Pléiades Neo Image quality indicators

VH-RODA Workshop 2021 | 20-23 April 2021 | Slide 1

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Pléiades Neo

Image quality indicators and products

Laurent COEURDEVEY,

Head of Pléiades Neo Image and Product Quality - Airbus DS – GEO


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Introduction to Pléiades Neo constellation


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Designed for a

10-YEAR NOMINAL LiFETIME

2017

Design & High Level Operations stabilized Launch Contract signed

2021

2x PLÉIADES-NEO LAUNCHED

2022

2x PLÉIADES-NEO LAUNCHED

› 30cm resolution,

6 Multi-Spectral

channels

› 2 Mio km2 global

coverage / day

› SpaceDataHighway

(EDRS) minimizing

data latency

› Reactive

Tasking & Delivery

Pléiades Neo Improved second-gen satellite

100% COMMERCIAL

ALREADY FUNDED

BY AIRBUS


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Funded by AIRBUS, building on partnerships with


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Capacity: • Daily take of 400 000 km²/sat. • Very high agility (30° depointing = 350km in 14 sec) • Revisit twice per day worldwide with depointing

General overview of Pléiades Neo

4 satellites • 2 Pléiades Neo launch 2021,

• 2 Pléiades Neo launch mi-2022

Main orbital characteristics: • sun synchronous - 620 km altitude • Ground track repetitive 26 days cycle / period 97 min • Local times 10:30 descending node

Technical characteristics: • GSD of 30 cm • Swath 14km

• Panchromatic + 6 MS

Pléiades 5

PAN PAN PAN PAN PAN PAN

Blue Coastal BGR Red Edge Near IR

Pléiades 4

Pléiades 3 Pléiades 6

/ year


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6 Simulation - Courtesy IGN France 2014/2015

30cm GSD

Panchromatic 30cm native GSD


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Simulation - Courtesy IGN France 2014/2015

6 MS bands

Multispectral 1.2m native GSD 7


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8 Simulation - Courtesy IGN France 2014/2015

6 MS bands

Multispectral 1.2m native GSD


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Dramatic increased reactivity

Customer request ~ 3h before upload

3 plans / sat per day

Time to acquire: 4 à 12h

Customer request < 40min before upload

15 plans / sat per day (1 per orbit)

Time to acquire: 30-60 min

Pléiades (x2)

Pléiades Neo (x4)

Tasking chronology: from Pléiades to Pléiades Neo


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Pléiades Neo (x4)

Pléiades Neo image request success Tasking: fresh weather forecast (cell 5 x 5km) at every plan Receiving: new IA algorithm for automatic cloud mask

city

clouds

snow

15 plans / sat per day (1 per orbit)


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General overview of Pléiades Neo ground segment

/ year

Exploitation ground segment of AIRBUS DS Brand new architecture Based on Cloud technology With a massive image production capacity Immediate processing and access to image products With a large network of Direct Receiving Stations (and associated processing and services centers)


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Pléiades Neo key image quality characteristics and

requirements


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push broom instrument Requirement

GSD-PAN @nadir 0,3 m

GSD-Multispectral @nadir 1,2 m

Swath width 14 km

Spectral bands 1 PAN + 6 multispectral

Image Archive

Raw sensor geometry (6 sub-swathes) Raw sensor radiometry (on board detector equalization)

INTERNAL and DIRECT RECEIVING STATION (DRS) PRODUCT

13

Pléiades Neo sensor and image quality features


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Pléiades Neo sensor spectral bands

~ 800 nm ~ 450 nm

Panchromatic

~ 380 nm ~ 880 nm

Blue Green Red NIR

Red Edge

Deep Blue Deep Red

Blue Blue Green Red Edge NIR Wave length

50%

25%

100%

75%

0

450-520 520-590 620-690 770-880

450-800 nm

nm

PAN

380-450 700-750

Snow

Water

Bare Soil

Vegetation


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Deep Blue An additional spectral channel for

bathymetry applications:

