Answer ten common questions about GPS

1. Is there any charge for GPS navigation and positioning services?

It is gratifying that this service does not charge any additional fees. You only need to purchase a navigation product, such as a GPS mobile phone, GPS PDA, or car GPS product, or even a GPS module to enjoy satellite positioning services for free.

2. Can GPS products purchased in China be used in foreign countries?

Yes, GPS products are actually a satellite signal receiver, which can be used in any place where the signal can be received. It just needs to be available for our use, but also with local map software.

3. What factors will affect the GPS reception signal?

1. The US Department of Defense SA satellite signal interference (for the sake of its own security, the US government has conducted a kind of interference called "Selective Availability (SA)" on the civilian code to ensure that its military system has the best Effectiveness. Because the SA randomly adds error information to the navigation message through the satellite, the positioning accuracy of the civil signal C / A code is reduced to about 100 meters. However, the use of differential GPS technology can reduce the system error to 10 to 15 meters. Inside.

2. Weather factors (including sunspots, bad weather, etc. reduce the strength of the received signal)

3. Under the shielding of buildings, vehicles, thermal insulation paper, or metal components, the GPS signal will be reduced or completely lost. In an open place, the GPS device receives the best signal.

4. How often is the GPS signal updated?

The satellite signal is transmitted once per second, so the signal received by the GPS is also updated once per second.

5. How many satellite signals are received to enable the GPS device to complete positioning?

Because GPS uses the principle of triangulation to locate, it is necessary to receive more than three satellite signals to locate successfully, and when there are four satellite signals, the corresponding altitude value can be obtained, but usually the altitude value error is relatively large. Not a simple sphere.

6. What kind of problem is the GPS device unable to locate?

1. GPS signals are easily blocked by buildings and metals, so make sure to use your GPS outdoors.

2. If you are unable to locate in the car, then put the GPS on the top of the car first, and then try again after cold starting the GPS, and then put it in the car after it is normal.

3. Please check if your GPS is connected to your device.

7. Why is there a "delay" phenomenon in GPS products?

1. Connection performance of the receiver;

2. PDA or PC CPU speed and memory card reading speed;

3. The RAM of the PDA should have more than 20MB of space to allow the navigation software to operate;

4. The GPS signal is transmitted once per second, which is more or less related.

8. Why does GPS navigation "drift"?

Earlier GPS always had a broken signal due to its weak ability to receive satellites, especially when it was used as a navigation in a city, which caused a lot of inconvenience. Some civilian GPS chips developed later included GPS signals that were not strong enough, which caused drift. But if under the same circumstances, the earlier GPS products will be completely disconnected, and it will not be accepted until a satellite with a strong signal can be found. So this is a relatively contradictory choice, but with the continuous development and upgrading of software and hardware, I believe that this situation will become less and less.

9. Current GPS product types and prices?

Currently, there are three types of GPS products on the market: car GPS, mobile phone / PDA with GPS function, and GPS module. The mainstream car GPS products are priced at around 3,000 yuan, and the cheapest ones are more than 1,000 yuan. Of course, the luxury ones are also sold at a high price of about 7,000 yuan; mobile phones with GPS functions are usually expensive, even if they are parallel imports, they also exceed 4,000 yuan The relative variety is relatively simple. This type of PDA is still cheap, the cheapest is only about 2000 yuan; GPS module can be said to be the most cost-effective, the price range is between 300-1000 yuan, with 600 yuan as the mainstream price.

In addition, it also includes special GPS products, such as GPS products specially customized for mountaineering, navigation, and industry. These products have large differences in use and the prices are very different.

10. What should I pay attention to when buying GPS products and selecting maps?

At present, there are many types of GPS maps on the market, including Lingtu Skywalker, Intercity Pass, Dadaotong, Kailide, etc., which are well known by many people. These products have their own pros and cons. Which one you choose to buy depends largely on your personal preferences. However, the most important thing is that the purchase needs to consider whether the map supports online update and the time when it can be updated for free, because the old and new maps have a considerable impact on the use.

Source: Zhongguancun Online