MTG Imager Consolidating Priorities and Open Issues March 2004 at EUMETSAT Darmstadt

Transcription

1 1 st Meteosat Third Generation Mission Team Meeting MTG Imager Consolidating Priorities and Open Issues MTG Mission Team and Invited Experts March 2004 at EUMETSAT Darmstadt P

2 Based on the assessment of observing techniques there are five candidate observation missions identified for MTG: Two distinct imagery missions dedicated to operational meteorology, with empha on nowcasting and very short term forecasting: - The High Resolution Fast Imagery (HRFI) mission, enhancement of the M HRV mission; - The Full Disk High Spectral resolution Imagery (FDHSI) mission, successor the MSG SEVIRI mission; P

3 High Resolution Fast Imagery(HRFI) Mission Successor of MSG HRV specified to meet the requirements information on rapid development phen MRD_HRFI.40 Repeat cycle: 5 min (2 min goal) (currently: 5 min accepted in trade off) MRD_HRFI.50 Coverage: 18 o *6 o variable MRD_HRFI.80 (6 o *6 shorter repeat c TBR highest priority is given to spatial resolu currently no priority regarding repeat cyc additional 7.3 µm channel for moisture c Spectral width and position of channels P

4 High Resolution Fast Imagery(HRFI) Mission D_HRFI.10 ll imaging modes, the HRFI mission shall provide quasi-simultaneous images in C 1]) spectral channels as shown below Visible and near-infrared Infrared Channels channels Products HR-VIS 0.6 HR-NIR 2.1 HR-IR 3.8 HR-IR 7.3 HR-IR 11.2 [TBC 1] Cloud detection Cloud motion vector. Cloud temp/pressure Water Vapour [TBC 2] Cloud microphysics P

5 High Resolution Fast Imagery(HRFI) Mission HRFI Band Number HR-IR 7.3 (TBC) Channel boundaries (mm) Minimum Signal Maximum Signal Reference Signal SNR / NEDT l min >7.0µm - l max < 7.7µm 165 K 290 K 250 K 0.5 K no / almost no surface contribution actual weighting function depends on actual humidity profile proposed for low level moisture convergence WV P

6 High Resolution Fast Imagery(HRFI) Mission D_HRFI.100 HRFI mission shall provide spectral images with high spatial resolution DX [km], r than 1km (DX 1km) at the sub satellite point (SSP), with a goal of 0.5 km for the 06, NIR 2.1 and IR 3.8 channels. Currently the following spatial resolution is requested: DX = 0.5 km for VIS-0.6, NIR-2.1, and IR-3.8 DX = 1.0 km for IR-7.3 (TBR), and DX = 1.5 km accepted for IR-11.2 (TBR), RD_HRFI.90 e system MTF for all HRFI channels shall comply with the template specified in below [TBC 1]. k ormalised Frequency, k N =, defined by the spatial frequency k=1/l [km -1 ] and 1 D X X [km], the spatial resolution. (DX=1km - THRESHOLD; GOAL DX=0.5km). P

7 1.1 High Resolution Fast Imagery(HRFI) Mission MTF requirements derived from ABI ABI solar channel DeltaX = 0.5km ABI IR channels DeltaX = 2km 0.7 MTF Proposal for Post MSG Imagery I-1 and I-2 Mission I-1: DX = 1km (goal 0.5km) I-2: DX = 3km (goal 1km) Normalised frequency [F/(1/DX)] withdx targeted 'spatial resolution' P

8 High Resolution Fast Imagery(HRFI) Mission MRD_HRFI.110 The Modulation Transfer Function (MTF) at any normalised spatial frequency between k NT = 0.0 and k NT = 0. 5 (TBC) shall not vary by more than 0.05 [TBC 1] between N/S and the E/W directions. MRD_HRFI.120 The inter-channel MTF differences as function of the normalised frequency shall be: - less than 0.1 between the VIS 0.6 NIR 2.1 and IR 3.8 channels; - less than 0.1 between the IR 7.3 and IR 11.2 channels. Inter-channel MTF differences in terms of a normalised frequency k n = k/(1/dx only meaningful for channels having the same DX currently: DX=0.5 km for VIS 0.6 and NIR 2.1 however DX=0.6 km for IR 3.8 P

