07-09 Nov. 2005 Walberberg Workshop MET image 1 This document - PDF document

Dr. B. Voß MET image 07-09 Nov. 2005 Walberberg Workshop MET image 1 This document contains information proprietary to Jena-Optronik GmbH. Any disclosure, use or duplication of this document is expressly prohibited.

MET image • General need for AVHRR successor Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. � Jena-Optronik proposed instrument concept MET image for future operational weather satellites (Polar platforms). � Various instrument concepts were established in a MET image study co- financed by DLR. MET image 2 Dr. B. Voß

Instrument requirements � Spectral coverage between VIS (400 nm) and Thermal IR (14 µm) Any disclosure, use or duplication of this document is expressly prohibited. � Only reflecting optical system can cover the complete This document contains information proprietary to Jena-Optronik GmbH. bandwidth � Wide swath width (> 2300 km) to allow global coverage � Spatial resolution between 250 m and 1 km � High absolute radiometric accuracy � Carefully devised calibration strategy � High accuracy calibration sources � Low polarisation sensitivity MET image 3 Dr. B. Voß

Development approach � Requirements are developing � Trade-off between user requirements and available Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. budget � Flexibility is the most important design driver � Flexible number of channels � Flexible SNR/NEdT � Flexible instrument configuration � METimage instrument family (A, B1, B2, C) MET image 4 Dr. B. Voß

Spectral separation � Dichroic beam splitters � Parallel beam required: afocal telescope + relay optics � Single detector for each channel Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. � Limited to ≤ 10 channels because of accommodation constraints � In-plane � Many channels in a small volume � Requires focal plane design with multiple detectors � Larger aperture required, but confocal telescope can be utilized � Image rotation to be compensated MET image 5 Dr. B. Voß

FPA design approach � Matrix detector based FPA � Fast random access ROICs � Telescope design independent from number of channels Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. � TDI � flexible SNR Spectral filter possible SNR possible SNR 450 450 400 400 350 350 Baseplate 300 300 Detector matrix SNR SNR 250 250 200 200 150 150 100 100 50 50 0 0 0 0 5 5 10 10 15 15 20 20 25 25 30 30 Number of detector elements in scan-direction Number of detector elements in scan-direction MET image 6 Dr. B. Voß

Dr. B. Voß MET image Time Delay Integration (TDI) 7 This document contains information proprietary to Jena-Optronik GmbH. Any disclosure, use or duplication of this document is expressly prohibited.

Scan geometry Pixel size over Scan region 4,5 1 GSD (ACT) 0,9 4 normalized SNR GSD (ALT) Pixel size [km] GSD (ACT) with steps 0,8 3,5 Any disclosure, use or duplication of this document is expressly prohibited. Normalized SNR This document contains information proprietary to Jena-Optronik GmbH. 0,7 3 0,6 2,5 0,5 2 0,4 1,5 0,3 1 0,2 0,5 0,1 0 0 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 0 3 6 9 Scan angle [deg] Pixel used for one earth pixel Imaged earth region MET image 8 Dr. B. Voß

Dr. B. Voß MET image Scan principle – rotating telescope Half angle mirror ω/2 9 ω This document contains information proprietary to Jena-Optronik GmbH. Any disclosure, use or duplication of this document is expressly prohibited.

Principle derotation mechanism BB1 Sun Diffusor PM Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. HAM SM FoV Entrance Deep space BB2 MET image 10 Dr. B. Voß

MET image C • Based on ESA future imager study requirements Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. • Up to 30 channels • Low polarisation < 1% due to polarisation scrambler • METimage exceeds chosen SNR requirements for 800m GSD • Ground sampling distance down to 250m possible with reduction of radiometric performance. MET image 11 Dr. B. Voß

Dr. B. Voß MET image MET image C Optics Polarisation scrambler 12 pupil IR entrance focal plane This document contains information proprietary to Jena-Optronik GmbH. Any disclosure, use or duplication of this document is expressly prohibited.

