rxb@rayssdb.UUCP (Richard A. Brooks) (10/04/86)
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Is there anyone out there that knows details on
the Space Telescope (ST)? My questions are :
(1) Will the transmissions from the ST be PUBLIC
DOMAIN? (free to be recieved by anyone with
the satellite equipment to pick them up)
(2) Will the transmissions be scrambled or encrypted
in any way to prevent interception? (other than
encoding necessary to send the video data to
earth)
(3) What Image Processing equipment would be required
to obtain a suitable input to a PC or VCR.
(4) If the answers to the above are favorable, does
anyone have projects in the works to do this?
I would be extremely grateful for any help. The ST is
about the only thing going up that would make it worth
getting a satellite reciever, Who needs HBO when you
can watch the STARS!!!
--
Richard Brooks {allegra, gatech, ihnp4, linus, raybed2}!rayssd!rayssdb!rxb
Raytheon
Submarine Signal Division Have Submarine Will Travel
Portsmouth, Rhode Island
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
The human animal differs from the lesser primates in his passion for
lists of "Ten Best".
-- H. Allen Smithjwp@uwmacc.UUCP (Jeffrey W Percival) (10/09/86)
In article <1322@rayssdb.UUCP> rxb@rayssdb.UUCP (Richard A. Brooks) writes: > > (1) Will the transmissions from the ST be PUBLIC DOMAIN? > (2) Will the transmissions be scrambled or encrypted > (3) What Image Processing equipment would be required > (4) Does anyone have projects in the works to do this? The HST will transmit its data at one of 2 rates (4 kbits/sec and 1 Mbit/sec) to a TDRS satellite, which will forward the data to White Sands. Thence they go to the east coast via DomSat, to be recieved at the data capture facility at Goddard. Processing is done there, as well as sending the signal via microwave link to the Science Institute in Baltimore. Before leaving the HST, the data have Reed-Solomon encoding performed on them, and then whatever blocking is required for the NASCOM transmission process. I don't know much more in the way of details, but it seems to me that it would require a bunch of effort to eavesdrop. We had a thermal vacuum test at Lockheed this summer, with the HST at times being commanded remotely from Goddard, and I know that at times, even *they* were quite pleased to get some data. -- Jeff Percival ...!uwvax!uwmacc!sal70!jwp or ...!uwmacc!jwp
henry@utzoo.UUCP (Henry Spencer) (10/09/86)
> (1) Will the transmissions from the ST be PUBLIC > DOMAIN? (free to be recieved by anyone with > the satellite equipment to pick them up) My understanding is that they are technically private. Space Telescope data is the property of the investigator for some relatively short period (six months? two years?) and then becomes public domain. This is intended to protect things like publication rights while making sure that the results eventually become available to everyone. Eavesdropping on the ST should thus fall under the general rule that radio transmissions not intended for public broadcast may be listened to but may not be passed on to others. (Note that various bits of legislation like local anti-scanner laws and the recent obnoxious anti-interception bill in Congress may modify this.) > (2) Will the transmissions be scrambled or encrypted > in any way to prevent interception? (other than > encoding necessary to send the video data to > earth) The transmission encoding probably isn't going to be trivial, but I don't think there is any plan to deliberately encrypt. > (3) What Image Processing equipment would be required > to obtain a suitable input to a PC or VCR. Basically you'd need something to capture the digital data coming down -- I think the ST transmissions will be all-digital -- into memory or a storage medium. After that, output onto a screen should be trivial, and onto a VCR will involve no more than the normal problems of transferring a computer-generated image to a VCR. The hard part will be deciphering the transmission in the first place, since the ST people probably haven't worried much about being compatible with existing standards. I'd also be surprised if they were using commercial-satellite frequencies, although the relay from White Sands to Goddard may. > ...Who needs HBO when you can watch the STARS!!! Bear in mind that most of the ST data is going to be exceptionally dull except to the astronomer who's waiting for it. Pictures of random star fields will pall quickly. It may be difficult to get sufficiently detailed advance information to pick interesting observing times. I believe the ST's slew rate is rather slow, also, so it will be "in transit" from one viewing direction to another quite a bit. Finally, note that only two of the five sensors aboard the ST are cameras; data from the others is going to be *really* uninteresting to the casual observer. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,decvax,pyramid}!utzoo!henry
jwp@uwmacc.UUCP (Jeffrey W Percival) (10/10/86)
Here's another complication. The ST's High Speed Photometer can sample the intensity of incoming light in several ways: a 12-bit a/d conversion of a photocurrent, and a readout of a photon counting device with either 8, 16, or 24 bit word size. What's more, we can alternate between 2 internal detectors. Our data stream can be quite complex: detector 1 "analog", detector 1 "digital", then repeat for detector 2, back to detector 1, and so on. And the information describing the interleaving is not part of the downlinked data. You'd have to try and figure it out on a case by case basis by staring at the numbers. Whew! -- Jeff Percival ...!uwvax!uwmacc!sal70!jwp or ...!uwmacc!jwp
news@husc6.HARVARD.EDU (USENET News System) (10/12/86)
The data from ST observations will be the property of the astronomer (Principal Investigator) for ONE YEAR. At that time it all becomes public-domain info. From: mmiller@husc4.harvard.edu (Martin Miller) Path: husc4!mmiller As others have said, it will all be unbelievably dull, except in its final, published form. If anyone is interested, there are rumors afoot of an Amateur Space Telescope, I believe a 24 inch to be launched in the 1990s, which will actually transmit its data on ham radio frequencies. I'd tell you more about it except that I threw the brochure away. Tony Lazar STScI, Baltimore