External alignment with X-Ray Telescope (XRT) and EUV Imaging Spectrometer (EIS)

Apr 17-22, 20061SOT17 @ NAOJ

External alignment with X-Ray Telescope (XRT) and EUV Imaging

Spectrometer (EIS)Y. Katsukawa (NAOJ) and SOT team

Apr 17-22, 2006 SOT17 @ NAOJ 2

Satellite coordinate definition

OTA1アライメントミラー②XRTアライメントミラー

③EISアライメントミラー①FPPアライメントミラー

④OBUアライメントミラー

⑤UFSS-SBアライメントミラー

⑦NSASアライメントミラー

⑥UFSS-SAアライメントミラー

ｱｸｾｽﾊ ﾈ゚ ﾙ

IRU-B1⑪ アライメントミラー

IRU-B2⑫ アライメントミラー

⑨STTアライメントミラー

⑧PSASアライメントミラー

BUS⑬ アライメントミラー

⑩IRU-SAアライメントミラー

5.　 UFSS-SA

1.　 OTA12.　 FPP

3.　 XRT

4.　 EIS

6.　 UFSS-SB

7.　 NSAS

8.　 STT

9.　 IRU-B1

10.　 IRU-B2

11.　OBU

13.　 BUS-Y

12.　 BUS+XX

Y

Z

XRT EISOTA

FPPEIS

UFSS UFSS

OTA

xX Y

Z

y

z z

x: N-Sy: E-W

z: Slit wrt Solar-N

Apr 17-22, 2006 SOT17 @ NAOJ 3

Alignment requirements

request to the S/C system Ver.2.1：（initial ver. 1999/11/22）

1hr DC offset

Req. reason Req. reason

X/Y 5” EIS scan(30”)/6

SOT FOV(10”)/2

80” EIS slit length (512”)/6

SOT slit length(164)/2

SOT-EIS

(BSOT+BEIS)

Z 40” SOT slit width(0.16”) /10 @84” 800” EIS slit width (1”) @256”

X/Y 16” XRT-FOV(256”)/16 100” XRT high image quality area (800”)/8

EIS-FOV(512”)/5

EIS-XRT

(BEIS+BXRT)

Z 80” EIS slit width (1”) /10 @256” 7200” Accuracy of flare location informed

from XRT 10”@256”(edge of EIS-FOV)

X/Y 16” XRT-FOV(256”)/16 100” XRT high image quality area (800”)/8

SOT-FOV(328”)/3

XRT-SOT

(BXRT+BSOT)

Z 40” SOT slit width(0.16”) /10 @84” 7200” Accuracy of flare location informed

from XRT 5”@164”(edge of SOT-FOV)

* all number in 0－p * technical reality should be studied for these numbers.

The pointing axis of SOT represents the pointing axis of Solar-B; alignment of each instrument is performed so that its pointing axis to be coincide with that of the SOT.

Apr 17-22, 2006 SOT17 @ NAOJ 4

Alignment cubes

Alignment cubes (cube mirrors) are attached to all the telescopes. Normal direction of the mirror surfaces represent the pointing direction of each telescope in the space-craft level test. The cubes are usually measured by a theodolite.

Offset angles of pointing direction was measured with respect to the alignment cubes in the instrument level tests.

OTA alignment cube

Theodolite measurement

x (“) y (“) z (“)

OTA 14 45 -73

XRT 764 -546

EIS -152 -419

Pointing direction wrt the cubes

Apr 17-22, 2006 SOT17 @ NAOJ 5

SOT pointing measurement

The field-of-view of SOT (OTA) is defined by the 2ndary field stop (2FS) located at the Gregorian focus. The FOV of 2FS is slightly larger than FPP NFI CCD.

The pointing axis of OTA is defined by the ray passing through the center of 2FS and the center of the entrance pupil.

The interferometer was aligned to the FOV center defined by 2FS in the WFE measurements. Tilt of the reference flat mirror provides the pointing direction of OTA.

Interferometer

Theodolite

Tiltmeter

X

Z

Alignment cube

Flat mirror

2ndary Field Stop

Apr 17-22, 2006 SOT17 @ NAOJ 6

OTA – FPP alignment check on S/C

A beam splitter was inserted between OTA and FPP. The theodolite was aligned to 2FS of OTA, and provides a beam into FPP.

The crosshair of the theodolite was well located at the center of CCD (better than 4” on the Sun).

Optical Bench

X

Z

theodolite

CCDFPP

Beam splitterreimaging lens

2ndary field stop

collimator lens unit

Apr 17-22, 2006 SOT17 @ NAOJ 7

Telescope alignment

Each telescope is mounted to the optical bench unit (OBU) by three mounting legs.

Tilt of the telescopes was aligned to OTA by adjusting lengths of the mounting legs.

When the adjustment, we used a telescope template which represents mechanical I/F of each telescope. Finally alignment was confirmed by the actual telescopes.

FPP templateXRT template

EIS template

FPP template

Apr 17-22, 2006 SOT17 @ NAOJ 8

Alignment cube measurements

We have measured the telescope alignment cubes in the integration, before and after the S/C vibration test.

Alignment cube (arcsec) Pointing error wrt OTA

x y z x y z

FPP Integration 2005.6.27 1019 -1437 1151

Pre-Vibration

2005.9.14 1016 -1459 1146

Post-Vibration

2005.11.21

1009 -1463 1148

Re-integration

2006.2.15 1011 -1440 1161

XRT Integration 2005.7.19 -765 593 -66 -15 2 7

Pre-Vibration

2005.9.14 -796 597 -46 -46 6 27

Post-Vibration

2005.11.21

-761 590 -47 -11 -1 26

EIS Integration 2005.7.14 138 422 -62 -28 -42 11

Pre-Vibration

2005.9.14 124 412 -72 -42 -52 1

Post-Vibration

2005.11.21

132 421 -65 -34 -43 8

UFSS

-SA

Pre-Vibration

2005.9.14 276 88 89 -21 4 -591

Post-Vibration

2005.11.21

285 91 71 -12 7 -609

Apr 17-22, 2006 SOT17 @ NAOJ 9

Summary

The measurement accuracy (repeatability) is better than 20” in the spacecraft-level measurements.

We have measured pointing alignment among SOT, XRT, EIS, and the sun-sensor several times, and the offsets are less than 1 arcmin for all the telescopes.

The final alignment measurement will be carried out before delivery to Uchinoura.