9 High Resolution Fast Imagery(HRFI) Mission RD_HRFI.20 he spectral response of the channels defined by the boundaries in Table above sh eet with the spectral response envelope given below. Normalised Spectral Transmittance 0% 0% C F F' C' Channels are defined channel boundaries A 50% E E' (FDHSI: l o and FWH 20% B B' A D A' 2% D' l -50% -40% -30% -20% -10% lo 10% 20% 30% 40% 50% -50% = channel lower boundary +50% = channel upper boundary 100% = Dlo Co-ordinates and amplitudes of template points (100% = l max -l min = Dl o ) A/A B/B C/C D/D E/E F/F Position [%] Position [Dl o ] Amplitude 2% 20% 100% 0% 50% 80% P

10 High Resolution Fast Imagery(HRFI) Mission patial resolution at SSP: 0.5 km (goal) km (threshold); all channels same Spatial Sampling Distance goal spatial resolution required for the VIS0.6, NIR2.1, IR3.8 channels, hreshold resolution accepted for the IR7.3 and IR11.2 channels with large ovesampling) der review HRFI Band Number Channel boundaries (mm) Minimum Signal Maximum Signal Reference Signal SNR / NEDT HR-VIS 0.6 l min >0.5µm - l max < 0.7µm 1% 120% 1% 10 HR-NIR 2.1 l min >2.1µm - l max < 2.3µm 1% 100% 1% 10 HR-IR 3.8 l min >3.5µm - l max < 4.1µm 165 K 350 K 300 K 0.2 K HR-IR 7.3 (TBC) l min >7.0µm - l max < 7.7µm 165 K 290 K 250 K 0.5 K HR-IR 11.2 l min >10.3µm-l max <12.5 µm 165 K 340 K 300 K 0.2 K

11 High Resolution Fast Imagery(HRFI) Mission MRD_HRFI.210 The absolute radiometric accuracy of the visible (HR-VIS 0.6) and the near IR/short wave (HR-NIR 2.1) channels shall be over their full dynamic range better than 5% with a goal better than 3%. MRD_HRFI.230 The absolute radiometric accuracy of the IR (HR-IR 3.8, HR-IR 7.3, and HR-IR 11.2) channels shall be better than 0.7K over their full dynamic range. MRD_HRFI.220 The relative radiometric accuracy of the visible (HR-VIS 0.6) and the near IR/short wave (HR-NIR 2.1) channels (repeatability) shall be better than 0.1% over the complete lifetime. L(tk ) -L(tj ) < RelativeAccu racy L(tk ) MRD_HRFI.240 The relative radiometric accuracy of the IR (HR-IR 3.8, HR-IR 7.3, and HR-IR 11.2) channels (repeatability) shall be better than 0.2K over the complete lifetime. Absolute/relative (with time) accuracy are requirements for climate applications (Definition of Relative Radiometric Accuracy not compliant with MRD_HRFI.240) Inter-channel Relative Radiometric Accuracy requirement missing 16th ST MET/ RSt ge 11

12 Full Disk High Spectral Resolution Imagery (FDHSI) Mission MRD_HRFI.50 Successor to remaining SEVIRI m specified to meet the requirements fo quantitative information MRD_HRFI.50 Repeat cycle: 15 min (5 min goal) (currently: THRESHOLD accepted in trade off MRD_HRFI o *18 o Full Disk Coverage MRD_HRFI o *6 o Local Area shorter repeat c (currently: THRESHOLD accepted in trade of [BRC LAC: 5 min (goal < 2min)]

13 RD_FDHSI.100 FDHSI Mission or all core and optional spectral channels, the FDHSI mission shall provide spectral ages with spatial resolution DX [km] smaller than 3km (DX 3km) at the sub satellite int, with a goal of DX=1km. RD_FDHSI.90 o achieve aligned samples of the FDHSI channel images, DX shall be equal for all annels ( core and optional FD-OP 1 and FD-OPT 2 channels). Same spatial resolution (and spatial sampling)is requested for all FDHSI channels and currently the THRESHOLD DX = 3 km is accepted in trade off MRD_FDHSI.80 The system MTF of the FDHSI core and optional channels shall comply with the template specified below. k ormalised Frequency, k =, defined by the spatial frequency k=1/l [km -1 N ] and 1 DX X [km], the spatial resolution. (DX=3 km - THRESHOLD; GOAL DX=1.0km).