Deeper penetration in water bodies

Clearer understanding of waterways

Improved safety of marine navigation

Pléiades Neo Pléiades Neo spectral bands


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Pléiades Neo

Red Edge An additional spectral channel for

vegetative applications:

Crop and vegetation status through

photosynthesis characterization

Pléiades Neo spectral bands


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Spectral bands from SPOT, Pléiades to Pléiades Neo

Pléiades

SPOT 6/7

PNEO

– Panchromatic: 1 band

Full range recording of visible spectrum

– Multispectral (MS): 6 bands

Simultaneous recording of intervals of wavelength

mm (ID Band)

Panchromatic

SPOT 0.450 – 0.745 (PAN)

Pléiades 0.480 – 0.830 (PAN)

Pléiades NEO

0.450 – 0.800 (PAN)

mm (ID Band)

Deep Blue Blue Green Red Red Edge NIR

SPOT - 0.450 – 0.520 (B0)

0.530 – 0.590 (B1)

0.625 – 0.695 (B2)

- 0.760 – 0.890 (B3)

Pléiades - 0.430 – 0.550 (B0)

0.490 – 0.610 (B1)

0.600 – 0.720 (B2)

- 0.750 – 0.950 (B3)

Pléiades PNEO

0.380 – 0.450 (DB)

0.450 – 0.520 (B)

0.520 – 0.590 (G)

0.620 – 0.690 (R)

0.700 – 0.750 (RE)

0.770 – 0.880 (NIR)


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Radiometric image quality feature: Signal to Noise Ratio (SNR) Requirement

SNR MS @100 W.m-2.sr-1.µm-1 > 130

SNR PAN @100 W.m-2.sr-1.µm-1 >100

SNR PAN @15 W.m-2.sr-1.µm-1 > 35

Pléiades Neo imagery quality features: radiometry

Radiometric image quality feature: Modulation Transfer Function (MTF)

Requirement

MTF PAN @Nyquist (dynamic effects included) > 0.06

MTF PAN on restored products > 0.15

MTF MS @Nyquist (dynamic effects included) > 0.15

Radiometric image quality feature: absolute radiometric calibration

Requirement (*)

Absolute calibration < 5% (3% achievable)

Cross-band relative absolute calibration at a same date < 5% (3% achievable)

Multi-temporal relative absolute calibration at two different dates < 1%

Multi-satellite cross-constellation absolute calibration < 5% (3% achievable)

(*) CNES calibration methodology accuracy


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Geometric image quality features Requirement

Location accuracy CE90 @nadir (w/o GCP) < 5 m

Location accuracy CE90 @nadir (with standard reference layer GCP - SRP) 3 m

Planimetric accuracy CE90 (with 3 perfect GCP) < 30 cm

Dynamic effects (line of sight stability) <0.2 PAN pixel LE99.7

PAN-MS and MS-MS registration <1 PAN pixel CE99.7

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Pléiades Neo imagery quality features: geometry


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Product level: enhancing geometric performance and quality

New worldwide location and altimetric reference layers: Space Reference Points (SRP) , WorldDEM4ORTHO (WD4O)

Geometric processing

• Primary • Projected • Ortho • Mosaic

SRP+WD4O: worlwide planimetric accuracy (ortho): Pléiades Neo @5mCE90 • Products: counts for the accuracy of the ORTHO (i.e assuming the “non perfect” DEM used at rectification process)

Courtesy ESRI, 2020 – before = SRTM / after = WD4O

More details in Vh-Roda 2021 Workshop | Day 2: Wednesday 21 April 2021 Fiducial Reference Measurements & Reference Cal/ Val Sites Pléiades Neo, Cal/val sites and new global reference databases

SRP: worldwide location accuracy: Pléiades Neo @3mCE90 • Products: counts for the accuracy of the intrinsic PRIMARY/PROJECTED image geometric model (rigourous and RPC)

