fivemack

NEA brainstorming 26/10/2019

Oct 26th, 2019
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  1. Further NEA brainstorming 25/10/2019
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  3. * Asteroid 204 Kallisto produces a plausible set of FITS files with a moving object
  4. This was at 2.8AU range and visible magnitude 14.3 at the time
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  6. * https://www.minorplanetcenter.net/iau/ECS/MPCAT-OBS/NumObs.txt.gz is the 3.1GB all-the-observations file
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  9. * Whilst the emissivity shows up both in the power-output and the temperature-at-equilibrium point, the integrated power isn't very much dependent on it. But the temperature defines the modal emission wavelength quite tightly.
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  11. * https://irsa.ipac.caltech.edu/applications/wise/#id=Hydra_wise_wise_5&RequestClass=ServerRequest&DoSearch=true&subsize=0.16666666800000002&cat_overlay=_none_&schema=allsky-4band&band=1,2,3,4&obj_name=204%20Kallisto&obj_naifid=2000204&preliminary_data=no&projectId=wise&searchName=wise_5&shortDesc=Solar%20System%20Object/Orbit&isBookmarkAble=true&isDrillDownRoot=true&isSearchResult=true is the WISE solar-system-object-to-image pipeline
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  13. (it is clear that the WISE camera at 10um is not very sensitive, but that the sky isn't too distracting; 20um is worse on both grounds)
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  16. - https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10709/0000/Development-of-astronomy-large-focal-plane-array-ALFA-at-Sofradir/10.1117/12.2311713.short looks interesting in an EU context; probably reading a load of Proc SPIE would be a good introduction to the IR detection world
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  18. - NASA tech review https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100030592.pdf
  19. - beyond 12 microns there is a strong temperature preference, and there is a clear technology threshold somewhere like 16 microns, so working at 10um would be very much more convenient
  20. - but the paper is on single pixels rather than arrays, so not useful for my purposes
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  22. http://web.ipac.caltech.edu/staff/sscnews/temp/neocam/NEOCam-detector-JOE.pdf is the new 10um HgCdTe array for NEOCAM
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  24. NEOCAM is quite expensive (about twice our mission budget); I can't find details about its telescope architecture
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  26. ... for a wide enough field we do need a three-mirror anastigmat (Korsch design)
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  29. - compare EUCLID (0.5 square degree field, 1.2 metre mirror, 4x4 array of 2kx2k H2RG in the near IR)
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  31. - Willstrop telescope in Cambridge: three mirrors awkwardly arranged (big one in the middle, FPA there too), five degree field f/1.6
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  33. - https://www.amostech.com/TechnicalPapers/2007/Telescopes_Instrumentation/Ackermann.pdf is a bit old and entertainingly polemical, mentions Rakich and Terebizh as relevant authorities.
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  35. - if we're at 10um with a half-metre aperture there's no need for exquisite image quality, 15um pixels would be quite exciting and diffraction limit is going to be about there at f/2
  36. - Euclid design wants very good sampling of image shape in the visible, which is why the focal length is so long
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