CESBIO contribution to the activities of the "Centre Aval de Traitement et des Données SMOS" (CATDS)

The CATDS (Centre Aval de Traitement et des Données SMOS) is split in three parts : C-PDC Production Center : produce and dissaminate L3/L4 data (l’IFREMER de Brest) C-EC SM Expertise Center dedicated to « Soil Moisture » (CESBIO, Toulouse) C-EC OS Expertise Center dedicated to « ocean  salinity » (IFREMER, Brest )

downlod CATDS logos

CNES is in charge of the CATDS, this center is dedicated to :

• Product and disseminate SMOS L3/L4 products
• Reprocess SMOS L3/L4 products when necessary
• Develop, test and validate the SMOS L3/L4 processing chains, in close cooperation with the scientific community (improvement of the processing chains)

Interfaces

♦ Data Processing Ground Segment (DPGS) = ESA Center for L1 data production
♦ Users :

• Send services/information requests
• Receive L3/L4 data (network and media) and services

♦Auxiliary data providers, Main auxiliary data provider is the European Centre for Medium-Range Weather Forecasts (ECMWF);
♦Scientific community : provides expertise with the means provided by the center (C-EC) :

• mock-up (algorithm test)
• specify the "algorithm theoritical baseline document" (ATBD)
• test and evaluation on SMOS data to C-EC

♦ C-PDC / C-EC : expertise and production centers.

Industry implication :

- System architecture : groupement ATOS Origin – GFI Informatique
- Processing chains : consortium CAP-Gemini Sud et ACRI-ST

Cooperations

♦ IFREMER will host the Data Production Centre in the CERSAT (=Centre ERS d'Archivage et de Traitement)

♦ CESBIO will host the SM Expertise Centre; and will deliver the L3+L4 algorithms specifications and mock-up (with the help of the other laboratories involved in L3/L4 SM)

♦IFREMER will host the OS Expertise Centre; and will deliver the L3+L4 algorithms specifications and mock-up (with the help of the other laboratories involved in L3/L4 OS)

♦Spain will develop CP34, another ground-segment dedicated to SMOS L3+L4 products processing

Level 2 Processor

The Soil Moisture Expert Support Laboratories (ESL) - consisting of 5 different laboratories :

1 the LI group with CESBIO and IPSL SA
2 the University of Roma
3 the Reading University
4 the INRA EPHYSE in Bordeaux

SMOS level 2 Processor for Soil Moisture ATBD (Algorithm Theoretical Based Document) Prepared by the Expert Support Laboratories CESBIO, IPSL-Service d’Aéronomie,INRA-EPHYSE, Reading University, Tor Vergata University For Array Systems Computing Inc. Issue 3.a   Date 05/12/2007
SMOS level 2 processor Soil moisture ATBD (31/08/2006)
SMOS level 2 processor for soil moisture - Algorithm Theoretical Based Document (ATBD) - Prepared by the Expert Support Laboratories (15/03/2006)
Algorithm Theoretical Based Document (ATBD) Date: 15/01/2006
SMOS SSS L2 ATBD (Draft issue 4, 3 Oct.. 2005)
"coordinated answer to the scientific contribution to the SMOS soil moisture prototype processor development" Date 29/09/2004

Artist's Views and Animation

	SMOS ANIMATION get here the mpg data file (2168 K)oB			SMOS - scientific and interactive animation (CESBIO / MIRA Productions)
	full resolution image :5500 x 2800 pixels (300 dpi)
	another one.... 3500 x2800 pixels (300 dpi)			SMOS : ESA 's water mission

Useful links

The ESA living planet programme Home page

ESA : for the ESA SMOS site

The SMOS missio main steps on the CNES web site

Site web d'EADS/CASA

Site web d'Alcatel Alenia Space

Site web des Lanceurs ROCKOT

Site web d'ACRI

Site web d'ARRAY

data sets

The NSIDC page : for passive microwave data and Snow and Ice data

The Global Soil Wetness project Page for the existing soil wetness data and research

Global soil Moisture Data Bank for soil moisture data sets

Other data sets of interest from USDA Remote Sensing of Soil Moisture, hydrology experiment...

Experiment and Mission

The Hydros page : for the other Soil moisture mission (NASA ESSP)

The GEWEX page : for the Global Energy an Water Experiment

the Aquarius page : for the other Sea Salinity mission (NASA ESSP)

MDB and NAFE Experiment : for the next SMOS campaign (CoSMAus)

Other sites...