Ortho free of rectification artifacts


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Pléiades Neo products


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Products An improved image production chain: -> high volumetry -> high reactivity -> fully automatic

Combined products Imagery Stereo Imagery Multi-Temporal stereo Imagery Geometrically

Consistent Series Imagery Mosaic Automatic DEM

Unitary products Primary Projected Ortho

Tailored products Ortho tailored Mosaic tailored DEM tailored

Standard products Primary Projected Ortho

Commercial offer Continuity PNEO/Pléiades/SPOT

Primary or Projected level

Ortho level

Product: from Pléiades to Pléiades Neo

NEW


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Standard Product: combined processing options

1 2 3

Panchro MS

• Bundle

• Pansharpened

+ =

MS Panchro Pansharpened

• Projected

• Ortho

• Primary • Basic

• Reflectance

• Display

North

Y (p

ixel)

X (pixel)

North

X(Lon or Easting)

Y(L

at

or

Nort

hin

g)

North

X(Lon or Easting)

Y(L

at

or

Nort

hin

g)

Spectral Band Combination

• Panchromatic • Multispectral • Bundle • Pan-sharpened



Radiometric processing

• Basic • Reflectance • Display


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Standard Product: geometric levels

PRIMARY

Sensor geometry synthesized on a perfect push-broom array along the field of view Rigourous and RPC models

PROJECTED («ortho-ready»)

Sensor projected at an iso-altitude value on an Earth CRS (UTM, WGS84) Sensor model capability preserved with RPC model

N

E

ORTHO

Georeferenced image in Earth geometry, corrected from acquisition and relief off-nadir effects (thanks to DSM/DTM)

N

E

COMMERCIAL PRODUCTS

GIS: Direct overlay with maps ? NO

GIS: Direct overlay with maps ? YES superimposable only at the iso-altitude

GIS: Direct overlay with maps ? YES fully superimposable

Col

Row



Band registration, restoration, denoising, location reset on reference layers…


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Merge:

Spectral bands

– Pléiades NEO (PNEO)

PAN MS

– SPOT 6 /7 & Pléiades

PAN MS

0.3m

1.2m

= Pan-sharpened

(0.3m) Pan-sharpened

Panchromatic band Precision & Resolution

Multispectral bands Thematic information

Spectral Band Combination

• Panchromatic • Multispectral • Bundle • Pan-sharpened


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DIMAP V2 containing

–Imagery format : JPEG2000 or GeoTIFF

–Metadata format : DIMAP XML

–Display: KMZ file (for easy and user-

friendly display of discovery metadata)

–RPC model for easy geometric processing

–Quality mask: cloud cover, Region of

Interest…

–Lineage files: processing, source

reference data identification…

DIMAP V2 layout

Product and Image format

• DIMAP – JPEG 2000 Optimized • DIMAP – JPEG 2000 Regular • DIMAP – GeoTIFF

Volume delivery ID

• DIMAP volume file (XML), HTM INDEX file (HTM)

{PAN, MS, PMS) image product folder

01_{PNEO, PHR, SPOT}_spectrum 02_{PNEO, PHR, SPOT}_spectrum

• JPG, preview file

• KMZ, google earth preview file

• JPEG2000/GeoTIFF, imagery file(s)

• J2W/TFW, ESRI world file(s)

• XML, DIMAP metadata file

• (Primary/Projected: XML, RPC file)

• (Reflectance: XML, LUT file)

• (XML, ISO 19115 metadata file) LINEAGE

• XML, processing file

Parameters files for product browsing

LIBRARY

• XSL, stylesheet • JPG, logos

MASKS

• GML, ROI mask • GML, water mask

• GML, cloud mask • (Others masks)

HTM, INDEX browsing file

DIMAP V2 metadata, layout: basically the same for SPOT, Pléiades, Pléiades NEO (PNEO)

