Acquiring Satellites
Acquiring Satellites, Awaiting Satellite Signal, The GPS signal was lost x seconds ago… This is the time of year when we start getting lots of questions about this message with people frustrated that their GPS “doesn’t work”. So what does this error message mean, and what (if anything) can you do to your GPS to make it get a signal faster?
In order to determine your location, a GPS needs to listen to the network of GPS satellites. In order to listen to the satellites, it helps if the GPS can predict “where” to listen for the signal. And in order to know where to listen, it helps to know where you are…. a nice little catch-22. (I’m oversimplifying things a bit for the sake of not conducting a physics class when people just want their GPS to work.)
So how do you get around this catch-22?
Tips for New GPS Devices
- Make Sure the GPS has a good, clear view of the sky. “Clear” does not need to be sunny. Overcast skies have no noticeable impact on GPS performance. But buildings and trees do. So take the GPS outside where you have the biggest sky view as you can.
- Next, wait for the GPS to acquire a signal. If this is the first time you have used it, expect it to take up to 20 minutes to find a signal. Most often it will take less, but prepare for 20 minute. Now for an important step… Once it has found your location, let it continue to sit there for about 30 minutes.
While the GPS is turned on with a signal, it is downloading “almanac” data from the satellites. This information will help it find the satellites much, much faster in the future because it will be better able to predict where to listen for the satellites.
It is important that while the GPS is acquiring a signal that you not move the GPS. A few feet is fine, however if you start driving with the GPS before it has locked into a signal, it will take much, much longer to acquire a signal, if it finds one at all.
Other Signal Impacts
Rural areas don’t make a difference like they do with devices that rely on terrestrial signals like mobile phones. The GPS system was designed to work nearly any place on Earth. In fact, urban areas with tall buildings nearby are the toughest challenges for GPS systems.
GPS manufacturers are constantly working on ways to improve their products, and acquiring GPS reception is no exception. So check if there are any software updates available for your GPS. Some GPS manufacturers like TomTom also offer updates on a periodic basis that help it with that “almanac” data. TomTom calls this “QuickFix” updates and you can download them to your GPS to help it find a signal faster.
Some types of windshields (specifically athermic windshields) don’t allow the GPS signal to pass through as easily. In this case, an external antenna can help if one is available for your GPS. If you live in urban area with lots of tall buildings, an external antenna can help in that situation as well.
Taking a trip?
Note that if you move the GPS a good distance from where it was last used (say more than 100 miles) it will take longer time to initially acquire a signal. If you fly somewhere for vacation and take your GPS with you in the rental car be ready for a double whammy. Not only will it take longer to acquire a signal because the GPS has moved a large distance since it was last turned on, but you will often start at the airport in a parking garage where you don’t have an unobstructed sky view to listen in to the GPS signal.
And if you are going on a trip you might want to check out our tips on traveling through airports with GPS where we discuss x-ray machines and other transportation tips.
Have you heard about SiRFInstantFixII?
Will this not give Garmin 700 series a serious lift against Tomtom?
I have read the Garmin 760 review and people have complained about this quite a lot.
Yes, however we haven’t seen any indication that Garmin is, or will, use that feature.
Could I not apply this myself?
Or any other fix that comes along with most of the shopping for gadgets now done online, you would won’t have a dealer to take it back too to upgrade?
No, you wouldn’t be able to apply it yourself.
I think I got it right
http://www.gpsreview.net/garmin-26-nuvi-update-sirf-instantfixii/
Is your blog for the same.
Tim,
What is the difference between external Bluetooth GPS vs regular GPS navigator in term of protocol? The reason I asked, because I have HP PocketPC with TomTom Bluetooth GPS (loaded with TomTom Navigator 6 software); somehow when it acquiring satellite signal, it’s faster than my friend’s Garmin, Mio & Magellan GPS (yes, he have three GPSs). Beside that, my Bluetooth GPS has better satellite signals than my friend’s GPS navigators. Friend’s GPS keep re-position itself or tries to acquiring satellite for every 5 seconds when came to mountainous terrain. This hesitate me buying new TomTom Go 730.
George
There really isn’t any difference in protocol– they both communicate with satellites in the same manner. I’ve got four or five Bluetooth GPS devices and none of them seem to have any significant difference over the PNDs I have when it comes to acquisition time or reception.
A Bluetooth device generally will have a little more design freedom though– since they are not quite as worried about size/shape, or screen placement– therefore I suppose it is possible they could overall have better reception.
Beside the size & shape limitation, Bluetooth GPS device does have advantage of location. It can be place outside of vehicle for better reception. My TomTom Bluetooth GPS is weather resistance, so I have no worry.
Tim, thanks for the info. I just ordered TomTom Go 730 online. Quick question… can my TomTom Bluetooth GPS be use with TT Go 730 with its Bluetooth capability? This will allow better reception if been place outside of the vehicle like an external antenna.
George
No, the 730 (as with most PNDs) can only use their internal chip. You can install an external antenna however if you find you need better reception.
Got you. Thanks Tim.
Hi
We purchased our NUVI 350 1 1/2-year a go and I don’t have any problem on it. But last couple of months it’s always stock up for 30 minutes and always in Poor satellite and low satellite reception. I did follow the instruction to reset but it doesn’t help. Warranty is already over (1 year???) Please help. THANKS,
If you’ve followed those steps and reset the device I’m not sure what else you could do other than contact Garmin for repair.