Dish Network's Dish Earth

A picture of Earth, supposedly from a camera on one of Dish Network’s satellites. Is this for real, or a conference camera in their office looking at a photo from National Geographic? :slight_smile: Channel 212.

I guess it’s the real deal. Would have thought a satellite in geosynchronous orbit would not be able to photograph the entire Earth, but apparently the camera lens is very wide-angle.

Oh, and they caught a UFO!

A geosynchronous orbit is 22,000 km up. I don’t think the satellite needs a wide angle lens at all.

Actually, from a geostationary orbit, the Earth only subtends an angle of about 16°. That’s about the angle subtended from your index to pinky finger if you make devil horns at arm’s length.

This could be captured (mostly filling the frame) with a 135mm lens on 35mm film. That’s a moderate telephoto…no need for a wide angle at all.

Hmm, at 22k miles, the Echostar is note quite 3 Earth diameters (8000 miles) away; I wonder how many degrees of the sky the Earth is at that distance? I get 11ish degrees, which probably isn’t right. ETA: doh! Thanks, aerodave

That’s pretty cool. :cool:

Eh, I messed up. It’s more like 20°. But it still almost fits in the field of view of that 135mm lens.

I’m surprised that a spot beam can work. These are Wildblue’s but I presume Dish Network delivers local stations in the same manner. I wonder if they can be aimed or if an area is served by whatever transponder happens to hit it.

I periodically browse through the All Channels to see what’s gone to HD and what’s new and worth entering into Favorites. Doing so a couple of days ago made me aware of this broadcast. While it’s not exactly thrilling or cutting edge, just the concept is pretty cool and a great teaching aid for younger kids.

I found this thread in a cautionary search before starting it myself. This is cool, viewing the Earth in almost real time from 22,000 miles out from the comfort of your couch. Surprising to see that so much of the surface on avearge is obscured by clouds. I wonder if the ISS or auroras would ever be visible?

If nothing else, talk about gaining some perspective.

Dish says the cameras have 12mm lenses and have a 30x22.4 degree field of view.

I’m not at all convinced of 12mm though, and think someone may have just lost a zero - that’s bug-eye territory with a field of view so wide that photographers have to be careful not to get their feet into a shot, and the lenses on the satellite cameras look pretty small and un-buggy.

When I first saw Dish Earth my first thought was this was soon going to be the favorite channel for TV-watching stoners everywhere.

I was house-sitting for a vacationing friend last week when I discovered this offering. Out of however many hundreds of channels available it became my default choice and I’d leave it onscreen with the sound off. Every so often while feeding the dogs or whatever, I’d look over at the TV and go, “Yep… Earth’s still there.” :slight_smile:

The NASA Channel used to show something like this during the day when nothing else was going on. I think it was called Earthview or something like that.

I was actually thinking about Dish Earth today. Why does the satellite seem to be positioned over the middle of the Pacific Ocean near the equator?

Are all the satellites for TV/radio there?

Is this why my Dish Network dish is pointed almost horizontal and facing southeast? Is this the reason my XM satellite radio loses the signal when I go under trees or there’s a hill in the way?

Why not put the satellite over the middle of the country, so everybody can get good reception no matter what?

I would never had these questions if not for seeing Dish Earth!

An orbit over the equator at 22,000 miles above the earth moves at the same speed as the earth rotates. It appears to be still to our dish antennas on the ground. Science fiction author Arthur C. Clarke figured this synchronous orbit thing out, and the orbit they are in around the equator is called the “Clarke Belt.” :slight_smile:
The ones I use here in Arkansas are at 119 Degrees and, I believe, 109 degrees, almost due South from the middle of the USA. Dish Network has four satellites, a pair for folks in the Eastern USA, and another pair for those in the West. With my C Band satellite receiver, I can’t see some satellites intended for use on the Eastern seaboard, or some intended for the far Western US.

TV satellites carry a lot more information than the radio satellites and must be aimed carefully. Radio satellites can keep receiving as you drive around in your car, but lose signal in a tunnel because the satellite signals can’t penetrate the tunnel wall.

At the equator, satellite dishes point straight up. In the Northern hemisphere, they point South, and in the Southern they point North. The angle varies as one moves North or South from the equator.