iasi-ng : cnes phase 0 study presentation...2nd iasi conference; annecy, january 2010 3 iasi-ng...
TRANSCRIPT
IASI-NG :
CNES phase 0 study presentation
2nd IASI conference
Annecy, January 2010
M. Albinet, B. Belon, F. Bernard, D. Blumstein, L. Buffet, C. Buil, L. Cadiergues,
P. Guay, P. Hebert, T. Maciaszek, E. Pequignot, C. Pierangelo, M. Saccoccio,
C. Serieys, T. Phulpin, T. Tirolien
2nd IASI conference; Annecy, January 2010 2
Content
1- IASI-NG performance objective and compliance with the EUMETSAT
POST-EPS IRS Mission Requirement Doc
2- IASI-NG CNES phase 0 technical synthesis
3- IASI-NG CNES phase 0 expected performances and budgets
4- IASI lessons learned from technical point of view
5- IASI-NG activities in 2010
2nd IASI conference; Annecy, January 2010 3
IASI-NG performance objective
■ Improve the IASI demonstrated performances :
Spectral Resolution by factor 2
Radiometric noise by factor 2
==> comparable to Post-EPS MRD 2.E breakthrough data
■ Keep the same spatial resolution as IASI (25km in average on ground at nadir) and the same IASI pixel size (12km)
■ Compliance of the IASI-NG specification to Post-EPS IRS requirements presented to PMET end of 2009.Main non compliances with MRD 2.E:
Viewing angle and coverage (will be the IASI one for IASI-NG)
Pointing knowledge (will be just a bit better than the IASI one)
Radiometric noise below 645cm-1 and above 2400cm-1
Accepted by PMET : MRD to be updated
2nd IASI conference; Annecy, January 2010 4
IASI-NG performance objective versus Post EPS MRD
Spectral resolution (level 1b)
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700 (cm-1)
Sp
ectr
al
reso
luti
on
(cm
-1)
IASI-NG SPEC level 0
MRD NWP breakthrough V2.E
MRD CHEM breakthrough V2.E
IRS1 :
Temp
Profile
IRS2 :
Temp & Water
vapour profiles,
surf & cloud
IRS
3 :
O3
co
lIR
S3
a :
O
3 p
rof
IRS
4 :
su
rf &
clo
ud
IRS5 :
Water vapour profile
IRS6 :
Water vapour profile
NO2 Column
IRS
8 :
T p
rofile
,
N2O
& C
O2
co
l
IRS9 :
Temp
profile
IRS10 :
SST, surfaces and
cloud properties
IRS
5b
:
T p
rofile
, N
2O
& C
H4
co
l
IRS
2a
:
C2
H6
IRS
2b
:
HN
O3
, C
FC
IRS
4a
:
SO
2IR
S4
b :
PA
N
IRS0 :
Water
vap
Prof IRS
7 : C
O c
ol
IRS
7a
: C
O p
rofile
IRS11
CH4
col
NWP
Pri 1
MWP or
Chem
Pri >=2
Chem
Pri 1
Priority
SPEC IASI-NG With Self-
Apodisation
OPD CHEM=4cm OPD CHEM=4cm SPEC CHEM without Self-
apodisation (0,6/OPD)
SPEC NWP With Self-
Apodisation
2nd IASI conference; Annecy, January 2010 5
IASI-NG performance objective versus Post EPS MRD
RADIOMETRIC NOISE @280K (Level 1b)
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700 (cm-1)
Ned
T @
280K
(K
)
IASI / 2 (sample 0.25cm-1)
IASI-NG SPEC (sample 0.125cm-1)
MRD CHEM Breakthrough V2.E
MRD NWP Breakthrough V2.E
IRS1 :
Temp
Profile
IRS2 :
Temp & Water
vapour profiles,
surf & cloud
IRS
3 :
O3 c
ol
IRS
3a :
O
3 p
rof
IRS
4 :
surf
& c
loud
IRS5 :
Water vapour profile
IRS6 :
Water vapour profile
NO2 Column
IRS
8 :
T p
rofile
,
N2O
& C
O2 c
ol
IRS9 :
Temp
profile
IRS10 :
SST, surfaces and
cloud properties
IRS
5b :
T p
rofile
, N
2O
& C
H4 c
ol
IRS
2a :
C
2H
2,
HC
N,
PA
N
IRS
2b :
H
NO
3,
CF
C
IRS
4a :
S
O2
IRS
4b :
PA
N
IRS0 :
Water
vap
Prof IRS
7 : C
O c
ol
IRS
7a :
CO
pro
file
IRS11
CH4
col
NWP
Pri 1
MWP or
Chem
Pri >=2
Chem
Pri 1
Priority
2nd IASI conference; Annecy, January 2010 6
IASI-NG : radiometric and spectral improvements
•Entrance pupil diameter Increase (flux):
IASI-NG = 120mm versus IASI = 80 mm
•Instrument Field of view Increase (integration time):
IASI-NG = 75*75km (9 pixels) versus
IASI = 50*50km (4 pixels) acquisition duration
for each interferogram = 450ms versus 150ms for
IASI
•Detectors temperature reduction (active cooling)
IASI-NG T detector < 65K versus IASI = 92K
Radiometry
Optical Path difference increase by factor 2:
• single sided interferometer