Hydrologie Laboratory Hydrology and Remote Sensing Laboratory (USDA)

AMSR page : for the existing almost low frequency radiometer

The Sea Salinity International Working Group Final Report of the First Workshop, february1998.

 

Mission characteristics

The SMOS mission was born from the conjonction of new technological developments (ASTRIUM/MMS-DASA, CASA) and the modeling needs for meteorological prediction.

The proposed instrument is based on a L-band interferometric radiometer (passive microwave, 1.4GHz) with an average spatial resolution of 43 km (30 to 50 depending on the view angle) and a repetition of 3 days at the equator (only ascending orbits). The instrument concept is very original (VLBI, used by astrophysicists) and it benefits from the experience acquired during the development of an airplane- mounted version : MIRAS (for the preparation of the ESA mission). The instrument can be placed on a PROTEUS-type mini-satelllite platform.

The CATDS (Centre Aval de Traitement des Données) is in phase B ( levels 3 & 4).

Mission Context

The SMOS mission does not have any competition for the moment, ISIS (NASA), HYDROSTAR (NASA) et MIRAS (ESA) projects have not been selected. American teams are lending strong support to the SMOS project.

Currently two projects are selected by NASA:
1. Aquarius which will measure ocean salinity with a precision of 0.2 PSU over a surface of 200X200 km2 every 10 days (the satellite repetition is 8 days with a long track of 300 km and a spatial resolution of 100 km)
2. HYDROS which will measure surface soil humidity with a repetition of 3 days and a resolution of 40 km and a precision of 4% vol.

These two projects are based on L-band radiometers and an active system in L-band. In comparison, SMOS will provide both the ocean surface salinity (0.1 PSU over 200x 200 km2 every 10 days), and the superficial humidity (4% vol every3 days with an average spatial resolution of 43 km). The originality of SMOS comes from directional measurements used in order to determine the vegetation water content.

Surface Monitoring Of Soil Reservoir EXperiment (SMOS REX)

