copernicus sentinel-2 mission performance centre (mpc...

Insert the title of your slide

Copernicus Sentinel-2 Mission Performance Centre (MPC)

Overview of the activities: Cal/Val activities, Quality Control

L. Pessiot (1), O. Thépaut (1), F. Gascon (2) (1) CS-SI, Toulouse, France, (2) ESA/ESRIN, Frascati, Italy

Insert the title of your slide Agenda

• Introduction

• Functionalities

• Presentation of the MPC

• Products Overview

• Cal/Val Activities

• Conclusion

Insert the title of your slide Introduction

• In order to meet the baseline products quality requirements, Cal/Val Plan and QC procedures will be systematically applied during both in-orbit commissioning and operational phases

• Operational phase is planned to start at Launch (Apr 2014) + 3 months after completion of the in-orbit commissioning phase

• Cal/Val activities during the operational phase will be performed by the Sentinel-2 Mission Performance Centre (MPC) as part of the ESA Sentinel-2 Ground Segment

• Handover to be prepared in coordination between the Commissioning and Operations Cal/Val teams

Insert the title of your slide Functionalities

Mission Performance Centre (MPC) functionalities:

• Calibration (CAL) – to update on-board and on-ground configuration data in order to meet product

quality requirements

• Validation (VAL) – to assess the quality of the generated data products

• Quality Control (QC) – to routinely monitor the status of the sensor and to check if the derived products

meet the quality requirements along mission lifetime

• Data Processors and Tools corrective and perfective Maintenance (PM & TM) – to manage the updates of the processors, quality control tools, calibration tools and

all auxiliary files

• End-to-End System Performance Monitoring (E2ESPM) – to monitor the performance of the Sentinel-2 system operations (including the

instrument) and assessing the system

Insert the title of your slide Presentation of the MPC

MPC Coordinating Centre (MPC/CC)

The MPC/CC entity

• primarily covers the – routine Calibration,

– Quality Control and

– End-to-End System Performance Monitoring of the MPC Service

• plus supports the functions performed by the – MPC/ESLs,

– MPC/PM and

– MPC/TM entities.


MPC Expert Support Laboratories (MPC/ESL)

The Expert Support Laboratories (ESLs) are MPC entities providing

• scientific expertise and

• engineering support to the mission


Teams members

(*) Astrium = Airbus D&S

(*)


Teams location

MPC/CC


Expert Support Labs (ESL) team

(***)

(*)

(**)

(*) Astrium = Airbus D&S

(**) Audrey Crespin , back-up Bruno Lafrance

(***) ESL_L2A still TBD, ITT open

Insert the title of your slide Products overview

Outline

Name High-level Description

Production Preservation Strategy

Volume

Level-1B Top-of-atmosphere radiance in sensor

geometry

Systematic Long-term ˜27 MB (each 25x23km2)

Level-1C Top-of-atmosphere reflectance in

cartographic geometry (UTM/WGS84)

Systematic Long-term ˜500 MB (each 100x100km2)

Level-2A Bottom-of-atmosphere reflectance in

cartographic geometry

On user side (using Sentinel-2 Toolbox)

None ˜600 MB (each 100x100km2)

Insert the title of your slide Products overview

Data quality targets

Radiometric Data Quality

Absolute radiometric uncertainty 3 % (goal) , 5 % (threshold)

Inter-band relative radiometric uncertainty 3%

Linearity knowledge accuracy 1 %

Modulation Transfer Function (MTF) 0.15 to 0.3 (for 10m bands)

<0.45 (for 20 & 60m bands)

Geometric Data Quality

Absolute geolocation uncertainty 20m 2σ (threshold)

12.5m 2σ (goal) with GCPs

Multi-temporal registration 0.3 pixel 2σ (goal) with GCPs

Multi-spectral registration

(for any couple of spectral bands)

0.3 pixel 3σ

For further details see Mission Requirements Document (MRD) at:

http://esamultimedia.esa.int/docs/GMES/Sentinel-2_MRD.pdf

Insert the title of your slide Cal/Val Activities

Level-1 Radiometric Calibration Activity Nom./Cont. Performer Method/Output Freq.

ESL_L1 Leader Airbus D&S-Toulouse

Dark Signal Calibration Nominal CC + ESL CS

DS average over the lines & VCU DS av. along the columns

auto. 2/month

Relative Gains Calibration (Equalization) Nominal CC + ESL CS

On-board relative gains & On-ground relative gains

auto. 1/month

Absolute Radiometric Calibration Nominal CC + ESL CS

Absolute calibration coeff. auto. 1/month

SWIR Detectors Re-arrangement Parameters Generation

Contingency CC + ESL CS

Selected pixels & vector (B10, B11 & B12) updated version

on demand

Crosstalk Correction Calibration Contingency ESL AD&S TBD on demand

MSI Refocusing Contingency ESL AD&S TBD on demand


Level-1 Radiometric Calibration

• Suitable calibration orbits for Dark-Signal Calibration in summer (left) and winter (right)

• Absolute Radiometric Calibration using the CSM in sun-diffuser position

• Example of crosstalk measurement on the VCU

See dedicated poster MultiSpectral Imager (MSI) Level-1 Radiometric Calibration


Level-1 Geometric Calibration

(*) depending on the initial localisation performance of the GRI related to the weather conditions (cloudy and seasonal), the solution proposed

either by CS or IGN will be chosen, leading to a better localisation accuracy.

