Best GNSS Receivers Ranking for 2020

Global Navigation Satellite Systems (GNSS) receivers are special devices designed to receive signals from global positioning systems QZZ, COMPASS, GPS, GLONASS, as well as SBAS correction systems. These satellites are located in different orbits that encircle our planet, or over its specific territories. Receivers (they are also satellite receivers), which have the ability to work with several systems at once, are called multi-system.

These devices are used by humans to determine the exact coordinates on the ground and not only (positioning in near-earth space is possible). In addition, they are able to measure the exact time and various parameters when objects are moving (for example, direction and speed). The method by which the positioning is performed is to calculate the distance between the satellite and the antenna of the GNSS receiver.

Thus, if the position of several satellites is known, then using the triangulation method, it is possible to establish the position of the desired object with high accuracy, using simple geometric calculations.

The satellites themselves transmit a digital signal containing ephemeris (that is, information about the orbit of the satellite from which the transmission is being conducted) and a common almanac (that is, information about the position of all satellites in the system being used), as well as the updated time. Information transfer takes place at special frequencies that are allocated for satellite transmission. As a rule, these are the ranges from 1100 to 1600 Megahertz.

The modern use of satellite devices has brought geodetic equipment to a completely new level - now it has become easy with its help to solve problems that are necessary not only for construction, but also for other areas of human activity. This branch of the high-precision industry is developing by leaps and bounds, various improvements are constantly appearing, so choosing the right GNSS receiver can be very difficult, due to the simple impossibility of tracking new items on a permanent basis. Moreover, it is difficult to determine the receiver parameters that the user will definitely need.

Some features of the functioning of receivers

GNSS receivers are not only capable of determining location both on the ground and in the air, but they can also measure the properties of objects, regardless of whether they are in a static position or moving. The essence of the calculation is to continuously measure the distance between the satellite and the tracking object. Every year the error of such calculations is steadily decreasing and, accordingly, the determination of the coordinates of the tracking object becomes more accurate. At the moment, the accuracy is already several meters.

Composition of satellite GNSS-set

As a rule, the receivers are not sold individually, but come immediately in the kit. A standard set of such equipment consists of:

• Two satellite receivers;
• Field controller with installed software;
• Satellite dish GNSS type;
• Transmitting device (modem).

Current technologies have already reached such a level of development that all of the above set can be enclosed in one device. The main field of application of these monoblocks is cadastral and geodetic works. There are devices in which the controller is taken out separately and such devices are called “handhelds”. It is very easy to update the operating system and control programs in them.

IMPORTANT! It is worth distinguishing between GNSS receivers and GPS tourist receivers. The former are high-precision industrial equipment and are intended for use in strictly defined areas. The latter are needed for travel and tourism and have much less functionality.

The current need for GNSS instruments

Receivers for geodetic works are subdivided into one- and two-system, as well as one- and two-frequency. Almost all modern models have the ability to take into account differential corrections for the implementation of navigation tasks. When using the latest software, it is possible to plan a geodetic survey in advance, save and transfer the obtained data to external devices (computer), carry out primary processing of the collected information, and form a digital map of space.

Applications of GNSS equipment

Such geodetic systems are widely used at the initial stages of the construction of buildings and structures, as well as for surveying land plots and their binding to geographic objects. The main advantage of using these devices is their extremely fast operating time, which makes it possible to transfer the obtained coordinates for processing almost immediately. Among other things, GNSS coordination will allow not only to build a house competently, but also to lay various communications accurately, from a water supply system to an electric power transmission network.

As a result, the priority areas are:

• Maintaining geodetic connections at all levels - from global to classic filming;
• Study of natural phenomena occurring on the earth's surface (movement of rocks and glaciers, seismic activity and volcanism, etc.);
• Maintenance of the laying of pipelines, various construction stages, as well as the solution of many engineering and applied problems;
• Assistance in land management and land allocation;
• Organization of leveling manipulations;
• Establishing a consistent timeline in high precision mode;
• Solving problems in the field of geoinformatics and cartography.

Basic methods of conducting a GNSS survey using receivers

Traditional the method is a statistical survey, which is optimally combined with all current dimensions of the bases. To do this, it is necessary to install two antennas at the designated control points, they will process the entire volume of incoming data. The receivers, in turn, will track satellites and record relatively similar parameters.For this method, it is possible to use the "fast statics" methods - a small error is put into the script of the received data by the user, but all the necessary information can be collected within 15 minutes.

Kinematic the method consists in quickly tracking several points at once, but in this case it is necessary to make sure that the equipment is at the desired point before the initialization process begins (roughly speaking, until the next moment of receiving a satellite signal). If you do not make it in time, then the whole procedure will have to start over. It is advisable to use this method in relatively large areas, when it is possible to quickly reach the next point, for example, by car.

Also, the kinematic method can be used in extremely small areas, using the "stand and walk" principle. In this case, the distance between the points should be minimal, and the main thing is that there are no objects in the area that can interfere with the passage of the satellite signal (high-rise buildings, power lines, etc.).

