Alonso, Kevin

Bachmann, Martin

Carmona, Emiliano

Cerra, Daniele

de los Reyes, Raquel

Dietrich, Daniele

Heiden, Uta

Knodt, Uwe

Krutz, David

Marshall, David

Müller, Rupert

Tegler, M.

English

Institute of Transport Research:Publications

Results of the DESIS Imaging Spectrometer on board the International Space Station Martin Bachmann(2), Kevin Alonso(1), Emiliano Carmona(1), Daniele Cerra(1), Daniele Dietrich(2), Uta Heiden(2), Uwe Knodt(3), David Krutz(4), David Marshall(2) , Rupert Müller(1), Raquel de los Reyes(1), Mirco Tegler(5)   Thanks to: Kara Bruch(6), Birgit Gerasch(1), Burghardt Günther(4), Heath Lester(7), Jack Ickes(7), Harald Krawczyk(1), Ben Murphy(7), Mary Pagnutti(6), Robert Ryan(6), Thomas Säuberlich(4), Ilse Sebastian(4), Ingo Walter(4)   (1) DLR German Aerospace Center, Remote sensing Technology Institute, Oberpfaffenhofen (2) DLR German Aerospace Center, German Remote Sensing Data Center, Oberpfaffenhofen (3) DLR German Aerospace Center, DLR Headquaters, Cologne (4) DLR German Aerospace Center, Institute of Optical Sensors, Berlin-Adlershof (5) DLR German Aerospace Center, German Remote Sensing Data Center, Neuztrelitz (6) I2R Innovative Imaging and Research Corp (7) Teledyne Brown Engineering       SBG Cal/Val Workshop, 23.07.2020 Content of the presentation  • Mission and instrument  • Product examples  • Calibration and Validation  • Application examples   DLR.de  •  Chart 2 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Teledyne  Teledyne Brown Engineering (USA) and DLR have partnered to build and operate the DLR Earth Sensing Imaging Spectrometer (DESIS) from the Teledyne-owned Multi-User System for Earth Sensing (MUSES) Platform on the ISS  DESIS, MUSES and ISS Teledyne  Teledyne Brown Engineering (USA) and DLR have partnered to build and operate the DLR Earth Sensing Imaging Spectrometer (DESIS) from the Teledyne-owned Multi-User System for Earth Sensing (MUSES) Platform on the ISS  MUSES provides accommodations for two large and  two small  hosted payloads and provides core services for the instruments like • Position via GPS (1 Hz) • Attitude via Startracker + MIMU (10 Hz) • Master time (acc. <150 µsec) • 2 Gimbals  ±25° for/back; 45° backboard; 5° starboard • Downlink 225 Gbit / day Ku band  DESIS, MUSES and ISS Teledyne  Teledyne Brown Engineering (USA) and DLR have partnered to build and operate the DLR Earth Sensing Imaging Spectrometer (DESIS) from the Teledyne-owned Multi-User System for Earth Sensing (MUSES) Platform on the ISS  DESIS, the hyperspectral sensor developped by  DLR, which is currently the first payload of MUSES.   DLR also established the Ground Segment and licensed the SW processors to Teledyne running in an Amazon Cloud  DESIS, MUSES and ISS DESIS Instrument DLR.de  •  Chart 6 • Equipped with: • Calibration Unit: 2 banks with 9 LED types. Allows for Radiometric & Spectral calibration/monitoring • Pointing Unit: Changes the instrument line of sight in the along-track direction between ±15° Allows for BRDF observation mode and Forward Motion Compensation (FMC) mode • GPS receiver: working as a time calibration unit for latency calibration and jitter measurement FEE: Front End Electronic FPA: Focal Plane Array TMA: Three Mirror Anastigmat POI: Pointing Unit • Hyperspectral instrument consisting of a Three-Mirror-Anastigmat (TMA) telescope combined with an Offner-type spectrometer Sensors 2019, 19(7), 1622; https://doi.org/10.3390/s19071622 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 DESIS Instrument DLR.de  •  Chart 7 FEE: Front End Electronic FPA: Focal Plane Array TMA: Three Mirror Anastigmat POI: Pointing Unit • Hyperspectral instrument consisting of a Three-Mirror-Anastigmat (TMA) telescope combined with an Offner-type spectrometer Sensors 2019, 19(7), 1622; https://doi.org/10.3390/s19071622 Mission Instrument MUSES/DESIS Target