Roland Meynart. Earth Oservation Programmes Directorate ESA

Transcription

1 Technologies for post-eps and possibly needed developments Roland Meynart Earth Oservation Programmes Directorate ESA With the contributions of my AEG colleagues M.Betto, U.Del Bello, C.C.Lin, Y. Durand, U.Klein

2 From EPS/METOP to? HIRS IASI AVHRR MHS AMSU -1-2 ASCAT GOME-2 Heritage instruments New-generation European instruments

3 From applications to measurement techniques (1) Post-EPS Missions Atmospheric sounding Wind profiling Clouds and precipitation Large scale land surface imaging Atmospheric chemistry Ocean topography Ocean Imaging Potential Instrument types Micro-Wave Radiometer, IR spectrometer, Differential Absorption Lidar, GNSS Occultation Doppler lidar, Doppler radar Cloud radar, Precipitation radar, Micro-Wave Radiometer, backscatter lidar, Multispectral imager (UV to SWIR) Micro-Wave Radiometer, Scatterometer, Multispectral imager (VNIR to TIR) Micro-Wave Limb sounder, Limb- and nadir-viewing spectrometer (UV to TIR), Differential Absorption Lidar Microwave altimeter, laser altimeter Micro-Wave Radiometer, Scatterometer, Multispectral imager (VNIR to TIR)

4 From applications to measurement techniques (2) Atmospheric sounding Wind profiling Cloud, precipitation Land imaging Ocean topography Ocean imaging Micro-Wave Radiometer, Limb sounder Scatterometer, Cloud, Precipitation& Doppler radar, Altimeter GNSS occultation Multispectral imager, Spectrometer Backscatter, Doppler, Altimeter and DIAL Passive μwave Active μwave Passive optical Active optical Atmospheric chemistry

5 Microwave sounder and imager: concept A Conically scanning imager (MIMR/EGPM type) Imager 13 channels: GHz Aperture: 1 m, Half power beam width: 1.3º at 18.7 GHz...0.3º at 89 GHz Scan rate: 26.5 rpm at 53 deg w.r.t. nadir Main Reflector 110 W, 175 kg, 52 Kb/s X-track scanning sounder (AMSU/MHS type) Sounder 26 Channels GHz (in 8 bands) Aperture: 360 mm Horiz. resolution: 40km at SSP (23GHz) Scan rate: 26.5 rpm 160 W, 110 kg, 27.5 Kb/s Cold Calibration Reflector Hot Calibration Target Feed Horns Rotating Part Hold Down & Release Mechanism Static Part

6 Microwave sounder and imager: concept B Concept B: Conically scanning imager/sounder 30 Channels GHz 150 Channels in parallel acquired Aperture: LF 700 / HF 360 mm Footprint: 23 GHz 15km at > 89GHz Scan rate: 20 rpm at 53 deg w.r.t. nadir Power consumption: 84 W Mass: 128 kg Gaps/developments for both concepts Requirement consolidation for the MW sounding channels (57 GHz band) Long-lifetime scanning mechanism Millimetre-wave receivers Feed-cluster

7 Polarimetric MW Radiometer (surface wind) WindSat/Coriolis - Measure ocean surface wind direction - 25-km spatial resolution - 6.8, 10.7, 18.7, 23.8, and 37 GHz, - Antenna diameter 1.83 m - Preliminary result indicates a comparable performance to scatterometers above 8 m/s - Sensitive to weather conditions (clouds and precipitation) - Further progress expected

8 L-band synthetic aperture radiometer SMOS, launch Sep 2007 Soil moisture (4% 35-50km resolution) Ocean salinity ( km, days) 2-D L-band synthetic aperture radiometer 69 receivers in 3 arms of 4.5 m length + central hub 50 km resolution in 1000 km alias-free image Orbit 760 km, SSO Mass: 680 kg, Power 900 W

9 MW Limb Sounder (1) ODIN (launch 2001) Limb sounder H 2 O, O 2, O 3,CO, N 2 O, NO 2, Radiometer: 3 channels 119 to 580 GHz Spectrometer: nm nm ACECHEM (2001) FTS limb scanner 3 channels in cm -1 Sub-mm-wave limb sounder 5 channels between 294 and 626 GHz

