Comments for Garmin StreetPilot c330

Comment on I’m getting ready to buy a Magellan handheld GPS “Satellite Navigator”. Says “No good for streets” but camping? by Wayner

Wayner — Sun, 20 May 2012 14:21:55 +0000

Your answer is in the posted information – it does not have the ability to download road and street info, so you can’t use it in your car for navigation. It’ll work fine for camping and other outdoor uses.

Consider getting one in which you can dowload topographic maps for these outdoor activities, though.

Comment on Q&A: How can i trace my built in gps phone htc that has been stolen? by guideg

guideg — Sun, 20 May 2012 14:04:38 +0000

Most phones comes with a manufacturing id. It would be printed at the back of your battery and also on the box in which the phone originally came. The cops can track this number even if the sim card is changed. They can pinpoint from which area the call was made and even disable the phone. At least that’s what the cops told me when I reported the theft of my phone a couple of years ago. I didn’t press charges as the phone was an inexpensive model and I didn’t want to land some poor bloke in trouble over it.

Emergency calls can now be tracked to the exact location as all cell phones have to come equipped with gps to help the 911 to come to the immediate rescue of people in trouble.

So, maybe that feature can be used to locate your phone but I am not sure if in case of theft this will be used. Ask the cops, they know best. Hope this helps.

Comment on I’m getting ready to buy a Magellan handheld GPS “Satellite Navigator”. Says “No good for streets” but camping? by Rick C

Rick C — Sun, 20 May 2012 13:40:29 +0000

Although Magellan makes many good GPS units Garmin is by far the best in technology and for the same money. I went through the same dilemma you did when I first purchased a handheld. My suggestion is the Garmin GPSMAP 76CSX. It has everything you seem to be looking for. I use http://www.gpsunitsandaccessories.com/ for my gps needs, they are reasonably priced and have always provided good service. They will also help you if you have more questions concerning a purchase. Best wishes on your gps adventures.

Comment on On in dash GPS/dvd units like the KENWOOD DNX5120 can you listen to music and use the gps at the same time? by Ray L

Ray L — Sun, 20 May 2012 13:25:01 +0000

well i have a pioneer z1 and i can listen to music while using my gps when u use your gps what happens is that the voice that gives the directions mutes the music while it explains the next step

Comment on How does google map work on a non gps phone ? by Pfo

Pfo — Sun, 20 May 2012 13:23:35 +0000

The phone communicates to cell towers, if it can find 3 towers in range it can tell the distance from each tower and if it knows the location of each tower, the phone can “figure out” where it is. It triangulates its position based on the strength of the cell tower signals.

Comment on Q&A: How can i trace my built in gps phone htc that has been stolen? by BeingGreenOnline

BeingGreenOnline — Sun, 20 May 2012 13:12:08 +0000

Sorry man, there is no way to trace your phone.

Regular consumer GPS devices are receive only, which means they are only capable of receiving a signal like a radio and do not have the ability to produce signals of their own. Without the GPS having the ability to send out its’ own signal there is nothing for you to receive or track it with.

The article in my source explains it a lot better.

Comment on I’m getting ready to buy a Magellan handheld GPS “Satellite Navigator”. Says “No good for streets” but camping? by coachp84

coachp84 — Sun, 20 May 2012 12:59:56 +0000

Hand-held GPSr give only a straight line from start to destination. It will not give you turn by turn directions.

Comment on Why are GPS satellites in medium orbit rather than geostationary? by purple bandit

purple bandit — Sat, 19 May 2012 14:58:24 +0000

The previous replies about geostationary orbits pretty much answered your questions.

However, there is also some misinformation about GPS given in the previous answers that I’d like to address:

SiriusB said: With GPS satellites it makes more sense to have them in a polar orbit so that they can cover the entire Earth’s surface over time.

Firstly, GPS satellites are NOT in polar orbits. Secondly, a polar orbit doesn’t cover the earth any more efficiently than non-polar orbits. What gives GPS satellites the coverage they do (which is 100% of the earth) is the way the 24+ satellites are distributed in their six orbital planes.

SiruisB said: Also I presume that putting a satellite at the relatively large distance required for a stationary orbit (22,000 miles) would significantly reduce the precision with which the distance could be measured

The presumption is incorrect. The control and space segments of GPS would still monitor satellite positions and update the system accordingly.

urwumpe said: The GPS distance means the constallations repeat every 72 hours, other distances change this.

GPS orbital periods are 12 hrs (11hrs, 56min).

Comment on how are clocks of gps receiver are synchronized with the precise atomic clock of the GPS? by Elizabeth

Elizabeth — Sat, 19 May 2012 14:18:37 +0000

The short answer is you don’t need to synchronise the clock on the GPS receiver with the clocks on the satellites. For example:

It is exactly 12 midday. You look at the signals from two satellites.

Satellite 1′s signal says ‘I’m located at this position in my orbit and the time is 12.00.00′
Satellite 2′s signal says ‘I’m at this position and the time is 11.59.59′

The atomic clocks in the satellites are synchronised (at least in the sense that they are extremely accurate). But the times read by the reciever will not be the same because of the slight delay in that signal arriving. In the above case, Satellite 2 is further way so the signal you recieve is offset from that of Satellite 1. You’re getting, if you like, the last tick of the clock on Satellite 2 because the current 12.00.00 tick signal is still in transit to you.

The GPS signal contains information about where the satellites are. What the receiver does is take the known position of satellite 1 and the known position of satellite 2, and then work out where on the earth’s surface it would have to be to get a 1 second delay (for the purposes of the example) in the signal. That only gives you one position, so you need at least another satellite to pinpoint your location. And of course the delays are extremely small.

Comment on Why are GPS satellites in medium orbit rather than geostationary? by urwumpe

urwumpe — Sat, 19 May 2012 14:15:31 +0000

No, they need to be in a medium orbit.

You want to use GPS even at high latitudes, but geostationary satellites are hard to receive close to the poles. Next, you want to have all satellites in a special constellation or formation. When the satellites are all close together in the sky, for example in a straight line or at the same point, the accuracy of the calculations drops as the signals will get the same disturbances because of the atmosphere. Also, the mathematical calculations inside the receiver will not work well then. Then, you also want this constellation to repeat in a good pattern at regular times. The GPS distance means the constallations repeat every 72 hours, other distances change this. Regular repetition patterns mean, that your receiver will have it easier to find satellites and calculate their position, even when the ground station of the GPS fails to update the orbit information onboard the satellites (The satellites don’t know this themselves, you need ground stations for the required accuracy).

Finally, you also have to consider the launch vehicles you can use. Today this is not such a big problem, but for GPS, there had been the Delta II planned, which has tight mass limitations.