Product delivering

–FTP delivery: compressed zip archive file

–Hard and drives, DVD

Standard product format: DIMAP


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Product and Image format

• DIMAP – JPEG 2000 Optimized • DIMAP – JPEG 2000 Regular • DIMAP – GeoTIFF

Format: DIMAP key metadata Metadata_Identification Metadata format and language identification

Dataset_Identification

Brief text and links for a visual representation of the dataset. Information is mainly provided for dataset search and discovery purposes

Rights and constraints to access and use

Dataset_Content

Localization of the dataset and geometric extent. User should use this information for cataloging purposes and not for accurate positioning

Links to the main files encapsulated into the current dataset (component)

Product_Information Responsible party of the product: contact, order, and delivery information

Coordinate_Reference_System

Coordinate Reference System (CRS) into which the data will be related. DIMAP CRS scheme based on the industrial standard EPSG.

• Projected: map projection, horizontal plane usually Cartesian coordinates in linear unit

• Geodetic: Earth mapping based on a geographic (angular unit) or geocentric shape of the Earth

• Vertical: CRS used for gravity-related (geoid) height or depth data

• Temporal: CRS used for recording time data

Projected and geodetic are the common ones for image mapping. Conventionally, Primary image are recorded with WGS84 geodetic CRS

CRS recorded to EPSG registry if known. Subsequent parameters only given if no identifier is found in the registry (commonly known as a "user-defined" definition)

Geoposition

Easiest relationship between the dataset coordinates and the CRS coordinates:

• Georectified image (Primary and Ortho): insertion point and dimension

• Sensor image (Primary): link to RPC analytic model

Processing_Information

Information on production facility, level of processing, processing settings: geometric, radiometric, sampling, MTF

Raster_Data Raster file path(s) and tiling size organization, encoding and displaying

Radiometric_Data

Radiometric information, how to set image count (pixel values) to radiometer measurement: dynamic range, radiometric adjustment performed on data, histogram, radiometric calibration values as spectral range, radiance, reflectance, solar irradiance

Geometric_Data

Geometric information:

• Sensor image (Primary): data for rigorous sensor model (acquisition time and date, ephemeris, attitudes, and geometric calibration of the instrument). Data is consistent with the inner image geometry and self-contained for the user processing (any data in other files is required)

• Pre-computed useful geometric location data at fixed posting in the image: acquisition angles, solar incidence, ground sample distances

Quality_Assessment

Quality information. Should be:

• Planimetric accuracy (Ortho Product)

• Vertical accuracy (DEM product)

• Link to various data giving quality information: lineage masks

Dataset_Sources

Original data identification from which the current dataset was made and a link to the corresponding lineage metadata file(s)


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Get ready for the launch in a few

days

Pléiades NEO 3

27th April 2021 From Kourou on VEGA launcher

01:50 UTC (03:50 in Paris, 22:50 in Kourou)


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Appendix

Vh-Roda 2021 Workshop | Day 2: Wednesday 21 April 2021

Fiducial Reference Measurements & Reference Cal/ Val Sites

Session commercial interest and needs in Cal/Val services

– Airbus: Pléiades Neo, Cal/val sites and new global reference

databases (slides)


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Focusing & MTF PSF assessment

Image

On-ground deconvolution,

etc.

Relative calibration DSNU (dark signal), PRNU

(inter-detector

normalization…),

Spectral response non-

uniformity

SNR (Signal to

Noise Ratio), etc.

On-ground denoising, etc.

Absolute calibration Temporal,

multi-temporal,

multi-sensors….

On-ground radiance,

reflectance parameters

Edge pattern: Salon de Provence, Baïdou

Extra-atmospheric bodies: stars

Point-like sources: Las Vegas, etc.

Radiometry: calibration and performance assessments

Vicarious calibration grant to CNES:

CNES stable natural sites: deserts

ESA/CNES photometers : La Crau, Gobabeb

Extra-atmospheric bodies: Moon, stars

DSNU: night acquisition (oceans)

Spectral response non-uniformity : homogeneous sites (ice sheets, etc.)