• one mobile cube having the same IASI stroke
• TWO mobile cubes having the IASI stroke / 2
• double sided interferometer
• one mobile cubes having the IASI stroke x 2
• TWO mobile cubes having the same IASI stroke
Spectral resolution
50 km
17 km
BUT: «self-apodisation»
For the spectral resolution, both the
Optical Path Difference AND the self-
apodisation must be improved.50 km
17 km
IASI
33 km
25 k
m
Different trade off’s done only for dynamic FTS
IASI-NG
2nd IASI conference; Annecy, January 2010 7
IASI-NG : the self-apodisation issue
Sounder pixel
• For each of the 9 sounding pixel, acquisition of sub-
pixels interferograms (typically 5x5 sub-pixels), then
combination of the interferograms by resampling at
“constant” OPD + filtering to generate one sounding pixel
interferogram
•Final Self-apodisation for the corner pixels = IASI one
Huge Data Processing (1Gbit/s of
data at the matrix output)
IASI-NG: Optical signal in the
detectors plane for n=2760cm-1
and OPDmax=4cm
Need a very GOOD focal
plane image quality
complex focal plane
Split the sounder pixel into many smaller pixels
Matrix detectorsSuppress/mitigate the self-apodisation effect
self-apodisation compensation
•Introduce, in the interferometer, a specific
mechanism that works in synchronization with
the Corner Cube Mechanism and that corrects,
for each sounding pixel (but the center one),
the Optical Path Difference by :
dO (1 – cos q), where dO is the OPD for a zero
field ALL the pixels should have a
similar behavior than the central pixel
q
IASI-NG CNES Phase 0
Reference option
The use of IASI like pixel acquisition concept is not possible. Two options has been studied.
2nd IASI conference; Annecy, January 2010 8
IASI-NG : Self-Apodisation compensation option
Direct acquisition of one interferogram by
sounder pixel using monoelement pixel
detectors (IASI like) or by matrix detectors with
hardware binning of the elementary pixels
New Genzel concept
Evolution of a corner pixel
optical signal for
monochromatic ray at
4mm, for OPD variation of
1mm, (between max and
min signal (l/4)) at OPD of
4cm
Without compensation
With compensation
OP
D e
volu
tio
n
Without compensation
With compensation
Optical simulation with and without active optical field compensation
Advantages
Drawbacks
New mechanism
OPD (cm)
CO
NTR
AST
Data processing IASI like (excepted for the
single sided processing)
IASI like cold optical focal plane
Reduction of the different defaults sensitivity
with regard to IASI (CCM, microvib’s)
Complexification of the
Laser Reference
accommodation
2nd IASI conference; Annecy, January 2010 9
Ground Pixel diameter of 12km (=IASI)
Ground sampling of 25km (both axis)
Number of sounder pixels per acquisition = 9 (IASI=4)
Number of earth view per line = 20 (30 IASI)
Interferogram acquisition duration = 450ms (IASI=150ms)
Inlet PUPIL = 120mm (IASI=80mm)
Focal plane :
4 bands (IASI=3)
9 sounder pixels per band (IASI=4)
PV detectors for all bands
(IASI PC for B1; PV for B2/B3)
detectors cooled at 65K with
one active cooler (LPTC)
(IASI=92K passive)
IASI like cold optic concept
IASI-NG : Baseline characteristics (CNES phase 0)
2nd IASI conference; Annecy, January 2010 10
IASI like SCAN with slight increase of
the motorization
One afocal telescope
One GENZEL interferometer
1 ZnSe Beam Splitter (80mm typical)
Single sided configuration
(to be justified more deeply)
2 Corner Cubes are linked together
and are activated by a single
mechanism (CCM) with a stroke of
11mm (IASI=20mm for one CC)
1 field compensation mechanism
One laser beam for OPD sampling
for each pixel
IASI-NG : Baseline characteristics (CNES phase 0)
2nd IASI conference; Annecy, January 2010 11
Genzel interferometer :
Mechanism for field compensation
9 individual independent flat mirrors. 8
mirrors are mobile. The central one is not
moving.
