FLEX-E: ESAs FLEX End-to-End Mission Performance …old.esaconferencebureau.com/Custom/14C04/Presentations/2.2_Vicent.pdfFLEX Sentinel-3 FLEX-E: ESA’s FLEX End-to-End Mission Performance

FLEX

Sentinel-3

FLEX-E: ESA’s FLEX End-to-End Mission Performance Simulator. Architecture design,

current status and preliminary results

5th International Workshop on Remote Sensing of Vegetation Fluorescence (22-24 April 2014)

J. Vicent*(1), J.R. Acarreta(2), L. Alonso(1), R. Franco(3), M. Manzano(4),J.P. Rivera(1), N. Sabater(1), C. Tenjo(1), J. Verrelst(1) & J. Moreno(1)

(1) Laboratory for Earth Observation (Univ. of Valencia, Spain)(2) Deimos Space S.L.U. (Madrid, Spain) (3) European Space Agency, ESTEC (Noordwijk, Netherlands)(4) GMV Aerospace & Defence (Madrid, Spain)

*[email protected]

End-to-End Mission Performance SimulatorsFLEX

Sentinel-3

Introduction

FLEX-E architecture design

FLEX-E activities and current status

Preliminary results

Summary

Introduction

o The FLEX mission is candidate for 8th Earth Explorer Opportunity missiono It will be the first mission designed to measure sun-induced vegetation chlorophyll

fluorescence emission at global scale

o FLEX operates a single high-spectral resolution (0.3-3nm) spectrometer (FLORIS)covering the range 500-800nm at 300m spatial resolution

o Fluorescence à Photosynthesiso Improved Global Cycle models (GPP)o Vegetation health statuso Non-invasive marker

o FLEX will fly in tandem with Copernicus’ satelliteSentinel-3. Synergy between the differentinstruments for:o Atmospheric characterization and correctiono Vegetation biophysical parameterso Surface temperature

Reliable retrieval of fluorescence emission +Characterization of overall photosynthetic activity

Introduction

An E2ES is a set of algorithms reproducingthe expected mission planning in order to:o Assess mission performanceo Consolidate technical requirements and system

implementationso Analyse suitability of implemented Level-1 and

Level-2 image processing algorithms

A modular architecture design allows:o Evolution in future phases (completeness)o Parallel development by third parties

according to their know-howo Improvement of implemented algorithms

(complexity)

Due to the mission complexity, ESA is promoting the development of a Phase A/B1End-to-End Mission Performance Simulator (E2ES) for the FLEX mission.

End-to-End Mission Performance Simulators

Reference modular Architecture (RA), investigated in ESA’s ARCHEO-E2E project,following a top-down design.

2. Instrument Type: architecture of HL modules in lower level Building-Blocks (BB)o BB mostly generic across different instrumentso Evolution in completeness/complexity è Complexity of HL modules architecture

(larger # of BB)

3. Evolution of E2ES implemented state-of-the-art algorithms:o Implementation (architecture) of BBo Use of external datao Use of additional mission parameters

1. Mission Type: determines high-level(HL) architecture and data flowo Pre-set combinations of modules and

interfaces between themo Coherence between different E2ES

End-to-End Mission Performance Simulators6 High-Level modules are generic to most passive optical missions:

o Simulates platform orbit and attitudeo Generates instrument observation geometry based on instrument type

o Simulates signal acquisition by instrument in the spectral/spatial domainso Adds instrument noise based on instrument configuration

o Distributes bio/geophysical and atmospheric parameters over the targetbeing observed

o Propagates the signal to be acquired by the instrument

o Simulates radiometric and spectral calibration of raw datao Recovers pixel uniformity and corrects from systematic errorso Generates Level-1 products

o Pre-processes the L1 data (e.g. re-calibration, geolocation with DEM)o Retrieves geophysical parameters objective of the mission

o Visualizes images and plots resultso Calculates error metrics and statistics by comparing pairs of reference-

retrieved data


Architecture design based on the RAconcept in ARCHEO-E2E:

Mission type:o Multi-platform in tandem configurationè FLEX orbit constrained by S3 orbit

o Multi-instrument:FLORIS (FLEX) and OLCI/SLSTR (S3)

o Synergy between L1b products

Instrument types:o Passive optical. VNIR to TIR spectral

rangeo Multi-/hyper-spectral resolutiono Spatial resolution: [0.3; 1] km

Simulation of Sentinel-3 geometry, instruments and L1:o Simplified but representative simulation of S3 platform, instruments and processingo Not biased or constrained by ESA’s simulatoro Focus efforts on simulation of FLEX/FLORIS

































FLEXSentinel-3


DAY

Geometry modules:o 2 platforms (FLEX and S3)è 2 geometry moduleso FLEX orbit constrained by Sentinel-3 orbit (already

fixed) and time delay between the platformso Delay between SLSTR nadir and oblique views

