• The SIM card must be activated with GPRS function;
• Do the correct setting for GPRS connection

(1) Please make sure there is no metal obstacles above the tracker. Please place the side with GPS antenna upside to the sky;

(2) Please check it at broad place;

(3) Please check if the GPS LED flash once every 3 seconds; place the tracker to other place, so as to make sure that it can receive the GPS siganl well

(4) In cloudy condition, it is a little hard to get the GPS signal, and the GPS coordinate might have some errors.

(1) The SIM card inside the device has no credit;

(2) The Alert-received mobile number is not programmed correctly, or the SMS command is not in correct format;

(3) The mailbox of the user’s mobile is full;

(1)The user password is wrong, please use the correct password or reset the password to test;

(2) Low power, please use outside power supply to power on the unit to test

• The GSM SIM card has no credit;
• The SIM card is protected by PIN code;
• Check the power supply, if 2 LEDs flash;
• The SIM card is placed correctly in the slot;

• Fix GPS antenna correctly.
• Choose an open place for receiving valid GPS signal and don’t let iron items to cover the signal.
• Try it in a sunny day.
• Change another available GPS antenna.

The causes of positioning errors of automotive GPS locators can be divided into three categories: satellite-related errors, errors related to signal propagation, and errors associated with automotive GPS locators. What are the errors related to the car GPS locator?

1. GPS GPS locator observation error

In addition to the resolution error of the observation, this type of error also includes the placement error of the GPS positioner antenna relative to the measurement station. According to experience, it is generally believed that the resolution error of the observation is about 1% of the signal wavelength. The observation error is an accidental error, and appropriately increasing the observation will significantly reduce its impact.

The placement error of the antenna of the Legal GPS Tracker Geofence Google Maps With RFID Camera Crash Sensor positioner relative to the center of the observation station mainly includes the error of the antenna leveling and centering error and the measurement of the antenna phase center height (antenna height). For example, when the antenna height is 1.6 m, if the antenna leveling error is 0.1°, the centering error of the optical plummet is thereby about 3 mm. Therefore, if it is in precision positioning work, it must be carefully operated to minimize the impact of such errors.

2. Car GPS Locator Clock

Automotive GPS locators are generally equipped with high-precision quartz clocks with a daily frequency stability of approximately 10-11. If the synchronization difference between the car GPS positioner clock and the satellite clock is 1 microsecond, the resulting equivalent distance error is about 300 m.

A more effective method for dealing with the clock difference of a car GPS locator is to introduce an unknown clock error parameter at each observatory, and solve it in the data processing together with the position parameter of the observing station. At this time, it is assumed that the clock difference is independent at each observation moment, and the processing is relatively simple. Therefore, this method is widely used in real-time dynamic absolute positioning. In the static absolute positioning, the GPS GPS locator clock difference can also be expressed as a polynomial form like a satellite clock, and the coefficients of the polynomial are solved in the adjustment calculation of the observation. However, this will involve the correctness of the assumptions made about the clock characteristics when constructing the clock difference model.

When the positioning accuracy is high, a high-precision external frequency standard (ie, time standard), such as a cesium atomic clock or a cesium atomic clock, can be used to improve the accuracy of the vehicle GPS positioner time standard. In the precision relative positioning, it is also possible to use the method of the difference of the observation values to effectively reduce the influence of the clock difference of the GPS locator of the automobile.

3. Car GPS locator antenna phase center deviation

In GNSS positioning, whether it is code pseudorange or phase pseudorange, the observations are based on the phase center position of the GPS locator antenna, and the phase center of the antenna should be theoretically consistent with its geometric center. However, in practice, the phase center position of the antenna varies with the intensity and direction of the signal input, that is, the instantaneous position of the phase center (generally referred to as the phase center) and the theoretical phase center position will be different. The influence of the deviation of the phase center of the antenna on the relative positioning result can be several millimeters to several centimeters depending on the performance of the antenna. Therefore, for precise relative positioning, this effect cannot be ignored. How to reduce the offset of the phase center is an urgent problem in antenna design.

In practice, if the same type of antenna is used and the same set of satellites are simultaneously observed on two or more observing stations not far apart, the influence of the phase center offset can be weakened by the difference of the observed values. However, at this time, the antennas of each observatory should be oriented according to the azimuth attached to the antenna so that it points to the magnetic north pole according to the compass. According to different accuracy requirements, the orientation deviation should be kept within 3 ° ~ 5 °.

4. Weekly jump and full-circumference ambiguity

The carrier phase observation accuracy is higher than the pseudorange observation, but there is a problem of the entire week ambiguity. In addition, the occlusion of the signal or the influence of external signals may cause a cycle slip during phase tracking, and a continuous long-term cycle jump may cause the signal to lose lock. Carrier phase observation is affected by the ambiguity and cycle slip of the whole week, which is a very critical issue in the data processing of precise positioning.

1. The accuracy of the civil GPS positioning terminal is up to 10 meters.

The GPS we are using now belongs to the civilian-grade GPS. We will not discuss the military level for the time being. In the case of GPS , in the case of good signal (under ideal conditions such as open ground and sunny weather), the GPS Phone Tracker accuracy is generally around 10 meters. If it is LBS (base station) positioning, the positioning accuracy is generally between 100 meters and 1000 meters.

The GPS positioning accuracy is achieved by a certain algorithm. The environment requirements at that time are very high. If there are high-rise buildings, interference signal sources, and cloudy weather, the positioning accuracy error will definitely be relatively large. The high precision mentioned in the market can only be achieved under ideal conditions. Even if it is the same machine, the same place, the positioning accuracy is different at different time periods is normal.