PRNU: Yaw steering mode SNR: Steady mode, etc.


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Geometry: calibration and performance assessments

Location accuracy Satellite on-board biases

calibration, sensor model

accuracy assessment

Static focal plane

Absolute calibration, relative calibration (MS-

MS/MS-PAN registration)

Dynamic stability Micro-vibration, temporal

drift

Planimetric (X,Y) and

vertical (Z) accuracies ORTHO and DEM

accuracy assessments

Geometric assessments grant to IGN:

Ultra-accurate (GCP and DSM) reference sites, with and without relief

Speed of CMG

Stars

Airbus highly stable calibration supersite (new):

Vaughn, New-Mexico, US: 18x18km, <15cmCE90, <30cmLE90

Worldwide measurements:

Airport sites Airbus database

Massive image registration statistics on GCPs


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• 3mCE90 GCP points, 3D consistent measurement (X,Y,Z) by SPOT6/7multi-stereo imagery

• Image chips from each SPOT stereo source centered on the GCP coordinate

– Designed for automatic and massive image matching

– location registration, geometric model enhancement of imagery, etc.

Stack of chips of SPOT images (one per input

source image) acquired at different dates, seasons, and using

different viewing angles

New worldwide location reference layer: Space Reference Points (SRP) database

AIRBUS DS and IGN partnership

World : ~80 millions GCPs

~800 millions image chips


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New worldwide location reference layer: Space Reference Points (SRP) Key facts requirements

<3m CE90

An unmatched, homogeneous and global performance

Thanks to the SRP world scale geometric foundation

2m GSD

Unmatched resolution for a global database

~136Mkm²

full land mass, without Antarctic, Greenland and large ice

fields. Include islands

1 GCP per 2km²

Very high, global, density

Up to 10 chips per GCP

different image chips from different dates and view points: easier

matching with the corresponding destination images.

Plus one extended image chip, 20m resolution

for larger and fast matching

Chandelier, L., Coeurdevey L. and all: A WORLDWIDE 3D GCP DATABASE INHERITED FROM 20 YEARS OF MASSIVE MULTI-SATELLITE OBSERVATIONS ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., V-2-2020, 15–23, https://doi.org/10.5194/isprs-annals-V-2-2020-15-2020

https://doi.org/10.5194/isprs-annals-V-2-2020-15-2020















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North Canada and Alaska @December 2021

SRP completion@08/2021: 127 Mkm² / 136 Mkm²

New worldwide location reference layer: Space Reference Points (SRP)



Positionning

accuracy

SRP Absolute

Quality Check

[0-3]m 93.1%

[0-5]m 99.6%

[0-10]m 100%

CE90 2.73m

Worldwide capability to enhanced image location accuracy @3mCE90 •Products: counts for the accuracy of the intrinsic PRIMARY/PROJECTED image geometric model (rigourous and RPC)

SRP: completion and qualified accuracy (CE90) SRP requirement: 3mCE90


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New worldwide location reference layer: Space Reference Points (SRP)



Worldwide capability to enhanced image location accuracy better than 3mCE90 •Even in difficult areas like mountain ranges, deserts, inter-tropical zones

SRP requirement • 1 GCP/2km²@1/100 square degree

SRP: GCP density

SRP completion@01/2021


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New worldwide altimetric reference layers: WorldDEM4Ortho V2 (WD4O V2)


• Ortho • Mosaic

WordDEM4Ortho pole-to-pole native coverage

Worldwide capability to enhanced image planimetric accuracy better than 5mCE90@slope<20% •Products: counts for the accuracy of the ORTHO (i.e assuming the “non perfect” DEM used at rectification process)

Hybrid DTM/DSM • Reduce rectification artifact

• Preserve altimetric accuracy

Documents

Pléiades Neo Image quality indicators