Do major earthquakes wreak havoc with dish setups?

[Bob2011]

I was just reading where the earthquake in Japan shifted some parts of the country 13 feet to the east and the earth's axis up to 6 inches. How does this change things on the ground for dish setups? So did everyone in Japan have to go out and adjust their dish to a new position?

Japan’s earthquake shifted balance of the planet - Yahoo! News

 

[Cadsulfide]

I think that right now it is the least of their worries.

 

[Mikey11]

So did everyone in Japan have to go out and adjust their dish to a new position?

i am pretty sure their satellite dishes are the least of their concerns or worries at this point in time....did they have to adjust their dishes?....most of them are probably floating around in the ocean right about now....or buried under 20 feet of water and cars and debris....

 

[Mikey11]

I think that right now it is the least of their worries.

beat me to it

 

[harshness]

As long as the pole remains plumb and doesn't rotate significantly, the signals will continue to be picked up.

 

[stanleyjohn]

I hope i never have to find out! Not very likely here in Ct

 

[NotTy]

Back in 93 or 94, we had an earthquake that bounced the car around, whipped the overhead wire around, trees were flailing, stuff fell off the shelves & out in the pasture, you could see the ground actually moving, but it didn't affect the satellite dish at all. That was the first thing I checked. Then I asked the wife if she was oK.

 

[Dee_Ann]

Wouldn't it be far, far easier for them to make a tiny adjustment to the satellites than it would be for 80 bazillion people having to go out and fiddle with stuff they don't understand and or send out millions of technicians to readjust dishes all around the world?

Just sayin..

 

[Bob2011]

I wasn't trying to be insensitive with the question but it just seemed interesting to me. I tried moving the location on dishpointer.com to see how long before there was a change and it took about a mile to register a tenth of a degree change in any number. So probably its meaningless for anything but the largest of dishes and weakest of signals.

Its still an interesting question though if the island of Honshu instead of moving due east it turned clockwise or counterclockwise.

 

[greg47]

It moved the japaneese islands 8 feet to the east, just being off a a little bit here on earth means hundreds of miles out in space so I would say that that the dishes would need a repoint for sure. I saw where all the GPS & naval navigation positioning is now incorrect so when things settle down there will be a lot of repoints needed. If ground moved and the mounting pole or attachment is not plum and true anymore that will have to be corrected also.

 

[cracklincrotch]

It moved the japaneese islands 8 feet to the east, just being off a a little bit here on earth means hundreds of miles out in space so I would say that that the dishes would need a repoint for sure.

I'd disagree with that. Think about it this way. It's night time. Look up at the moon. Now move eight feet to the east. Your view to the moon hasn't changed. One might argue in the instance of moving yourself eight feet a tree or building might obscure your view after moving but in the case of Japan the whole island moved, trees and all.

The average sat is 35000 to 45000 kilometers away from you. Moving a mount eight feet in any direction isn't going to make a difference that anyone would see. This excludes of course line of sight issues or avoiding sources of TI.

I've got a couple of friends that were adamant that a dish had to be on a roof to work. I just explained to them that the extra 10, 20, etc., feet in the air makes no difference in receiving signals from that far away. For the same reason dishes do not have to be on a roof to work.

The closer the targeted object is to the viewer the more likely the aim would need to be changed. But at geostationary positions around the equator the distances are so great that it's not worth even looking at tweaking.

Sure, if the mount is no longer plumb or the dish azimuth has changed it will need to be fixed.

 

[NotTy]

Another instance was when I moved 30 miles from where I originally set up my dish. I parked the dish on G5, (at that time, G5 still had transponders 2-24). unbolted the dish mount that mounts the dish to the pole & moved the entire dish assembly. Once I had a new pole mounted in concrete at my new place, 30 miles away, I remounted the entire assembly onto the new pole, found G5, locked down the bolts, & the entire satellite track was still on.

 

[Dee_Ann]

I'd disagree with that. Think about it this way. It's night time. Look up at the moon. Now move eight feet to the east. Your view to the moon hasn't changed. One might argue in the instance of moving yourself eight feet a tree or building might obscure your view after moving but in the case of Japan the whole island moved, trees and all.

The average sat is 35000 to 45000 kilometers away from you. Moving a mount eight feet in any direction isn't going to make a difference that anyone would see. This excludes of course line of sight issues or avoiding sources of TI.

I've got a couple of friends that were adamant that a dish had to be on a roof to work. I just explained to them that the extra 10, 20, etc., feet in the air makes no difference in receiving signals from that far away. For the same reason dishes do not have to be on a roof to work.

The closer the targeted object is to the viewer the more likely the aim would need to be changed. But at geostationary positions around the equator the distances are so great that it's not worth even looking at tweaking.

Sure, if the mount is no longer plumb or the dish azimuth has changed it will need to be fixed.

But what if the island skewed? As in twisted rather than simply slid left or right or up or down? Wouldn't that mess it up?

 

[SatelliteAV]

The minimal shifting of a dish of this event would not be significant in areas outside of the fault. Major surface heaving or the island skewing (as Dee suggests) would promote a slight alignment issue.

Maybe a brain on this forum could calculate how much an axis shift reducing a 24 hour day by 1.8 microseconds affects the aiming at a position 23,000 miles above the equator from a determined longitude, latitude and altitude.

For DTH installations with small apeture, wide beam width dishes, which are reasonably peaked at a satellite drifting somewhere within the box, these installations would never see this small of alignment shift. In fact, it might actually improve some installation's aiming!

 

[cracklincrotch]

But what if the island skewed? As in twisted rather than simply slid left or right or up or down? Wouldn't that mess it up?

Yes. But like Brian and I had said, if the azimuth had changed, the dish would need to be fixed.

 

[AcWxRadar]

One point to be made, regarding the whole earth axis shifting, is that the satellite positions are controlled very precisely from the ground control stations, Therefore, any error introduced in this way would nearly immediately be detected and corrected to put it back in the same position (well actually a NEW position since the satellites didn't move, the earth did). But, this would be for communication satellites.

I don't know how they would handle a GPS satellite! What would you do? Would the satellites be corrected? Or would you remap the globe? Yeah, think about that one!

RADAR