1. Sentinel-4 and Sentinel-5 Overview and Status
Ben Veihelmann, Jörg Langen
ESA/ESTEC

2. Copernicus Atmosphere Monitoring Service
Operational information services for policy makers, …, citizens
Protocol compliance monitoring: ozone layer (Montreal, …), air quality (Göteborg, …), climate (Kyoto, …), emission verification
Near-real-time services: Local air quality, health warning, aviation routing
Assessments: Improve understanding of processes, validate chemical transport models, ground measurement networks
Pre-operational: MACC,
Uses observations from current satellites,
in the future also from Sentinel-4, -5, -5P, … 2

3. The Copernicus Atmospheric Missions: Sentinel-4, -5p and -5
Environmental Themes
stratospheric ozone and surface UV
air quality
climate
Missions and Services
Sentinel-4
Sentinel-5p Sentinel-5
regional AQ at 1h temporal res.
emission and abundance monitoring
forecast
global AQ at 1d temporal res.
emission and abundance monitoring
forecast
climate
GHG emission monitoring
aerosol
ozone
long term O3 evolution (total column and low resolution profile)
surface UV (health)
first AQ mission approved for geostationary orbit (embarked on MTG-S)
diurnal variation, e.g. NO2, aerosol
part of CEOS virtual constellation
bridging between OMI and S-5
CO and CH4
x6 step in 2-D spatial resolution vs. OMI
some diurnal information (with GOME-2)
continuity and long-term datasets
synergies with meteo payloads
(embarked on Metop-SG)
CH4 from 2 bands
Some CO2 (quality not sufficient for operational monitoring)
boundary conditions for S-4

4. Requirements Flow GMES implementation group (2009)
High-level user needs
Capacity study (2005)
User requirements
Camelot study
(2009)
Mission requirements
S-4/-5 MAG
System requirements
Instrument development
L2 product requirements
Level-2 product development

5. GEO+LEO GEOstationary (GEO) Low Earth Orbit (LEO)
Hourly revisit time over Europe
Mainly air quality
Diurnal cycle of tropospheric composition
Sentinel-4
Low Earth Orbit (LEO)
Daily revisit time global coverage
Climate, air quality, ozone & UV
Tropospheric & stratospheric composition
Sentinel-5 (9h30 orbit)
Sentinel-5 Precursor (13h30 orbit)

6. Utilization of data from
GEO+LEO
Mission
Instrument
Utilization of data from
Imager
Infrared sounder
Other
Sentinel-4
UVN spectrometer (1)
FCI (2)
IRS (1)
LI (2,*)
Sentinel-5
UVNS spectrometer (3)
VII (3)
IAS (3)
3MI (3)
Sentinel-5 Precursor
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
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
MTG = Meteosat Third Generation
MetOp-SG = MetOp-Second Generation
SNPP = Suomi National Polar-orbiting Partnership
JPSS = Joint Polar Satellite System

7. KARI GEMS JAXA GMAP-ASIA
GEO+GEO+GEO+LEO
NASA TEMPO
ESA Sentinel-4
KARI GEMS JAXA GMAP-ASIA
CEOS Atmospheric Composition Virtual Constellation
USA TEMPO
Europe Sentinel-4
Korea GEMS
Sentinel-5/-5P
Orbit
Geostationary
LEO
Domain
North America
Europe and surrounding
Asia-Pacific
global
Revisit [h]
1 hour
Daily, higher lat
Spectral ranges
UV-Vis
UV-Vis-NIR
UV-Vis-NIR-SWIR
Key products
O3, NO2, SO2, HCHO, CHOCHO, aerosol
O3, NO2, SO2, HCHO, CHOCHO (TBC), aerosol
O3, NO2, SO2, HCHO, aerosol
O3, NO2, SO2, HCHO, CHOCHO, aerosol, CH4, CO, …
Spatial resolution [km2]
9 x 5 at 35°N
8 x 8 at 40°N
8 x 7 (gas), 8 x 3.5 (aerosol) at 38°N
7 x 7 at nadir

8. Sentinel-4 UVN Instrument
Optical Instrument Module
Optical Path Sun calibration
Sun Baffle
Diffuser Wheel
Diffuser Wheel Drive
White Light Source
Scan Mirror
Aperture Cover
NIR FPA
Beam Splitter Assembly
NIR Spectrometer OA
TSA Structure
Grating
GRISM Assembly
UV-VIS Collimator
UV-VIS Camera
UV-VIS FPA
Telescope
Summer FoV
Heater Envelope
Scanner Cover
YUVN
ZUVN
XUVN
Thermal Heat Shields

9. Sentinel-4/UVN Instrument
Revisit time 1h
Geographic coverage
Europe + part of Atlantic + part of Sahara, FoV = 4° N/S, 11°-14° E/W
Spatial sampling
8 km at 45°N, 530 x 570 spatial samples
Spatial resolution
8.9 km N/S, 11.7 km E/W at 45°N
Spectral range
UV-VIS: nm, NIR: nm
Spectral resolution
UV-VIS ≤ 0.5 nm, NIR ≤ 0.12 nm
Spectral sampling ratio
>3
Envelope
1000 x 1000 x 1500 mm3
Mass
200 kg
Power
180 W
Data rate (nominal operation)
30 Mbps

