PRISMA MissionAn overview & preliminary data analysis

Claudia Giardino (CNR-IREA)

IOCCG-25 Virtual Committee Meeting, 13 May 2021

Mariano Bresciani, Alice Fabbretto, Nicola Ghirardi, Salvatore Mangano (CNR-IREA)

Federica Braga, Vittorio E. Brando, Simone Colella, Javier Concha, Federico Falcini, Gianluigi Liberti, Emanuele Organelli, Jaime Pitarch, Lia Santoleri, Gian Marco Scarpa (CNR-ISMAR)

National Research Council of Italy

Outline of the presentation

• Main characteristics of PRISMA (PRecursore IperSpettrale della Missione Applicativa)

• Overview on Level 1 and Level 2 products for aquatic systems (as part of the multiple applications of imaging spectroscopy technology)

• Retrieval of water quality parameters (lakes and coastal zones)• Summary slide

• 22-03-19: Vega begins its ascentfrom the Spaceportin French Guiana, carrying PRISMA

• 31-01-21: end of the commissioning phase

Orbit altitude reference 615 kmField of View (FOV) 2.77°Instantaneous FOV 48.34 mradSwath 30 km

Ground Sampling Distance

Hyperspectral camera: 30 mPanchromatic camera: 5 m

Spectral rangeVNIR: 400 – 1100 nm (66 bands)SWIR: 920 – 2500 nm (173 bands)PAN: 400 – 700 nm

Signal-to-noise ratioVNIR: > 160 (450 at 650 nm)SWIR: > 100 (> 360 at 1550 nm)PAN: > 240

Spectral Width ≤ 14 nmSpectral Calibration Accuracy ± 0.1 nm

Radiometric quantisation 12 bits

Repeat cycle 29 days (450 orbits)Relook time < 7 daysLifetime 5 years

0

200

400

600

0.40 0.60 0.80 1.00

SNR

0

200

400

600

1.1 1.6 2.1 2.6

SNR

Image: Arianespace ©

Main characteristics

Sea water

Dark water

Floating algae

SoilsVegetation

Soils

Vegetation

Full VIS-NIR-SWIR range

Coverage

PRISMA Chesapeake Bay, 16 Nov. 2020

Strip mode (up to 300 km)

Over

view

afte

r 4 m

onth

s fro

m th

e la

unch

60 km

• Background acquisitioncapability: ASI managesperiodic acquisitions on target areas of interest by exploitinglong term planning functions

• Foreground acquisitioncapability: tasking from users

Acquisition plan

CNES-ASI (PICS rad)6% RadCalNet (PICS rad)

1%

LandNet CEOS Reference Sites (PICS rad)

1%HYPERNETS (cal/val)

2%PRISCAV (cal/val-products)

5%

Leonardo CALVAL Facility1%

Aeronet-ACIX (Atmo-products)1%

ICOS (land products)7%

EFDC (land)1%

ENVIRONET (land)1%LTER (land)

0%

TERN (land)3%

LPV NASA CEOS (land products)5%

FRM4VEG(CEOS) (land products)6%

AERONET-OC-FRM4SOC (water-products)

3%NEON (land/water products)6%

CryoNet (WMO) (Cryo Products)6%

ASTRO (land/water analog)4%

FunDIVEurope2%

CHIME interest7%

FLEX interest3%

Hyperspectral Colleagues sites20%

National Interest7%

CNES-ASI Agreement3%

Level 1 (Hyperspectral / PAN) - radiometrically corrected and calibrated radiance data in physical units.This product provides• Top-of-Atmosphere Spectral Radiance• Calibration and characterization data used• Masks: Cloud, Sun-glint & land-cover classification

L1PRISMA L1

From L2 to aquatic

products

Simulation of in situ data with 6SV+ S2

PRISMA L2D

Productsin-flight calibration systematically performed by means of the Internal Calibration Unit (ICU)

Level 0 (Hyperspectral / PAN) - formatted data product with appended metadata, including ancillary data and file formatting information

Level 2b Geolocated at Ground Spectral Radiance Product (Hyperspectral /PAN)

Level 2c Geolocated At-surface Reflectance Product (Hyperspectral / PAN).This product includes: Aerosol Characterization, Water Vapour, Cloud Characterization.

In situ data + Sentinel-2, Sentinel-3

Level 2d the geocoded version of the level 2c products (Hyperspectral / PAN)

Giardino et al., 2020 Sensors

In situ: red dots are AERONET-OC, blue is for PANTHYR (->Hypernets) and yellow is for the WISPStation (EOMORES, Water Insight )

L1 Products: TOA

The blue lines show SNR values from two L1 PRISMA

products from coastal to open waters (acquired on

27/03/2020 and on 02/07/2020, with SZAs of 35 and

26 degrees, respectively); green bars are values for

Sentinel-2 (Pahlevan et al., 2017)

Example of TOA radiances from an

homogenous open water dark target

for computing Signal-to-Noise ratio as

in Wettle et al., 2004

L1 Products: SNR

0

20

40

60

80

400 500 600 700 800 900 1000

TOA

radi

ance

(mW

m-2

nm

sr-1

)

Wavelenght (nm)

L2 Products

L2 Products

0

0.01

0.02

0.03

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

Rrs

[sr-1

]

