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Messages - Physicist13

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1
This looks interesting.... on background extraction http://arxiv.org/abs/1608.02700
Patrick

2
General / Re: Deconvolution question
« on: 2015 December 02 05:28:43 »
disagree. Its applying a SPF and doing a mathematical deconvolution.
Patrick

3
General / Re: Deconvolution question
« on: 2015 December 02 01:18:08 »
why only lum?? isnt deconv a means to make non-circular stars circular? should apply to all channels??
Patrick

4
General / Re: Wrong Temperature/Duration Darks
« on: 2015 December 02 01:14:05 »
problem is that the dark noise is function of both duration and temperature..and non-linear to boot! the scaling is doing, essentially, a best fit routine (correct me if wron please Juan!!). The closer in both time and temp the calib dark is the better. PLus there is the general global minimisation problem..but that another matter ;// . Temperature tends to be the main power dependancy so closer to light frame temp the better...duration tends to scale better (more linear) .
Patrick

5
Great!! sounds like science to me!  ;)

6
General / Re: Best number of subs
« on: 2014 December 03 01:18:44 »
Always work reading Craig Starks notes on signal to noise! huge amounts of confusion abound. The main point is whether you are Read noise dominated or not. The number of subs needed to get a particular SNR level changes...the scaling is different. But crucially even if Read noise dominated it still improves....it just takes longer! (ie the total exp time needs to increase).
Patrick

7
 :) great! thanks!!

8
will file size be affected much by this? Are there any potential issues when moving file locations? thanks.
Patrick

9
Worked fine for me! New file format looks good too!
Patrick

10
Gallery / Re: First try of DrizzleIntegration: Omega Cent
« on: 2014 June 03 00:55:34 »
*falls off chair !! WOW!

11
Gallery / Re: M83 (Southern Pinwheel)
« on: 2014 May 13 00:38:24 »
lovely! I've seen the red fringing on side before...not completely sure but my suspicion is that, the red will always have a larger spot size due to its longer wavelength so the R channe stars should, in theory, be shrunk slightly to match the GB channels. Also the one sidedness could indicate a sligtly non flat focal plance...which cld be due to filter tilt, camera chip tilt etc..
Patrick

12
lovely!! Thanks for sharing that! there is a heck of a lot of structure in that one!!!
Patrick

13
General / Re: Drizzle tool?
« on: 2014 March 21 01:38:58 »
Phil, If I've got my sums about right (and using Rayleigh limit)..your Optical resolution for each of these setup is 2arcsec and 0.13arcsec respectively. If your pixal resolution is 2.2 and 0.71 then for the 80mm scope your about matched, so little gain. For the other scope you are oversampling by about x5 so would gain...BUT!! remember you will prob be atmospherics limited!
Patrick

14
General / Re: Drizzle tool?
« on: 2014 March 19 12:44:26 »
Juan, many thanks tht sounds great!!!!! Wasn't trying to pressurise you! ;) with pixel rejection that's really Drizzle++ :)) not aware of any other progs that would do that!!
Phil, it's a means of recovering spatial resolution if you are under sampling , ie pixel resolution is not as good as the optical resolution....as is the case with HST ;)) it does require that data was taken using dithering (ie random walk) as well.
Patrick

15
General / Drizzle tool?
« on: 2014 March 19 02:09:29 »
Sorry if thsi is an old question already answered! Is there a Drizzle tool in PI...seen some ealy posts about it but cant seem to see the final implementation...thenks,
Patrick

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