10. Sentinel-4/UVN Scan Strategy
Instantaneous Field of View
SZA = 90 °
SZA = 92°
equinox

11. Sentinel-5 UVNS Instrument

12. Sentinel-5/UVNS Instrument
Temporal resolution
≤ 24 h
Geographic coverage
global
Spatial sampling
< 45 km ( nm), < 7.5 km (> 300nm) at nadir;
216 samples within 2670 km swath
Spatial resolution
~ spatial sampling distance
Spectral range
UV-VIS: 270 – 500 nm, NIR: 685 – 710 nm and 755 – 773 nm,
SWIR: 1590 – 1675 nm and 2305 – 2385 nm
Spectral resolution
1.0 nm ( UV < 300nm), 0.5 nm (UV-VIS 300 – 500 nm),
0.4 nm (NIR), 0.25 nm (SWIR)
Spectral sampling ratio
3 (UV-VIS and NIR), 2.5 (SWIR)
Envelope
1145 x 1032 x 1026 mm3
Mass
270 kg
Power
300 W
Data rate (nominal operation)
20 Mbps

13. Spatial Footprint GOME-2 Sciamachy OMI
Image: Google maps
GOME-2
Sciamachy
OMI
Sentinel-4/-5/5P spatial resolution & sampling
Better than heritage (Sciamachy/GOME-2/OMI)
Big step toward resolving sources

14. S-5p expected performance
Level-2 Products
species
Characteristics
S-5p expected performance
S-4 target performance
S-5 priority O3
vertical profile
10-30 % (strat. 6 km res.)
enhanced sensitivity to lower trop. (1,4) 1
total column
3.5 – 5 %
3 - 4%
trop. column %
NO2
total column and trop. column
strat. < 10%, trop %
1.5*1015 molec/cm² or
30% (goal) / 50% (threshold)
SO2
total column and height
30 – 50 %
1.0*1016 molec/cm² or
80% (goal) / 100% (threshold)
HCHO
40 – 80 %
1.5*1016 molec/cm² or
50% (goal) / 100% (threshold)
CHOCHO
x (4)
50% (goal) / 100% (threshold) (4)
CH4
1.5 % - CO
< 15 %
Cloud
optical depth, fraction, height
<20 % (all parameters)
x (2), x (3,4)
Aerosol
UV absorption index
~1 AAI
0.3 (goal) / 0.5 (threshold)
layer height
< 100 hPa
1 km
optical depth (OD)
0.05 (SUR) 2
absorption OD
fine mode OD x
Surface
effective reflectance
first BRF parameter 0.01
Surface UV
spectral irradiance, UV index
x (FMI)
H2O
CO2
BrO
OClO IO 3
HDO
Synergy with IRS
Will exploit FCI L2 cloud product if available
Synergetic with FCI L1c
funding not yet secured
S4 target performance given for
VZA and SZA<60° (all products)
Cloud fraction <20% (trace gas col)
Clear sky (aer, surf, o3 pro)

15. Sentinel-4 Mission Implementation Status
S4/UVN instrument & Level-1b Prototype Processor developed by ESA with Airbus Defence & Space as prime
Preliminary Design Review completed
Critical Design Review mid 2016
Flight Acceptance Review early 2021
Level-1b geometric processing developed on platform level
Level-2 Operational Processor developed by ESA with DLR as prime
Kick-off 2 June 2015
Prototype and Operational Processor
System Integration & Verification, support to Commissioning
EUMETSAT will operate the instrument and process the mission data up to Level-2

16. Sentinel-5 Mission Implementation Status
S5/UVNS instrument & Level-1b Prototype Processor developed by ESA with Airbus Defence & Space as prime
System Preliminary Design Review completed
Critical Design Review Nov. 2017
Flight Acceptance Review Dec. 2020
Level-2 Prototype Processor will be developed by ESA, Operational Processor by EUMETSAT
EUMETSAT will operate the instrument and process the mission data up to Level-2

17. Schedule + Long-Term Perspective
GOME-2 (9.30h) and OMI/TROPOMI (13.30h) provide partial diurnal information, before geostationary missions takes over with hourly data
S4 and S5, together with IR sounders and 3MI, will be Europe’s long-term contribution to operational nadir-viewing atmospheric composition sounding
The geostationary missions GEMS, S4, and Tempo together with S5/S5P form a global atmospheric composition constellation
Guaranteed provision of long-term datasets in synergy with meteorological payloads is based on identical instruments  no innovation on space instrument until 2035/40
Update of geophysical requirements for future successors is under EU responsibility:
GMES-PURE contract (2013/14)
Requirements Framework for the next generation of the Copernicus Space Component (2015–18) (“small scale exercise” for atmosphere complementing PURE)

18. Thanks for listening! MetOp-SG B SCA MWI RO ICI Argos–4 MTG-S IRS
Sentinel-4
Sentinel-5P
TROPOMI
MTG-I
FCI LI
MetOp-SG A
METimage
IASI-NG
MWS RO
Sentinel-5
3MI
Thanks for listening!
Ben Veihelmann, Jörg Langen
ESA/ESTEC
OMI STM 19, de Bilt, NL, Sept 2015
Graphics: ESA