# Presentation: 686616

## EUV Imaging Spectrometer(EIS)

**EUV Imaging Spectrometer****(EIS)**

**H. Hara**
**National Astronomical Observatory of Japan**

## EIS Science

***Yohkoh******, SOHO, and TRACE***:
-      reveal dynamic solar corona (flare, plasmoid, jet, coronal expansion ...)
- → Necessity of higher-cadence coronal velocity-field measurements

- Photospheric motions

- Energy injection to corona
- Energy dissipation in corona

- Observation with
**EUV imaging spectrometer (EIS)**
- in emission-line spectroscopy and
- high-cadence imaging with XRT

- Observation with SOT

**Photosphere-corona connections**

***Coronal heating***

***Flare/CME physics***

- Reconnection physics, Site of large non-thermal line broadening, ...

## International Collaboration

**NAOJ**

**JAXA**

**NRL**

**NASA GSFC**

**MSSL**
**BU**
**RAL**

- Japan

- UK

- US

- Norway

**Univ. Oslo**

**EIS Development team**

- The development started in 1999.
- The EIS was delivered to JAXA in summer 2003.

## EIS Optical Layout

- Slit exchanger

- Primary mirror (offset parabola)

- Entrance filter

- Concave grating

- Filter

- CCD

- Shutter

- 1939 mm

- 1440mm

- 1000mm

**S**

**L**

**L**

**S**

## Performance

- Large Effective Area in EUV band:     170-210 A & 250-290 A
-        Mo/Si **multi-layer coated** Mirror and Grating
-         High QE CCD: Two 2048×1024 back illuminated CCD
- Spatial resolution: 2 arcsec resolution over raster-scan area
-                                    (1 arcsec pixel sampling)
- Line spectroscopy of 20-30 km/s pixel sampling
- Instrumental width in emission lines for 1 arcsec slit observation:
-                                    short- band: 47 mA,  long- band: 58 mA
- Raster-scan area (EW×NS): 590×512  arcsec2 max.
-                                        FOV center can move in East-West direction by 890 arcsec.
- Wide temperature coverage: log T = 4.7, 5.4, 6.0-7.3
- Simultaneous observation of multiple lines up to **25**

**short-******** band     long-******** band**

## EIS Effective Area

## EIS Sensitivity

| Ion | Wavelength
(A) | logT | Nphotons |  |
| --- | --- | --- | --- | --- |
|  |  |  | AR | M2-Flare |
| Fe X | 184.54 | 6.00 | 15 | 36 |
| Fe XII | 186.85 / 186.88 | 6.11 | 13/21 | 105/130 |
| Fe XXI | 187.89 | 7.00 | - | 346 |
| Fe XI | 188.23 / 188.30 | 6.11 | 41 / 15 | 110/47 |
| Fe XXIV | 192.04 | 7.30 | - | 4.0104 |
| Fe XII | 192.39 | 6.11 | 46 | 120 |
| Ca XVII | 192.82 | 6.70 | 31 | 1.8103 |
| Fe XII | 193.52 | 6.11 | 135 | 305 |
| Fe XII | 195.12 / 195.13 | 6.11 | 241/16 | 538/133 |
| Fe XIII | 200.02 | 6.20 | 20 | 113 |
| Fe XIII | 202.04 | 6.20 | 35 | 82 |
| Fe XIII | 203.80 / 203.83 | 6.20 | 7/20 | 38/114 |

- Detected photons per 11 area of the sun per 1 sec exposure.

| Ion | Wavelength
(A) | logT | Nphotons |  |
| --- | --- | --- | --- | --- |
|  |  |  | AR | M2-Flare |
| Fe XVI | 251.07 | 6.40 | - | 108 |
| Fe XXII | 253.16 | 7.11 | - | 71 |
| Fe XVII | 254.87 | 6.60 | - | 109 |
| Fe XXVI | 255.10 | 7.30 | - | 3.3103 |
| He II | 256.32 | 4.70 | 16 | 3.6103 |
| Si X | 258.37 | 6.11 | 14 | 62 |
| Fe XVI | 262.98 | 6.40 | 15 | 437 |
| Fe XXIII | 263.76 | 7.20 | - | 1.2103 |
| Fe XIV | 264.78 | 6.30 | 20 | 217 |
| Fe XIV | 270.51 | 6.30 | 17 | 104 |
| Fe XIV | 274.20 | 6.30 | 14 | 76 |
| Fe XV | 284.16 | 6.35 | 111 | 1.5103 |

- AR: active region

## Observables

**Information from a single emission line**
- Line intensity
- Line shift by Doppler motion
- Line width:    temperature,  non-thermal motion
**Information from selected two line ratio**
- Temperature
- Density

## Four slit selections available
Direction of slit length: north-south direction
EUV line spectroscopy
     - 1 arcsec  L arcsec slit for the best quality of image/spectrum quality
      - 2 arcsec  L arcsec slit for a higher throughput

EUV Imaging (Velocity information is convolved.)
     - 40 arcsec  L arcsec slot for imaging with little overlap
     -266 arcsec  L arcsec slot for hunting transient events  