lifetime 2018-2023 Off-nadir tilting (across-track, along-track) -45° (backboard) to +5° (starboard), -40° to +40° (by MUSES and DESIS) Spectral range 400 nm to 1000 nm Spectral Sampling (res., acc.,bands) 2.55 nm, 0.5 nm,  235 bands, 118 (bin 2), 79 (bin 3), 60 (bin 4) Software Binning (sampling distance, number bands) Binning 2 (5.1 nm, 118 bands) Binning 3 (7.6 nm, 79 bands) Binning 4 (10.1 nm, 60 bands) Radiometry (res., acc.) 13 bits, ~10% Spatial (res., swath) 30 m, 30 km (@ 400 km) SNR (signal-to-noise) 195 (w/o bin.) / 386 (4 bin.) @ 550 nm Instrument (mass) 93 kg Capacity (km, storage) 2360 km per day, 225 GBit > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 DESIS Chronology   DLR.de  •  Chart 8 2014 / 2015 MUSES / DESIS mission starts 27. - 28. August 2018 Unpacking of DESIS and installation in MUSES 29. June 2018 DESIS launch from  Cape Canaveral to ISS via SpaceX Dragon Spring 2019 Complete first part of commissioning Now Data distribution started CAL/VAL ongoing 7. June 2017 MUSES installation on ISS > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Orbit and Products DLR.de  •  Chart 9 Previsat Software V3.6.4 DESIS L1A product catalogue (https://teledyne.tcloudhost.com) • Not Sun-synchronous orbit at ~400 km altitude, 51.6° inclination, covers 75% of Earth and 95% of populated Earth (between 55° N and 52° S). Orbit period 93 minutes. Revisit time 3 to 5 days (average) > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Data Policy • DESIS is operated by Teledyne (TBE), data are distributed  under NOAA License and: • TBE has the exclusive right to license or transfer image data for commercial use • For scientific and humanitarian purposes, DLR has the right to: • Task 2000 minutes/year • Request archived data  • For scientific purposes only DLR can share DESIS 10.2 nm data with other scientific organizations within projects (data are free for the partners). Scientific use includes: • basic and application oriented research • projects by national and international educational or research institutions or by governmental institutions • development and demonstration of future applications for scientific and/or operational use and • preparation and execution of government-funded education, research and development programs  • Distribution of 2.55, 5.1 nm spectral sampled data is subjected to NOAA approval • Currently these data are restricted to US governmental agencies and DLR (through waiver) • DLR Scientific partners willing to use 2.55 and 5.1 nm data would require a waiver from NOAA DLR.de  •  Chart 10 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 DLR.de  •  Chart 11 & Approver DESIS Mission Overview – Two Ground Segments   > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Data Processing Which products are getting the user  Level 1A ProcessorTranscriptionLevel 1B ProcessorSystematic and Radiometric CorrectionLevel 1C ProcessorOrthorectificationLevel 2A ProcessorAtmospheric CorrectionL1B Product*L1C Product*L2A Product*Long Term ArchiveL1A DataRaw DataEarth datatakesExperimental datatakesCalibration mesaurementsOrbit and AttitudeProductsAuxilary DataIn-flight Calibration ProcessCalibration &ReferenceProductsGlobalDEM DatabaseAtmospheric LUTUpdateCal TablesPublishCal MeasurementsScreening Calibration &ReferenceProductsGlobalREF DatabaseProcessors at the Ground Segments  • Fully automated • Run ‘on-request’ over archived data  • Two instances: one at Teledyne (Amazon Cloud), one at DLR. Same processing   Products: • Level 0 (L0) • Raw data (Datatakes up 100 tiles 30x30 km², trajectory files, DC)  • Level 1A (L1A) • Tiled images, browse image, metadata, quality flags <= archived • Level 1B (L1B)* • Top of Atmosphere (TOA) radiance (W·m-2·sr-1·μm-1) • Systematic and radiometric correction (rolling shutter, smile, suspicious pixels,….) • All metadata attached for further processing • Level 1C (L1C)* • Level 1B data ortho-rectified, re-sampled to a specified grid • Global DEM (SRTM, 1arcsec), sensor model refinement using global reference image (Landsat-8 PAN with acc. 18m CE90) • Level 2A (L2A)* • Ground surface reflectance (i.e. after atmospheric corrections) • With and w/o terrain correction     *Delivery product DLR.de  •  Chart 12 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Product Example L1B DLR.de  •  Chart 13 • Corrections applied: • Dark Current  • Absolute Radiometric  • Rolling Shutter  • Smile correction • Relative radiometric (de-striping)   > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 DLR.de  •  Chart 14 • Corrections applied: • Dark Current  • Absolute Radiometric  • Rolling Shutter  • Smile correction • Relative radiometric (de-striping)   Product Example L1B > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Product Example L1C DLR.de  •  Chart 15 Product Example L1C DLR.de  •  Chart 16 Geometric accuracy within 1 pixel (image-to-image matching), RMS ~20m  DLR.de  •  Chart 17 Product Example L2A DLR.de  •  Chart 18 Land Mask Product Example L2A masks DLR.de  •  Chart 19 Land Mask Water Mask Product Example L2A masks DLR.de  •  Chart 20 Land Mask Water Mask Cloud Mask Product Example L2A masks DLR.de  •  Chart 21 Land Mask Water Mask Cloud Shadow over land Mask Cloud Mask Product Example L2A masks DLR.de  •  Chart 22 Land Mask Water Mask Cloud Shadow over land Mask Cloud Mask Haze over land Mask Product Example L2A masks DLR.de  •  Chart 23 Land Mask Water Mask Cloud Shadow over land Mask Cloud Mask Haze over land Mask Haze over water Mask Product Example L2A masks DLR.de  •  Chart 24 Land Mask Water Mask Cloud Shadow over land Mask Cloud Mask Haze over land Mask Haze over water Mask AOT Map Product Example L2A masks DLR.de  •  Chart 25 Land Mask Water Mask Cloud Shadow over land Mask Cloud Mask Haze over land Mask Haze over water Mask AOT Map Mask WV Map Mask Product Example L2A masks DLR.de  •  Chart 26 Product Example L3 Suspended Matter in Water 0 10 mg / l DESIS Cal/Val Concept • Lab. calibration by DLR  • Characterization of LEDs & detector  • During commissioning phase (DLR & I2R) • Instrument in-orbit characterization using on-board LEDs + telemetry  • Update of defective / unstable pixel mask (only 0.3%) • Fine-adjustment of spectral and radiometric calibration using vicarious approaches • Absolute radiometry: RadCalNet, cross-CalVal using S2 and L8  • Relative radiometry: CEOS PICS  • Validation: Aeronet sites, Pinnacles (CSIRO), S2 & L8, airborne sensors  • Fine-adjustment of processors & instrument modes • standard gain settings, SW instead of HW binning,   • Operational phase • Minor update of radiometric calibration table • Continuous validation activities by DLR & I2R   DLR.de  •  Chart 27 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Commissioning Phase Activities – In-Orbit Spectral Characterization • Using on-board calibration sources (LEDs) • Pre- and post-launch characteristics  • Incl. temperature stability & other HK / telemetry data    > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 DLR.de  •  Chart 28 Vicarious Spectral Characterization - Atmospheric Absorption Features DLR.de  •  Chart 29 • Performed on regular DESIS Earth datatakes, L1B processing, no smile correction applied  • Shift confirmed for Oxygen absorption region (762 nm) & other wavelengths (483, 524 & 819 nm)  > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Fit for 2 datatakes with different ΔT  • Earth datatakes without smile correction are used • Fitting step size: 0.05 nm  Ongoing validation & re-calibration activities @ DLR and I2R DLR.de  •  Chart 30 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Comparison DESIS & RadCalNet Ongoing validation & re-calibration activities @ DLR and I2R DLR.de  •  Chart 31 TOA-Ref within 10% (typically <5%) relative to RadCalNet > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Ongoing validation & re-calibration activities @ DLR and I2R DLR.de  •  Chart 32 BOA-Ref within 10% relative to RadCalNet > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 TOA-Ref within 10% (typically <5%) relative to RadCalNet Ongoing validation & re-calibration activities @ DLR and I2R DLR.de  •  Chart 33 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 TOA-Ref within 10% relative to L8 & S2 for PICS  Figures by I2R Product Example L1C DLR.de  •  Chart 34 Geometric accuracy within 1 pixel (image-to-image matching), RMS ~20m  Reference Image (Landsat 8 Pan, ~18 m CE90) DESIS Image (after coarse rectification) Selected GCP to improve DESIS sensor model (on-the-fly and for boresight calibration) Others are used for Quality Assessment Railroad Valley, USA 13-12-2018 18:23:11 UTC 38.4467°N 115.7512° W Sun: 64.14°, 160.58° Incident Angle: 0.8° Geometric Calibration & Accuracy Cascade of matching • BRISK (Binary Robust Invariant Scalable Keypoints) • LLSQ (Local Least Squares) • SIFT (Scale-Invariant Feature Transform) Accuracy w.r.t. Reference  19 scenes  #GCP: avarage 282 per scene #Control Points: avarage 1357 per scene  In case image matching works for a scene RMSE (east)  = 20.1 ± 4.4 m RMSE (north) = 20.3 ± 2.9 m  In case matching does not work and relying on boresight calibration RMSE ~400 m, but with peak values up to 1 km Application examples • Hyperspectral imagery for water quality studies related to agricultural activities within the National Wetland Térraba Sierpe, Costa Rica  DLR.de  •  Chart 36 Sierpe, Costa Rica 2019-03-04 RGB: 440 nm, 550 nm,  650 nm   Total suspended matter concentration  0 5 Colored Dissolved Organic Matter CDOM Absorption at 440 nm 0 1 Phytoplankton concentration 0 10 Nicole Pinnel & Peter Gege DLR EOC [mg m-3] [m-1] [g m-3] > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Application examples • Rare Earth Elements (REE) @ Mt. Pass mine (USA / California) DLR.de  •  Chart 37  Gregg Swayze from USGS Spec Lab  “So this may be the first demonstration of REE detection from space  but may also have high enough resolution and SNR to allow  differentiation of individual REE minerals”  Element: Neodymium (Nd); Class:  Lanthanoide  Usage: Magnets, Laser, Glas,…  > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Application examples • Data Fusion: Enhance Ground Sampling Distance (GSD) of DESIS using Sentinel 2 DLR.de  •  Chart 38 DESIS, 30 m GSD Sentinel 2, 10 m GSD Fusion results, 10 m GSD Better Target Detection  Solar panels by  spectral similarity  Solar panels locations Detection  (fused product) Detection Sentinel 2 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Summary • DESIS in-orbit functional tests successful. Instrument operating on a stable and correct manner • Processing chain up and running. Products include L1B, L1C up to L2A • Including smile & rolling shutter correction • Relative radiometric correction (de-striping) • Radiometric within ~10% (typically within 5%) for TOA reflectance based on RadCalNet, S2, L8 comparisons • Geometric accuracy within 1 pixel (image-to-image matching), RMS ~20 m • BOA reflectance within <~10% based on RadCalNet, Pinnacles, S2 comparisons • DESIS can be used as base for  higher level products. • Outlook: looking forward to cross-calibration with Hisui and Prisma     DLR.de  •  Chart 39 > SBG CalVal > M. Bachmann et al.  •  DESIS Results > 23.07.2020 Thank you for your attention ! DESIS Website https://www.dlr.de/eoc/desktopdefault.aspx/tabid-13614/  

Results of the DESIS Imaging Spectrometer on board the International Space Station

https://elib.dlr.de/135646/1/SBG_CalVal_DESIS_Bachmann_NoMovie.pdf

Results of the DESIS Imaging Spectrometer on board the International Space Station

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