10 MW Limb Sounder (2) MASTER AMIPAS Mass Power Datarate 360 kg 260 W 120 kbps Mass Power Datarate 280 kg 270 W 30 Mbps

11 MW Limb Sounder (3) MARSCHALS Airborne Demonstrator Millimetre-wave limb sounder, 300 GHz, 325 GHz, 345 GHz Optimised to sound UT & LS region Can be flown on Geophysica or stratospheric balloon Limb sounder antenna demonstrator Main reflector size 2.2 m 0.8 m Quasi-optical multiplexing for: , , , , GHz Gaps/developments: Receiver technology, wide-band spectrometer

12 Heritage of optical imagers/ spectrometers: ENVISAT MERIS MIPAS AATSR SCIAMACHY

13 Interferometric sounders (1) MIPAS O 3, H 2 O, CH 4, N 2 O,HNO 3,T, CFC s Michelson interferometer, limb sounder cm-1 resolution, from 4.15 microns to 14.6 microns ( cm -1 ) IASI vertical profiles T, H 2 O Michelson interferometer, X-track scanner 0.5 cm -1 resolution, from 645 to 2760 cm -1

14 Interferometric sounders (2) Example: AMIPAS for process studies between troposphere and stratosphere medium spectral resolution (<0.14 cm-1) enhanced vertical spatial resolution (2 km) and along-track sampling (100 km) - 2-D detector array Future improved sounders/spectrometers will benefit from developments for sounding mission of Meteosat Third Generation e.g. very-long-wavelength detector arrays, advanced spectrometers

15 European atmospheric sounding/chemistry spectrometers OMI on AURA Pushbroom, nm nm resolution GOME-2 on METOP nm nm resolution X-track scanner SCIAMACHY on ENVISAT nm, nm resolution Limb, nadir, sun - MTG and Sentinel-4 developments will also stimulate new generation of instruments - European SWIR detector (1-2.5 μm) development completed

16 VIRI-M: Visible & Infra-Red Imager - Concept studied for replacement of AVHRR on METOP-3 - Includes AVHRR + new channels - Scanner, 150 mm aperture, - 73 kg, 98 W, Mbps Developments: Long lifetime scanning mechanisms Radiator cover Two-stage passive radiator Optical bench Telescope Scan unit Channel ME AH AH VI AH3A AH3B 3.74 MO SE AH AH SE Blackbody Wavelength (μm) Main structure VIS & IR modules

17 Ocean & Global land imager/spectrometer MERIS Pushbroom, 300/1200 m resolution 15 narrow channels between 400 and 1050 nm AATSR Scanner, dual-view, 1km resolution, 500 km swath Channels: 0.55µm, 0.66µm, 0.87µm, 1.6µm, 3.7µm, 11µm, 12µm

18 Sentinel-3 Further instrument developments for Sentinel-3 will consolidate technological expertise Requirements for ocean/land global imaging and altimetry addressed by S-3

19 Scatterometer (1) ASCAT Active radar at 5,255 GHz Measures 2-dimensional wind fields on oceans (all weather) Left and right swath, 500 km each, illuminated by 6 antennas (3 pairs) 25/50 km spatial resolution Transmit power: 120 W peak 41 kbps /sec

20 Scatterometer (2) New Concept - Rotating fanbeam antenna 3.3 rpm - Trade-offs: Choice among C- and Ku-bands, single, dual and quad-polarisations km continuous swath coverage with comparable performance to ERS-Scat/ASCAT - Large overlaps of foot-print during successive sweeps (each pixel imaged several times during an overpass) Gap: Trade-off of ocean-wind measurement techniques Scatterometer vs. Polarimetric radiometer

21 Precipitation radar KaPR 35.5 GHz 5km IFOV 120 km swath 5km IFOV 245 km swath Technology well mastered in Japan. Major development required in Europe

22 Altimetry (1): conventional altimeters Strong European heritage in Ocean altimetry C/Ku altimeters on ERS1/2 Topex-Poseidon Envisat Jason-1/-2 Cryosat Sentinel-3 Jason-1

23 Altimetry (2): SAR/interferometric altimeters CryoSat, launch Interferometric/synthetic aperture altimeter for sea ice, ice sheet margins Conventional pulse-limited operation for ice sheet interiors (and oceans) Synthetic aperture operation for sea ice, using a single receive channel to obtain an along-track resolution of about 250 m Mass: 710 kg, power: 800 W peak And later: wide-swath altimeters

