how close togeather are sattlellets in space

[joem919]

after scrolling n scrolling threw the chat and going out fiddleing with the dish just curious but realy how far apart are all the sats ?i mean if i move a cpl inches n the dish im on amc 4 then move it not even a inch to 2 inches im on amc 1 ? are they all really that spread closed to each other ?

 

[Mr Tony]

They are spread in most cases 2 degrees apart (93, 95, 97, 99W etc) but since they are 22240 miles up in space when they come down to earth they seem to be right close to each other.

When I aim the 6 footer at C-Band satellites I can sometimes get 2 sats at once

 

[joem919]

wow 2 degrees ? that seems so close so in moveing the dish i should move it like what a half a foot or 2 feet ?

 

[Wescopc]

we are talking about 2 or 3 millimeters on the pole (less then 1/10th of an inch).
Bob

 

[Mr Tony]

yep. I've moved a dish 1/16" on the mast (as is mark on the mast and move it 1/16") and it was 6 degrees

 

[joem919]

i learn more in more from this sight it just shocks me.

 

[joem919]

ok so them being so close what about the arch do u need to change the settings each time or leave it as it sits ?

 

[Mr Tony]

the elevation?

it depends on where you are in the world and how many sats are next to each other.

Where I am located (Minneapolis, MN) I'm at 93W.....so thats my true south (highest satellite in the sky)...for me there are a bunch of satellites that are at or real close to the same elevation...see the below pic...anyone in the midwest kinda runs this same setup...a bunch of sats near the same elevation

but for someone say on the coasts (E or W) the amount of satellites that are the same elevation is probably smaller due to the amount of sats in that area. West coast especially. The gap for sats is more than the Midwest...west coast would have 129,127,123,121,116.8,113,111.1,107.3...theres some big gaps there versus midwest where its every 2 degrees from 83 to 107.3

 

[joem919]

ya somehow i dont know why it just seems amc 1 and amc 4 i can get in im gonna play around with it tomorow i keep following all your advice u give me and it is paying off and again im a rookie on the east coast

 

[bloomdog]

To answer the original, question:

The approx. distance bewteen any two satellites can be roughly calculated as follows:

The distance = 2 x pie x r x degrees bewteen satellites/360

Now the distance is usually referred to as "arc" as it not a straight line, but is a measurement over a curved line (i.e. the circumference of a circle); and "pie" = 3.14

So, for sake of round numbers, if the clark belt is approx. 22,000 miles above the surface of the earth, and the earth's radius is approx. 4000 miles, then, the "r" in our equation becomes 26,000 miles.

Doing the rough math, we get 453.5 miles for every one degee of separation bewteen satellites. So, if two satellites are 2 degrees apart, then the arc between them is approx. 900 miles long. The straight line distance is a bit less, but this is a good start.

This is a VERY ROUGH approximation. Interesting, though, eh?

 

[joem919]

wowsers

 

[joem919]

im getting better spent some time in the rain but somehow im getting partial g 25

 

[mastermesh]

set up a htoh motor... makes it easier to get elevation/skew/azimuth since you more or less set it up and it automatically changes everything for you after you finally get it set up just right.

 

[joem919]

i check that when i call sadouns tomorow because im just gonna get a new system this 1 is wore out

 

[satcom1]

Bloomdog, that really puts things in perspective. I worked at RCA Americom in the early 80's. We had a STATION KEEPING requirement of keeping the satellite inside an area about the size of a football stadium. This was done with slight nudges with the Hydrozen Jets.

 

[bloomdog]

If you think about how fast the birds are moving through space the distance of 800 miles or so between them is really not very great. As I recall, the speed of the earth's rotation at the latitude of the clark belt is around 900-1000 miles per hour. Since the satellites are geosynchronus (they stay in the same place above the earth at all times) and are some 22,000 miles above the earth, their speed is on the order of 6800 mph (see: How Orbits Work ) (too tired to do the math, but this seems right to me, qualitatively). At this speed, the brids are flying at 113 miles per minute, so if they are really only 8 minutes apart. They're next door neighbors in a reference frame of space.