAS (IASI-NG)
O3 and CO profiles
SO2, NH3, CH3OH, HCOOH
CH4, H2O, HNO3, PAN
C2H2, HCN
CFC-11, CFC-12, C2H4, N2O, HONO, CO2, volcanic ash
3MI
aerosol/cirrus optical depth
aerosol single scattering albedo, effective radius, refractive index
surface reflectance
VII (MetImage)
aerosol/cirrus optical depth
aerosol type, effective radius, single scattering albedo
cloud characterisation
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 16
Sentinel–5 scientific study activities
Consolidation of requirements
•
•
•
•
•
radiometric errors (offset, scaling, spectrally varying)
spatial co-registration (cloud, surface albedo impact), spatial resolution
spectral resolution vs. SNR
knowledge of slit function
added value of O2-B band
Performance assessment
•
•
•
•
•
error budget
band trade-offs (eg. 2-band vs. 3-band CH4 retrieval)
vertically resolved aerosol product
spectroscopic errors
fluorescence
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 17
AROMAT
(Airborne ROmanian Measurements of Aerosols and Trace gases)
Objectives
• To combine airborne, satellite and coincident ground activities
• To investigate consistency and complementarity of different
measurement approaches
Targets
• NO2, SO2, and aerosols in exhaust plumes of large power stations
(Turceni and Rovinari) and around the Bucharest urban area.
Setup
• 2 imaging DOAS, scanning lidar, NO2 sondes
• high pollution levels and strong gradients
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 18
Sentinel-4 and -5
Status and L2 Products
Ben Veihelmann, Jörg Langen, Dirk Schüttemeyer, Paul Ingmann
ESA/ESTEC
Thanks for listening!
OMI Science Team Meeting 18
March 2014, KNMI, De Bilt, The Netherlands
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 20
Preliminary spectral fit-windows
per Level-2 product
UV-Visible band
Near Infrared band
Ozone
NO2
SO2
HCHO
CHOCHO
Aerosol
Cloud
Surface
300
400
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 21
500
600
Wavelength [nm]
700
800
Sentinel-4 Instrument
on Meteosat Third Generation (MTG)
MTG-Sounder
InfraRed Sounder (IRS)
Sentinel-4/UVN (S4/UVN)
MTG-Imager
Flexible Combined Imager (FCI)
Lighting Imager (LI)
OMI STM 18 | KNMI De Bilt, NL | March 2014 | Slide 22
UVN = UV + Visible + Near infrared