Activity Nom./Cont. Performer Method/Output Freq.

ESL_L1 Leader Airbus D&S-Toulouse

Global Reference Images Generation Nominal ESL IGN + CS (TBC*)

GRI & GRI assessment by spatiotriangulation (GCP+TP)

auto. 1/year

Absolute Calibration of the Viewing Frames for the Reference Band

Contingency ESL AD&S + GMV

Biases of MSI geom. model VF On-board yaw-steering model

on demand

Relative Calibration of the Viewing Frames for Non-Reference Bands


Attitude (p, r, y) mean biases between SWIR and VNIR VF

on demand

Absolute Calibration of the Focal Plane for the Reference Band


Lines of sight of the VNIR B4 on demand

Relative Calibration of the Focal Plane for Non-Reference Bands


Lines of sight of the various bands

on demand


Level-1 Geometric Calibration

Left: GCPs in white and Tie points in blue

Up: Refinement of the Geometric Model

Down: accuracy map illustration

See dedicated poster Constitution of a Global Reference Image for Sentinel-2


Level-1 Radiometric Validation Activity Nom./Cont. Performer Method/Output Freq.

ESL_L1_VAL Leader TAS-Cannes

Equalization Validation Nominal ESL TAS Rep., e.g. MPI (FPN, MEN) 2/year

CC Support + report 1/month

Absolute Radiometry Vicarious Validation Nominal ESL Argans Rep., abs. rad. uncertainty ev. 2/year


Absolute Radiometry Cross-Mission Validation

Nominal ESL Argans Rep., bias w.r.t. other missions 4/year


Multi-temporal Relative Radiometry Vicarious Validation

Nominal ESL Argans Rep., reflectance LTM trends 4/year


Inter-band Relative Radiometric Uncertainty Validation

Nominal ESL ONERA Rep., rel. rad. uncertainty ev. 2/year


SNR Validation Nominal ESL TAS Rep., e.g. noise model paramet. 2/year


Pixel Response Validation Nominal CC Vectors per defective/saturated pixels

1/day & 1/month

MTF Validation Nominal ESL ONERA Report 1/year


Level-1 Radiometric Validation

• Suitable calibration orbits over Dome-C within winter repeat-cycles

• Schematic edge (up) and pulse (down) targets for MTF validation

• Illustration: Bronx Whitestone Bridge, ALI image


Level-1 Geometric Validation Activity Nom./Cont. Performer Method/Output Freq.

ESL_L1_VAL Leader TAS-Cannes

Geolocation Uncertainty Validation Nominal ESL-TAS Syst.lev., loc. (m) or r, p, y (rd) est. 1/year

CC Prod.lev., geolocation accuracy 3/month

Multi-spectral Registration Uncertainty Validation

Nominal ESL-TAS Syst.lev., multispec. reg. perf. (px) 2/year

CC Prod.lev., report, MPI 3/month

Multi-temporal Registration Uncertainty Validation

Nominal ESL-TAS Report, MPI 2/year

CC Report, MPI 3/month

Global Reference Images Validation Nominal ESL-TAS Rep., GRI geoloc. accur+comp. 1/year


Level-1 Geometric Validation

• Geolocation Uncertainty Validation activity

• Multi-spectral Registration Uncertainty Validation activity

Statistical AnalysisGCP extraction on

image #k

S2-Validation

images

GCP

DatabaseMean shift

computation

for image #k

(dxk;dyk)

GeoLocation

Model

GeoLocation

Performance @ 2s


Level-2A Calibration

Activity Nom./Cont. Performer Method/Output Freq.

Radiometric

Cloud Screening Parameterization

Nominal ESL_L2A Algorithms calibration based on an empirical approach using an imagery dataset

Atmospheric Correction Parameterization Nominal ESL_L2A Calibration using a set of test site representative of main surface-atmosphere types

Scene Classification

Classification Algorithm Parameterization Nominal ESL_L2A Includes parameterization of the cloud screening algorithm


Level-2A Calibration

• Cloud and snow threshold calibration NDSI = (band 3 – band 11) / (band 3 + band 11)

• BRDF correction in rugged terrain imagery Left: image without BRDF correction Center: after BRDF correction with threshold angle βT = 65◦ Right: illumination map = cos β


Level-2A Validation Activity Nom./Cont. Performer Method/Output Freq.

Radiometric

Atmospheric Correction Validation

Nominal ESL_L2A On-Ground ad-hoc validation campaigns, using LANDNET sites or other reference sites

Cloud Screening Validation

Nominal ESL_L2A Visual inspection of images and on-ground observations of the atmosphere status

Scene Classification

Classification Algorithm Validation

Nominal ESL_L2A Includes validation of the cloud screening algorithm results


Level-2A Validation • Cloud shadowing

Left: original image Center: neural network classification Right: “Dark areas” class (white)

• Classification Map

Insert the title of your slide Conclusion

• Sentinel-2 MPC set up in order to meet the expected products quality requirements thanks to a highly skilled team, ESL_L2A still to be selected

• Operational phase planned to start at Launch (Apr 2014) + 3 months after completion of the in-orbit commissioning phase

• Cal/Val activities during the operational phase will be performed by the MPC as part of the ESA Sentinel-2 Ground Segment

• Handover to be prepared in coordination between the Commissioning and Operations Cal/Val teams

Insert the title of your slide Any Question?

Thank you for your attention!

For further details see http://sentinel.esa.int

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