| Re: finding star-like objects in images [message #94899 is a reply to message #94858] |
Mon, 27 November 2017 03:29  |
Helder
Messages: 10
Registered: October 2017
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Junior Member |
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On Wednesday, 8 November 2017 15:24:00 UTC+1, wlandsman wrote:
> You could try find.pro based on a popular software package(DAOPHOT) used by astronomers
> https://idlastro.gsfc.nasa.gov/ftp/pro/idlphot/find.pro
> The image is convolved with a lowered Gaussian with the approximate FWHM of the stars.
>
> Note, though, that astronomers want to detect stars but not cosmic rays so there are sharpness and roundness criteria (with stars being less sharp and more round than cosmic rays).
>
> --Wayne
>
> On Wednesday, November 8, 2017 at 5:12:06 AM UTC-5, Helder wrote:
>> Hi,
>> I'm not an astronomer and I guess that this is something that astronomers have been confronted with quite often in their lives.
>> I have a detector where particle events generate intensity across some pixels (2-5 x 2-5) [*]. Typically their integral intensity is constant (lets say 100 +/- 20). These events show over a noisy bkg.
>> Apart from having a constant intensity, these events are similar to stars (that have a varying luminosity).
>>
>> What approaches are typically used for detecting/locating such events?
>>
>> Any IDL solution readily available out there?
>>
>> Thanks for reading so far and for any suggestions.
>>
>> Regards,
>> Helder
>>
>> [*] - threshold methods would not work very well, because the total intensity of 100 may be distributed over 2x2 pixels (~25 per pixel) or 5x5 (~10 per pixel).
Dear Markus and Wayne,
thank you very much for your insight. It took me some time implement the above (as part of a bigger analysis) and I'm now very happy with it.
Regards,
Helder
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