L'expérience de terrain SMOSREX (Surface Monitoring Of Soil Reservoir EXperiment) est conduite dans la cadre de la préparation à la mission satellitale SMOS (Soil Moisture and Ocean Salinity). SMOSREX consiste à utiliser simultanément : (1) la télédétection en bande L (mise en place de l'instrument LEWIS), (2) mesures multi-fréquences (bandes L, IRT, PIR, VIS), (3) des mesures terrain (météo, sol, végétation) dont l'humidité du sol à différentes profondeurs. (4) des modèles de processus de surface et de transfert radiatif. SMOSREX (2003-2010), permet de considérer une large gamme de conditions météorologiques, hydrologiques, phénologiques ainsi que leurs interactions. Le site expérimental est situé sur le complexe de l'ONERA (43°23'N, 1°17'E, altitude 188m altitude), environ 30km au sud de Toulouse. SMOSREX est conduite en partenariat avec le CNRM, l'ONERA et l'INRA-Bordeaux et est partie intégrante du programme PIRRENE : Programme Interdisciplinaire de Recherche sur la Radiométrie en Environnement Extérieur Conduite conjointement avec la campagne aéroportée CoSMOS en 2005, SMOSREX permet de considérer tant les questions théoriques liées à la télédétection de l'humidité du sol, que ses applications de la pour la modélisation. Les objectifs de cette campagne de terrain sont donc multiples (1) d'une part de développer et d'améliorer les algorithmes direct et inverse en bande L, (2) d'autre part d'étudier l'apport de la télédétection de l'humidité des sols pour la compréhension et la modélisation des processus d'interaction sol-plante-atmosphère.   L band Radiometer for Estimating Water In Soils " (LEWIS) Dans le cadre de la mission SMOS, un site expérimental de terrain a été développé et installé . L'objectif principal est de tester et d'évaluer les algorithmes utilisé pour estimer l'humidité en surface et en profondeur. Pour cela le site a été équipé de l'instrument "L band Radiometer for Estimatingring Water In Soils " (LEWIS) Grâce aux mesures ( températures de brillance, météorologie) nous pouvons également : - étudier l'humidité des sols lors d'événements météorologique ponctuels comme le gel, la rosée.... - influence de la présence de la végétation sur le signal mesuré en bande L. - pour estimer l'humidité du sol en zone racinaire. Pour celà un site près de Toulouse a été équipé sur deux types de surfaces (sol nu et sol herbacé). Une structure porteuse a été construite avec un système de pointageet d'acquisition de données pour porter le radiomètre en bande L. Après une période de test le système est opérationnel. LEWIS"L band Radiometer High Quality Ground based radiometer1.4 GHz, H & V sensitivity 0.1 K Stability < 0.05K main lobe 12.5 @3db, 22° beam efficiency 0.986 No « visible » back lobes ONERA/CESBIO Operational since 23/1/2003 Design and Test of the Ground-Based L band Radiometer for Estimatingring Water In Soils ( LEWIS)  Exemple de cycle diurne de la température de brillance acquis par l'instrument LEWIS en polarisation H/V sur un sol nu et sur un couvert herbacé.     Scientific products around SMOSREX and LEWIS Escorihuela, MJ, Chanzy A.,, Wigneron J.-P. and Kerr, YH (2010) Effective soil moisture depth of L-band radiometry: A case study, Remote Sensing of Environment, article in press, doi:10.1016/j.rse.2009.12.011 Etude des effets de la rugosité sur l'émission en bande-L du sol nu MIALON Arnaud, WIGNERON Jean-Pierre, DEROSNAY Patricia, Escorihuela M.-J.KERR Yann Présentation poster à la conférence : MICRORAD 2008, Florencia, Italy abstract    Escorihuela, MJ and Kerr, YH and de Rosnay, P. and Wigneron, J.P. and Calvet, J.C. and Lemaitre, F., 2007. A Simple Model of the Bare Soil Microwave Emission at L-Band, Geosc. Remote Sens., vol.45 (n7 Part 1),p 1978-1987. de Rosnay P., Calvet J.-C., Kerr Y., Wigneron J.-P., Lemaître F., Escorihuela M.J., Muñoz-Sabater J., Saleh K., Barrié J., Bouhours G., Coret L., Cherel G., Dedieu G., Durbe R., Fritz N.E.D., Froissard F., Hoedjes J., Kruszewski A., Lavenu F., Suquia D., Waldteufel P. : "SMOSREX: A Long Term Field Campaign Experiment for Soil Moisture and Land Surface Processes Remote Sensing" Remote Sensing of Environment, 102, 377-389, 2006 doi:10.1016/j.rse.2006.02.021 Rapport du workshop EGU du 27 avril 2005 a Vienne : 1 - introduction 2 - A Brief Overview of Passive Microwave Experiments over Land - 3 - SMOSREX: A Long Term Field Campaign Experiment for Soil Moisture and Land Surface Processes Remote Sensing. 4 - L-Band Radiometry Experiments with ELBARA 5 - NAFE - National Airborne Field Experiment 6 - Assimilation: field and airborne campaigns SMOSMANIA SMOS Rex Case Study : Determination of the effective Temperature for L-band  Radiometry,  (EGU-2004)  P. de Rosnay, T. Holmes., J.P. Wigneron Y. Kerr, J.C. Calvet, M.J. Escorihuela, K. Saleh,   F. Lemaître  SMOSREX : Surface Monitoring Of the Soil Reservoir EXperiment  Experiment design and results (EGU-2004)  M.J. Escorihuela, P. de Rosnay, Y. Kerr, J.C. Calvet, F. Lemaitre,  J.P. Wigneron, J.P. Waldteufel, N.E.D. Fritz Télédétection de l'humidité des sols. Présentation de l'expérience SMOSREX  P. de Rosnay, Y. Kerr, J.C. Calvet, F. Lemaître, M.J. Escorihuela, J.P. Wigneron  Expérience SMOSREX  Télédétection de l'humidité des sols  P. de Rosnay, Y. Kerr, J.C. Calvet, F. Lemaître, R. Duirbe, J.P. Wigneron, M.J. Escorihuela,  N.E.D. Fritz, F. Lavenu, T. Holmes Préparation de la mission SMOS Extraction de l'Humidité du soll à partir des données LEWIS- Maria José Escorihuela (juin 2003) DEA MICROONDES ET TRANSMISSION OPTIQUE

TECHNICAL NOTES

These technical notes are intended to those who want
to get a deeper insight of the SMOS system.

