Signal Propagation

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 48767
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Signal Propagation

Post by Stanley » 12 Aug 2015, 03:45

What a splendidly esoteric post! Well up to OG standards. (I think I understood some parts of it.....)
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
Tizer
Global Moderator
Global Moderator
Posts: 10340
Joined: 23 Jan 2012, 19:46
Location: Somerset, UK

Re: Signal Propagation

Post by Tizer » 12 Aug 2015, 09:12

Fascinating stuff...I can hear Michael Caine's voice saying `not many people know that'.

There was some news in the last week or so about a British radio enthusiast managing to communicate with the International Space Station. Is it really something knew? I thought it had been done before.

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 8442
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Signal Propagation

Post by PanBiker » 12 Aug 2015, 11:18

Thanks for your comment Stanley, lots of ways to communicate using the various natural occurrences, aurora, meteor scatter, moon bounce, (yes some actually do that), not forgetting of course some man made methods, the OSCARS, Orbital Satellite Carrying Amateur Radio. Radio amatuers have built dozens of satellites over the years and had them deployed as secondary payloads on commercial launches. The Russians actually deployed six amateur robot satellites by opening the door of an orbiting Soyuz and chucking them out at predetermined deployment points around the earth. This ensured that one or more were always accessible from anywhere on earth at any given time. That was back in the 1980's, amateurs now have digital "funcube" satellites deployed to play with along with the more conventional orbiting repeater talk through types.

To answer Tizers question, yes it has, many times before. From the ISS point of view it can only be done if there is a crew member onboard who is a licenced radio amateur. They will schedule contacts or call during their rest periods.

I had the pleasure of contacting Dr Owen Garriott who was the first American to operate amateur radio from space during his 1983 STS-9 Space shuttle mission. He was a seasoned astronaut by then having crewed Skylab 3 back in the 70's followed by a spell on Spacelab 1. I heard him calling on my 2m mobile transceiver I had in the car just as I parked up on the Main Street in Portpatrick. I had nipped down into town to get some bread, we were camping up on the hill at Dunskey Castle. STS-9 was on an overhead pass 250 miles straight above me, we exchanged signal reports and pleasantries, I have the confirmation (QSL) card somewhere.

Owen K. Garriott
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 48767
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Signal Propagation

Post by Stanley » 13 Aug 2015, 03:07

That figures.... pop out for some bread, have a chat with a man in a space vehicle, go back for breakfast....I told you it was esoteric....
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
Tizer
Global Moderator
Global Moderator
Posts: 10340
Joined: 23 Jan 2012, 19:46
Location: Somerset, UK

Re: Signal Propagation

Post by Tizer » 13 Aug 2015, 16:10

Well done with the Garriott contact Ian. It's amazing what you radio buffs can do!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 8442
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Signal Propagation

Post by PanBiker » 17 Feb 2019, 10:06

Strangely enough, following on from my last post in here. My friend Kevin (M0XLT) sent me an image he had downloaded from The International Space Station celebrating the anniversary of the first NASA astronauts transmissions from the STS9 Space Shuttle, Dr Owen Garriott.

The ISS is currently conducting a series of SSTV (Slow Scan Television) experiments by transmitting a different image on each orbital pas of the station. I captured these two yesterday as the ISS made a couple of medium azimuth passes. The green noise bands are caused by fading on the signal. You can copy about 6 minutes of data on a fairly low azimuth path which equates to about 2.5 data streams of the same image. You can hear it transmitting as it comes over the horizon and the first image may be only partial. There is about a one minute pause and then the transmission starts again. It takes about 90 seconds to transmit the full image. The Space Station transmits on 145.800MHz. SSTV is transmitted as a stream of audio tones and I use an application on my mobile phone to capture and resolve the image. You can get similar applications for the computer if you have your transceivers audio output interfaced as I do. I have downloaded a program for the PC and will give that a go at some point.

The first one celebrates the Curiosity Rover on Mars:

Image

The next pass sent this one featuring the Hubble Space Telescope:

Image

Not bad reception for only a medium azimuth pass from 250 miles altitude.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 48767
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Signal Propagation

Post by Stanley » 18 Feb 2019, 03:46

I can remember when having a telephone was the peak of home technology..... I can see the attraction though but too late for me!
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

Post Reply

Return to “Amateur Radio”