Lick AO Control SystemPSF Data Gathering

PSF Workshop – 5/11/04

D. Palmer

Upgrade Overview• upgraded ~10 year old AO

Control System on Lick Shane3M telescope to replace aging,no longer supported hardware

• benefits:– combined 3 computers into 1– transformed experimental

control system into facility-grade system

– improved maintainability andusability

– provided the ability to ‘easily’experiment with new things,such as PSF reconstruction…

PSF Introduction• the ability to collect PSF data has been incorporated into the

upgraded Lick AO Control System

• PSF data collection can be started and stopped with commandsaffectionately called pon and poff

• these commands are generally executed automatically when anexposure is started and stopped

• when data collection is in process, various data are accumulated,as described in the following

• when data collection is stopped, means and covariances arecomputed and stored to disk

• these means and covariances are then post-processed todetermine the PSF

Data Flow, Physical

Red Hat Linux

Red Hat Linux

centroids

actuator settings

camera

ADCcounts

pixel data

DeformableMirror

Tip/Tiltmirror

voltages

voltages

disk

PSFdata

TT errors

FSM RTLinux

lickao kernel module

Hard Real-Time Processor (HRT)

lickao host application

Soft Real-Time Processor (SRT)

sharedmemory

Control System StructureLick AO Control System Structure

camerainterface

SW

cameraconfig

raw cameradata

DM controlalgorithm

gains;flat file

DACcounts

actuatorsetting

applyrecon.matrix

controlmatrix

computecentroids

and TT error

dark data;referencecentroids

centroids,pixeldata

DAC SWdriver

centroidsactuatorerrors

DACcounts

DAC SW

driver

TTcontroller

gains

TT errorsand

settings

cameraSW driver

DMAboard

camera

generalpurpose I/OSW driver

APD TTsensor

ADCcounts

ADCcounts

generalpurpose I/O

board

pulses

ADC counts;pulse counts

ADCcounts

ADCcounts

TTerrors

DACcounts

DACSW driver

DACcounts

DAC SWdriver

DACs &amps

DACs &amps

DACs &amps

DACs &amps

DACcounts

DeformableMirror

DACcounts

Tip/Tiltmirror

lasersteering

telescopecontrol

DACcounts

DACcounts

voltages

voltages

voltages

voltages

diagnosticdata handler

1

systemcontroller

initialconfig

hostinterface

hostcomputer

1

1

111

commands

data/status

2

2

22

telemetrydata

3

3

disk

diagnosticdata

ADC counts;pulse counts

2

accumulatePSF data

1

PSFdata

PSFdata

2

file datahandler

disk

setupdata

filemanager

setupdata

italics indicates SRTnon-italics indicates HTR

other HRTthreads

setupdata

TT error

Data Flow, LogicalDM controlalgorithm

actuatorsetting

applyrecon.matrix

computecentroids

and TT error

centroids,pixeldata

centroids actuatorerrors

TTcontroller

TT errors

cameraADC

counts

TTerrors

DACs &amps

DACs &amps

DACcounts

DeformableMirror

DACcounts

Tip/Tiltmirror

voltages

voltages

disk

accumulatePSF data

PSFdata

TT error

PSF DataInputs Description Units

pixel data raw camera data minus background and clipped to zero if less than zero (this is the input to the centroider)

ADC counts

centroids result of centroider algorithm (e.g., quad cell) minus reference centroids, image-sharpening centroid offsets, and tip/tilt errors

pixel units (-1 to 1)

TT errors average centroid results in the X and Y directions pixel units (-1 to 1) actuator settings

voltages being applied to the DM actuators (results of VMM with control law applied, piston removed, and clipped to -5 to +5 Volts)

Volts

Intermediate Data Description accumulated pixel data pixel data, accumulated over an exposure accumulated centroid data centroids with TT errors added back in, accumulated over an exposure accumulated actuator data actuator settings with ‘sharp’ DM shape subtracted, accumulated over an exposure accumulated pixel data, 2n d order each element of pixel data multiplied by all elements, accumulated over an exposure accumulated centroid data, 2n d order each element of centroids with TT errors added back in multiplied by all elements, accumulated

over an exposure accumulated actuator data, 2n d order each element of actuator settings with ‘sharp’ DM shape subtracted multiplied by all elements,

accumulated over an exposure

Outputs Description 1st order pixel data means of accumulated pixel data 1st order centroid data means of accumulated centroid data 1st order actuator data means of accumulated actuator data 2n d order pixel data covariances computed using accumulated pixel data, 2n d order 2n d order centroid data covariances computed using accumulated centroid data, 2n d order 2n d order actuator data covariances computed using accumulated actuator data, 2n d order