OK, so some of our trails aren't being maintained much anymore... but hey, the government is planning a major, $8B to upgrade GPS! Expect higher accuracy and dependability. Read more about it here.

maybe my old pos garmin will stop taking me around in circles...

LOL... I hope that wasn't a Garmin Geko 301 -- I just got one last week!! :)

actually, it is. it's horrible



















...just kidding. I don't know which one it is. I know it was one of the first ones that came out, it's the size of a brick hah! I'm running old maps on it and surprisingly, it's still half decent

Since I was working in that industry, I had my own Magellan GPS receiver in 1995. Then I upgraded to a Garmin in 1997, and it still works fine to this day. It didn't even take external map data. We've come a long way.

--B.G.--

OK, so some of our trails aren't being maintained much anymore... but hey, the government is planning a major, $8B to upgrade GPS! Expect higher accuracy and dependability. Read more about it here.

The new system is designed to pinpoint someone's location within an arm's length, compared with a margin of error of 20 feet or more today. With that kind of precision, a GPS-enabled mobile phone could guide you right to the front steps of Starbucks, rather than somewhere on the block.

Bob, you read me wrong. I was not negative about GPS at all. Read my post again -- esp. the phrase "expect higher accuracy and dependability".

I hope it allows my gps to get a location fix faster. It seems like it would. Now I just need to reduce the loading time of maps/waypoints/tracks on my gps.

Eugene, most of the things that govern the time to first fix (TTFF) are within the receiver, not in the space segment.

--B.G.--

Wouldn't having a stronger more stable signal make it that much easier for the receiver to do its job?

The signals leaving the satellites are already strong enough and stable enough to light up your receiver on earth, even though they are down around -150 dBm. That is a tiny signal.

One of the few reasons why they might goose up the satellite downlink signal is to make it harder for our military adversaries to jam it. But, if adversaries did that for very long, it would probably provoke an incoming cruise missile or drone attack.

--B.G.--

Ben,

Bob, you read me wrong. I was not negative about GPS at all. Read my post again -- esp. the phrase "expect higher accuracy and dependability".

Edited by blean on 05/27/2010 00:01:44 MDT.

Bob:

I think increasing accuracy will come not from our GPS units but from the qualitative and quantitative improvements of the satellites (the more there are up there and the more powerful signals they can beam back -- then the more accurate the triangulation that our GPS units can compute.

As for GPS units, methinks they will become ever cheaper and yet ever more feature rich.

First of all, civilian GPS receivers only receive the L1 civilian GPS downlink frequency, so they fundamentally get only the precision that comes with L1.

If you had military GPS receivers and could receive L1 and L2 frequencies, you can get much better accuracy. However, you don't have sufficient access, so you can't get a military receiver or the crypto codes to run it right.

Air Force Space Command is trying to spiffy up the newer satellites to have other downlink frequencies as well, with the intention that they can do other snazzy services and stay one step ahead of the EU and Galileo.

Personally, I would not want to have my GPS receiver getting a downlink when it is in a parking garage, because the downlink would be bouncing around terribly to get there, and that is terrible for position accuracy.

I can see a little good out of having more satellites up, but not a lot of good. You already get an overdetermined PVT solution as it is, and the only situation where more satellites would help would be if you were deep in a box canyon. I've had twelve "birds" showing on my receiver, and that is only three times as many as I need.

The receiver's GPS chipsets are getting better because the designers are putting more and more digital correlator circuits in there. That is what is getting you the quick TTFF. They need to design in more heuristics to the receiver user interface.

--B.G.--