GNSS antenna, which is called Global Navigation Satellite Systems antenna, can be described as a significant part of the GNSS receiver system that receives the satellite signals and then calculates the appropriate position. GNSS antenna’s major function is to receive the signals and then pass them through a GPS receiver. The transfer ensures the GPS receiver can calculate its direction, speed, and position. GNSS antennas come in many types, and each type has unique benefits.
Here, we will be discussing the main function and features of the GNSS antenna as well as how they function. Also, we’ll explore the various advantages that customers should expect when they make use of the GNSS antenna for their applications.
What are GNP GNSS Antennas?
The GPS GNSS antenna helps in receiving and amplifying the radio signals that are transmitted on some frequencies by the GNSS satellites. It then converts them into electronic signals utilized by the GPS or GNSS receiver. This output of the GPS or GNSS antenna is then fed into the GPS or GNSS receiver which can compute its position.
Furthermore, these antennas form the main interface through which the GPS or GNSS receivers can take the external UTC input as well as offer information on UTC traceability through the output signals present in TOD, 10MHz, and 1PPS.
What are the Types of GNSS Antenna?
Below is a comparison of the types of GNSS antenna. These include handheld, rover, and geodetic.
Handheld Antennas
The handheld receiver antenna is a L1 single band structure that is optimized for cost and size. You can fund them in different implementations, like patch antennas, helical, and surface mount ceramic chips. Also, their pattern of radiation is known as quasi-hemispherical. Due to their small sizes, phase and AR center performance are usually a compromise.
Rover Antenna
They are useful in forestry, land survey, construction, as well as other mobile or portable applications. In addition, they offer the user reliable accuracy when optimizing it for portability. Comparing the phase center horizontal variation versus the azimuth must be low since the antenna’s orientation with regards to the magnetic north is most times unknown and can’t be corrected in the receiver.
Geodetic Antenna
Fixed site high-precision GNSS applications usually require the geodetic-class antennas and receivers. These offer the users the best position accuracy possible.
What are the Properties of the GNSS Antenna?
We will be explaining the properties of the GNSS antennas generally. Though this discussion holds for virtually all antennas, we will be focusing on some unique requirements for the GNSS antennas. Also, we will compare the three antenna types utilized in the GNSS applications.
Regarding the GNSS antennas, we’re referring to GPS antennas because for years, GPS has formed the main navigation system. However, there are other systems that are being and have been developed. Also, some frequencies utilized by the other systems stand out. These include the GLONASS L1 and E6 band of Galileo. However, all antennas might not cover this frequency range. However, aside from frequency coverage, every GNSS antenna shares similar properties.
The GNSS antennas come with some significant properties that affect performance and functionality. These include:
- Gain pattern
- Frequency coverage
- Circular polarization
- Phase center
- Multipath suppression
- Interference handling
- Impact on the receiver sensitivity
Briefly, we will be discussing some of these properties
Frequency coverage
What GPS receivers have been able to bring into the market today includes some frequency bands like GPS L5, the Galileo E5 and E6, GLONASS bands coupled with legacy GPS BANDS. The antenna that feeds the receiver might have to cover either all or some of the bands.
Phase center
The position fix inside the GNSS navigation is known to be relative to the antenna’s electrical phase center. This phase center can be described as the point inside space whereby the rays seem to converge on or emanate from the antenna.
Explaining further, we can say that it is a point whereby electromagnetic fields gotten from the incident rays seem to add up. It is important to determine this phase center in the GNSS applications, most especially whenever there is need for millimeter-positioning resolution.
Circular polarization
The space borne system at the L-Band utilizes the circular polarization signals in transmission as well as receiving signals. This changing orientation of the transmission as well as receiving CP antenna as satellites go round the earth doesn’t result in polarization fading just like it does for the linearly polarized antennas and signals.
Multipath suppression
The signals that come from satellites usually arrive at the antenna of the GNSS receiver, which is placed directly from space. However, they might be reflected as well off the buildings, ground, as well as other obstacles. It then arrives at an antenna many times and then is delayed. This is called multipath. This degrades the positioning accuracy, and you need to avoid this.
Also, the high-end receiver can suppress multipath to some extent; however, it is a great engineering practice for suppressing multipath inside the antenna the best way possible.
Benefits to Expect From Your Preferred Antenna
For the seamless wireless connections, as well as different applications, GNSS antennas can be regarded as the best choice. They offer great performance in any challenging environment and can be customized so as to meet the unique needs of all applications. Some of the benefits to expect from your preferred antenna include
- Ideal wireless connections
- Access to different applications
- Full customization that meets all needs
Ideal wireless connections
Another importance of antennas is its ideal wireless connections. With antennas, devices can communicate with themselves wirelessly without requiring cables or wires. Also, it creates an efficient and very convenient way for connecting devices.
Access to different applications
Antennas come with one important benefit, which is giving you access to different applications. GPS is the most known applications for the GNSS antenna. Also, Galileo, BeiDou, GLONASS also make use of antennas. Finally, satellite, cellular, and Wi-Fi communications usually leverage antennas
Full customization that meets all needs
Antennas are fully customizable in order to fit all needs. Many sizes and designs of antenna are available. Also, custom solutions can be tailored to the specific needs of the application. For example, the design of the antenna is important for the operation of UAVs through long distances.