2. Not a battery can be used as a long standby GPS positioning terminal.

For the ultra-long standby GPS positioning terminal, the capacity and characteristics of the battery determine the length of the standby time.

We all know that the standby time is proportional to the battery capacity, the capacity is about the same, and the endurance is stronger. Therefore, the battery capacity can be roughly used as a judgment method.

Then not all high-capacity batteries are suitable for such positioning. There are many types of batteries, and there will be self-discharge during normal use, which means that the battery will consume power. If the self-discharge of the battery itself is very high, even the large capacity will not support the concept of long standby.

A very obvious battery that cannot be used for long standby is the polymer battery pack battery. Under normal circumstances, the self-discharge of this battery is very high, you can imagine your own mobile phone battery. Look at how long it takes to turn it on after a month.

1.WIFI positioning is not necessarily the most accurate.

Many people think that the triple positioning and quadruple positioning locators are very powerful, especially the WIFI positioning, which is very high-tech, and can be positioned accurately even indoors. In fact, this is just a gimmick. If you understand the principle of WIFI positioning, you may not have such a high hope for WIFI positioning.

Simply speaking, WIFI positioning only uses the WIFI signal source to determine the IP address of the signal and then resolve it to your location. That is the address you registered with the operator when you pulled the cable. But now almost every family has WIFI, and no one knows which of these signals will be obtained, so the resolution of the location will be accurate to what extent, think about it.

WIFI positioning does have an auxiliary side, but don’t rely too much on it.

2.The smaller the positioner, the higher the technical content, but not as small as possible.

The smaller the volume of the positioner, the higher the technical content without reducing the component configuration. Because for the R&D personnel, it is necessary to lay out so many lines and components in the limited area, and test your comprehensive control ability and overall planning ability. But not as small as possible.

The most important part of the locator is the GPS module and the Cheapest Wrist Watch GPS+LBS+SOS+GSM GPS Tracker For Kid antenna, and the space occupied by the two is relatively large. If the space is neglected, the impact on the signal is quite large. There is no fixed GSM antenna, even a small wire to replace, such a signal is not only poor, but also extremely unstable.

3.Small size wireless locator has difficulty in standby for 5 years.

As we said above, the wireless GPS positioning terminal relies heavily on the battery, especially the battery capacity. If the volume is too small, the battery capacity must not be too large. In the case where the battery capacity is not sufficient, the probability that the positioner can stand by for 5 years is small. To stand for 5 years, the battery capacity must be at least 10,000 mA.

(1) Vehicle tracking

GPS and electronic maps can be used to display the actual position of the vehicle in real time, and can be arbitrarily enlarged, reduced, restored, and changed; can be moved with the target to keep the target on the screen; multi-window, multi-vehicle, multi-screen Track at the same time. Use this feature to track and transport important vehicles and goods.

(2) Provide travel route planning and navigation

Providing travel route planning is an important auxiliary function of Wireless Gps Car Tracker For Vehicle Real Time Navigation systems, including automatic route planning and manual line design. The automatic route planning is determined by the driver to determine the starting point and destination. The computer software automatically designs the optimal driving route according to the requirements, including the fastest route, the simplest route, and the calculation of the route with the least number of highway sections. The artificial line design is automatically created by the driver according to his destination design start point, end point and route point. After the route is planned, the display can display the design route on the electronic map, and simultaneously display the car running path and operation method.

(3) Information inquiry

Provide users with major objects, such as tourist attractions, hotels, hospitals and other databases, users can display their location on the electronic map. At the same time, the monitoring center can use the monitoring console to query the location of any target in the area, and the vehicle information will be displayed in digital form on the electronic map of the control center.

(4) Traffic command

The command center can monitor the running condition of the vehicles in the area and make reasonable dispatch of the monitored vehicles. The command center can also talk to the tracked target at any time to implement management.

(5) Emergency assistance

Through the GPS positioning and monitoring management system, emergency assistance can be provided to vehicles in danger or accidents. The electronic map of the monitoring station displays the help information and alarm targets, plans the optimal assistance plan, and alerts the on-duty personnel to the emergency treatment with the alarm sound and light.

1. Tracking and positioning

The monitoring center can monitor the real-time position, driving direction and driving speed of all controlled vehicles 24 hours a day, so as to get the most timely information on the vehicle.

2. Track playback

The monitoring center can play back the historical history and track record of the custom time period in the past 60 days at any time. (Optional track DVD burning service depending on the situation)

3. Alarm (report)

3.1, overspeed alarm: when the vehicle travel speed exceeds the preset speed of the monitoring center, report it to the monitoring center in time.

3.2. Area alarm (electronic fence): The monitoring center sets the area range. If the vehicle exceeds or enters the preset area, it will give corresponding alarm to the monitoring and dispatching center.

3.3. Parking report: The dispatching center can generate a report in the form of text on the historical parking record of the vehicle, which describes the parking location, time and driving time of the vehicle, and can print it.

3.4. Emergency alarm: In case of emergency (such as robbery, etc.), please press the emergency alarm button immediately to report to the supervision center. The supervision center will immediately know that you are in a state of emergency and your location. After verification, enter the police handling procedures to help you escape.

3.5, undervoltage alarm, when the car battery voltage is too low, the car host will automatically report to the monitoring center, the monitoring center attendant reminds the user to charge the vehicle in time.

3.6. Trimming alarm. When the main battery of the vehicle is destroyed or cannot be powered, the built-in backup battery can keep the product working and send a trim alarm to the monitoring center.