14 1.1 FDHSI Mission MTF requirements derived from ABI ABI solar channel DeltaX = 0.5km ABI IR channels DeltaX = 2km 0.7 MTF Proposal for Post MSG Imagery I-1 and I-2 Mission I-1: DX = 1km (goal 0.5km) I-2: DX = 3km (goal 1km) Normalised frequency [F/(1/DX)] withdx targeted 'spatial resolution'

15 FDHSI Mission _FDHSI.110 MTF at any normalised spatial frequency between k NT = 0.0 and k NT = 0. 5 shall ary by more than 0.05 [TBC 1] between S/N and the E/W directions. D_FDHSI.120 inter-channel MTF differences as function of the normalised spatial frequency shall s than 0.1 between FD-VIS 0.4, FD-VIS 0.6, FD-VIS 0.8, FD-NIR 1.3, FD-NIR 1.6, NIR 2.1, FD-IR 3.8 and FD-OPT-1 (if executed); ss than 0.1 between FD-IR 6.7; FD-IR 7.3; FD-IR 8.5; FD-IR 9.7; FD-IR 10.8; FD-IR ; FD-IR 13.4; FD-IR 14.0, and FDHSI-OPT 2 channels (if executed); s than 0.2 between both groups of channels defined above, with a goal of 0.1. Inter-channel MTF differences in terms of a normalised frequency k n = k/(1/dx) only meaningful for channels having same DX, as requested

16 RD_FDHSI.140 RD_FDHSI.130 FDHSI Mission ata from all mission channels obtained for the same point of the Earth s surface shall be oincident within 2.5 seconds. he inter-channel co-registration between groups of channels and between channels ithin groups defined below shall be better than specified in tables follow [TBC 1] in nits of achieved SSD at SSP, with a goal as shown in second table. FD-VIS FD-NIR FD-TIR FD-IR WV FD-IR O 3 FD-IR CO 2 FD-OPT 1 FD-OPT 2 0.4, 0.6, 0.8 mm 1.3, 1.6, 2.1 mm 3.8, 8.5, 10.8, 12.0 mm 6.7, 7.3 mm 9.7 mm 13.4, 14.0 mm 0.76 mm (4 channels) 14 mm (9 channels) Table 1: Grouping of core- and optional channels of the FDHSI mission

17 FD-TIR FD-IR WV FD-IR O 3 FDHSI Mission FD-VIS FD-NIR FD-TIR FD-IR WV FD-IR O 3 FD-IR CO 2 FD-OPT 1 FD-OPT 2 FD-VIS 0.1SSD 0.25 SSD 0.5 SSD no requir. no requir SSD no requir. FD-NIR 0.1 SSD 0.5 SSD no requir. no requir SSD no requir. 0.1 SSD 0.25 SSD 0.1SSD 0.25 SSD no requir. N/A no requir. no requir. no requir. no requir 0.25 SSD 0.5 SSD 0.5 SSD N/A FD-IR CO SSD FD-OPT SSD No requir. FD-OPT SSD Table 1: Co-registration requirements (TBC) between groups of channels and between channels in one group (diagonal) in units of achieved spatial distance SSD. FD-VIS FD-NIR FD-TIR FD-IR WV FD-IR O 3 FD-IR CO 2 FD-OPT 1 FD-OPT 2 FD-VIS SSD 0.25 no requir. no requir. 0.1 SSD no requir. SSD SSD FD-NIR no requir. no requir. 0.1 SSD no requir. SSD SSD FD-TIR SSD 0.1 SSD no requir. 0.1 SSD SSD FD-IR WV 0.05 SSD no requir. no requir SSD FD-IR O 3 N/A no requir SSD FD-IR CO SSD no requir N/A FD-OPT SSD no requir. FD-OPT SSD Table 1: Co-registration goal (TBC) between groups of channels and between channels in one group (diagonal) in units of achieved spatial distance SSD.