They cover instrument characteristics (FOV), retrieval
accuracies, perturbations and more should come!

They were all written by Philippe Waldteufel.

Radiometric sensitivity of SMOS

SMOS Field of View

L Band Salinity retrieval: SST and receiver effects

L Band Salinity retrieval:Sky and optical thickness effects

Faraday Rotation

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Mission objectives

The scientific objective of this mission is to obtain a better estimate of the spatio-temporal water budget at the global scale and ocean/atmosphere interactions.

Over continental surfaces, it is necessary to estimate the soil surface humidity for global circulation models and boundary conditions for large hydrological models. Sensitivity analyses show the importance of knowing a precise value on the soil surface humidity for precipitation field reconstruction. Moreover, new approaches permit the estimation of the root zone water content. Finally, multi-angular and dual polarization measures from SMOS will allow a quantification of the vegetation water content

Over the oceans, it is necessary to estimate the salinity which is a very important variable for ocean circulation dynamics and for ocean/atmosphere coupling. Currently, no measures of this nature are available on the global scale.

Project status

This project was submitted to ESA by the CESBIO in response to the call for proposals " Earth Explorer Opportunity Missions " in November, 1998. 

 It was classed second and therefore it was selected. In mid-January 2004, the project passed into phase C/D at ESA. Opportunity mission scheduled for launch in 2009.

Ground Segment : Expert Support Laboratory (ESL) and industry have been selected to prepare prototype for Soil Moisture and Sea Salinity algorithms

The payload of the SMOS instrument has successfully completed this year all certification tests (vibration, acoustics, vacuum ...). The instrument is now ready, SMOS is scheduled for launch in september 2009 for a lifetime of 5 years. The scientists will be able to benefit from these data at the end of this summer. In the meantime, they can now become familiar with the first simulations of SMOS data generated for about forty dates.

CAL-VAL

Welcome to the submission area for the AO for SMOS Calibration and Validation.

The 1st. Announcement of Opportunity for the SMOS Mission aiming specifically at Calibration and Validation activities is open now. Details are available from: http://eopi.esa.int/smos

You can read some CESBIO responses :

Cal-val SMOS- MALI / NIGER

Principal Investigator: Manuela Grippa (CESBIO/CNAP), Thierry Pellarin (Laboratoire d'étude des Transferts en Hydrologie et Environnement, LTHE), Bernard Cappelaere (Hydro Sciences, Montpellier - HSM)

Primary Application Domain: Calibration/Validation
Secondary Application Domain: Hydrology

Title : Multiscale validation of SMOS brightness temperature and products over West Africa

The aim of this project is to use both ground measurements and land surface modeling approaches to compare and validate SMOS products over West Africa in the framework of AMMA project.
more details and results

Cal Val SMOS Murray-Darling Basin : National Airborne ield Experiment (NAFE)

Principal Investigator : Gilles Boulet (CESBIO/IRD)

Primary Application Domain: Calibration/Validation
Secondary Application Domain: Hydrology

The aim of this proposal is to use a combination of gridded airborne L-band brightness temperature, NDVI and surface temperature data and distributed in-situ soil moisture data acquired at the scale of several SMOS pixels during two field experiments in SE Australia (NAFE) to test 1- the SMOS soil-moisture retrieval algorithms (inversion of local soil moisture from airborne brightness temperature data) 2- the SMOS disaggregation algorithms (inversion of local soil moisture from coarse brightness temperature and auxillary remote-sensing data). This proposal falls within the Cal/Val SMOS activities for which a joint proposal with the same objectives is submitted to the adhoc program at ESA, lead by our Australian partners represented by Prof. Jetse Kalma.

more details

website of NAFE

ESA presentation for the CaL-Val

Results of the (COSMOS/NAFE'05 Experiment

Calibration of SMOS products Geolocalisation Biases

Principal Investigator. : Francois Cabot (CESBIO/CNES)

Primary Application Domain: Calibration/Validation

The aim of this study is to deliver a full characterization of on-orbit geolocalisation biases as observables in SMOS products.
more details

AACESS Australian Airborne Cal/Val Experiments for SMOS

The AACESS campaign is part the SMOS Validation/Calibration activities. It has been organized by Jeff Walker, Chris Rüdiger, Sandy Peischl (University of Melbourne), with the main objectives of validating the SMOS products (brightness temperatures and soil moisture) and monitoring soil moisture.

