View Full Version : What direction is Azimuth?
JayeDVXIII
02-05-03, 09:25 AM
Hey everyone
I don't know how to word this question; so please bear with me.
I live in a large house in Roswell, Georgia 30076 and currently have a Dish 500 system and a secondary dish pointing at 61.5. The dishes are pointing in extremely different directions and elevations. The Dish500 is on a corner of my deck and the 61.5 dish is on the ground on the other side of the house pointing in an entirely different direction (sorry, I dont know what direction LOL) . I am moving to a condo in in Wilsonville, Oregon 97070 that has a balcony which faces due south with a pretty much unobstructed view ( on a hill).
I do not have such a large area anymore to mount dish antennas, so my primary concern is being able to successfully point my dish 500, but I really really really want to be able to use the secondary dish :-(
I realize that since I am moving to the other side of the country, my dishes will be pointing in different directions (Southeast instead of Southwest); however I was told that I only have to make sure that I at least have some sort of Southern view. I was also told that since I am moving to the Pac NW, it would be better to use 148 instead of 61.5; especially if I have limited mounting space. The international programming I get (RFI and TV5) is also repeated on 148, so I have no problem with this..
My question is, is 148 a lot closer to 119/110? Also, I have the azimuth/elevation calculator for my new zip code-- The Dish500's azimuth is 150 degrees, and it says the dish pointing at 148 degrees needs an azimuth of 195 degrees. My question is this, is 195 degrees further WEST or further EAST than 150 degrees?
Thanks
Etienne
Chris Blount
02-05-03, 09:39 AM
Hi Jaye and welcome to DBSTalk! :hi:
195 degrees is farther WEST. What that means if you are standing behind your Dish 500, it will be pointing in a southeast direction while your Dish pointed at 148 will point a little off to the right. And yes, 148 is much closer to 110/119. Hope this helps.
JayeDVXIII
02-05-03, 09:56 AM
LOL "lurker"? I joined..I"m not a lurker! :-)
chris, yes the reason I'm concerned, as you may know, in Atlanta, 61.5 is a completely different direction than 110/119..and you know that in a condo/apartment, you dont have balconies that point in all directions..it was a big chore just to make sure they got one for me that pointed south ;-)
I'm just hoping that I'll have enough "look room" to see 110, 119 and 148...one day I want to try the new "toroidial" dish too
Martyva
02-05-03, 11:04 AM
Think of 180 degrees azimuth, as being due south of your home. 195 would be SSW from your location.
JayeDVXIII
02-05-03, 12:21 PM
This is sort of a side question, but if you'ren ot pointing at 110 or 119 degrees, (even though that is what the satellite is called) then why are they called 110, 119 and 148?
Martyva
02-05-03, 01:02 PM
i think that's their position on a longitudinal grid? 22,300 miles above the equator.
RJS1111111
02-05-03, 03:04 PM
Originally posted by Martyva
i think that's their position on a longitudinal grid? 22,300 miles above the equator.
There's a name for the geostationary arc;
can't think of it; the *?* belt.
Note that the azimuth angles are also corrected for
local magnetic anomaly, meaning that you can use a
compass to find the angle, instead of having to base
it on true north. This correction is old enough, though,
to start making some of these pointing angles not quite
correct to the nearest degree. Magnetic anomaly can
change significantly in many areas over the course of
a few years. An occasional new survey is needed to
keep track of it. I think it has something to do with
changing currents deep within the earth. The overall
magnetic field is currently decreasing. Many people
are convinced that it periodically reverses itself.
JayeDVXIII
02-05-03, 03:52 PM
so I can't base my azimuth location on just looking at a compass?
DarrellP
02-06-03, 05:39 PM
Jaye, I am 10 miles south of Wilsonville in Woodburn and have the same setup you do. My dish for 61.5 is pointing about 65 degrees to the east in relation to the Dish 500 and the elevation of the dish is 12 degrees. The 61.5 dish looks like it is pointing toward the ground.
I bought a 24" dish because I was losing 61.5 to rain fade. The 24" dish has pretty well eliminated that issue. Unless you really want the Demo channel, there is no reason not to use 148, it is at a higher elevation and should be less prone to rain fade.
As far as space goes, you can mount both dishes on the same pole, or a corner of the house or a 4x4. Before I moved, I had them both mounted on a support 4x4 for a second story deck and it worked just fine. Luckily the beam was facing South so I mounted the Dish 500 there and mounted the 61.5 to the East facing side of the beam.
Welcome to the Hood! (Mt. Hood that is).
JayeDVXIII
02-07-03, 09:32 AM
haha..i'm from Oregon, so it's more of a "welcome back to the Hood" :-)
I am moving back because I finished school last November and hate Atlanta, can't wait to get back.
Woodburn eh? I seem to remember lots of open space to mount a dish and a really cool outlet mall there.
TNGTony
02-07-03, 10:11 AM
RSJ,
The name you are thinking of is the Clarke Belt. This was named after Arthur C. Clark (author of 2001: A Space Odyssey among many, many others) who first proposed geostationary satellites 22,300 miles over the equator in one of his stories.
The satellites are stated as being at 110, 119, etc because that is their longitidinal position 22,300 miles over the globe.
As to what direction the Azimuth (on Dish) means...
000 = Due north (magnetic)
045 = Northeast (magnetic)
090 = Due East (magnetic)
135 = Southeast (magnetic)
180 = Due South (magnetic)
225 = Southwest (magnetic)
270 = Due West (magnetic)
315 = Northwest (magnetic)
359 = Almost Due North (magnetic)
360 = 000
See ya
Tony
The numbers assigned to the satellite locations (61.5, 110, 119, 148, etc.) are the longitude that the satellite. For example, the 110 satellite is over the equator at 110 degrees West longitude.
The azimuth is the angle you point the dish at. The azimuth is determined by where you are on the earth, and the location of the satellite. The math for doing this is pretty complicated, as it involves spherical geometry. But you don't have to worry--in the receiver setup screen (both D* & E*, I believe) there is a way to type in your zip code, and it will give you the correct azimuth & elevation (and skew for the Dish500 dish) for that location. There are also websites that will do the same computations for you. :)
DarrellP
02-07-03, 05:22 PM
Woodburn eh? I seem to remember lots of open space to mount a dish
Yeah, I lucked out and found a new home that borders the Urban Growth Boundary and there is a farm on the other side of my fence, so I will never have neighbors to the North. The land is very flat so I have no obstructions at all, even for 61.5.
The Outlet Mall is still a pretty hot shopping spot. I've never been there, but the place is always jam packed.
Originally posted by JayeDVXIII
My question is, is 148 a lot closer to 119/110?More important than being closer, it will be at a much higher elevation. I know there are some people able to get 61.5 as far north as Oregon, but its elevation will be extremely low. Here in the SF Bay Area it's around 14 degrees. The "look angle" on the dish is actually slightly downward because of the offset of the head, which looks "up" when reflecting off the dish.
The result of the bird being at higher elevation is much better signal strength, resistance to rain fade (which you won't get in Oregon ... heh heh :-), and a better chance of clearing buildings and trees from more locations. When I re-aimed from 61.5 to 148, the result was quite good, even though I already had a very good signal from 61.5. My only regret is that I won't be able to get HD Demo if/when I ever get an HD-capable receiver.
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