Transcript Document
IRTF POETS (Orange) Preship review Anticipated shipment date 22 APR 2008 Anticipated mounting 30 APR – 05 MAY 2008 18 April 2008, aasg Outline • Overview of POETS IRTF Project • Lab testing results • Packing plan • Shipping Plan • Mounting Plan POETS IRTF team MIT, Boston • • • • Amanda Gulbis (P.I.) Jim Elliot (Co-I.) Folkers Rojas (mechanical design and fabrication) Mike Person & Matt Lockhart (instrument consultation & observers) IfA, Hawaii • • • • • Bobby Bus (observing and long term support) John Rayner (optical design, SpeX interface) Vern Stahlberger (mechanical design) Lars Bergknut (mounting & work at summit) Alan Tokunaga (IRTF division chief) POETS IRTF Summary • Our goal is to mount a high-speed, visible wavelength camera system on the IRTF (NASA’s 3-m Infrared Telescope Facility) • The instrument is based on existing MIT-Williams College POETS (Portable Occultation, Eclipse, and Transit Systems) • The instrument will be mounted on the side-facing exit window of SpeX – a dichroic allows entry for light < 8000 Å or 9500 Å • Fore-optics box uses 3:1 reducing optics to ret f/9.32 beam and 60” FOV POETS IRTF Overview • Schematic of full setup POETS IRTF Overview • Schematic of full setup • Optical path POETS IRTF Components • Fore-optics box (28 pieces, 1 mirror, 3 lenses, 1 filter wheel, 1 filter wheel motor, and assorted dowel pins and screws) • Camera (Andor Ixon, 512 x 512 frame transfer BI E2V CCD with 16 m pixels; including power cable & computer cable) • Computer (Shuttle; including power cord, PCI card, keyboard, & mouse) • GPS (Spectrum Inst.; including power supply, 25-m cable, control cable, and antenna) • Fore-optics box • Camera • Computer Two computers are shown here -the top is a current POETS machine. The bottom is the IRTF machine, which we have yet to get functioning properly with the camera. We have ordered a new computer, as similar to the top machine as we possible. If that machine does not work, we will ship a current POETS computer and swap at a later date. • GPS Lab Testing • Setup: • • • • All components assemble and disassemble as planned Dowel pins are used for accurate alignment during assembly No play in components once assembled Light tightness can’t be tested until mounted – all components overlap • Remaining issues: • attachment to SpeX (was tested onsite) • Manual shutter (functions, but attachment not tested) • Instrument Computer (original system won’t work with the camera. new system ordered, ETA at MIT 18 April 2008) • Filter wheel (parts are in place, no filters or driving mechanism) • Replacement lenses (lens 1 chipped at edges during initial fitting - doesn’t seem to effect images, but spare lenses have been ordered) Lab Testing • Calibrations • Cooling: TE cooler run for hours at -70º C at room temp • Read Noise and Gain • Were measured in lab prior to fore-optics box setup, are consistent with spec. sheet • Difficulties in obtaining accurate flatfields while camera is attached to fore optics Lab Testing Lab Testing • Vignetting • Illuminated frames show slight vignetting at corners • Vignetting pattern changes with adjustment of lens 2 & 3 positions, but cannot be eliminated Lab Testing • As evenly illuminated as possible: note vignetting (spots are dust on lenses) Lab Testing • Images • Test charts placed at approximate TFP (0.3” in front of lens 1) can be made to come into a clear focus • Camera can be adjusted greater than 1” in z-extension for focusing adjustment – threaded at 32 threads per inch to allow fine tuning • No distortions are apparent across the image, centering looks OK – can’t confirm without higher accuracy of TFP Lab Testing Test charts placed at TFP Images Packing Plan • F. Rojas to be in charge of packing fore-optics box • Preassembled, with lens mounts removed • shipped in hard, ex-PCCD container • All associated box hardware and camera cables can fit in this package • Packages to ship • • • • Fore-optics box GPS (packaged as shipped to us) Computer (packaged as shipped to us) Some possibility for consolidation (i.e. GPS may fit in fore-optics box) Shipping Plan • Online quote for DHL 2-day shipping from zip codes 02139 to 96720 is ~ $500 (100 lb. box with rough dimensions of our fore optics box) • Plan to ship no later than 23 April (Wed.) for mounting one week later (30 April) • If computer testing takes longer, can ship as late as the 25th • Hand-carried components • Camera • Optics Mounting Plan B. Bus (observing, long term support), J. Rayner (SpeX interfacing, testing), L. Bergknut (mounting, summit work), A. Tokunaga (big problems) Engineering Run Preparation • • • • • Submitted plan to A. Tokunaga Verified plan is reasonable with B. Bus Completed ORF - requested lodging at PH and IRTF vehicle Faxed Driver’s Clearance form Contacted George Koenig re: instrument delivery • • Confirmed DHL 2-day shipping will work • Confirmed shipping address Working on night plans for observations with C. Zuluaga Engineering Run Preparation Immediate to do • Telecon with Hawaii to ensure we’re all on the same page • Contact Miranda Hawarden-Ogata re: network interface • Confirm engineering observing times Longer term to do • Compile documentation • Engineering diagrams • Setup and usage manual Basic version for observers and more advanced for supporters • Maintenance manual The End Slides on possible observing targets to follow POETS IRTF Engineering Observations • Calibrations • On-telescope biases • On-telescope flats (sky and dome) • Focus • standard star target? • ensure co-focal with SpeX • Image variations due to pointing • Check variations with telescope pointing • Check variations at different airmass • Throughput & exp. times • standard star target grid – range of stars from ~ 8 to 20 mag., B & R stars, versus range of exposure times in conv.and EM modes Engineering Observations II • Possible science targets • • • KBO and star for 06 May 2008 appulse Other KBOs Occultation candidate stars