Long range WiFi antennas help to optimize the strength of the signal and allow you to utilize the linked gadgets inside the wider range of different places.
What Purpose Does GPS Antenna Systems Serve?
The GPS antenna systems help in receiving and amplifying the satellite signals. These amplified signals are then passed onto the GPS receiver that uses this information for calculating the location of the antenna. Antennas that are GPS polarized only receives the signals either horizontally or vertically polarized. Noise amplifiers are also present, which allows interference and noise to be filtered out by this GPS receiver.
GPS antenna systems serve one man purpose, which is offering accurate and clear signals to GPS receivers without any interference.
Selecting the GNSS Antenna Location
Below are the requirements for choosing the best installation location for a GNSS antenna. Regarding the instructions of ways of installing the GPS/GNSS antenna, signal cable, accessories like weatherproofing kits, surge protectors, or amplifiers, just work with the documentation you find with that equipment.
The location for mounting external GNSS antennas must be free of any object that can obstruct the visibility of the satellite from straight overhead to about 20 degrees horizon in every direction.
Points to note
- For optimizing the timing accuracy, this GNSS receiver strives to track the spread out satellites far across the sky. This GNSS receiver has to track four or more satellites to obtain the time synchronization. Also, obstructions blocking a huge part of the sky lead to degraded performance.
The GPS antennas require separation from the surrounding metal materials. All metals in that area alter the reception pattern’s shape of that antenna. Also, all metallic materials or buildings near this antenna could create some shadows. This could shield this antenna from receiving any signals in that direction.
- The separation in-between many antennas: When the installation of antennas is done closely, there can be a potential interaction between antennas, which leads to loss of sensitivity. The antennas’ search pattern could be adversely affected as well leading to the tracking of fewer satellites.
- Normally, antennas have to be separated properly. This is to ensure they are isolated from being affected by any anomaly like falling objects or a close lighting strike.
- The GPS antennas can be described as the receive-only antennas that don’t transmit signals intentionally. Although this will reduce the separation required between many antennas, it is advisable that they are separated a few meters apart to help isolate these antennas. This limits any EMI interference which is caused by active components in the antennas
- When there is noticeable decrease in the sensitivity, thereby causing weak strengths of a signal and a few satellites are tracked, try to reposition these antennas so as to improve the reception of the satellite.
What are the Types of GNSS Systems?
Four GNSS systems are available. These include GPS (United States), BeiDou (China), Galileo (EU), and GLONASS (Russia). Furthermore, two regional systems are also available. These are NavIC or IRNSS (India) and QZSS (Japan).
Global Positioning System (GPS)
This can be described as the oldest form of GNSS system. It started operations back in 1978 and from 1994, it became available for use globally. Its innovation was driven by the need to create military navigation ability. The United States military was the first to achieve this. Therefore, in 1964, the deployment of this transit system happened for the purpose.
Transit, also called NAVSAT, used the Doppler Effect in providing information on the location as well as navigation to the surface ships, missile submarines, and to geodetic surveying and hydrographic survey to the United States Army.
GLONASS
This is Russia’s global navigation system. It is also called the Global Navigation Satellite System. GLONASS was functional from 1993 having 12 satellites present in 2 orbits and at a height of about 19,370 km. Presently, 27 satellites in total are available in orbit, and they are all operational. The operation of GLONASS is done by the Aerospace Defense Forces of Russia and it is the 2nd navigation system operating presently.
GPS GNSS Beidou Antenna
This is China’s satellite navigation system. There are 22 functional satellites in its orbit and its complete constellation plans to have 35 satellites. Also, GPS GNSS Beidou Antennafeatures two different constellations, which are BeiDou-2 and BeiDou-1.
The latter is called the first generation, which is a constellation composed of three different satellites. It started functioning in 2000, and it provided limited navigation and coverage services, majorly for Chinese users and other neighboring regions.
Galileo
Galileo is the GNSS constellation of the European Union which the Europe Space Agency has put together. The Europe GNSS Agency will be in charge of operating it. This global navigation system is mainly for both commercial and civilian use.
This completely deployed system would be made up of six in-orbit spares, as well as thirty operational satellites. Currently, 22 out of the 30 satellites are now in orbit. It started operations in 2016 and by then it was expected to operate fully by 2020.
Conclusion
In summary, GNSS antenna can be described as a significant part of the GNSS receiver system that receives the satellite signals and then calculates the appropriate position. GNSS antenna’s major function is to receive the signals and then pass them through a GPS receiver. The transfer ensures the GPS receiver can calculate its direction, speed, and position. Also, the GPS GNSS antenna helps in receiving and amplifying the radio signals that are transmitted on some frequencies by the GNSS satellites. It then converts them into electronic signals utilized by the GPS or GNSS receiver. This output of the GPS or GNSS antenna is then fed into the GPS or GNSS receiver which can compute its position.
