OT Satellite images

So do I. It's very hypnotic but it has it's limitations. I think I mentioned it in one of my rants up thread somewhere. The problem is that it barely works for low wind speeds (

Ivan Shmakov wrote

I use Sirenza VCOs in some of my designs:

very stable VCOs in my experience and cheap on ebay.

BTW likely you can receive that sat with an RTL-SDR stick, I do receive weather sats with it. That modis . gov link reports as untrusted here, so I do not want to look up that .goc site.

Jeff Liebermann ranted

Exactly, there is no 100% guarantee, the models are limited. There is also the 'butterfly effect' You sneeze once and the whole prediction goes (blows...) out of the window... :-)

But it is a great tool.

On the DoD front at least one of the big goals of developing near real-time high-resolution optical, radar, and infrared imaging was to make driving around in a transporter-erector-launcher vehicle one of the most undesirable jobs in the Soviet Union during a conflict.

Every 90 minutes not really good enough, those things can probably do

25-30 mph even on unpaved roads they long gone from wherever they were before in 90 minutes.

Laserdics! I remember seeing a couple of those in the store when I was a kid. I don't think I ever knew anyone who actually owned a player, though, even in the 1980s.

I doubt it. hubble can image the disc of nearby stars so its pixels can handle star intensity earth is orders of magnitude less intense.

eg:

Also assembly would have been real tricky if that were the case,

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     ?

I don't think they really got popular until the 90's

Try NASA Direct Readout Labs; The interesting stuff is under Links: and under Downloads:

Also see: NASA Earthdata MODIS Subsets: which will soon be replaced by Worldview and GIBS (Global Imagery Browse Services)

If you want to try receiving Terra, Aqua, and others: Looks like a really old frequency list and I'm too lazy or busy to find something better. Well, here's Terra and Aqua:

8212.5 OQPSK and 8160 SQPSK MHz both using some kind of protocol by the CCSDS: I was about to recycle all the X-band junk that I've accumulated over the years, but maybe I'll try throwing together a tracking satellite dish antenna and X-band receiver. (Yet another project).

EOS makes GPS/GNSS receivers.

1192 Mhz is in the GPS band. The RF components might work, but you'll probably need a higher IF frequency to handle the 30Mhz occupied bandwidth used by Terra.

What make and model? It might be easier to repair than to install a new LO. However, all you'll be able to receive is NOAA 17, 18, etc on L-band. The birds you want to chase are probably all on X-band.

Sure. I have a 2K25 klystron oscillator that should provide days of amusement and frustration. It will probably drift badly and will certainly be rather noisy, but might be worth the effort just for the bragging rights.

Do you want a synthesizer or fixed crystal oscillator?

My guess(tm) would be a synthesizer. I suggest one of the ADF4350 or ADV4351 based synthesizer boards commonly found on eBay. For example: or just get one in a box ready to play:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I don't think it ever was popular in the US at all, the wiki claims the players and discs were cheaper in Asia than here.

Asia always seemed more diverse wrt niche audio and video media formats finding larger adoption than the US, also Video CD and Minidisc were available in the early 1990s there.

In the area of the US I grew up in the LP was dead as a mainstream format and the audio cassette nearly so by the time I was old enough to want to buy my own stuff regularly, I bought a few cassettes into the

1990s because they were often a bit cheaper than CDs and portable CD players were large and clunky but by the mid 1990s audio cassettes were gone from major stores too.

Audio CD and VHS tapes were basically the formats that were widely available at reasonable price for most of the 1990s; a Minidisc or Laserdisc player was the kind of thing that one wealthy eccentric relative might have I might have seen one if I'd had a relative like that.

bitrex wrote

I was once 'ordered' to Eindhoven and they wanted me to write the service documentation for it. I did not want to move to Eindhoven, and they did not pay enough. I did make some suggestions on the design.... for a dropout compensator.... Never happened I think. I already had a look at the picture quality before that... Those guys had a really short time from idea to product, weeks. Digital and MPEG compression algos killed it soon afterwards. I may still have some docs on it in the attic, lemme see

kept it under the uranium and radium, dunno why, probably radioactive by now... So much dust...

sigh

Ya, big budget but ultimately DOA technology, sometimes seemingly because company like RCA couldn't conceive people wouldn't prefer their inferior technology just because it was made by them, or didn't stop to think or care about what others were working on and would show up on the market in a few years. Being first doesn't always make a winner.

"you spent so much time thinking whether you could, you didn't stop to think about whether you should"

The Hubble 2.4 m main mirror diffraction limit at visible light is about 0.2 micro radians (0.04 arcsec), so from a 400 km orbit, the theoretical resolution is 8 cm. Due to atmospheric instability it is worse than that.

Spy satellite "better than Hubble", what does it mean ? I can think of only two (unlikely) explanations:

1.) The main mirror is larger than KH-11/Hubble 2.4 m diameter. What would the need for larger mirror in spy functions, when the atmosphere limits the actual resolution. The Space Shuttle payload bay or rocket shroud diameter limits the maximum fixed mirror diameter. 2.) A mirror with better surface accuracy than HST in order to be able to take pictures in the UV range. The need for UV accuracy for a spy satellite is questionable due to the ozone layer.

snipped-for-privacy@downunder.com wrote in news: snipped-for-privacy@4ax.com:

can-

Simple google images search on "telescope mirror comparison"

Segmented mirror/active optics?