Rocket Carries New Gps Satellite Into Space

[harizanov]

http://www.cnn.com/2005/TECH/space/09/26/r...h.ap/index.html

[Neo_Geo]

Does anyone know what PRN (psuedo random number) this satellite will be, and when we might see it on our satellite pages?

Edited September 26, 2005 by Neo_Geo

[+RumJungle]

Visit the USNO site -- :

 

Link to list

Link to Current GPS Constellation

 

Looks to me that it is PRN 17 vehicle 53. They are not showing the type of oscillator reference. Most likely a rubidium.

[+jacques0]

The launch of the satellite, as well as a discussion of its benefits, is also discussed in this article. I'm intrigued by these paragraphs:

 

The third new signal will be a second frequency for civilian users, reducing the navigation errors caused by the layer of charged particles in the Earth's upper atmosphere.

 

"This is a pretty huge step," said Air Force Colonel Allan Ballenger, head of the GPS programme office, speaking to the Associated Press. "The military has been using two frequencies from day one of GPS. This will be first time that we are adding a second frequency for civilian users."

 

Often, on these forums, the question comes up of whether solar flare activity affects gps performance. Just recently, there were several questions posted about erratic readings and these coincided with the eruption of an X Class flare on the Sun. I wonder if the second frequency referred to in the quoted paragraphs, above, will address this?

[+Right Wing Wacko]

The launch of the satellite, as well as a discussion of its benefits, is also discussed in this article. I'm intrigued by these paragraphs:

 

The third new signal will be a second frequency for civilian users, reducing the navigation errors caused by the layer of charged particles in the Earth's upper atmosphere.

 

"This is a pretty huge step," said Air Force Colonel Allan Ballenger, head of the GPS programme office, speaking to the Associated Press. "The military has been using two frequencies from day one of GPS. This will be first time that we are adding a second frequency for civilian users."

 

Often, on these forums, the question comes up of whether solar flare activity affects gps performance. Just recently, there were several questions posted about erratic readings and these coincided with the eruption of an X Class flare on the Sun. I wonder if the second frequency referred to in the quoted paragraphs, above, will address this?

But will this new signal require new receivers?

[peter]

But will this new signal require new receivers?

Yes, but it'll be some time before there are enough dual civilian frequency satellites up there to make a difference.

 

The main advantage of having two frequencies is to allow better modeling of the delays as the signal passes through the atmosphere and therefore provide better accuracy without the need for corrections from WAAS, EGNOS or other SBAS systems. The two frequencies are delayed by slightly different amounts so by comparing the two the receiver would be able to estimate how much the total delay is for each signal.

The military signal has already made use of two frequencies but civilian receivers have been limited to a single frequency up to now.

[+Allen_L]

Spaceflightnow.com article http://www.spaceflightnow.com/delta/d313a/ says

Ballenger said some civilian receivers already on the market can pick up the new signal, while older units will have to be replaced.

Of course it didn't mention which ones can already pick up the new signals.

[+jacques0]

This will a be an interesting discussion thread to follow. Some good info coming out already (thanks, Peter, for your input re: delayed signals).

 

Presently, I think only the eXplorist 200 can receive the new frequency (OK, just kidding. Wishful thinking. I guess I'd better begin saving for a new GPSr).

[+Rick618]

This article wasn't much better other than to id the sat.

 

http://www.isrjournal.com/story.php?F=328116

 

The U.S. Air Force placed an upgraded Global Positioning System (GPS) in orbit June 23.

 

The Lockheed Martin-built satellite was launched from Cape Canaveral, Fla., aboard a Boeing Delta II rocket at 6:54 p.m.

 

The satellite, designated GPS IIR-12, will join 28 other operational GPS satellites now on orbit, and will improve global coverage and increase the overall performance of the GPS constellation, Lockheed Martin said. The company has delivered nine more of the satellites to the Navstar GPS Joint Program Office, Space and Missile Systems Center, to sustain the GPS constellation.

 

The satellite was the 11th launch of the new-generation GPS IIR spacecraft. The satellite’s upgrades include an advanced antenna panel, which will increase power for GPS receivers, the company said.

 

The Global Positioning System allows any properly equipped user to determine precise time and velocity and worldwide latitude, longitude and altitude to within a few meters. Although originally designed as a guidance and navigational tool for the military, the system has many civil and commercial applications, such as mapping, geodetic surveys, and search and rescue operations.

[+GPSlug]

Make sure you don't confuse commercial civilian users and consumer civilian users.

 

Commercial civilian receivers have been using the second frequency (L2) for a long time. There are some tricks needed to track that military signal which makes the quality not as good. But it's been very useful in the commercial domain.

 

It will be a few years before there are enough L2C (the new civilian signal) capable satellites are up to justify the added expense of the second frequency in consumer units.

[+EScout]

It looks like the one just launched will show as number 17, but is not usable yet. I know that it will have the new frequencey, but will it send WAAS corrections like the current 2 WAAS sats?

[peter]

will it send WAAS corrections like the current 2 WAAS sats?

A new communications satellite was launched earlier this month (Sept. 9th?) that will broadcast WAAS corrections from the W107° equatorial slot. There's also a launch scheduled for later this week of a satellite that will be located at W133° that will also broadcast WAAS signals. Not sure when either of these is scheduled to have testing complete and start sending operational correction messages. Should make reception of WAAS much easier in the central and western states and Canada.

[+EraSeek]

will it send WAAS corrections like the current 2 WAAS sats?

A new communications satellite was launched earlier this month (Sept. 9th?) that will broadcast WAAS corrections from the W107° equatorial slot. There's also a launch scheduled for later this week of a satellite that will be located at W133° that will also broadcast WAAS signals. Not sure when either of these is scheduled to have testing complete and start sending operational correction messages. Should make reception of WAAS much easier in the central and western states and Canada.

Supposed to be ready sometime this fall. Beside being easier to get the signal due to position, it is also security of the system. With the WAAS sats up now if you loose one you loose half the country. With the new ones you are covered if one goes down.

 

Edited September 27, 2005 by EraSeek

[+EScout]

Good news on the 2 new WAAS sats (Map shows one at W125 and one at W107)..

Will existing units be able to identify and use these, or is firmware update needed? Will they show on magellan's screen as a W like the 2 existing ones? Will firmware use just the 2 closest/strongest WAAS, or more than 2?

 

I often receive both of the current ones. Yesterday I got 11 sats plus the 2 WAAS for 13 total on my eXplorist and have seen 14 total.

[peter]

The new WAAS birds shouldn't require firmware changes.

 

The Galaxy 15 launch has been postponed to mid-October due to some problems with the Ariane-5 vehicle. Not sure why the map indicates W125°. That's the slot for the Galaxy 14 satellite so maybe it was originally supposed to be on that one.

http://hraunfoss.fcc.gov/edocs_public/atta...A-05-2509A1.txt indicates that Galaxy 15, with the WAAS channel, will be tested at 150° but then moved to W133° for normal operation.

[jcc123]

All this means is that we'll all soon be buying new GPSs to take advantage of the signals.

Edited September 29, 2005 by jcc123

[+apersson850]

Or still use the capabilities of the receivers we have. After all, positioning within 5-10 meters everywhere on the earth is pretty amazing, even if we now have got used to it.