Forums before death by AOL, social media and spammers... "We can't have nice things"
|    sci.optics    |    Discussion relating to the science of op    |    12,750 messages    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
|    Message 12,373 of 12,750    |
|    Behzat Sahin to Phil Hobbs    |
|    Re: Rayleigh vs. Nyquist    |
|    15 Dec 17 00:12:49    |
      From: behzatsahin@gmail.com              Dr Phil, Sir, please watch your language, there are children around! software       guy? I am a 15 yr rf-photonics engineer, and been building prototype mm sub-mm       imaging systems for the last 7 yrs. My team and I have built a W band material       (plaster, foam,        composite laminate etc.)inspection purpose reflection and transmission       michelson interferometric imaging system last year, w/ 1.5 mm su       er-resolution. That is half lambda btw, in mm land we love our huge waves.       Regards and respects and happy holidays,        Asaf.       On Thursday, December 14, 2017 at 5:58:03 PM UTC+3, Phil Hobbs wrote:       > On 12/13/2017 02:36 PM, Behzat Sahin wrote:       > > On Wednesday, December 13, 2017 at 2:36:45 AM UTC+3, RichD wrote:       > >> Consider the Nyquist criterion for sampling a continuous waveform -       > >> 2x bandwidth - then the Rayleigh resolution principle - peaks must       > >> separate by at least 1 wavelength.       > >>        > >> Don't these look much analogous? Especially as λ = 1/f       > >>        > >> Ruminating a bit more... Nyquist sampling can be viewed as a       > >> mandate to sample each period, at least twice. And, Rayleigh       > >> mandates that the image be 'sampled' twice, in the sense of a peak       > >> and trough.       > >>        > >> It strikes me they may be equivalent, in some deeper sense. Has       > >> anyone ever tried to derive such a result, mathematically?       > >>        > >> I can't be the first to ever conjecture this -       > >>        > >> -- Rich       > >        > > Both Rayleigh Limit and Nyquist Rate are so 20th century.. They are       > > basically hard limits for differentiation between two close entities       > > (in time or space). It has been shown that you can operate below       > > these limits; that is for good enough snr optical systems yo can       > > achieve resolutions below rayleigh limit, and for sparse or       > > compressible (lossy usually) data you can use undersampling or       > > compressive sampling. It is in the EOTB, if you can understand what       > > you see or hear that is enough. Regards, Asaf        > > http://www.laserfocusworld.com/articles/print/volume-52/issu       -12/world-news/imaging-theory-breaking-rayleigh-s-limit-imaging-       esolution-not-defined-by-the-criterion.html       > >       > >        > statweb.stanford.edu/~markad/publications/ddek-chapter1-2011.pdf       > >        >        > Spoken like a true software guy. ;)       >        > Cheers       >        > Phil Hobbs       >        > --        > Dr Philip C D Hobbs       > Principal Consultant       > ElectroOptical Innovations LLC / Hobbs ElectroOptics       > Optics, Electro-optics, Photonics, Analog Electronics       > Briarcliff Manor NY 10510       >        > http://electrooptical.net       > http://hobbs-eo.com              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
(c) 1994, bbs@darkrealms.ca