Garmin takes FOREVER to acquire satellites!! what gives

[MrMatt]

I got a nuvi (255W) recently. It works fine, but the problem is it takes about 6 minutes to acquire satellites. And even then, it takes about another minute or so to pin down where I am. I live about 1 mile from downtown Boston so I know it's not an issue with being out in the boondocks. Does anyone else have this problem?

I actually have it sitting on my desk right now, it shows me as being on the next street over, and traveling west at 1.3 mph. lol

 

[Pulsar]

GPS uses satellites. Being out in the boondocks doesn't matter a whit. Being around tall buildings matters greatly, because they block line-of-sight, and GPS is primarily a line-of-sight system. Roofs and buildings attenuate the single too much.

So having in inside, on your desk, have having it be confused isn't a terrible surprise. Especially if you're on the lower floor of a many storied building, or have new taller structures close by.

Take it out into an open field without tall buildings and try it again. Likewise, putting it up in the window where it wants to be, not lower down in your cup holder etc will help somewhat.

 

[amdhunter]

I have the same GPS. I initially hated it because of the adverts when using traffic, but it turns out it is a decent GPS. I never had any real issues acquiring satellites, or it being "off" when using it.

Do you update it at all on the web to get the newest satellite points?

 

[boomerang]

I have a TomTom that is doing the same thing. I read within the last year or so that the GPS satellite system is in big trouble. Failing satellites, no funds for replacement or upgrading.

I got an update for mine regarding satellites and it made no difference. TomTom says that it is normal for it to take up to ten minutes to lock onto enough satellites to enable functionality. This, from a phone call to them regarding another issue.

 

[amdhunter]

I have a TomTom that is doing the same thing. I read within the last year or so that the GPS satellite system is in big trouble. Failing satellites, no funds for replacement or upgrading.

I got an update for mine regarding satellites and it made no difference. TomTom says that it is normal for it to take up to ten minutes to lock onto enough satellites to enable functionality. This, from a phone call to them regarding another issue.

Damn. I never thought about maintenance for those things. Gonna suck when they all go down.

 

[LTC8K6]

It's because you are in a big city with tall buildings and lots of interference.

My Garmin is quick to acquire satellites and quick to locate me exactly.

Of course, the longer the unit has been without good sat reception, the longer it takes to get the initial fix and the less accurate it will be.

If mine has been in storage for a week, it can take it a full minute or more to figure out where it is when I turn it on.

If I've used it recently, it's about 20 seconds.

 

[vshah]

my cell phones have always been way quicker than standalone GPS units and my in-dash nav for me. no idea why. i think my dad has a nuvi 770 or something, it also takes ages to lock on, even near a window with a good view of the sky. we've noticed it takes longer when the unit has moved a large distance since it was last switched on.

 

[PhoKingGuy]

Weird, my BBerry curve 8900 and my VW RNS-510 both connect in about 10 seconds. My old Mio C310X took like 20 seconds max usually.

 

[Zenmervolt]

my cell phones have always been way quicker than standalone GPS units and my in-dash nav for me. no idea why. i think my dad has a nuvi 770 or something, it also takes ages to lock on, even near a window with a good view of the sky. we've noticed it takes longer when the unit has moved a large distance since it was last switched on.

The systems use predictive positioning based on an internal clock. So if you fire it up again the very next day from the same spot, it will lock on faster because it has a rough idea of which satellites it should be looking for and where it is. When you let it sit for a long time or when you've moved very far since the last time it was used, that predictive algorithm doesn't help, so it has to check each satellite and figure the position from scratch. This is why it's much faster if you're turning the unit on near the same place where it was turned off.

Cell phones can get rough location from the cell towers (within a couple km), which, if combined with good good enough programming, can be used to approximate the spot and speed GPS acquisition. Essentially, the unit doesn't have to "remember" a rough position, because it always "knows" the rough position from cell tower signals.

At least, that's my theory for why cell phones lock on faster based on my understanding of how the predictive algorithms are used to speed GPS acquisition in Garmin units.

ZV

 

[ivan2]

doesnt seem that long to me, i have the same unit. maybe a few minutes

 

[mizzou]

What I always tell my wife "give nuvi some air to breathe"

make sure you give it an open sky view when acquiring initial satellite

 

[alpineranger]

my cell phones have always been way quicker than standalone GPS units and my in-dash nav for me. no idea why. i think my dad has a nuvi 770 or something, it also takes ages to lock on, even near a window with a good view of the sky. we've noticed it takes longer when the unit has moved a large distance since it was last switched on.

Cell phones use assisted gps. The actual data processing is done on a centralized server, not your phone. It gets a constant stream of data from various phones in the same geographic area, so when you come on to the system it doesn't need to guess what satellites are overhead.

