miris, compact wide-field ir space telescope system design

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1 / 53UN BSS Workshop, 22 Sep 2009 KASI

MIRIS, Compact Wide-Field IR Space Telescope System

Design Wonyong Han

Dae-Hee Lee, Uk-Won Nam, Youngsik Park, Woong-Seob Jeong, Chang Hee Ree, Bongkon Moon, Sung-Joon Park, Sang-Mok Cha,

Jang-Hyun Park, Duk-Hang Lee, Kwang-Il Seon, In-Soo Yuk, Hyung Mok Lee,

Sun Choel Yang, Jong-Oh Park, Seung-Wu Rhee, Toshio Matsumoto

Korea Astronomy & Space Science Institute (KASI)

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- Korea Sci & Tech Satellite (STSAT) began 1999- Korea Sci & Tech Satellite (STSAT) began 1999

- FIMS : KASI developed- FIMS : KASI developed FIMS,FIMS, Main Payload of Main Payload of

STSAT-1,STSAT-1,

in collaboration with KAIST & UC Berkeleyin collaboration with KAIST & UC Berkeley

- STSAT-1 (FIMS) Launched in 2003- STSAT-1 (FIMS) Launched in 2003

- FIMS Science Results were Published on ApJL in - FIMS Science Results were Published on ApJL in

20062006

- STSAT-3 Program started in 2007 - STSAT-3 Program started in 2007

- KASI Proposal, MIRIS was Chosen as Main Payload- KASI Proposal, MIRIS was Chosen as Main Payload

- MIRIS is compact wide-field IR Space Telescope - MIRIS is compact wide-field IR Space Telescope

[ [ MMulti-purpose ulti-purpose IInfra-nfra-RRed ed IImaging maging SSystem ]ystem ]

BackgroundBackground

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STSAT1– FIMS (Far UV IMaging Spectrograph)

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FIMS Optical System

Grating L & S

Parabolic

Cylinder Mirror

UV Lights From Space

Slit & Shutter

Assembly

Detector Assembly

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FIMS Flight Model

Mirror house

Vacuum Box

Card Cage Structure

Opening Door

Sun Warning SensorVacuum Pumping Port

Vacuum Valve Shaft

Shutter box

Detector BoxAmp Unit

Enable Plug

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FIMS & STSAT-1 (Sci & Tech SAT-1)

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Launch : 27 Sep 2003Russia, PlesetskBy Cosmos RocketSuccessfully Launched

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FIMS : Main ScienceSupernova Explosion

Models for Hot Gas

To Study Distribution, Properties of Hot Gas, ISM in Galaxy

?What’s the natureof the Hot Gas inour Galaxy ?

Still Unknown...

Galaxy

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FIMS Heritage

• ApJL, 2006, Vol 644, Special Issue

- First results from the FIMS Mission

- 9 papers published including Instruments & System Performances

Total diffuse intensity map of the sky for the SPEAR/FIMS L-band (1360-1730 A) observations. Evident features include the Galactic plane, the Sco-Cen association, and the LMC.

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MIRIS

MMulti-purpose ulti-purpose IInfra-nfra-RRed ed IImaging maging SSystemystem

The Main Payload of STSAT-3

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MIRIS Project Summary

• Objectives– Space observation camera (SOC)

• Pa-α emission line Galactic plane survey• Extragalactic Cosmic IR Background (CIB) observation

– Earth observation camera (EOC)• Wide angle NIR imaging of Korean peninsula• Developing space IR technologies

• Duration : 2007. 05~2011. 04 (4 years)• Budget : ~ 3M USD• Participants : KASI, KBSI, SNU, Green Optics

• Spacecraft : STSAT-3 (SaTReC, KAIST)

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MIRIS : Scientific Goal (1/3)• Galactic Plane Survey (1/2)

Origin of the Warm Ionized Medium (WIM)– Challenge to the current paradigm of the Ionization theory– Test the effect of Dust scattering for the WIM observation

Observation : Pa survey – Pa (MIRIS) vs. H (Ground-based) : Scattering difference– Pa is better than H in the turbulence study of the WIM because

of the lower dust-extinction

Hαmap from a ground-based survey

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Scientific Goal (2/3)

• Galactic Plane Survey (2/2)

Physical Properties of Turbulence in the Galaxy– Survey the physical parameters of turbulence in the Galaxy– Derive Magnetic field strength from the structure characteristics of

turbulence

Observation : Pa survey – Pa (MIRIS) vs. H (Ground-based) : Extinction difference

Measurement of the turbulence structure

Turbulence model

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Scientific Goal (3/3)

• Cosmic Infrared Background (CIB) Observation

Origin of the Near-IR CIB– Test the hypothesis of the Pop III origin– Confirm the degree-scale fluctuation suggested by IRTS & AKARI and reveal its

nature Observation : I & H-band – I-band (no Pop III) vs. H-band (Pop III expected)

Matsumoto et al. 2005

Spectral bump suspected to be redshifted from the Pop III Ly-cutoff

Degree-scale fluctuation in the power spectrum from IRTS

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• Filters: I & H bands Blank (dark

calibration)

