GNSS Surveying Equipment
Surveying has been an essential human activity since the times of the Egyptians. Today, its uses include boundary, navigation, construction and machine control, plus many other measurement operations. As surveying technology develops, accuracy improves and the list of applications expands. GNSS-based surveying represents the greatest advancement in modern times.
What Is GNSS?
GNSS stands for Global Navigation Satellite System. It is actually an umbrella term covering several distinct positioning sub-systems. The most well-known of these is the U.S. Global Positioning System. GPS receivers are now ubiquitous in smartphones where they are commonly used for route navigation.
Any of the GNSS systems in use worldwide consists of two additional components besides the satellite constellations themselves. These are a ground control network and the GNSS receiver in user equipment.
The uses for GNSS systems are many, varied and growing far beyond air, sea and land navigation:
- Land and topography surveys
- Geodesy
- Geophysical exploration
- Transportation and delivery
- Precision UAV-based agriculture
How Does GNSS Work?
GNSS satellites produce signals processed by GNSS receivers that contain sufficient information for the receiver to accurately determine its position, velocity and time or PVT.
Communication between the satellites and receiver is continuous as both change position simultaneously. Triangulation of three signals, at minimum, plus complex calculations by the receiver are required to determine PVT.
The accuracy of GNSS is influenced by several factors, including atmospheric conditions, clock error, orbital error and intrinsic receiver error. A phone's GPS is typically accurate to about 10 meters horizontally and 15 meters vertically, whereas professional GNSS survey equipment can achieve 3D sub-centimeter accuracy with the addition of augmenting technologies such as Real-Time Kinematics.
How Many GNSS Systems Are There?
The U.S. NAVSTAR GPS is the most widely used positioning system today, but other GNSS-compatible systems exist or are being developed. The Russian GLONASS, European Galileo and Chinese BeiDou systems already provide worldwide coverage. Other GNSS systems under development include QZSS and IRNSS.
In all, there are approximately 130 GNSS operational or reserve satellites in orbit.
Advantages of GNSS Over Other Positioning Systems
All GNSS receivers are compatible with GPS signals, but many GPS receivers are not compatible with all GNSS systems. Receivers that utilize GNSS versus GPS alone benefit from higher signal availability and increased reliability.
Furthermore, even the most accurate GPS for surveying cannot normally match the accuracy of GNSS survey equipment due to the latter's ability to access more satellites, which also improves coverage in tight spaces, such as between buildings or under tree cover.
Older survey equipment, such as theodolites, clinometers and compasses, do have one advantage over modern GNSS equipment in that they do not need electrical power except in cases where electronics have been added, such as EDMs. They are also immune to radio interference or satellite failure.
The Advantages of Buying GNSS Receivers From Superior Instrument
Superior Instrument offers state-of-the-art GNSS receivers for surveying projects of any type or size. Our selection of lightweight, durable and reliable receivers features the latest hardware and software advances:
- RTK GNSS receivers compatible with GPS, GLONASS, Galileo and other GNSS satellite systems
- The ability to synchronize with SBAS or on-ground data collectors for increased accuracy
- Connectivity via physical ports or multiple radio technologies, such as Bluetooth, Wi-Fi and 4G
- Smart antennas to expand data collection for the largest mapping and survey projects
As a result, our receivers provide surveyors with maximum versatility, accuracy and value under the toughest conditions. We also offer the best surveying GPS deals and GNSS equipment prices.
Order your new GNSS receiver now or consult with our expert team to select a receiver precisely meeting your needs.