When a handheld gps is turned on, if often doesn't know how long it's been off for (some newer units do use this information). Thus, when it gets the satellite signals, it has to do a sort of brute force decoding of this information to figure first what satellites are in view, and then, decode the data they are sending (it's like each satellite uses a unique language, and you first have to figure out what language is being used before being able to understand what it is saying). This is also why, the shorter the interval since it has turned on (or the farther the unit has moved), the less likely any of the previously seen satellites are still overhead.

 

[sontakke]

The GPS system was designed many decades ago. The compute power at that time was quite low as compared to what it is today. The current 6 minutes to lock would be equivalent to 6 days to lock (I am exaggerating little bit but not a lot). I certainly do not think that older GPS needed days to lock on to get the initial fix. Today we have Ghz processors. When GPS was designed, I doubt we even had Mhz processors. There has been at least 1000 fold improvement in the cpu power. Where has all that power gone?

My conclusion? Lazy programmers using inefficient way of doing things; blame it on Microsoft Bloat! The same reason that 386 DOS booted quicker than your latest Windows7 machine

 

[MrMatt]

Hmmmmmm. It's doing it even when I'm out in the suburbs though. I tried the other day driving from where I work to a store about 5 minutes away. I got to the store before it got the signal. It's not that big of a deal I guess, since I'll be using it mainly for long trips, but I just found it odd is all

 

[Bignate603]

I have a TomTom that is doing the same thing. I read within the last year or so that the GPS satellite system is in big trouble. Failing satellites, no funds for replacement or upgrading.

I got an update for mine regarding satellites and it made no difference. TomTom says that it is normal for it to take up to ten minutes to lock onto enough satellites to enable functionality. This, from a phone call to them regarding another issue.

Everybody quotes the government accountability saying they had concerns about the longterm viability of the GPS. Nobody pays any attention to the Air Force's response two days later that said that they didn't foresee anything that was a high risk to the GPS system.

They're on track to launch 10 more satellites in 2010 and 2011 which should be enough to keep the system up and running. The best part about the new ones is that the new block IIF satellites should drastically increase the ability to pick up a solid signal and allow civilian GPS to get a more accurate signal.

As for it being slow to locate where it is, my boss mentioned something that may help. Apparently his GPS remembers where it was last used and uses that as a starting point for trying to figure out where it is when you turn it on. If it's near where it was when it was turned off it is able to figure out its location significantly faster.

 

[maddogchen]

i've dealt with a Garmin that has exactly that same problem! What I did to make it acquire a satellite faster is to tell it which city i'm going too. I don't know why but that works. When I tell it which city I'm in, it won't work.

Odd...

 

[boomerang]

Everybody quotes the government accountability saying they had concerns about the longterm viability of the GPS. Nobody pays any attention to the Air Force's response two days later that said that they didn't foresee anything that was a high risk to the GPS system.

They're on track to launch 10 more satellites in 2010 and 2011 which should be enough to keep the system up and running. The best part about the new ones is that the new block IIF satellites should drastically increase the ability to pick up a solid signal and allow civilian GPS to get a more accurate signal.

As for it being slow to locate where it is, my boss mentioned something that may help. Apparently his GPS remembers where it was last used and uses that as a starting point for trying to figure out where it is when you turn it on. If it's near where it was when it was turned off it is able to figure out its location significantly faster.

Very good. Thanks for pointing that out. I was one of those that missed the Air Force's response. I was actually wondering why there wasn't more coverage of this. It's a national security issue too.

The last used facet has already been covered and makes perfect sense. I rarely use mine so that may be why mine is slow to acquire satellites.

 

[Viperoni]

Yeah my Garmin is quite sluggish too IMO.

 

[Meghan54]

I've noticed more what Zenmervolt stated.

If I power up my Garmin at the same point I shut it off, it connects to the sats quite quickly.

On the other hand, if I power it up when I've moved, esp. a long distance, it can take a few minutes to sync with the sats.

And if you're moving while trying to find the sats, it'll increase the time even more.

 

[drbrock]

my garmin was VERY slow, took forever to find the satelites however with the most recent update from garmin it has reduced the time considerably.

Good luck

 

[thomsbrain]

The systems use predictive positioning based on an internal clock. So if you fire it up again the very next day from the same spot, it will lock on faster because it has a rough idea of which satellites it should be looking for and where it is. When you let it sit for a long time or when you've moved very far since the last time it was used, that predictive algorithm doesn't help, so it has to check each satellite and figure the position from scratch. This is why it's much faster if you're turning the unit on near the same place where it was turned off.

Cell phones can get rough location from the cell towers (within a couple km), which, if combined with good good enough programming, can be used to approximate the spot and speed GPS acquisition. Essentially, the unit doesn't have to "remember" a rough position, because it always "knows" the rough position from cell tower signals.

At least, that's my theory for why cell phones lock on faster based on my understanding of how the predictive algorithms are used to speed GPS acquisition in Garmin units.

ZV

This makes sense to me. I had chalked it up to the vastly more powerful processor in my smartphone, but the cell tower theory actually seems more likely, especially given the variety of lock-on times for my Garmin depending on time/distance since the last power-on.