What Interferes with a GPS Signal – Weak Signal GPS Troubleshooting
At present, GPS is divided into civil and military categories.
Therefore, the global navigation satellite system sends signals at L frequency: L1 for civilian use and L2 for military use.
L2 is highly encrypted and stronger to improve the accuracy of military GPS.
This regulation is intended to make it impossible for any terrorist organization to use advanced signals on the L2 frequency for destruction.
In addition, the United States reserves the right to change or limit the signal strength or angle of the two frequencies, if required.
This is possible because NAVSTAR, a global navigation satellite system owned by the United States, is the only fully functional space network.
The current GPS constellation is supported by 31 active satellites orbiting the Earth in six different orbits, with at least four satellites in each orbit.
The GPS system ensures that Earth-based GPS devices and GPS servers receive signals from five or more satellites around the clock (
Even if GPS devices can use signals from four satellites).
In order to improve the accuracy of GPS equipment, the track is 55 degrees per tilt, which is convenient for different but direct (straight)
Signal path to Earth-
GPS devices without any obstacles.
Nevertheless, there are several factors that interfere with the GPS signal, resulting in a GPS outage or a reduction in the accuracy of the GPS device.
The next section will check the factors that interfere with the GPS signal.
Weak signal GPS-the most common factor that interferes with GPS signals is the so-called \"city Canyon \".
\"The term refers to high-rise concrete buildings and skyscrapers that do not allow signals to pass through.
These city buildings either completely block the radio signals sent by satellites or change their path so that they do not reach a GPS server or a GPS device.
Even if the signals can pass through the building, they become so weak that the receiver of the GPS device explains that the signal becomes weak.
The radio signal must go through a long distance before it reaches the GPS device.
On this trip, it passed through a vacuum (in space)
Different levels of the Earth\'s atmosphere.
Radio signals may not be distracted or disturbed in space (
Flying Stone or gathering dust clouds).
Once it enters the Earth\'s atmosphere, the journey becomes difficult.
Several factors that interfere with GPS signals: natural elements such as Miyun, dust particles, mountains, and even people
Make flying objects, such as aircraft.
If the GPS device is used underwater, such as on a submarine, the distance of the radio signal to maintain strength is too long.
The density of seawater also leads to the weakening of radio signals.
In short, there are a lot of things that interfere with the GPS signal, although the current GPS system is designed in such a way that a ground-based receiver is provided in a straight line, as described in Part I.
The next page continues to discuss weak signal GPS, while providing differential GPS as a solution to improve accuracy.
Weak signal GPS-one of the other factors that interfere with GPS signals is the intersection of two or more signal paths.
During signal path conflicts from different satellites, data may change or be damaged.
Although the placement of the satellite is well thought out, sometimes the signal will naturally intersect, resulting in data damage.
The purpose of the GPS satellite is to provide a straight path to transmit data to the GPS without any radio signal interference.
However, it is not always successful.
On the contrary, this problem rarely happens.
The intelligent global navigation satellite system receiver inside the GPS device is able to detect the error data and stop the calculation before starting to receive the correct data.
In the case of a GPS power outage, the navigation estimation method or map matching can be used.
Both methods use previous data to create navigation information.
Finally, let you believe that GPS is not used indoors.
GPS signal strength is really weak when you are inside any building, but that doesn\'t mean you can\'t use the device indoors.
The solution is to re-radiation.
When a ground-based GPS device receives a signal, it filters the signal to extract the data: Three planes (
X, Y, z axis)
The satellite receiving the signal, the location of each satellite, the timestamp of each signal and the possible redundant clock error at the end of the satellite.
Based on all of this data, GPS devices filter, enhance, and find the strongest GPS signal before calculating to provide you with the information you need.
In the process of locating the strongest GPS signal, the GPS device may find that the strongest signal is a very weak signal, which must extract the data sent by the satellite.
Still, GPS is a technology that won\'t disappoint you.
In other methods, WAAS (
Also known as SBAS)
Is a way to recreate GPS accuracy.
Weak signal GPS-use WAAS to obtain proper GPS accuracy through wide area enhancement system (WAAS)
Originally developed for airlines.
In the case of weak signals, navigation to obtain proper GPS accuracy is a common feature in most GPS devices, especially in portable models.
If the GPS device contains WAAS, it has multiple receivers.
The first receiver is stationary and receives data from a specific satellite.
The other is the tour.
WAAS uses a ground-based GPS reference network
When it detects an error or a weak GPS signal.
The technology mainly uses GPS reference stations in Hawaii and North America to determine changes in GPS signals.
These reference stations then send these measurements to the main station.
At present, there are five active ground
GPS stations around the world.
Once the master station receives the measured value, it sends the measured value back to the satellite in the GPS system in the form of a signal.
The satellite processes incorrect measurements and sends the corrected signal back to the Earth-based GPS-
Station and GPS equipment.
Therefore, while obtaining complete data based on the weakest signal, it is easy to determine the integrity of the data.
Since the GPS device has easy access to up to six satellites at a time, the WAAS enabled GPS device makes the most of the facility to calculate the weak signal GPS and give accurate results.
Note: it is the radio wave that loses its strength in distance and resistance, not the data carried by the radio wave.
This fact makes it easy for WAAS technology to show results when using weak signal GPS.