1. CNES Agency Report for GSICS
Presented by Denis Jouglet
Contributions :
IASI: E. Jacquette, C. Maraldi, D. Jouglet, O. Vandermarcq
IASI-NG: F. Bermudo, S. Rousseau, F. Bernard, E. Péquignot
VIS/NIR: Aimé Meygret Bertrand Fougnie
GSICS meeting, March 2015, Delhi, India

2. Status of the IASI program (IASI-A and B)
Status of the IASI inter-comparisons
Status of the IASI-NG program
Status of VIS/NIR activities

3. Status of the IASI program (IASI-A and B)
Status of the IASI inter-comparisons
Status of the IASI-NG program
Status of VIS/NIR activities

4. IASI-A and IASI-B status
IASI-A and IASI-B L1C data quality on normal operation mode:
~ 99.4% (B3), 99.6% (B1&B2) of good quality L1C spectra
IASI-A and IASI-B radiometric noises are very close to each other and very stable
Ice effect between 700 and 1000 cm-1 (condensation on the field lens)
Decontamination of IASI-A from 8th to 13rd September 2014 : the last one until end of life
Decontamination of IASI-B from 10th to 14th March 2014 (first one in routine), next one should be performed on beginning 2016.
IASI-A and IASI-B instruments are both very stable
No drift since last performances presentation at 2014 GSICS meeting
IASI-A
IASI-B

5. In-flight IASI Compensation Device (CD) stop operations
The CD was made to compensate possible perturbations induced by the cube corner movements of IASI on the MetOp attitude control.
Decision to perform in-flight CD stop operations : test the capability to operate IASI without CD activated.
On IASI-A, CD stop operations were performed during 2 days end of November.
On IASI-B, 3 weeks of unexpected data with the CD stopped are available (due to a probable Single Event Transient on the 18th December 2014)
IASI-A and IASI-B performances have been analysed during these 2 periods of Compensation Device stopped in-flight
But simulations and ground tests showed that the CD have an impact on IASI performances and that the impact on MetOp should be low
Perturbation in the ISRF (replicating it at about ±14cm-1) mainly caused by micro-vibrations of the interferometer beam-splitter induced by the CD
 Spectral and radiometric impact

6. Results – performances with CD stopped
CD ON
CD OFF
Credit: Tim Hultberg
Evidences of the presence of ghost:
PC Scores (EUMETSAT): example with 1 PC related to the ghost (or at least instrument artefact). Particular pattern disappears when the CD is stopped.
Correlation matrix: correlation of all the IASI channels (8461) of black body (BB) spectra acquired on BB external calibration. One major contributor of the correlation between channels when the noise is low is the ghost effect.
CD ON CD OFF
“Ghost effect” almost totally eliminated by the stop of the CD, leading to an improvement of the IASI spectral and radiometric performances.
The CD stop does not disrupt the geolocation, at IASI or MetOp platform level.
Credit: Bernard Tournier

7. Status of the IASI program (IASI-A and B)
Status of the IASI inter-comparisons
Status of the IASI-NG program
Status of VIS/NIR activities

8. In-flight IASI inter-calibration activities
3 independent tools for inter-comparison:
Common observations (SNOs or quasi-SNOs), operational for the 5 couples of sensors:
IASI-A / IASI-B, IASI-A / AIRS, IASI-A / CRIS, IASI-B / AIRS, IASI-B / CRIS
IASI-A global massive mean vs IASI-B global massive mean
IASI comparison with NWP+RT  (IASI-A calc – obs ) – (IASI-B calc – obs)
The tools will be operational for a long time, inclusion of future sensors (IASI-C, IASI-NG, etc.)
New outputs for 2015:
Increased size of the dataset (> 2 years for IASI-B)
IASI comparison with NWP+RT developed by LMD and under operationalization at CNES
Main result: very accurate cross-calibration
IASI-B / IASI-A: bias < 0.1K, IASI / AIRS & CRIS: bias < 0.2K)
On-going activities:
Reduction of the quasi-SNO database size
IASI linearity tables investigation and update for B1
IASI uncertainty budget under progress for action GRWG_14.13
See presentation 1n (mini conference)

9. Status of the IASI program (IASI-A and B)
Status of the IASI inter-comparisons
Status of the IASI-NG program
Status of VIS/NIR activities

