[Nottingham] LibreOffice cloud?

[Martin]

On 21/01/14 11:20, Duncan wrote:
> On 20/01/14 23:52, Martin wrote:

>> Thanks, this is turning into quite an adventure of cloudy pieces :-P
>>
> Little Fluffy Clouds

Very apt for going Orbital... ;-)

OK, that gets added into the playlist :-)


>> (Hope your baby far above the clouds is doing well! :-) )
>>
> 
> Appears to be.  Going through Astrium commissioning atm. Some of my
> team received their first data over the weekend to help with that.
> ESA have released an interesting but rather odd first light image[2].
> Odd because we will never see images like this after commissioning.
> At the time the image was taken the mirrors were not in focus and
> the instrument temperature was still dropping so it is noisier and
> not as sharp as it should be.  It is also a mess because it is a
> magnitude 2.9 star that has caused saturation of the CCD (should
> be obvious from the image) and highlights the diffraction (PSF) spikes.
> The lack of obvious blooming also indicates the CCD anti-blooming drain
> (drains excess (saturated) charge to the solar arrays so it doesn't
> leak into neighboring pixels) works.  We don't know the orientation
> of the image but if it follows the mission-standard the read-out
> register should be in the top right-hand corner.  All very good.
> 
> 
> [2] http://sci.esa.int/gaia/53616-first-star-shines-for-gaia/

To my eye and cynicism, that looks to be chosen just because it
photojournalistically "looks pretty" and the "public are all ignorant"
and the technical merit be damned.


Hopefully being not so ignorant...

Why the bifurcation for the vertical blooms?

Is that an artefact of the star image falling an a seam between CCD
chips or something more interesting?

Also, what determines the angle of the flaring? Is that from optical
interferometry effects from internal multipath, or an artefact of the
CCDs? (Is there in reality just a clean bright spot hitting the sensor?)

Could a bright star on the very edge of a CCD splatter or channel light
through/along the surface of the CCDs to create ghosting?... (OK, lots
more questions but those can wait for a few beers ;-) )


The limiting of the blooming looks blooming good for giving well defined
edges to the blooming! :-)


Good luck!

Cheers,
Martin

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