Satellite Spy - Forum: MySatKnowHow™ Simple:Press Version Satellite Spy on Login Problem Corrected MySatKnowHow™ Some of you might have encountered a MySatelliteSpy Member Login problem of late. Well, it's been fixed!

Logging in via the Forum here has been fine, but any member logging in using the normal Login form elsewhere on the website will have hit "ERROR - Incorrect Password". Those who reset their password will have seen the same error.

I only learned of this a couple of days ago thanks to a member, Chris Benson. He kindly spent some time investigating it and sent me a detailed 'test report'.

I tracked it down to just a minor 'engine room' problem and corrected it today. At no time were your login details, passwords etc. at any risk, so you can relax on that score.
Please accept my apologies if this glitch has caused you any inconvenience.


Sat, 25 Jan 2014 16:47:33 +1000
Satellite Spy on How Far is a Light Year? MySatKnowHow™ I guess most people know that the velocity of light in a vacuum is c = 2.99792458 x 10**8 metres/second, or about 186,282 miles per second. In materials the velocity is less, depending upon the refractive index of the material. And it's not just light that exhibits this fundamental property but all electromagnetic waves, irrespective of their frequency.

Ole Rømer first demonstrated in 1676 that light travelled at a finite speed (as opposed to instantaneously) by studying the apparent motion of Jupiter's moon Io. In 1865, James Clerk Maxwell proposed that light was an electromagnetic wave, and therefore travelled at the speed c appearing in his theory of electromagnetism. And in 1905, Albert Einstein postulated that the speed of light with respect to any inertial frame is independent of the motion of the light source, which led to his famous Special Theory of Relativity.

After centuries of increasingly precise measurements, in 1975 the speed of light was known to be 299,792,458 m/s with a measurement uncertainty of 4 parts per billion. In 1983, the metre itself was redefined in the International System of Units (SI) as the distance travelled by light in vacuum in 1/299,792,458 of a second. As a result, the numerical value of c in metres per second is now fixed exactly by the definition of the metre.

All interesting stuff, but what is a light year? It's simply the distance travelled by light in one year; basically, a heck of a long way!
As a close-to-home example consider a phone call which happens to go via a geostationary satellite as opposed to the more usual fibre optic link. These satellites sit in a circular orbit some 36,000km above the equator and the round-trip delay of the microwave signals from ground to satellite and back to ground is about a quarter of a second, which is why one hears that delay in speech.

But to really put the concept of a light year into perspective have a look at this blog post by Bruce McClure in EarthSky's Astronomy Essentials
This short article really puts things into perspective and gives some useful "rules of thumb" which you can get your head around.

Sat, 27 Jul 2013 21:52:14 +1000
Satellite Spy on Someone Else Wrote Maxwell's Equations MySatKnowHow™ That's really interesting and informative, Chris.
You've obviously spent a lot of time researching this, so thank you very much indeed for sharing.

Speaking of Oliver Heaviside, many people will have heard of the Heaviside Layer. Heaviside advanced the idea that the Earth's uppermost atmosphere contained an ionized layer known as the ionosphere; in this regard, he predicted the existence of what later was dubbed the Kennelly–Heaviside layer. However, it was not until 1924 that its existence was shown by British scientist Edward V. Appleton, for which he received the 1947 Nobel Prize in Physics.
It is this layer that makes over-the-horizon propagation of medium frequency radio waves possible.

Wikipedia has a comprehensive summary of Heaviside's many achievements =>

Tue, 23 Jul 2013 16:23:02 +1000
Christopher Benson on Someone Else Wrote Maxwell's Equations MySatKnowHow™

Satellite Spy said

A controversial article in the IEEE News Source "The Institute":
This will wobble those folks who are into electromagnetics et al .....

It seems that the title of that IEEE article should have been "Someone else reformulated Maxwell's [original] equations into manageable form". I don't wish to take away credit clearly due to Mr Oliver Heavisde; Maxwell's original formulation of 20 scale-dependent equations were "altogether too Scottish" for most engineers (see [1]). Heaviside reduced and reformulated 12 of those 20 equations into the four we know today. Heaviside left school at age 16, and never attended a university or even a college. He was an "amateur" in every sense: although he lived to the age of 74, the only employment of his life was as a telegraph operator starting at age 18. His Uncle Charlie got him the job (see [2]). After just six years into his only job, at age 24, he resigned to focus on a book. He had come across a copy of Maxwell's "Treatise on Electricity and Magnetism" and the rest, as they say, is history. Or in Heaviside's own words:

"I was very ignorant. I had no knowledge of mathematics [...] It took me several years before I could understand as much as I possibly could. Then I set Maxwell aside and followed my own course. And I progressed much more quickly."

Of course he had to quit his job. Maxwell's brand new treatise was 375 pages laid out in 324 sections across two volumes of intense academic discussion as well as practical observations. It wasn't exactly written for the uneducated reader. Despite that and 50 subsequent years of unemployment and poverty, Heaviside achieved much. He independently derived a continuous-time generalisation of Laplace's z-transform, and even invented and patented coaxial cable. He later became a Fellow of the Royal Society - not bad for a poor uneducated amateur from Camden Town in London.
[1]. Maxwell's Equations were indeed written by others BEFORE him, though. The four standard equations in usual order were originally formulated by Gauss, Gauss, Faraday, and Ampere respectively - though with modifications to all but the first by Maxwell. Maxwell's treatise clearly credits Gauss and Faraday in its preface.
[2].. Oliver Heaviside's Uncle Charlie was Sir Charles Wheatstone, famous for the Wheatsone bridge (an electrical instrument that he didn't invent), but not famous for the concertina (a musical instrument that he did invent).
Chris Benson.

