Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.apo.nmsu.edu/arc35m/Instruments/ARCTIC/Development/ImagerPDR/grizli_performance.pdf Дата изменения: Thu Dec 5 20:44:30 2013 Дата индексирования: Thu Feb 27 21:08:29 2014 Кодировка:

GRIZLI Science Performance Goals Includes also some performance goals for telescope and software 16 October 2011 A. Instrument specs 1. Delivered image quality, in each filter, across entire FOV Goal: 0.5" FWHM, with well-behaved PSF, at high altitude (low airmass) 2. Limiting magnitude Goal: 26th mag in griz gives S/N=10 in 3 min exposure sky-limited in all filters with no moon 3. Exposure time - minimum exposure <= 1 sec, with shutter illumination pattern repeatable (able to calibrate to 0.1%) - maximum exposure at least 10 minutes, more for narrowband option 4. Readout Goal: 10 seconds for all 4 chips in parallel 5. Detector performance Goals: - read noise < 5 e- per (binned 2x2) pixel - dark current < 1 e- per (binned 2x2) pixel in 5 minutes - full well should be close to or slightly above saturation limit - linear response to at least 40K DN (assuming 63K range/saturation) 6. Throughput Goal: 75% throughput 7. Fringing Goals: (for 3 min exposure) - less than 1% in i - less than 5% in z 8. Scattered light Goal: less than 0.1% effect over full field 9. Optical system performance - optical system performance in each of griz measured and provided to high accuracy. - Should be constant across FOV and stable in time. - Provide comparison to standard SDSS passbands, e.g. http://www.sdss.org/dr3/instruments/imager/#filters - Feasibility of transformation to standard SDSS system demonstrated.


10. Alignment of images Goal: sky coverage of different filters overlaps at 99% level 11. Metrology from instrument reported to Hub/TUI, placed in image headers as appropriate B. Next items also depend on telescope 12. Field of view Goal: 10' diameter circular unobstructed FOV 18' diameter FOV with modest vignetting by tertiary baffle 13. Guiding Goal: centroid shift less than 0.2" for three minute exposure 14. Focus Goal: Fast focusing method, and ability to update focus quickly while observing. C. Next items relate to flatfielding, image processing, software, future upgrades 15. Photometry Goal: Ability to take out of focus images of bright objects, and flatfield to obtain competitive differential photometry, 0.001 mags precision Goal: Ability to do competitive absolute photometry to obtain 0.01 mag precision (depends on flatfielding, scattered light, fringing) 16. Software to process and co-add images quickly (needed if using short exposures for on-chip guiding) 17. Photometric transformation from instrument griz to SDSS griz 18. Geometric transformations between griz images 19. Narrow band filter specs, TBD.