Radiometric performance – solar channels Wave Spectr. Minimal typical Maximal Req. Possib. Possib. Possib. length band radiance radiance radiance SNR @ SNR @ SNR @ SNR @ width L min L typ L max L typ L typ L typ L typ λ Δλ [W/(m² � sr [W/(m² � sr [W/(m² � sr @ 800m @ 800m @ 400m @ 250m Any disclosure, use or duplication of this document is expressly prohibited. � µm)] � µm)] � µm)] [µm] [nm] GSD GSD GSD GSD This document contains information proprietary to Jena-Optronik GmbH. 0,443 20 8 42 585 1100 2176 515 179 0,490 20 11 31 582,7 800 1627 396 197 0,554 20 8 18,5 528 700 1508 342 117 0,670 20 2,7 9 1010 585 1493 348 120 0,708 20 2 7 425,1 350 951 209 72 0,750 14 2 5 377 406 963 210 71 0,877 35 1,5 3,2 631 297 794 179 61 1,375 30 6 6 109 200 627 160 58 1,610 60 0,4 3,8 104 200 742 196 71 2,25 60 0,1 3,2 31,7 71 314 72 25 MET image 13 Dr. B. Voß

Radiometric performance – thermal channels Wave Spectral Minimal Typical Maximal Req. Poss. Poss. length band temp. temp. temp. NEdT NEdT NEdT λ width T min T typ T max @ T typ @ T typ @ T typ Δλ [µm] [K] [K] [K] [K] [K] [K] [nm] @ 800m @ 400m @ 250m Any disclosure, use or duplication of this document is expressly prohibited. GSD GSD GSD This document contains information proprietary to Jena-Optronik GmbH. 3.70 380 190 270 335 0.08 0.08 0.21 6.30 1000 190 240 300 0.3 0.26 0.83 7.30 1000 190 240 300 0.3 0.28 0.92 8.55 1000 190 300 335 0.1 0.1 0.3 10.85 950 190 270 340 0.08 0.08 0.2 12 1000 190 270 340 0.08 0.07 0.2 13.40 600 190 270 270 0.3 0.29 0.77 • METimage exceeds chosen SNR requirements for 800m GSD • Reduction of GSD down to 250m possible with reduction of radiometric performance. MET image 14 Dr. B. Voß

Performance MET image Polarisation With Without 5,00% Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. polarisation polarisation 4,50% scrambler scrambler polarisation sensitivity 4,00% 3,50% 3,00% 2,50% 442nm: 1% 442nm: 11% 2,00% 670nm: 0.5% 670nm: 3% 1,50% 1,00% 855nm: 0.5% 855nm: 2.7% 0,50% 0,00% 400 500 600 700 800 900 1000 wavelength [nm] Except for blue channel, 5% polarisation Polarisation sensitivity of one reflective surface requirement can be met without scrambler MET image 15 Dr. B. Voß

METimage B2 MIR/TIR Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. Calibration FPA Sources VNIR/SWIR FPA Half Angle Mirror Volume: 65 x 83 x 70 cm³ Mass: 85 kg 65 x 68 x 70 cm³ MET image 16 Dr. B. Voß

Reduced SNR requirements � METimage B1 • Entrance pupil and with that complete optical instrument can be scaled. Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. • Based on ESA VIRI-M requirements • METimage B1 exceeds the VIRI-M requirements: – Solar channels can be operated at 400m GSD by reducing the detector pixel size. – Thermal IR channels meet requirements with 800m GSD MET image 17 Dr. B. Voß

MET image B1 Budget for VIRI-M requirements 260 mm 330 mm Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. FPAs • Volume: m – Instrument: 26 x 33 x m 0 28 cm³ 8 2 – ICU: 30 x 24 x 25 cm³ Half angle mirror • Mass: 40kg MET image 18 Dr. B. Voß

VIRI-M requirements Channel Centre Spectral Required SNR possible possible wavelength [µm] Width [µm] SNR/NedT @ SNR/NedT @ 800m GSD 400m GSD ME443 0.443 0.02 20 109 23 AH1 0.670 0.02 20 226 51 Any disclosure, use or duplication of this document is expressly prohibited. This document contains information proprietary to Jena-Optronik GmbH. AH2 0.865 0.02 20 165 36 VI1.38 1.375 0.03 40 180 40 AH3A 1.61 0.03 40 215 46 AH3B 3.74 0.38 0.1K 0.07K 0.28K MO6.7 6.7 0.36 0.3K 0.24K 1.35K SE8.7 8.7 0.3 0.1K 0.10K 0.45K AH4 10.8 1.0 0.1K 0.08K 0.34K AH5 12.0 1.0 0.1K 0.09K 0.40K SE13.4 13.4 0.3 0.2K 0.19K 0.83K • METimage B1 exceeds the VIRI-M requirements: – Solar channels can be operated at 400m GSD by reducing the detector pixel size. – Thermal IR channels meet requirements with 800m GSD MET image 19 Dr. B. Voß