Project Proposal

“Optical Modeling of the

RIT-Yale Tip-Tilt Speckle Imager-Plus”

Kevin Beaulieu Advisor: Elliot Horch

Chester F. Carlson Center for Imaging Science Rochester Institute of Technology

November 19, 2001

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Advisor Approval I have read the attached proposal and believe Kevin Beaulieu can accomplish the proposed work. I will work with Kevin Beaulieu and provide the necessary resources to complete this research by the course deadlines. __________________________________ __________________________________ Print Name Signature

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Abstract This paper proposes the research to be conducted throughout the 2001-2002

academic year at Rochester Institute of Technology’s Center for Imaging Science on the

optical modeling of the RIT-Yale Tip-Tilt Speckle Imager-Plus. The long-term goal of the

RYTSI-Plus project is to use an upgrade to the original RYTSI for use at the WIYN

Observatory for diffraction-limited speckle imaging with little to no observation dead time.

The RYTSI-Plus design incorporates two CCD cameras and a “flip” mirror, which greatly

reduces this dead time.

The optics of the new RYTSI-Plus design will be modeled in Sinclair Optics’ ray-

tracing software package, OSLO. By tracing a source from the moment the point (since we

are dealing with stars, we are in effect dealing with point sources) enters the shutter to the

moment when the point hits the CCD, I will be able to determine which lenses are to be

selected for optimal image quality. After precise modeling of the system, the resultant

optical aberrations will be measured.

In this proposal, you will find background information on the RYTSI and RYSTI-

Plus projects, detailed information on my upcoming research, and my biographical sketch.

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Table of Contents Background and Significance……………………………………………….…………...… 5 Specific Aims…………………………………………………………………......…..…… 6 Experimental Design and Methods………………………………………….……………7,8 Timetable…………………………………………………………………………….…... .9 Resources and Environment…………………………………………………....…….…...10 Budget & Budget Justification…………………………………………………….………10 Biographical Sketch………………………………………………………....……...…..11,12 Literature Cited…………………………………………………………………..….……13

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Background and Significance

Speckle imaging has long been a popular method for obtaining diffraction-limited

images effected by atmospheric turbulence. Since 1970, speckle imaging has been used to

derive diffraction-limited images of various objects including binary stars, asteroids, planets,

young stars, and brown dwarfs. However, speckle imaging places strict requirements on the

imaging system; the frame readout time is approximately 30 to 100 frames per second for

reasonable observing conditions. CCDs in the late 1970s and early 1980s were not

compatible with the speckle imaging method since they had such slow readout rates and high

readout noise. Various cameras had been used for speckle imagery at that time. Intensified

CCDs, PAPA detectors, resistive anode detectors, and wedge-and-strip detectors have all

been useful in imaging bright objects. Although expensive and technologically challenging,

adaptive optics allows high-resolution images to be collected onto the CCDs , which results

in higher quantum efficiency. Since many observatories have smaller budgets, research on

increasing the readout rate of CCDs while decreasing read noise has been ongoing.

Since 1997, Rochester Institute of Technology has been using CCDs in speckle

imaging as part of a solid-state detector program. The camera that has been used, a Kodak

KAF-4200 CCD, is a front illuminated CCD with a readout rate of 500 kHz and a root-

mean-square read noise of approximately 10 electrons. The software package which controls

this system, PMIS, allows the astronomer to read out subarrays of the chip, execute charge

transfer commands, and operate the camera shutter. Since some CCDs do not have these

charge transfer capabilities, Elliott Horch, Zoran Ninkov and William van Altena (Horch et

al. 1998; 1999) proposed the creation of a “tip-tilt” speckle imager, which could be used with

any CCD camera and would increase efficiency. Using the method, a tip-tilt mirror would

deflect the image onto all areas of the CCD, using the CCD as a memory cache of previous

speckle images. However, the final product, the RIT-Yale Tip-tilt Speckle Imager (RYTSI

(pronounced- rit Zee))(Horch et al. 2001) is still inefficient, because the system uses only one

CCD, resulting in a significant amount of dead time during readout. Thus, the new system

to be modeled, the RYTSI-Plus, incorporates two high speed, low readout noise CCDs and a

“flip” mirror for ray deflection, in effect, eradicating this dead observing time.

Thus, in this project, I plan to accomplish the optical modeling of the new system:

the RYTSI-Plus.

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Specific Aims

Since the long-term objective is to successfully construct and implement a low noise,

high efficiency astronomical data collection system, the optical modeling of the RYTSI-Plus

is an extremely important aspect in the development process. By modeling the optics of this

system, Elliott Horch and Reed Meyer will thus have accurate data supporting the selection

of specific lenses to be installed in the RYTSI-Plus system.

As a result of this RYTSI-Plus project, we hope to be able to decrease astronomical

data collection dead time at observatories while obtaining diffraction-limited, low noise

images. Once the system has proved to be accurate and efficient, astronomical research will

be conducted using the RYTSI-Plus at the WIYN Observatory at Kitt Peak, Arizona,

primarily to study binary stars.

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Experimental Design and Methods

As an upgrade from the original RYTSI, a new system needs to be optically

designed which incorporates two CCD cameras along with a new two-position “flip” mirror

wheel. Figure 1 illustrates the basic plan for the RYTSI-Plus. While CCD 1 is collecting

data, CCD 2 will be reading out. When CCD 1 has been filled with speckle images, the

“flip” mirror will deflect the light onto CCD 2 and CCD 1 will concurrently read out. This

process will continue until the observations are complete. The new system will significantly

improve the efficiency of the speckle data collection process. The testing and evaluation of

the new system, the RIT-Yale Tip-tilt Speckle Imager-Plus, will be completed over a two-

year period.