18 D_FDHSI.190 MRD_FDHSI.180 FDHSI Mission The absolute geometric accuracy, defined as the RMS absolute position error of all p within an image shall be less than ½ the locally achieved Spatial Sampling Dis (SSD). [TBC 1]. e relative geometric accuracy between two consecutive images, defined as the RMS of variation in the absolute pixel position for all pixels in a nominal image, shall be less n 0.6[m/s]* Dt sc [s]. Dt sc refers to the repeat cycle between these two images. equirement assures accurate wind tracking! inks the accepted Pointing/Navigation Error of 0.6 m/s to the achieved repeat cycle(s) GIFTS m/s (~25.0µrad/0.5hr) > Frame to Frame pointing accuracy m/s (~11.1µrad/0.5hr) > stability of pointing v/pointingerror = 0.6m/s (Frame-to-Frame + 1/2 stability) TBR: BRC: 60/15 (goal 15/5) min pointing accuracy GOAL THRESHOLD LAC 0.07 km 0.18 km FDC 0.18 km 0.54 km

19 High Resolution Fast Imagery(HRFI) Mission _FDHSI.30 spectral response of the Core and Optional channels defined by central wavelength idth below shall meet with the spectral response envelope plotted below in Normalised Spectral Transmittance C C' F F' Channels are defined l o and 1/2Dl B E E' B' A D D' A' -50% -40% -30% -20% -10% lo 10% 20% 30% 40% 50% central wavelength of channel 100% = Dlo 50% = 1/2Dlo = Width -ordinates and Amplitudes of Template Points (50% = 1/2Dl o = Width specified in ror! Reference source not found.) A/A B/B C/C D/D E/E F/F Position [%] Position [Width/FWHM] Amplitude 2% 50% 100% 0% 50% 80%

20 G heritage w Channels der review tions Core channels Central wavelength (mm) FDHSI Mission Width (mm) Minimum Signal Maximum Signal Reference Signal SNR/NEDT FD-VIS % 120% 1% 10 FD-VIS % 120% 1% 10 FD-VIS % 120% 1% 10 FD-NIR % 100% 1% 10 FD-NIR % 100% 1% 10 FD-NIR % 100% 1% 10 FD-IR K 350 K 300 K 0.1 K FD-IR K 270 K 250 K 0.3 K FD-IR K 285 K 250 K 0.3 K FD-IR K 330 K 300 K 0.1 K FD-IR 9.7 * K 310 K 250 K 0.3 K FD-IR K 340 K 300 K 0.1 K FD-IR K 340 K 300 K 0.1 K FD-IR K 300 K 270 K 0.2 K FD-IR K 290 K 250 K 0.2 K * Channel FD-IR 9.7 will be discarded if a companion IR-Sounding mission is selected. + Channels FD-IR 13.4/ FD-IR 14.0 will be discarded if option FD-OPT 2 is selected.

21 NeDT MSG Observed/Specification en from: PT] Imaging with IQGSE Report (COM ), EUM/MSG/RPT/483, Issue 2, 17/06/2003 nnel Range of observed noise measurements (NEDT)* Ambient Calibrations Heated Calibrations 0.13K-0.13K 0.08K-0.08K 0.04K-0.05K 0.04K-0.04K 0.06K-0.07K 0.05K-0.05K 0.07K-0.07K 0.06K-0.06K 0.11K-0.12K 0.09K-0.10K 0.06K-0.07K 0.06K-0.06K 0.12K-0.12K 0.10K-0.10K 0.18K-0.19K 0.17K-0.17K SY-2 Specification* K K K K K K K K Table 36 Summary of noise accuracy results for the cold channels for COM between 26 th and 28 th of May 2003 with IQGSE Version Observed noise is at beginning of life while specification is end of life the small difference between the noise values derived from ambient heated calibrations is expected and corresponds to a constant SNR.