• CIB dedicated phase: 1 month

• Primary target NEP (North Ecliptic Pole)

– 6.2 sq. deg. observed by AKARI – Whole area: 10ox10o

– 7 x 7 fields– 1 sec. integration x 600 frames

• Secondary targets– SEP (South Ecliptic Pole)– NGP (North Galactic Pole)– SGP (South Galactic Pole)

CIB Observational Plan

: AKARI Obs Region

MIRIS NEP Obs Region

: MIRIS FoV

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MIRIS System Design

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Space Observation Camera

Earth Observation Camera

Secondary Payload, COMIS

Sun Avoidance = ±90 degree

Earth Avoidance = ±30 degree

Sun Avoidance = ±30 degree

Star Tracker

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STSAT-3 Summary

Item Specification

Mission Orbit 400 ~ 800 km, Sun synchronous (2011, TBC)

Mission Life 2 years

Satellite Mass ~ 135 kg

Power ~ 286 W

Attitude control3-axis stabilized, Pointing knowledge : 0.13o , pointing stability : 0.007o

Downlink S-band (19.2 kbps), X-band (10 Mbps)

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MIRIS Specifications

Space Obs. Camera (SOC)

Wavelength 0.9 – 2 um

Aperture 80 mm

Focal ratio f/2

Pixel FOV 51.6 arcsec

Detector FOV 3.67o x 3.67o

Ground pixel size

Swath width

Sensor Teledyne PICNIC

Filter Filter Wheel (6 filters)

Telescope Temp 180-200 K (passive cooling)

Sensor Temp 77 K

Performance MTF > 60%

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MIRIS Sensitivity

Filters: I & H bands, Blank

1sec 600 frame

Readout noise = 40 e-

Photon noise Thermal emission Zodiacal light Extragalactic component

Expected Sensitivity (3) (Instrumental noise only) I band: 18.0 AB mag. H band: 17.8 AB mag.

10

100

0.2 0.4 0.6 0.8 1 3 5

residual_summary

IRTS/NIRS

model by Totani et al. 2001

Totani et al. 2001

Bernstein et al. 2002

DIRBE/COBE

Wright and Rees 2000 Fazio et al. 2004

Madau and Pozzetti 2000

Cambrecy et al. 2001

Su

rface b

rig

htn

ess

(n

Wm･-2

sr･-1

)

Wavelength (m)

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MIRIS Space Observation Camera (SOC)

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MIRIS Optics Specification

• Specifications of Space Observation Camera– Wavelength: 0.9 ~ 2m − Aperture: 80 mm– Pixel FOV: 51.6 arcsec − Detector FOV: 3.67o x 3.67o

– Telescope & Sensor Temp.: 180 ~ 200K (Passive Cooling), 100K– Filters (6 filters)

• I (1.05m), H (1.6m), blank• Pa (1.876m), Pa Cont1, Pa Cont2• Pa Cont1, Pa Cont2 → Double band filter

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MIRIS Array Specification

Parameter Specification

Detector technology HgCdTe(PACE)

Detector input circuit SFD

Readout mode Ripple(per quadrant)

Pixel readout rate Up to 200kHz

Pixel format 256x256

Pixel pitch 40um

Fill factor >90

Output ports 4 total(1 per quadrant)

Clocks 6

Spectral range 0.9 ~ 2.5umQuantum Efficiency

@2.3um>75%

Read noise: multiple sample

<20

Dark current <0.2 e-/sec(@77K)

Well capacity 200,000 e-

Pixel operability >99%

PICNIC sensor

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SOC Filter System

Purpose ID CWL (um) FWHM (um)

Cosmic Infrared Background

I 1.05 0.3

H 1.6 0.8

Galactic Plane Survey

Pa alpha 1.876 0.0188

Pa alpha cont 1 1.84 0.0184

Pa alpha cont 2 1.92 0.0192

Dark & Shutter Blank

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Performance of SOC Optics

Field(degree)

RMS spot size (um)

0.000 12.4

0.895 10.8

1.790 12.0

2.612 24.0

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SOC Layout

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SOC Optics Operation temp. : 300K => 180K

Flexure

Barrel

Spacer

RetainerLens

Flexure

G1G2

G3

G4G5

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Fabricated Parts Re-assembly

* For Lens Stress Re-calculation, Lens Gap Inspection, and Lens Contact Inspection

Unit: mm

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SOC Dewar

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Assembled SOC Dewar Layout

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Attitude control requirements

Item Axis MIRIS Req. (3σ) Bus Spec. (3σ) Remarks

Attitude update rate > 1 Hz 1~4 Hz

Pointing Knowledge

x, z < ±0.13o ±0.12o Refer to Mosaic overlap requirements

y < ±0.22o ±0.15o Field shift by rotation < 1 pixel

Pointing Accuracy

x, z < ±0.13o ±0.13o Refer to Mosaic overlap requirements

Y < ±0.22o ±0.16o Field shift by rotation < 1 pixel

Stability(Drift+Jitter)

x, z < ±0.007o/sec ±0.007o/sec < 1 pixel

y < ±0.070o/sec ±0.052o/sec Drift by rotation + x,

z drift < 1 pixel

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SOC : Pa cont. & Dual-band filter