The first objective of this research is to become acquainted with OSLO, the ray

tracing software package. Once the package is understood, accurate optical modeling of the

new RYTSI-Plus system can be achieved and proper lenses for the system can be selected to

optimize image quality. The second objective of this research, once the optical modeling is

complete, will be to investigate the optical aberrations of the system. The particular

aberrations prevalent within the system will be determined as it is being modeled. Data on

the aberrations (astigmatism, being definite in analysis thusfar) will be available through

analysis in the OSLO software package.

Next year, for those who will move further in this project, once the RYTSI-Plus is

constructed, testing of this system for practical use at the WIYN Observatory will

commence. Theoretically, the most significant result from this project will be zero dead time

per 1000 frames, an increase in efficiency from 32.6 seconds of dead time per 1000 frames

using the first model of RYTSI.

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Figure 1: The new RIT-Yale Tip-Tilt Speckle Imager- Plus

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Timetable

The expected starting time for the first element of the research (getting familiar with OSLO)

will be in early November 2001.

Chronological list of research items and approximate times for accomplishment:

· November 2001 - December 2001 Become familiar with OSLO, the ray tracing software package from Sinclair Optics

· January 2001 - March 2002

Model layout of RYTSI-Plus system · April 2002 - Early May 2002

Characterize optical aberrations of system

· May 2002 Create poster describing accomplished work

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Resources and Environment

All work on the optical modeling of the RYTSI-Plus will be performed in the

basement of the Chester F. Carlson Center for Imaging Science in Rochester, NY. In the

laboratory, there is enough appropriate equipment such as optical benches, newly

constructed computers (1.2 GHz Athlons), and other optical tools owned by Elliott Horch

and Reed Meyer that will be used throughout the progression of this project.

Budget & Budget Justification Credit hours requesting in the winter and spring to complete project:

Winter Quarter: 2 credit hours Spring Quarter: 2 credit hours

Funding requesting from senior research (CIS) funds: $100 TOTAL requesting from CIS funds

-Supplies and storage media (250 MB ZIP storage, poster materials/costs) Funding that will be received from others:

OSLO is being provided free of charge thanks to Mr. Robert MacIntyre.

The following is a list of required equipment needed for the RYTSI-Plus project:

(Some items will eventually need to be bought, but might not be utilized in this particular

segment of the project. If time allows by April, however, the items will certainly be

required.):

· Two 2,000 x 2,000 back-illuminated CCD cameras and a control computer

(Finger Lakes Instrumentation, Marconi 42-40 chip)

· A protected silver mirror and wheel to deflect the beam from CCD to CCD

· Additional optics (filters and lenses) to have a range of magnification and band pass

choices on both channels of the instrument

· Risley prisms

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Biographical Sketch

Education Rochester Institute of Technology Rochester, New York B.S. Imaging Science: Expected Graduation Date- May 2002 Liberal Arts Minor: Science, Technology, and Environmental Studies (expected)

Work Experience RIT Center for Imaging Science 9/01 – current Rochester, NY Astronomical Data Analysis ▪ Analysis of binary star data obtained by Dr. Elliott Horch in Argentina in 1994 is being

performed. My knowledge of UNIX, IDL, astronomical imaging, and image processing/analysis has become useful in these studies.

RIT Center for Imaging Science 6/01 – 8/01 Rochester, NY RIT Observatory Automation Project ▪ With the long-term goal in mind of fully-automating the RIT Observatory, this summer

was devoted to collecting astronomical data to test the TASS Mark IV data pipeline created by Dr. Michael Richmond as well as to collaborate with observatories around the globe in the study of a cataclysmic variable binary star system, WZ Sge. ▪ Assisted Dr. Joel Kastner and Dr. Robert Kremens in electronics analysis of the RIT Observatory ASH DOME

Spinnaker Coating 5/00 – 9/00 Westbrook, ME

Assistant of the Technical Service Manager and Process Engineers

▪ Part of a team that obtained, organized, and analyzed data to support a specification reduction in one of the company products thereby saving Spinnaker Industries over $500,000 per year.

▪ Responded to requests for sample identification by performing various tests for Spinnaker's customers. ▪ Organized Material Safety Data Sheets of the 83 chemicals used in the Spinnaker Plant by transferring data from a web browser (Internet Explorer) on the company's Intranet system, to a word-processing program (Microsoft Word). Edited the materials for inclusion in OSHA-required employee manuals. ▪ Performed testing to validate consumer product complaints.

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Spinnaker Coating 5/99 – 9/99 Westbrook, Maine Test Laboratory Technician

▪ Tested various grades of laminate paper produced by a paper-coating machine to ensure that the quality of the product met several distinct requirements and standards before being shipped to labeling companies nationwide.

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Literature Cited E. Horch, Z. Ninkov and W.F van Altena 1998, “A new low-noise high-quantum-

efficiency speckle imaging system,” Optical Astronomical Instrumentation, SPIE Proceedings, 3355, pp. 777-785.

E. Horch, Z. Ninkov and W.F van Altena 1999, “Progress report on the RIT-Yale Tip-

Tilt Speckle Imaging System,” Bulletin of the Amercain Astronomical Society, 31, p. 837.

E.P. Horch, Z. Ninkov, R.D. Meyer and W.F. van Altena 2001, “RYTSI: A new way to

do speckle imaging,” Bulletin of the American Astronomical Society, 22, pp. 790- 791.

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