22 FDHSI Mission FD-OPT 1 Optional channel FD-OPT 1: for cloud top height determination by differential absorption in the oxygen A-Band (divided into 4 narrow bands) TBR: The FD-OPT 1 channels will be selected/recommended if they do not become a design driver for the FDHSI instrument. If an UVS chemistry mission is selected as part of the baseline, it is expected that the FD-Opt 1 channels will become supported within the UVS mission. Channel Option FD-OPT 1 Central wavelength (nm) Width (nm) Minimum Radiance (Wm -2 sr -1 µm -1 ) Reference Radiance (Wm -2 sr -1 µm -1 ) Maximum Radiance (Wm -2 sr -1 µm -1 ) FD-OPT FD-OPT FD-OPT FD-OPT er review SNR

23 FDHSI Mission FD-OPT 2 Optional channel FD-OPT 2: for cloud top height determination by CO 2 -slicing in the 14µm CO 2 band (originally divided into 9 sounding channels) TBR: The added value of increasing the number of CO 2 -slicing channels to a total of nine for cloud top height determination needs to be justified by a sensitivity study. Currently it is proposed to limit the FD-Opt 2 to the maximum of 5 channels as listed above. Channel Central Width Minimum Maximum Reference NEDT wavelength (mm) Signal Signal Signal (K) Option (mm) (K) (K) (K) FD-OPT 2 Threshold Goal [TBC] FD-OPT K FD-OPT K FD-OPT K FD-OPT K FD-OPT K f channels as well as position and width under review Thr. Goal

24 B(w,T (p)) t (w, p) dp (w) - R (w) e f p p s cloud w p = c p s ) - R (w ) e o cloud o w o f B(w o,t (p)) t (w o, p) dp p p c FDHSI Mission FD-OPT 2 P k = N c = k = 1 c k = N p ( k) w ( k) k = 1 w ( k ) 2 2 C f = B clear R ( w o clear, T ( w skin o ) ) - R - B cloud cloud ( w ( w o o ), T( p wave length (µm)

25 FDHSI Mission FD-OPT 2 wave length (µm) Estimate on cloud top height maximum RMSE (m) using MTG-OPT 2, MTG-CORE, MSG-1 MTG-OPT 2 MTG-CORE MSG-1 baseline Layers (km) NEdT(K) cloud amounts cloud amounts cloud amounts > 0.8 > 0.6 > 0.4 > 0.8 > 0.6 > 0.4 > 0.8 >0.6 >0.4 (CO 2 NEdT = 0.19K)

26 FDHSI Mission FD-OPT 2 TBR ults are for black clouds only -latitude summer only her # of channels improve complex situations f channels, location, and width until July 04 nge from CO2-slicing to 1DVAR Cm wind. Jun Li et 2001 JAM pp312-33

27 FDHSI Mission MRD_FDHSI.210 The absolute radiometric accuracy for a uniform scene of the visible and the near IR/short wave core and optional channels shall be over their full dynamic range better than 5%, with a goal of 3%. MRD_FDHSI.230 The absolute radiometric accuracy of the IR core and optional channels over their full dynamic range shall be better than 0.7K. Absolute Radiometric and Relative Radiometric Accuracy for Climate Applications MRD_FDHSI.220 The relative radiometric accuracy of the visible and the near IR/short wave core and optional channels (repeatability) shall be better than 0.1% over the complete lifetime. L(tk ) -L(tj ) MRD_FDHSI.240 L(tk ) The relative radiometric accuracy of the IR core and optional channels (repeatability) shall be better than 0.1K over the complete lifetime. < RelativeAccu racy Definition not compliant with MRD FDHSI.240 MRD_FDHSI.250 The inter-channel temperature differences between all channels within the FD-TIR, FD IR WV, FD-IR O3, FD-IR CO2 and FD-OPT 2 groups defined above, looking at the same black body scene, shall be less than 0.1 K [TBC 1]. 16th ST MET/ RSt ge 27