- Direction of slit length: north-south direction
**EUV line spectroscopy**
-      - 1 arcsec  L arcsec slit for the best quality of image/spectrum quality
-       - 2 arcsec  L arcsec slit for a higher throughput
**EUV Imaging** (Velocity information is convolved.)
-      - 40 arcsec  L arcsec slot for imaging with little overlap
-      -266 arcsec  L arcsec slot for hunting transient events

- EIS Slit/Slot

**L > 1024 arcsec (=CCD height)**

##        EIS Field-of-View (FOV)

**N**

**E**

**S**

**W**

## EIS Science Targets

**Active regions/Flares**

**Quiet Sun/**
**Network brightening**

**Limb/beyond the limb**

**Coronal Hole**

**Coronal Hole Boundary**

**Bright Point**

**Polar Plume**

**S/C re-pointing required**

## EIS Observations

**40****"**** slit raster**

**2****"**** slit raster**

**1****"**** slit raster**

**266****"**** slit raster**
- (no mirror motion)

**Examples of 240" ********240" Raster Scan**

- 240 "

- 240 "

- Contribution of
- other emission lines

- Wider instrumental width

- EUV imaging  of
- less contamination
- by other lines

- Discontinuous
- raster

##     Expected Accuracy of Velocity 

**Doppler **
**Velocity**

**Line **
**Width**

- FL-line (GOES-M2)

**Number of detected photons**
**(1****"********1****"**** area)****-1**** **

- AR-line

- AR-line

**Fe XII 195**

**Fe XII 195**

**Fe XV 284**

**Fe XV 284**

**Fe XXIV 255**

**Fe XXIV 255**

## EIS Image Data

- CCD1

- CCD0

**CCD readout**

- Software window (SW)

**Assemble all SWs**

- EIS data size to MDP
- = total sum of software windows
- =  (window width)i * (window height)i

- height

- MDP

- JPEG

- DPCM

- Compression ratio
- = compressed data size/ input data size to MDP

- Data rate ~ [EIS data size to MDP] * [Compression Ratio] / Cadence

- EIS data of CCSDS format

**Compression**

**Raw data**

- height

## EIS Data Flow

- 2Mbps max
- 1.3 Mbps

- CCD Readout
- Electronics

- EIS ICU

- Large hardware
- CCD window

- S/C MDP

- Small spectral
- window (25 max)

- Data compression
- DPCM(loss less) or 12bit-JPEG

-  260 kbps max
- for short duration,
-  45 kbps average

- Telemetry
- data format

- Average rate depends
- on number of downlink
- stations.

-                 1 slit obs.  40 slot obs.    250 slot obs.
- Spec.width         16               40                250
- Spatial width    256           512              256
- No. of lines          8                 4                   4
- Compression*  25%           20 %              20%
- Cadence            3 sec          6 sec             20 sec
- Rate                42.7 kbps   42.7 kbps      40 kbps

- 13 min cadence for 44 rastering

**Observation table**

**control**

******* ****for 16 bit/pixel data**

## EIS Science Operation

**Science**

- Team core science
- Initial science targets
- Proposal from users

**Preparation for EIS SO**

- Check of
- Obs. Table
- using PM

- _[Observation](slide12.xml)_
- _[in orbit](slide12.xml)_

- Downlink stations

- JAXA data storage

- Data
- Reformat
- EGSE

- Data check

- - Obs. table
- - S/C CMDs

- Analysis

- Outcome

- ISACS-PLN

- Uplink station

**Spacecraft**

- Merging EIS SO
- in S/C operation

- EIS
- Planning
- EGSE

- Final S/C plan

- Observation
- Planning

**Data for analysis**
- Level0 data
- Level1 data
- Level2 data

- Telemetry

- Plan approved
- for EIS operation

- Data centers

**Users**

**Feedback**

- Line selection
- Exp. duration
- Compression
- FOV size etc.

- Data rate
- _[Compression](slide19.xml)_
- Instrument CAL

**Feedback**

## Summary

- EIS is an excellent instrument to investigate the dynamical solar upper atmospheres.
- Scientific output will strongly depend on the EIS observation planning in which ideas of scientists are deeply contained.

- END

## MDP JPEG Compression

- AR spectrum for 5 sec integration

- _[Fe XII](slide21.xml)_

- Fe XI

- Fe XXIV

- Fe XII

- Ca XVII

- Fe XII

- Fe XII

- Fe XIII

- Fe XIII

- He II

- Fe XVI

- Fe XIV

- Fe XIV

- Fe XV

- 224 pixels

- 256 pixels

## JPEG compression error

- X: signal – offset [DN] ; offset~ 500
- Y: decomp( comp( Original ) ) – Original [DN]

- DN17nm

- DN29nm

## Compression Error for Q=85

**Diff/ ********I**

**Diff/ ********v**

**Diff/ ********FWHM**

**v**

**original**

**original**

**original**

**FWHM**

**I**

- =

- =

- =

- Compression ratio = 0.19