Unit Frame Size1.2 Mbit/frame

(256x256 센서 1 개 , 16bit)

1 Day Obs Frame

CIB

Priority Obs

6,000 frame/day(600 frame/orbit x 10 orbits)

Normal Obs

3,600 frame/day(GP : 600 frames x 4 orbits)(CAL : 600 frames x 2 orbits)

1 day Data Production *

CIB

Priority Obs

7 Gbit/day(6,000 frame/day x 1.2 Mbit/frame)

Normal Obs

4.2 Gbit/day(3,600 frame/day x 1.2 Mbit/frame)

* RS Encoding & Packet frame were NOT included

Data Communication Requirements

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Passive Cooling for SOC (1/2)

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Passive Cooling for SOC (1/2)Temperature profile during one orbit

(1) The telescope can be cooled below the goal temperature of 200K(2) The detector can be cooled below the goal temperature of 80K

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MIRIS Electronics

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MIRIS Electronics Box

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SOC Electronics

Q1 Q2

Q3 Q4 AMP ADC

PATTERNGENERATOR

4 channel VIDEO SiganalProcessing

IMAGEDATA

DECODER

AMP ADC

AMP ADC

AMP ADC

FPGA

MEMEORYIMAGE

BUFFER

CONTROLCOMMAND

MMS

GSE

DSP UNIT

PICNIC256256ARRAY

BIAS

CLOCK

FIFO FIFO

SOC READOUT UNIT

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MIRIS Operation

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Observation Plan

• CIB : NEP/SEP

• Galactic plane survey : Eclipse period

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MIRIS Operation Concept

Mode Test (3 months) 1st Year 2nd Year

Bus Test 10 orbits/day(1 month)

(if needed) (if needed)

Space Observation -Galactic Plane -Cosmic Background -Calibration

(1 month)4 orbits/day4 orbits/day2 orbits/day

6 orbits/day2 orbits/day2 orbits/day

User time(if needed)

Earth Observation(1 month)2 orbits/day

Regular Test & Emergency Observation

6 orbits/day

Ground Contact 4 orbits/day 4 orbits/day 4 orbits/day

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Plan for Galactic Plan Survey

6°

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Plan for Galactic Plan Survey

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Current Status : Dewar

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2009. 4. 6. ~ 2009. 4. 10. (Genesia)

Current Status : Optics

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Test Plan

Optics• Lens (SO, EO)• Barrel (SO, EO)• Baffle (SO, EO)

Optics• Lens (SO, EO)• Barrel (SO, EO)• Baffle (SO, EO)

Mechanics• E-box• Dewar/Filters (SO)• Cooler box/Cooler (SO)• Skin (SO, EO)• MLI (SO)• Supporters (SO)

Mechanics• E-box• Dewar/Filters (SO)• Cooler box/Cooler (SO)• Skin (SO, EO)• MLI (SO)• Supporters (SO)

Part Module System

Electronics • PCBs• Harness/Connectors• Sensors

Electronics • PCBs• Harness/Connectors• Sensors

Environmental test• Vibration test• Thermal/Vac test

Environmental test• Vibration test• Thermal/Vac test

Optics• SO Function test• EO Function test

Optics• SO Function test• EO Function test

Mechanics• Filter wheel test (SO)

Mechanics• Filter wheel test (SO)

Electronics • Image acquisition (SO) • Image acquisition (EO)• SCIF test • Radiation test

Electronics • Image acquisition (SO) • Image acquisition (EO)• SCIF test • Radiation test

SO• Cooling test• Focus test• Noise test

SO• Cooling test• Focus test• Noise test

EO• Field test

EO• Field test

Test Equipment• Vacuum chamber• Collimator• Light source• GSE

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Integrating sphereMonochrometer

Collimator & Optical Table

Thermal-cryo vacuum chamber

Test Equipment

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Data Reduction Pipeline

• After post-processing, the observations of Galactic plane and CIB are processed by the individual pipeline.

Local Data Server

Preprocessing

Main Processing

Post-processing

data formatting pointing data + observation data observing log register to database

Un-calibrated data

Calibrated data

mask bad/dead pixels mask saturated pixels subtract dark remove cosmic rays correct signal linearity flatten pixels correct distortion resampling image

correct shift & rotation between images adjust sky level coadding of images

Galactic Plane Survey

CIB Observations

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Summary

• Pa- survey– MIRIS is optimized for Pa- emission line survey from diffuse

WIM in the Galactic plane

• CIB Observation– Detecting the Cosmic Infrared Background is important to

understand the birth and the evolution of the first stars– The combination of field of view and band coverage makes

MIRIS unique and complementary to other space-borne measurements with HST, Spitzer, and AKARI on finer angular scales.

• Current status– EQM environment test– CDR in September 2009

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Thank you

[email protected]

miris, compact wide-field ir space telescope system design

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