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Wednesday 6 February 2013

The Rhyme of the L3 Satellite

Unfortunately I've been writing "poetry" in the AGES observing log again. And that means blog readers will have to suffer my verbal effluence as I ramble incoherently about the problems of satellite-induced RFI and the merits of cats in Coleridge-esque manner.

Pretty pictures will follow shortly to placate those not enamoured of Coleridge spoofs.

The Rhyme of The L3 Satellite

How an Astronomer suffered from interference from a Satellite transmitting in the L3 frequency band, and how the Observatory came to be full of Cats, and the many strange things that befell, and by what means the Astronomer learned to cope with the interference.

Part I

It is an orbiting satellite,
And it transmiteth at L3,
'By thou cursed and wretched RFI,
Wherefore must you lower sensitivity ? 

ALFA's cover is opened wide,
And I am happily observing,
I baked these brownies specially,
A feast of which I am deserving.'

I've developed a tendency to bake things. Amongst other things it makes the observing runs a lot more pleasant.

It holds him with its transmitting strength,
"There was a ship," quoth he,
"Hold off ! Unhand me, satellite, SOON !"
Eftsoons his strength dropped he.

It holds him with its RFI,
The astronomer sat still,
And listens like a three-years' child,
The satellite hath its will.

The Astronomer sat on a chair,
He cannot but choose to fear,
The ruin of his collected data,
From the satellite so near.

'The rocket was cheered, the launch-pad cleared,
Merrily did it aloft,
Above the sky, above the clouds,
Above the control-room top.

(A source rose up upon the left,
O'er the dish came he!
And he shone bright, then on the right
Set below the Observatory.)

Higher and higher every minute,
Toward orbit the rocket went around - "
The Astronomer here had a pang of fear,
For he heard a gong-like sound.

CIMA, the software which controls the telescope, is want to produce many a strange sound when anything happens. A gong indicates something has just finished.

CIMA hath found some errors,
Red on the screen were thee,
Shaking his head with much regret,
The Astronomer preferred to flee.

The Astronomer sat on a chair,
He cannot but choose to fear,
The ruin of his collected data,
From the satellite so near.

But now a new source arose, and it,
Was tyrannous and strong:
It caused unpleasant Gibbs ringing,
But lasted not for long.

Gibbs ringing is caused by very bright sources - basically it just means that the data gets slightly noisier than it should be.

With heavy heart and furrowed brow,
As those struck with RFI must know,
To fear the signal from their foe,
And forward hangs his head,
The Astronomer stuck fast, ignored the blast,
Of the satellite overhead.


Rhys is away
No poetry today
Problems with the ALFA rotator
Solved before they affected the data

I must turn on the ALFA again
To observe the slowly-drifting sky
And all I ask is a big dish
And a star to steer it by


And in Cardiff it grew wondrous cold,
There came both ice and snow,
The Astronomer sighed, and wondered why,
He was in sunny Puerto Rico.

And through the trees a warming breeze,
Did gift a sweaty sheen,
Nor sign of detection to be ken,
The RFI was all between.

The satellite was still here, up over by there,
Its RFI was all around:
It flushed and caw'd, and gong'd and roared,
In CIMA's many sounds !

There is a running joke about how to navigate in Wales.

At length there sat a kitty-cat,
Down from a hill she came,
As since she was so very thin,
We fed her to make her tame.

She ate the food she ne'er had ate,
And fatter and fatter she grew,
Until one day she stole away,
To produce kittens all anew !

And a good routine was started then,
The kittens they did follow,
And every day, for food and play,
Came to the astronomer's gazebo !

In mist and cloud, when rain allowed,
They for chicken skin did whine;
Whilst all the night, through fog-smoke white,
They slept soundly all the time.

"I despise thee, orbiting satellite,
Your RFI requires I distract,
From this feline-engrossed state ." - "But outside the gate" 
"Someone smote that kitty-cat."

Alas, one of the three kittens had an unfortunate accident with a car - no, NOT my car, actually, I was away at the time. But two remain.

You'll be glad to know that there isn't any more AGES observing scheduled for a while, and in any case the Rime of the Ancient Mariner is quite long, so it will be a long time before part 2 is ready.

1 comment:

  1. I can safely use the word 'epic' to describe this. Carry on...


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