10. IASI New Generation PROGRAM
In the frame of the Second Generation of EUMETSAT Polar System (EPS-SG), a New Generation of Infrared Atmospheric Sounding Interferometer (IASI-NG) will be developed by CNES in collaboration with EUMETSAT
IASI New Generation is a follow-on system wrt IASI first generation on MetOp. Its objective is to provide operational observations from polar orbit for numerical weather prediction, atmospheric chemistry and climate monitoring in the 2020 to 2045 timeframe
With respect to the first generation, IASI-NG will :
ensure continuity of essential operational observations without gap;
improve the accuracy / resolution of the measurements ( NedT, spectral resolution)
EPS-SG is a collaborative program between EUMETSAT, ESA and CNES
EUMETSAT is responsible for overall mission requirements, procurement of the launchers and LEOP services, development of the ground segments, space and ground segment operations
ESA is responsible for the development and procurement of the MetOp-SG SL which consists in two series of SL: Sat -A and Sat-B
CNES is responsible for the development and procurement of the IASI-NG System (space and ground segments) and performs TEC operations

11. IASI New Generation System
CNES is in charge of the technical development management of :
IASI-NG instruments to be flown on MetOp-SG A Satellites
Technical Expertise Centre in charge of in-flight calibration/validation and instrument performances monitoring
Level 1 Processor for post-processing instrument data : high resolution spectra measurements continuously from 3.6 µm to 15.5 µm

12. IASI-NG Schedule overview
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
Phase 0
Phase A
Phase B
Phase C/D
Operations
EPS-SG System Development
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2027
2035
Pre-Phase A
Phase A/B1
Phase B2/C/D
Phase E
MetOp-SG A Satellite Development
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
Phase 0
Phase A
Phase B
Phase C/D
Phase E
IASI-NG System Development
Instrument
PDR
Instrument
CDR

13. From IASI to IASI-NG: Main requirements and improvements
User Requirement (L1C)
Objective
Spectral
Continuous Spectral coverage
IASI ([ cm-1] or [ ] µm)
Spectral Resolution
IASI/2 (0.25 cm-1 or [6-33] nm )
Spectral Sampling
IASI/2 (0.25 cm-1 or [3-16] nm)
 Spectral Channels
Radiometric Error due to spectral decalibration
IASI/2 ( dσ/σ=10-6)
Radiometry
(≈ 1/SNR)
IASI/2
Absolute Radiometric Error
IASI/2 (
Geometry
Pixel Size
IASI ( 12km)
Spatial Sampling
IASI ( 25km)
Navigation
Geolocation Error
IASI ( 1km)
Lifetime
7.5 years
Main technical challenges

14. SPACE SEGMENT OVERVIEW
Major improvement: Large FOV enabled by a field compensation device made of 2 moving prisms

15. Instrument Budgets & Accommodation
I-OH
I-EM
100 kg
IFM
IASI NG Instrument prime
540 W BOL
500 W EOL
260 kg

16. Status of the IASI program (IASI-A and B)
Status of the IASI inter-comparisons
Status of the IASI-NG program
Status of VIS/NIR activities

17. SADE / MUSCLE database (1/2)
Deserts (PICS): SADE operational data base very rich and still improving:
32 sensors, from 1987 to 2015…
more than multi-spectral measurements
LANDSAT-8 being moved from the test data base to the operational base
Desert sites – cross calibration method improvements:
geometrical matching between ref sensor and the sensor to calibrate using site BRDF
atmospheric contribution : aerosol climatology, radiative transfer code instead of SMAC
surface spectral interpolation using hyperspectral data
Preparation for a systematic generation of an error budget
Calibration over the Rayleigh scattering:
Optimization for high resolution sensors (SPOT7 commissioning phase + future sensors)

18. SADE / MUSCLE database (2/2)
Calibration over the Moon:
Pleiades Orbital Lunar Observations – “POLO”
 Intensive in-orbit acquisitions have been performed (1150 images from PLEIADES-1A and 1B under different viewing conditions)
Objectives:
to better understand the ROLO model
to contribute to improve the use of lunar acquisitions; phase angle dependence
to perform temporal stability monitoring, cross-sensor calibration, cross-band calibration and absolute calibration
SADE database for lunar observations: A lot of sensors (PHR-1A, 1B, MODIS, MSG1, MSG2,LANDSAT-8) with different characteristics: spatial and spectral resolution, phase angle range, absolute radiometric accuracy,… data quality improvement and cross calibration activities on-going

19. VIS/NIR activities
2014 / 2015: CNES involved in several cal/val including preparation (Spot7, Sentinel-2/MSI, Sentinel-3/OLCI & SLSTR, Venµs) and in new developments (3MI etc.)
Some GRWG Actions assigned to CNES are still on-going:
GRWG_06.8 about ATBD desert
GRWG_14.4 about Smoothed DCC BRDF
GLCWS_14.4 about Present moon acquisitions for PARASOL
Main actions for 2014:
Construction of a DCC BRDF Model based on PARASOL data
 presented in webMeeting and CALCON’14
Co-organisation of the Lunar Calibration Workshop with EUMETSAT/USGS/NASA
 see talk 3k Outcome (presented by S.Wagner)