The area of study is the Murrumbidgee River catchment covering an area of about 100 x 500 km, corresponding to 20 SMOS pixels.

The first part of the campaign took place between the 18th of January and 22th of February 2010. The campaign consists in field measurements (soil moisture, vegetation, meteorological data) and airborne measurements (L-band, Thermal InfraRed, Near InfraRed, Visible). To validate the SMOS brightness temperatures, an aircraft is equipped with the a L band instrument PLRM (Polarimetric L-band Multibeam Radiometer).

CAL-VAL CAROLS 2010 (Cooperative airborne radiometer for ocean and land studies)
Principal Investigator : Mehrez Zribi (CESBIO/IRD)

If the principle of interferometry is perfectly mastered in the astronomy domain, this is the first time that such an instrument is used to observe Earth from space (SMOS orbit is at 755 km). A similar radiometer (CAROLS) was fdesigned and used to validate the findings and prepare algorithms for data processing of the SMOS radiometer.

Constructed by the CETP (LATMOS), in collaboration with "'Université Technologique du Danemark" and the INSU technical division, CAROLS runs at the same frequency than the SMOS radiometer (1.4 GHz) and can be loaded aboard the ATR42 research aircraft of Météo France managed by UMS SAFIRE (CNRS-INSU / Météo France / CNES).

CAROLS ' antenna. © CESBIO,

conducted since 2007, the number of campaigns that have raised doubts that might have scientists on the use of an instrument whose operation is based on small antennas arranged on a deployable structure and interconnected. This helped to validate this operation, especially the quality of measured data, the calibration protocols and the influence of the disruptive effects associated with radio frequency interferences.

Context and objectives

in the context of an airborne campaign sheduled in spring 2010, CAROLS will play an important role during the SMOS in-orbit commissioning. The goal is to provide multisetups independent measurements which will be used to assess SMOS data quality. This campaign will be conducted in coordination with other in situ measurements campaigns (additional data needed for analysis), namely ground-based observations made by Météo France (CNRM), INRA and INSU (CESBIO) and an oceanographic campaign, coordinated by the LOCEAN and made from a ship of INSU.

Airborne Campaign

Dates et lieux La campagne 2010 se déroulera durant trois mois (avril, mai et juin) et sur trois sites : Golfe de Gascogne, Sud-Ouest de la France et Valence (Espagne). Les vols seront effectués à partir de l’aéroport de Francazal à Toulouse (point d’attache de l’opérateur SAFIRE) et à partir de Brest. Moyens déployés Le radiomètre micro-onde CAROLS sera embarqué à bord de l’ATR42 avec le radar aéroporté STORM du LATMOS et le récepteur GPS GOLD-RTR installé par une équipe espagnole. L’avion effectuera plus de 35 vols répartis sur les trois sites d’étude, avec des départs de Brest et de Toulouse.

Dates and places : The 2010 campaign will run for three months (April, May and June) and on three sites: the Bay of Biscay, south-west France and Valencia (Spain). The flights will be operated from the Francazal airport in Toulouse (attachment point of the SAFIRE operator ) and from Brest.

deployed resources: microwave radiometer CAROLS will be flown on board the ATR42 with the STORM airborne radar of LATMOS and the GPS receiver and the GOLD-RTR installed by a Spanish team. The aircraft will operate more than 35 flights spread over the three study sites, with departures from Brest and Toulouse.

CESBIO's contact: Mehrez Zribi

SMOS in-orbit commissioning

SMOS in-orbit commissioning as been on track since the succesful launch of the satellite on November 2nd, 2009.

Following accurate injection, payload arms deployment and fine tuning of the orbit, the first period was dedicated to PROTEUS bus. Full review of platform capability being conducted, after the instrument was switched on on November 17th, 2009, mission commissioning per se was started.

After a full functional health check of all calibration and acquisition modes, instrument characterisation has begun in sequences, each of which yielding an improvement in data quality.

Only concerns have been with one of the local oscillator, which had to be switched to backup side, and with strong presence of RFI over some specific areas.

Current status is that the instrument is behaving better than expected and studies are being initiated to mitigate RFI impact.

For more information, details in real time on the in-orbit are published on the blog: SMOS_blog