Tue, 23 Jul 2013 11:59:39 +1000
Satellite Spy on Pole Dancing - Where is True North? MySatKnowHow™ If you weren't confused before, then you will be after you watch this.

Actually, you won't. This is an excellent, rapid summary about the earth's magnetic fields and their origin within our little globe. For me, a "must watch" video.

Many thanks to Rob Drysdale (@projmgr on Twitter) for alerting me to this little gem.

Tue, 02 Jul 2013 00:59:04 +1000
Satellite Spy on The Problem of Space Debris MySatKnowHow™ Many people are not aware of the very real and worsening problem of space debris. Here's a Lockheed Martin video that gives a graphic overview of the problem.
For example, when a satellite is launched there are very specific "holds" put into the launch window so that specific pieces of space junk are avoided during the rocket ascent and the injection of the payload into orbit.
In the future, look out for red, amber and green lights in the sky. Not UFOs - traffic lights!

Mon, 01 Jul 2013 23:02:44 +1000
Satellite Spy on Cooperation Agreement between NASA and the Italian Space Agency MySatKnowHow™ NASA and the Italian Space Agency just signed a cooperation agreement
For me, it was really nice to see this current photo of my old friend and colleague, Enrico Saggese (who is now President of the Italian Space Agency) sitting down with Charles Bolden, NASA's Administrator, to cement this agreement.

Share photos on twitter with TwitpicImage Enlarger

Enrico and I were involved in the setting up of EUTELSAT and negotiating the transfer of "my" ECS satellites (well, ESA's) to "his" organisation (well, EUTELSAT).
Enrico was always a good negotiator! Congratulations to both NASA and the Italian Space Agency Smile

Thu, 20 Jun 2013 22:39:07 +1000
Satellite Spy on Thwart Hackers and Eavesdroppers - Get a Strong VPN MySatKnowHow™ Recent news stories about the possible interception and logging of people’s emails and internet activities have made Hacking and Eavesdropping very hot topics indeed. In a way, that’s a good thing because the majority of people have no idea just how prevalent hacking and interception already is. Not necessarily by Governments, but by the many criminal elements who are out there trying to steal your money and even your identity!

To read more and find out how easy it is to avoid being hacked and snooped upon, then read the full article here.
The blog post has links to other information sources as well.

If you're concerned about identity theft, the security of your internet connection or anonymity for your online presence, then I most definitely recommend Strong VPN. Protection for mobile devices and iPhones too! Just follow this link for more information.

Wed, 19 Jun 2013 17:23:29 +1000
Satellite Spy on Where's the Earth Station? MySatKnowHow™ Yes, I've noticed similar glitches on GE, and not only on this particular view.

I worked at this earth station for over two years, on & off. I worked for ESA in The Netherlands and spent more time here than there for a few years. Setting up and executing the OTS-1 satellite in-orbit testing.

I could write a book about the area - both experiences and adventures! Here's but one here
That article also has a link to another, when I was in an earthquake there. A dangerous place!

Sun, 09 Jun 2013 21:39:52 +1000
Satellite Spy on ESA's Ariane Launch Complex. So Just Where is Kourou? MySatKnowHow™ How many people actually know where ESA's Ariane satellite launch site at Kourou is? Sure, French Guiana in South America but exactly where?
It's here, of course:

[mapsmarker map="3"]

And just over a year ago Europe's new satellite launcher, VEGA, was given it's first launch from here. See the article

Sun, 09 Jun 2013 21:18:29 +1000
Satellite Spy on Some Recommended Satcom Books MySatKnowHow™ Adrian,
I think that is one of the hardest questions I’ve ever been asked! Why - because I’m not that familiar with recent introductory books on satellite communications.
However, a number of the best books have undergone many revisions and updates over the years. These core books, by respected authors, have survived the test of time. I will identify but two, though of course there are so many other good books out there:

“Introduction to Satellite Communication” by Bruce Elbert. Published 30th June 2008. You can find it on Amazon here

“Satellite Communications Systems: Systems, Techniques and Technology” by Gerard Maral & Michel Bousquet. Published 1st February 2010. You can find it on Amazon here

There’s another book, though older, which is excellent and which I use all the time. It does dive deep into the maths etc. and might be better as the next book to get after an introductory book. When you’re looking at the two above, do an Amazon search for “Digital Communications by Satellite” by James J. Spilker. I see they have a number of used ones from $6.78 – a steal at that price. I paid well over $100 for my copy quite a few years ago!
If anyone else can recommend their best introductory books, please let everyone know by posting a reply on the forum.

Sun, 09 Jun 2013 19:45:38 +1000
Adrian Rose on Some Recommended Satcom Books MySatKnowHow™ So, for someone who works in the satellite industry, but not in SatComs, what would you read first as a primer?

Thanks, AdrianR

Sun, 09 Jun 2013 17:08:01 +1000
Adrian Rose on Where's the Earth Station? MySatKnowHow™ Yes, I can, but it would be cheating as I've worked there. Finding it on GE is interesting, as it disappears at some zoom levels it's there, and some it isn't.


Sun, 09 Jun 2013 17:00:37 +1000