Curonian Lagoon

PRS-20-Sep-2020GRND-20-Sep-2020S2S3

WISPStation

fixed position autonomous radiometer

Hand-held WISP-3 radiometer

R2 RMSE SAM N

L1 0.98 0.9-4.7 (mWm−2sr−1nm−1) 0.8-3.4 9

L2D 0.81 0.0012-0.0093 (sr-1) 11-26 21

Hyperion

NE D

R(0-

) E

PRISMA

Brando & Dekker, 2003

• The environmental noise-equivalent reflectance difference NEDR(0-)E computed from PRISMA scenes (e.g. Lucinda, ) is lower than 0.1% (apart the shortest bands) used as reference for water quality retrieval in Brando & Dekker (2003)

• The PRISMA NEDR(0-)E noise is definitely lower than Hyperion (also after the low pass filter which aimed to reduce the NEDR(0-)E from ~0.3 to ~0.1%)

L2 Products: SNR

Preliminary products: shallow waters

Bio-optical model inversion (BOMBER) (Giardino, Candiani, Bresciani, Lee, et al. 2012)

0.5 1 1.5 >3Depth [m]

0 25 50 75 100

Macrophyte coverage (%)

PRISMA Venice lagoon, 23 Mar. 2021

sea

river

near coast

whitish bloom (cocco?)

Coccolithophore? (Organelli et al., work in progress with QAA applied to PRISMA)

65

2

43

1

7

0

0.005

0.01

0.015

0.02

0.025

400 450 500 550 600 650 700 750 800

RRS

[sr-1

]

Wavelength [nm]

PRISMA L1+ATCOR

ROI1ROI2ROI3

ROI4ROI5

ROI6ROI7

Examples of PRISMA spectra in estuaries (Ebro, Spain; Rhone, France; Po, Italy) and of

the related chromaticity coordinates

x, y pairs from PRISMA after a spectral convolution based on the response filters of human eye

Preliminary products: estuaries

PRISMA Po river estuary, 24 Nov. 2020

PRISMA Ebro river estuary, 16 Jul. 2020

The plot shows ranges from turbid to deep clear waters and different bottom types

Shallow areas / Turbidity in rivers

Chl-a (mg/m3)

0.01 1

Shallow waters

Blue waters

ResuspensionPRISMA Lucinda, 25 Jul. 2019

Preliminary products: coastal zoneson-going: aLMI for water quality mapping

PRISMA Lake Hume, 22 Apr. 2020, L2D (7 sites)

Floating algae/scum

Phyc

ocya

nin

High sediments

High phytoplankton biomass

Preliminary products: lakes

0

0.01

0.02

0.03

0.04

0.05

400 500 600 700 800 900 1000

Rrs (

sr-1

)

[Red] [Green] [Blue] [Yellow][Cyan] [Magenta] [Maroon] Lake Hume in situ and

modelled data

PRISMA Lake Hume, 22 Apr. 2020, L1 (two sites)

on-going: aLMI for water quality mapping

Phycocyanine

concentrations of the

Curonian Lagoon

(Lithuania) and Lake

Trasimeno (Italy) from

Simis et al 2007 and

Mixture Density Networks

(MDN)

O’Shea, Pahlevan, et al., in

preparation

Non-finite or negative values are

shown in grey

The normalized difference water

index (NDWI) is used with a

threshold of 0.1 to identify the

water regions.

Preliminary products: phycocyainine

0

0.005

0.01

0.015

0.02

0.025

400 500 600 700 800 900 1000R

rs (-

)

wvl (nm)

PRISMA image

WISP-3 in situ

S2 simulated

S2-E simulated

0.008

0.01

0.012

0.014

0.016

0.018

0.02

0.022

550 570 590 610 630 650 670

Rrs

(sr-1

)

wvl (nm)

PRISMA imageWISP-3 in situS2 simulatedS2-E simulated

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

770 790 810 830 850

Rrs

(sr-1

)

wvl (nm)

PRISMA imageWISP-3 in situS2 simulatedS2-E simulated

2. CHIME-SBGAVIRIS, PRISMA match ups (May-June 2021)

Supporting studies

3. PRISMA Second Generation (PSG)PSG Is the operational follow-on of the in-orbit PRISMA mission, to be launched in 2025.

https://ares-observatory.ch/esa_chime_mission_2021/

End of May, 2021 Jun. 2021

Turbid productive waters (Trasimeno)

Shallow waters (Venice lagoon)

1. Sentinel-2-Next Generation (NG)PRISMA + in situ

• Satellite successfully launched• Open free data policy• The archive already counts thousands of images (capacity of 200 images

per day); tasking on pre-defined target is working fine• L1 and L2 are systematically produced on-demand

• L1 data are accurate shows consistent to data acquired by other missions• L2 data show variable degree of accuracy (on-going work: SNR, clear waters, adjacency effects,

water quality mapping)

• PRISMA overall shows promising data for water resources mapping and monitoring (in synergy with e.g., Sentinel-2, Landsat-8, Sentinel-3 OLCI)

• The mission is also supporting developments of future/synergic satellite missions (e.g. Sentinel-2-NG; CHIME, SBG, PRISMA-SG)

Conclusions

• The link for registration is:https://prismauserregistration.asi.it/

• After registration, the PRISMA documentation (e.g., PRISMA Product Specifications) is also available in the same portal for data search and download at:

https://prisma.asi.it

• The PRISMA web page can be found here:http://www.prisma-i.it/index.php/en/

Useful links

• The link for registration is:https://prismauserregistration.asi.it/

• After registration, the PRISMA documentation (e.g., PRISMA Product Specifications) is also available in the same portal for data search and download at:

https://prisma.asi.it

• The PRISMA web page can be found here:http://www.prisma-i.it/index.php/en/

Useful links

Thanks a lot for your attention!

PRISCAVCHIME: Mission Requirement Consolidation Study

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