24 The EarthCARE mission EarthCARE mission (2012) CPR Quantify aerosol-cloud-radiation interactions for inclusion in climate and numerical weather forecasting models EarthCARE payload Multi Spectral Imager (MSI) BroadBand Radiometer (BBR) Backscatter Lidar (ATLID) Cloud Profiling Radar (CPR) BBR MSI ATLID CPR 94 GHz nadir beam ( 700 m foot-print) 400 m vertical resolution -36 dbz sensitivity at top-of-the-atmosphere 1 m/s Doppler resolution (vertical speed) Note: Doppler Radar capability can be used to measure wind speed when tracers are available (extreme events)

25 Aeolus mission Doppler Wind Lidar ADM-Aeolus, launch Sep 2008 Tropospheric horizontal wind speed profiles, 1 2 m/s accuracy 50 km horizontal integration, 200 km sampling km vertical resolution between 0-20 km Demonstration of NWP improvement: potential for future operational missions Doppler wind 355 nm Tripled-frequency Nd:YAG laser, 150 mj/pulse/25 Hz average 1.5-m diameter telescope Incoherent detection with highresolution interferometers, molecular + aerosols Single LOS, 35 deg roll Orbit 400 km, SSO dawn-dusk Mass: 1100 kg, 2200 W

26 Aeolus mission Technology S/C STM Laser transmitter EQM New generation DWL will require Power efficiency improvement Laser technology improvement for long lifetime Receiver improvement limited State-of-the-art high resolution filters with optimum energy use Detection close to photon counting

27 Backscatter lidar Backscatter Lidar (ATLID) -Vertical profiles of aerosols -Vertical profiles/altitude of clouds CPR - Detect thin cirrus cloud (extinction coeff: < 0.05 km-1) in daytime above dense cloud deck MSI - Altitude range: -0.5 to 30 km - Horizontal sampling interval: < 100 m - Vertical sampling interval: 100 m below 20 km - Tripled-frequency Nd:YAG laser mj/ Hz - Receivers: High-res Fabry-Pérot filters BBR ATLID Further developments for the ATLID backscatter lidar Lower-power high-efficiency and longlifetime Nd:YAG lasers High-resolution filters technology

28 Differential Absorption Lidar (DIAL) Vertical profiling of H 2 O by DIAL (WALES) 450 km altitude, dawn-dusk 1.5 ton, 3kW+solar arrays (instrument: 1.5 kw) m single- or multiple-aperture telescope 4 wavelengths (3 on, one off) near 935 nm to optimise vertical coverage from 2 lasers (75 mj at 25 Hz each wavelength) Each laser made of one double-frequency Nd:YAG laser, pumping alternatively 2 Ti:Sapphire seeded by stabilised injection lasers. Receivers: High-resolution Fabry-Pérot filters Technology chosen for performance and availability Considered feasible, but more complex than Aeolus

29 Greenhouse gases monitoring by Laser instruments Studies to investigate the feasibility of spaceborne lidar systems to monitor greenhouse gases Different classes of lidar instruments : -Range-Resolved DIAL (like for H 2 O) too demanding (250Wm 2 ) CO 2 CH 4 N 2 O Vertical Planetary Boundary layer sampling Height 10 m assignment Horizontal km resolution Precision 1 ppm 10 ppb 0.1 ppb Temporal resolution Week (revisiting time) - Integrated Path Differential Absorption reasonable instrument size for both CO 2 and CH 4. - Continuous-Wave Laser very reasonable instrument but no range/pressure information + possible contamination by aerosols. New technique to measure total column content of CO 2 or CH 4, within reach of European capabilities. Technological development required, especially for 2-um lasers and detectors

30 Conclusions Next steps Translation of application requirements MRD SRD Some analysis gaps to be filled to avoid requirements iterations System of large potential complexity requires early priority setting Technology requirements Some generic technology requirements can be anticipated Long-lifetime scanning mechanisms, cooling Optical detectors, microwave receivers Parallel developments will assist maturation of post-eps missions MTG, Sentinels, Explorers Optimum risk reduction is only possible when system concepts are mature