PALM-3000

PALM-3000 Instrument Architecture

Antonin Bouchez

PALM-3000 Requirements Review

November 12, 2007

PALM-3000

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Instrument Concept

Instrument Requirements Document:http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Palomar/Palm3000/SystemsEngineering

PALMAO components to be reused:• AO cart (used to transport the AO system)

• AO spit (used to support the AO system during lab work)• AO optical bench and Cassegrain interface support structure.• Relay optics: eg. Off-axis parabolas (OAP), fast steering mirror (FSM), fold mirrors.• 349-actuator Xinetics deformable mirror (DM349).• Low-Order Wavefront Sensor (LOWFS), as an interim tip/tilt/focus sensor.

Project phases:• Phase 0: Interim relay (current optics recoated, focus shifted).• Phase 1: Develop and deploy DM3368, HOWFS, wavefront processor, etc.• Phase 2: Develop and deploy IRTT, TWFS and related electronics and software.

PALM-3000

OAP1

OAP2

FSM

DM3368

DM349

FM2

FM3

FM1

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Optical Layout (1)

AO Stimulus:• Simultaneous NGS and LGS stimuli.• X-Y translation of NGS stimulus to accommodate multiple instruments.

AO Relay:• A single off-axis parabola relay.• DM3368 at the pupil• DM3349 conjugate to <±1.5 km.

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Optical Layout (2)

Beam splitter AO Mode

#1 #2 #3 Comments

NGS-IR open 970 LP open

LGS-IR 30% 1100-1780 R 970 LP 589 NR

NGS-IR from LGS-IR 30% 1100-1780 R 970 LP open 30% loss in sensitivity in J and H.

NGS-V open 50% R or 650 LP open #2 choice depends on science band.

LGS-V 1000-1780 R 595 LP 589 NR No science at <595 nm.

NGS-V from LGS-V 1000-1780 R 595 LP open No science at <595 nm.

Wavefront sensor beam splitting •Large beamsplitters (6-8”) are fixed, only changed out with instruments.• Splitter #3 on actuated stage to switch between NGS and LGS modes.• Space constraints pose greatest chanllenge.

PALM-3000Beam Splitter Layout Schematic

IRTT

HOWFS

TWFS

ACQ

Science Instrument

#1

#2 #3

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Wavefront Sensors

High Order WFS (Phase 1)• NGS and LGS sensor, using CCD50 detector (128x128)• 8x8, 16x16, 32x32, 64x64 pupil sampling.• Adjustable field stop for spatial filtering.

Infrared Tip/Tilt WFS (Phase 2)• Wide-field imaging camera based on HAWAII2-RG.• Full-field acquisition and region-of-interest readout.• Single filter, J+H (1100-1780nm).

Low-Order WFS (Phase 1)• 3x3 Shack-Hartmann sensor using CCD39.

Truth WFS (Phase 2)• 2x2 Shack-Hartmann sensor using CCD39• Provides focus and back-up tip/tilt capability.

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Electronics

Cassegrain Cage• Controller rack• DM349 driver rack• DM3368 driver rack.• Active cooling!

Computer room• Wavefront Processor:

NVIDIA 8800 GPUs (17)Housed in 9 PCs

• Telemetry serverData room• Operator workstation

CA

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I/F

SW

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I/F

GP

U 2

GP

U 1

CPU

PC 1

Bur

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Dat

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AM

SW

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Dis

k A

rray

CPU

PC 8

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LW

FP

CPU

PC 0

Switched

Network

……

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Data Server

Eth

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Gigabit Ethernet

Data User 1

Data User n

……

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DM control algorithms

Solution: Implement both pathways for DM349 control.

PALM-3000

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Operational Systems Software

• Provide low-level control of all AO system functions (servo loop state, motor positions, etc.)

• Provide displays of system status and performance (live display of servo loop state, WFS pixels, DM actuator positions, servo loop strip charts).

• High-level automations:• Guide star acquisition on all wavefront sensors

• Wavefront sensor background recording• Wavefront sensor to DM registration• Flexure and atmospheric refraction compensation• Phase-diversity measurement of the static aberrations

seen by the science instrument• Optimization of the LGS reconstructor using Palomar

MASS Cn2 data

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Laser Guidestar Facility

Planned Improvements• Relocate the Chicago Sum

Frequency Laser to the lower Coude lab.

• Potentially space of a second laser in the same lab.

• Improvements to LLT image quality are still required.

• Aircraft safety system automation based on Table Mountain Observatory system.

Lower Coude