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How GNSS is used in positioning technology

gps gnss module

Satellite navigation and positioning technology GNSS most commonly used in consumer GNSS devices, gps gnss modulelocation-based applications in cell phones and tablets, is more widespread. There are also some other factors, including the widespread use of in-vehicle navigation, for example, by tracking a fleet of cars to obtain real-time logistics information, the use of personal tracking applications to monitor workers and keep the elderly safe, etc.

The popularity of location-based tracking applications through consumer electronic devices with built-in GPS, such as digital cameras and sports watches, pet tracking devices and services, and more.

GNSS chips have a wide range of applications

GNSS chips are moving toward multimodality

It is due to the rapid growth of the GNSS market that traditional WLAN and cell phone chip manufacturers, too, are actively working on GNSS chips and modules, and the GPS/GNSS chip market is rapidly entering a new market.

GNSS chips are developing in the direction of multi-mode, that is, a single chip supports multiple GNSS systems, such as GPS+GLONASS, GPS+Galileo, GPS+Beidou, etc. In addition, GNSS has applications in the field of high precision, mainly in some industry applications, including mapping, aircraft, aerospace and defense applications, guidance systems in UAVs or missiles, etc. Testing of consumer GNSS devices and applications.

High-precision GNSS baseband chip

GNSS System Description

The GNSS system is divided into three main sections.

Space segment consists of satellites or spacecraft (SV) for transmitting navigation messages containing satellite orbit, position, and transmission time.

The control segment refers to the ground monitoring station and the main control center, which are used to track satellite signals, collect pseudo-range measurements and atmospheric model data, provide navigation information updates, atmospheric information and correction information, and perform satellite control.

User segment refers to GNSS receiver.

GNSS receiver working principle

Three-sided measurement method

GNSS receiver, calculates its own position by the trilateral measurement method.

It uses the transmission time and position data in the navigation message, measures the time delay of the satellite signal, and from this calculates the distance between the receiver and the satellite (pseudo-range).

First, all possible positions of a GNSS receiver at a specific distance (pseudo-range) from a satellite form a sphere. The intersection of two spheres is a circle. The intersection of three spheres is then two points.

Finally a fourth data is needed to determine the correct position of the receiver. The fourth data can be the Earth's surface, i.e., if the receiver is located on the Earth's surface, the point on the Earth's surface is the correct location of the receiver. For a more general solution, the pseudo-range of the fourth satellite is needed for positioning.

Also by measuring the four satellites, it is possible to determine not only the location information of the receiver, i.e. longitude, latitude and altitude, but also to correct the clock error of the receiver and determine the correct time.

What is housed within a GPS module?

Small processors and antennas found in GPS modules are used to directly receive data from satellites using specific RF frequencies. From there, it will get data from various sources, including timestamps from all visible satellites.

Why are GNSS not precise?

Receivers' inability to accurately detect their position from faulty satellite signals is one of the drawbacks of Global Navigation Satellite Systems (GNSS). The lack of a direct line of sight between the satellite and receiver may be the cause of this uncertainty.

What is the GPS module's range?

Each antenna is made to pick up the 1.5752 GHz GPS L1 frequency. GPS functions best when the antenna is placed and designed properly. Higher precision x shorter downrange it can travel. Finding your location is typically possible in less than 30 seconds, with accuracy down to +/- 10m and most modules down to +/-3m.

Are GNSS and GPS equivalent?

The North American Global Positioning System, also known as GPS, is the term most commonly used. The International Multi-Constellation Satellite System is referred to as GNSS. GPS, GLONASS, Baidu, Galileo, and other constellation systems are examples of GNSS.

How is GPS determined?

Utilize the following equation to determine the separation between a satellite and a receiver: Distance from the satellite to the receiver in miles equals (186,000 mi/sec) x (signal travel time in seconds). A network of satellites called the Global Positioning System (GPS) orbits the Earth at a distance of around 11,000 miles.