Scene Generator Module:o Instruments swaths overlappingà common target location

o Similar spectral range and spatial resolutionà same radiative transfer model

Common SGM for the 3 instruments:o Same algorithmso Same configuration and external datao 4 observation geometries (4 scenes)

Scene Definition

FLORISForward Model

Geometry-Scene

interaction

S3 Forward Model

Geophysical parameters map

Scene geometry and topography

FLEX Geometry

Sentinel-3 Geometry

FLORIS hires scene

OLCI+SLSTR hires scene


FLORIS Instrument Module:o Divided in Low/High Resolution spectrometerso Spatial/spectral convolution of high-resolution

input scene by PSF and ISRFo Systematic and random instrument noises:

o Spectral stabilityo Detector performanceo Temporal, intra-/inter-band co-registrationo Spectral/spatial radiometric errors

Sentinel-3 Instrument and Level-1 modules:o Simulation of OLCI and SLSTR (nadir & oblique). Overlapping FLORIS swatho Spatial/spectral convolution of high-resolution input scene by PSF and ISRFo Instrument noises + L1 correction = non-perfect L1 calibration system errors

FLORIS Level-1 Processing module:o Calibrationo Radiometric correctiono Geolocation

o Scene defined in a uniform gridin UTM coordinates

o Non-uniform convolution in focalplane geometry


Level-2 Retrieval module:Synergy between FLEX and Sentinel-3 Level-1b data:o Geometric co-registration and radiometric cross-calibrationo Atmospheric state characterized from Sentinel-3 measurementso Additional parameters: biophysical products (Chl, LAI), surface

temperature…

FLEXSentinel-3FLORIS

TOA RadOLCI

TOA RadSLSTR

TOA Rad

Atmospheric Atmospheric State

Cloud Mask

Atmospheric Atmospheric Correction

FLORIS TOC Refl

OLCI / SLSTR

TOC Refl

Dual View

FLORIS TOC Etot

L2 BIOPHYS Params

Fluorescence Fluorescence Retrieval

Biophysical Biophysical Retrieval

L2 FluoMap

L2 Photo-synthesis

registrationCo-

registrationSpectral

CalibrationCross-

calibration

1. Pre-processing

2. Atmospheric correctiono Aerosol optical propertieso Water vapor contento Pressure and temperatureo Cloud screening

3. Retrieval of final products

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TOA

Rad

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e [m

W m

-2sr

-1nm

-1]

OLCIFLORIS


Performance Evaluation module:Evaluates mission performance comparingreference and retrieved data:o Geometric correctiono Calibration and recovery of pixel uniformityo Fluorescence and surface reflectance retrievalo Atmospheric correctiono Retrieval of biophysical parameters

Algorithms Library

Plotting & Reporting

tools

File Access

Config. files

Models outputs

Plots andReports

Config. data andModels outputs

Processed outputs

Session for generation of PEM inputs

Simulation 1. Configuration set 1

FLORIS module

FLORIS L1 processing module

Simulation 2. Configuration set 2

FLORIS module

FLORIS L1 processing module

Simulation 3. PEM

Performance Evaluation module

The PEM is executed at the end ofa simulation session, comparing theresults from different simulations:o Sensitivity analysiso Different sensor and platform

configurations

FLEX-E activities and current statusProject management, schedule and current status:o Developed by the Spanish consortium: Univ. of Valencia, GMV and Deimos Spaceo Two external industrial contractors developing the GEO, FLORIS and L1 moduleso Currently in integration phase after definition of tech. specifications and design of

architecture/interfaces

FLEX-E version Beta 1 Beta 2 v1.0 v1.1 v2.0 v2.1

FLEX

-E M

odul

e

SGM v1.0 v1.0 v1.0 v1.0 v1.0 v1.0S3G v1.0 v1.0 v1.0 v1.0 v1.0 v1.0GEO #1 v1.0 v1.0 v1.0 v1.0 v1.0 v1.0FLO #1 - Beta v1.0 v1.0 v1.0 v1.0L1F #1 - Beta v1.0 v1.0 v1.0 v1.0S3I Beta v1.0 v1.0 v1.0 v1.0 v1.0L2R Beta v1.0 v1.0 v1.0 v1.0 v1.0PEM Beta Beta v1.0 v1.0 v1.0 v1.0GEO #2 - Beta v1.0 v1.0 v1.0 v1.0FLO #2 - - Beta v1.0 v1.0 v1.0L1F #2 - - - Beta v1.0 v1.0

o Beta2: All modules integrated at least inbeta version

o V1.0: System verified and scientificallyvalidated

o V1.1: After mission performanceassessment

FLEX-E activities and current statusIntegration:o 8 modules developed by 5 teams in different coding languages, following the architecture

design and interfaces definitiono Integration within a common simulation framework (openSF):

