Satellite datacoms at ~500THz

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manuka

Senior Member
Gasp - Morse Code from the heavens? Relax- it's probably not something in your seasonal egg nog, but the Japanese LEO (low earth orbital of ~400km) FITSAT-1 CubeSat pulsing visible LED messages! Binoculars are recommended but messages are apparently even likely to be visible unaided in very dark regions.

Check here for an online 2-way Morse translator/player.
 

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K

Kecked

Member
manuka said:
Gasp - Morse Code from the heavens? Relax- it's probably not something in your seasonal egg nog, but the Japanese LEO (low earth orbital of ~400km) FITSAT-1 CubeSat pulsing visible LED messages! Binoculars are recommended but messages are apparently even likely to be visible unaided in very dark regions.

Check here for an online 2-way Morse translator/player.
Click to expand...
What does it say?
 
Buzby

Buzby

Senior Member
From the FITSAT website :

NIWAKA will carry a mounted neodymium magnet to force it to always point to magnetic north like a compass.
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What a smart idea !.

Does it work ?.
 
S

srnet

Senior Member
Buzby said:
From the FITSAT website :

What a smart idea !.

Does it work ?.
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Yes, although the satellite can still oscillate a bit, so some form of damping of the connection between the magnet and the satellite body helps, such as putting the magnet in a tube fitted with viscous fluid, at least that is what I have been told.
 
N

NoEinstein

Member
That's nothing. The N. Koreans have one ready to launch so that every time you look up at the sun, you see this:

 
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G

geoff07

Senior Member
If you want to know where FITSAT-1 is right now, go to:

http://www.n2yo.com/?s=38853

If you want to predict where it will be, install 'gpredict' (free, gpl licensing) and update the NORAD data for the cubesats (which gpredict can do for you). This will show you when it will be overhead your location. gpredict was developed for Linux but there are versions for MAC and for those that still use Windows.
 
S

srnet

Senior Member
manuka said:
Gasp - Morse Code from the heavens? ...... pulsing visible LED messages!
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mmmm, got me thinking now.

My satellite board can deal with the Morse, and it even has a single 1206 LED which I had thought pointless as there would be no-one about to see it ......

I wonder ........
 
hippy

hippy

Ex-Staff (retired)
srnet said:
My satellite board can deal with the Morse, and it even has a single 1206 LED which I had thought pointless as there would be no-one about to see it ......

I wonder ........
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From the FITSAT page ( http://www.fit.ac.jp/~tanaka/fitsat.shtml ) ... "NIWAKA's high power LEDs will be driven with more than 200W pulses to produce extremely bright flashes. These, we hope, will be observable by the unaided eye or with small binoculars" ... so that's going to require quite a bit of current !

Worse to come...................................
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Let's not go too far though or there will be a purging on the cards ;-)
 
fernando_g

fernando_g

Senior Member
The world's most handsome man, according to The Onion.
China's official media actually picked it up as legit news.
 
M

manuka

Senior Member
Although long traditional, & readily identified with eyes/binoculars,visible light signalling is probably not a wise use of limited transmitter energy. It may be quaint in this application, but satellite orientation,outdoor "heads up" viewing & clear night skies are crucial.

In contrast a few Watts of VHF from above would be easily detected on even a $$ receiver, & could be heard night & day, for a longer pass, under cloudy skies (& perhaps even indoors) with the data readily recordable/machine decoded. Naturally some Doppler frequency shift may arise, but this is now readily handled.

Although wide band receivers & decent antenna are needed foranalog picture decoding, a cheap hand held scanner with just a mere rubber duckie whip antenna can readily detect passing NOAA weather satellites (WXsat) on ~137MHz.

Such VHF satellite transmisions are "ancient" technology! Back in 1958 signals from the US "Explorer 1" were sent to the ground by a pair of (then leading edge) transistor transmitters - one a 60 mW (with internal antenna) on 108.03 MHz, & the other (feeding 4 flexible external whips) a mere 10 mW on 108.00 MHz. In 1962 OSCAR 1 (Orbital Satellite Carrying Amateur Radio) sent Morse ..../.. ("HI") at ~146MHz.

Stan (ZL2APS since 1967)
 
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G

g6ejd

Senior Member
I don't recognise the morse characters, here's my best guess:

9CCFB

- - - - Does not exist
.-.-. Does not exist
-.-. C
..-. F
-... B
Combine ---- with first dit of second group gives 9, then it's a C then C then F then B
 
G

g6ejd

Senior Member
Well in wabun morse (Japanese) it's :
KO N NI CHI HA

But why do this when the rest of the world only reads international morse, I tried it backwards:
V L unknown or AA unknown or RN unknown or MM or OT
 
S

srnet

Senior Member
hippy said:
"NIWAKA's high power LEDs will be driven with more than 200W pulses to produce extremely bright flashes. These, we hope, will be observable by the unaided eye or with small binoculars" ... so that's going to require quite a bit of current !
Click to expand...
So you reckon my red LED on a 3V supply with a 2k2 series resistor wont be enough ?

Even if it is one of the high efficiency types ?
 
Buzby

Buzby

Senior Member
I can't remember the link right now, maybe 'mikeselectricstuff', but did any of you see in real life the multi-Kw airborne LED display built for the launch of HALO ?
 
T

Thalass

New Member
It might be a poor use of power, but normal people (that is, not people like us :p) rarely look up at the sky at all. I've pointed out the ISS several times to coworkers and they're always amazed at the speed and brightness as she passes overhead. A blinkety light could catch many people's attention, and spark an interest. Especially if kids see it.

Though really it'd have to be several times brighter to catch someone's attention when their nose is buried in a smartphone :p
 
S

SAborn

Senior Member
Though really it'd have to be several times brighter to catch some one's attention when their nose is buried in a smartphone :p
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Their smart phone would have an App to locate the satellite and decode the information while sitting on the toilet or still in bed, why would they look at the sky ??

Once we were interested in a bug that moved, and either squashed it or studied it, todays approach is reach for the bug spray or download an App to do it for you.

What will tomorrow bring.
 
S

srnet

Senior Member
SAborn said:
todays approach is reach for the bug spray or download an App to do it for you.
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Someone ought to develop a 'crossing the road app' that warns you when you are about to be run over.

Would not surprise me if someone already has ..........
 
G

geoff07

Senior Member
Well in wabun morse (Japanese) it's :
KO N NI CHI HA
Click to expand...
This looks remarkably like Konichiwa, which is 'Hello' and is about all I remember from having to do a welcome speech in Japanese some years ago.
 
P

Paix

Senior Member
From the statistics, it sounds like they have been unsuccessfully field testing such a device for many years !
 
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