Each individual mirror is activated in
rotation by one independent piezzo in
coordination with the Corner Cube
Mechanism (the mirror on the center is
not moving) :
– OPD=0 No rotation; all the mirrors are in
the same plane
– OPD max maximum rotation of typically
1.5mrad
A breadboard is under development at
CNES
Rotationaxis
IASI-NG : Baseline characteristics (CNES phase 0)
OPD=0 OPD=4cm OPD=0
2nd IASI conference; Annecy, January 2010 12
Data processing :
Earth precalibrated spectra are downloaded + IR image
DPS with high heritage of IASI for the algorithms excepted for the single sided
interferogram processing
LEON’s processor + FFT coprocessors (FFT of 65536 samples is done in 1ms)
Spacewire bus
IR integrated Imager :
IASI like with increased field of view
Instrument Management :
Classical with 1553 bus
Mechanical & thermal:
IASI-NG accommodation on the
satellite velocity face with access to
a second deep space calibration view
IASI-NG : Baseline characteristics (CNES phase 0)
2nd IASI conference; Annecy, January 2010 13
Mechanical & thermal:
Interferometer equipments are mounted on a stiff
CFRP optical bench
ALL the others panels are aluminum honeycomb
panels
ALL equipments, panels and baffles are controlled
at 293K (excepted the detectors at 65K)
No Launch Locking and microvibrations Filtering
Device
IASI-NG : Baseline characteristics (CNES phase 0)
2nd IASI conference; Annecy, January 2010 14
MASS
IASI-NG : 260Kg (best estimate without margin)
IASI = 235Kg
VOLUME
IASI-NG : 1700mm x 1400mm x 800mm in a single box (1,9m3)
Optimization can be envisaged
IASI : one sensor module + deported IMS/DPS inside the satellite ==>
total = 1,7m3
■POWER (EOL):
IASI-NG : 370W (best estimate without margin) (active cooling
main contributor)
IASI = 240W
■TM DATA RATE:
IASI-NG : 3.1Mbit/s
IASI : 1.5Mbit/s
IASI-NG : Baseline characteristics (CNES phase 0)
2nd IASI conference; Annecy, January 2010 15
IRS2 End of phase 0 CNES budget estimation; IRS2 SPECIFICATION
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
1,1
1,2
600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800
Sigma (cm-1)
Ned
T @
280K
(K
)
IRS2 SPEC IRS2 phase 0
IRS1 :
Temp
Profile
NedT @ 280K
IRS2 :
Temp & Water
vapour profiles,
surf & cloud
IRS
3 :
O3 c
ol
IRS
3a :
O
3 p
rof
IRS
4 :
surf
& c
loud
IRS5 :
Water vapour profile
IRS6 :
Water vapour profile
NO2 Column
IRS
8 :
T p
rofile
,
N2O
& C
O2 c
ol
IRS9 :
Temp
profile
IRS10 :
SST, surfaces and
cloud properties
IRS
5b :
T p
rofile
, N
2O
& C
H4 c
ol
IRS
2a :
C
2H
2,
HC
N,
PA
N
IRS
2b :
H
NO
3,
CF
C
IRS
4a :
S
O2
IRS
4b :
PA
N
IRS0 :
Water
vap
Prof IRS
7 : C
O c
ol
IRS
7a :
CO
pro
file
IRS11
CH4
col
NWP
Pri 1
MWP or
Chem
Pri >=2
Chem
Pri 1
Priority
IASI-NG Phase 0 instrument
Performance estimate
IASI-NG Phase A Requirement
Spectral resolution at level 1b = 0.15cm-1 almost constant all over the
spectral bandwidth. =0.25cm-1 at level 1c (after numerical apodisation)
Radiometric noise (level 0 for samples of 0.125cm-1):
IASI-NG : Baseline characteristics (CNES phase 0)
2nd IASI conference; Annecy, January 2010 16
IASI lessons learned applicable for IASI-NG
■ Engineering & AIT constraints improvements / IASI
Thanks to a very stiff interferometer :
The instrument performances should not be sensitive to gravity
The instrument performances should be much less sensitive to microvibrations
The corner cube compensation mechanism (<10Hz) should be
avoided (one main source of microvibration for IASI)
Thanks to an active cryocooler and a sealed cold box/focal plane:
the instrument should be able to cool the detectors by itself at ambient
cleanroom condition (Possibility to do representative EMC tests at ambient, ...)
No need of the quite complex IASI test jig and cryopannel for the satellite TV
tests
The ice contamination of the cold optics should be minimized
Can fly on any sun-synchronous orbit <10h30 and >13h30 with minor
modification on the warm thermal radiators
2nd IASI conference; Annecy, January 2010 17
IASI configuration for TV test !!
IASI flight configuration
IASI lessons learned applicable for IASI-NG
2nd IASI conference; Annecy, January 2010 18
■ Engineering & AIT constraints improvements / IASI
Should avoid Locking and Filtering device no storage and
transportation constraints
The CCM locking/unlocking mechanism should be simplified
The instrument shall be able to be fully functional with the satellite in
vertical position and for one horizontal position
No deported equipments (IMS/DPS for IASI) inside the satellite
Easy accessibility to all of the equipments including the cold focal
plane should be possible
■ Operational improvements / IASI
The unavailability period due to ice decontamination should be
significantly reduced
Following an anomaly, the recovery time should be significantly
reduced
IASI lessons learned applicable for IASI-NG
2nd IASI conference; Annecy, January 2010 19
IASI-NG Phase A in 2010
A competitive industrial IASI-NG instrument phase A has
started with ASTRIUM and THALES beginning of 2010.
Both industries will evaluate the CNES phase 0 concept
AND some others ones. A concept selection will be done
before mid 2010 for more deep analysis studies.
The end of this IASI-NG phase A is expected for
beginning of 2011.
Discussion start with EUMETSAT about IASI-NG ground
segment