Platform for the integration of models and product exploitation tools allowing the interactionwith the user for the definition, configuration and execution of the E2E simulator

o Precedes system verification and scientific validation

o Integration of separate moduleso User definition of simulation chaino Edition of configuration parameterso Control the execution of E2E simulationo Edition and visualization of simulator

outputs

Integration steps:o Modules compiled with input config. files; and

input/output data folderso Integrate modules and define their I/O linking

them according to openSFo Test behavior of integrated module vs. stand-

alone executionModels

openSF platform (HMI)

Database

Tools

Help System

Modelsinterface

Toolsinterface

FLEX-E activities and current statusMission Performance Assessment:o Check that mission/instrument concept meet system requirementso Propagation of instrument noises through the L1 processing chain:

o Geometric correctiono Spectral/radiometric calibration and correction of instrumental artefactso Instrumental errors, either all together or by groups

o Performance of L2 retrieval algorithms:o Fluorescence retrieval and decoupling of background surface reflectanceo Atmospheric correctiono Retrieval of biophysical param., spectral reflectance changes and surface temperatureo Image pre-processing: spectral re-calibration, radiometric cross-calibration and co-

registration between sensors

Performance Evaluation Module

(PEM)

Real Geometry

SGM outputs

L1 outputs

L2 outputs

o Comparison of reference vs. retrieved data using the PEMo Band-per-band and full-spectrum error metrics, applied

pixel-wise and statistical measurements over the whole imageo Proposed set of scenarios with different configuration (scene,

instrument…) to study mission performance

FLEX-E activities and current status

Level-2 products Comments• Total fluorescence emission

(spectrally integrated value)

• Peak values (F680 and F740)• PSI-PSII contributions

Integrated values at canopy level are the ones required by models.

for instantaneous observations.300 m original spatial resolution.

• Non-photochemical energydissipation

Includes as sub-products carotenoids/chlorophyll ratio and violaxanthin/zeaxanthin ratio, responsible for regulated energy dissipation. Accounts for thefraction of light absorbed by non-photochemical pigments (anthocyanin).

• Fluorescence quantum efficiencyRatio between energy emitted as fluorescence versus energy absorbed by chlorophyll-a. Accounts for actual chlorophyll specific absorption.

• Photosynthesis rateActual electron current after charge separation at PSII, also accounts forinstantaneous surface temperature effects.

• Vegetation stress Defined as “actual photosynthesis / potential photosynthesis”• Vegetation productivity (GPP) Defined at Level-2, but recommended usage as Level-3 product

o Performance assessment of L2 products with instrument noises On/Offo Analysis of L2 pre-processing and atmospheric correctiono Study of instrument noises on L1 data and its propagation to L2 products

( ) -2 -1 -10.2 mWm sr nmsFε ≤

Preliminary results

Distribution of parameters over the scene according to global maps and generationof high resolution top-of-atmosphere (TOA) radiance

Offline simulation of FLEX orbitfrom Sentinel-3 current orbit file

Class map Chlorophyll Water vapor

Output data from Geometry module(FLEX and S3) intersects scene location

-0.46 -0.44 -0.42 -0.445.12

45.13

45.14

45.15

45.16

45.17

Longitude [deg]

Latit

ude

[deg

]

FLORISOLCISLSTR (nadir)SLSTR (oblique)

Scene location

Preliminary results

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350

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450

Wavelength [nm]

TOA

Rad

ianc

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W m

-2sr

-1nm

-1]

TOA Radiance (OLCI)

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TOA

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TOA Radiance (FLORIS)

Scene generator outputs data with a spectraland spatial scale factor ×3-10 with respect to instrument resolution

Simulation of reflectance, fluorescence and TOA radiance according to inputbiophysical and atmospheric parameters

Fluorescence and Reflectance

Summaryo The FLEX Earth Explorer 8th candidate missions will be the first mission to measure sun-

induced fluorescence emission from space at global scale

o Due to the mission complexity, ESA is developing an E2ES based on a ReferenceArchitecture adapted to the FLEX/Sentinel-3 tandem mission

o The different modules developed in FLEX E2ES have been introduced, showing the mainfeatures implemented and their architecture design according to the mission andinstrument types

o FLEX E2ES high-level architecture and interfaces between modules have already beendefined

o The project is currently on the integration phase and the first modules are beingassembled together within a common simulator framework

o Upcoming steps: verification, validation and mission performance assessment

o First results point out towards the successful implementation of the proposed ReferenceArchitecture and design methodology

THANKS FOR YOURATTENTION

FLEX

Sentinel-3

Questions? [email protected] for Earth Observation (Spain)

FLEX-E: ESAs FLEX End-to-End Mission Performance …old.esaconferencebureau.com/Custom/14C04/Presentations/2.2_Vicent.pdfFLEX Sentinel-3 FLEX-E: ESA’s FLEX End-to-End Mission Performance

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