Among other things, positioning can be carried out in real time: the communication between the receiver and the satellite is practically uninterrupted. However, this method will require high energy costs, which the GNSS receiver battery may not be able to handle. Usually such solutions are used by cadastral engineers or surveyors.

Choosing the right location for the base receiver

Location is critical to a successful survey. When performing postprocessing or real-time surveying with a single or dual frequency receiver, remember that the position of the rover (moving antenna) will be constantly referenced to the base position. Any error in determining the coordinates of the base by a moving antenna will inevitably lead to distortion of the coordinates of the rover itself.

Thus, two conditions must be met:

• Reliability of GNSS reception;
• The known / unknown coordinates of the base itself.

There may also be a third condition, which is the environment of the base. The base antenna should be installed as high as possible so that there are no obstacles to signal reception along the horizontal plane and the maximum range is reached.

Condition # 1: GNSS reception

Make sure that the antenna is installed in a location where there are no obstructions to the view of a specific area of ​​the sky in a vertical direction (here we are not talking about ground shielding obstacles located horizontally). A clear space above the base will allow collecting data from the maximum number of satellites flying over it. Such an arrangement guarantees the favorable operation of the system as a whole and the receipt of reliable data even from satellites in geostationary orbit, not to mention low-flying ones.

Condition # 2: known / unknown location of the base

With some survey methods, it may well be that the position of the base is not exactly known to the rover. Therefore, the following measures must be taken: if it is necessary to achieve centimeter measurement accuracy, then you should use the approximate coordinates in centimeters, which are known for the area where the base antenna is installed. If this cannot be done, then a small error should be put into the measurement script, which can then be eliminated by knowing the exact coordinates of the base.

Initialization process

Initialization is a procedure in which the receiver in real time (or a program in post-processing) can set the ambiguity of an integer coordinate number that is characteristic of the carrier phase of processing. This solution is a necessary condition for the receiver and its software to obtain measurements with an accuracy of the centimeter. Accordingly, for highly accurate calculations, it is necessary to constantly monitor this parameter.

IMPORTANT! This process should not be confused with the initialization of the receiver by the satellite, when primary communication is established between devices.With primary communication, the accuracy of coordinates is 5-10 meters.

Main parameters of GNSS equipment that require close attention

The key role in the operation of the receiver will be played by:

• Signal processing technology and the number of channels used. When working in difficult weather or geographic conditions, the accuracy of the measurements obtained will directly depend on the stability of the signal, and therefore on the number of channels used. Modern technologies for suppression of extraneous noise and multi-beam of some models allow you to work effectively in inclement weather on rough terrain;
• Battery life and power. It is worth taking care of the presence of an additional battery in the kit for "hot swapping" the used one. The current standard for a single battery is one day of field work;
• Dust and moisture protection of equipment and temperature conditions. The most expensive and modernized samples can operate in the range from -40 to +60 degrees Celsius. The IP rating of the enclosure must be indicated on the device itself. For example, IP67 means that the device can even be submerged in water for a short time, and its case is completely protected from dust;
• Data format for transmission. They must be the same for the rover and base equipment. Any discrepancies are immediately excluded if it is equipment of the same company. If the manufacturers of devices are different, then it is possible to use the RTCM standard, which is universal for all samples.

The right choice of GNSS receivers upon purchase

Even if a potential buyer is not a professional surveyor and has never dealt with such equipment before, the criteria listed below will help you not to make a mistake with the choice:

• Easy to use and reliable. Any equipment of this type should have a simple and intuitive interface, not have too many multi-level menus and options. Simply put, the plug-and-play principle must be followed;
• The ability to connect the receiver with other external devices: from a modem and a computer to a smartphone;
• Supported satellite constellations. Here it is necessary to decide in which area the longer work is expected. For Europe, Galileo is suitable, for Russia and the CIS countries it is better to use GLONASS, on a global scale - GPS. It is worth knowing in advance whether the chosen model is multi-system - these are usually more expensive;
• The presence of a digital display. Naturally, it is better when it is present in the model. Moreover, it is preferable to choose a model with a multi-pixel LCD screen, rather than with pre-installed images. It is much easier and more pleasant to work with a good non-static screen;
• Manufacturer. GNSS receivers are technically complex equipment, so surveyors prefer samples from Western manufacturers. At the same time, they do not bypass Japan either - models from Leica (a division of Panasonic), which are characterized by increased accuracy, are especially popular.

Best GNSS Receivers Ranking for 2020

5th place: SP ProMark 220

This model uses advanced ZED-Blade technology for faster initialization and increased accuracy even on extended baselines. The receiver tries to make the most of all GNSS constellations, which means high efficiency and measurement accuracy even in difficult conditions.

• Used innovative technologies;
• Extremely affordable price;
• Good completeness of the kit.

• Works only with 2 systems: GLONASS and GPS.

4th place: Set SOUTH S660

This sample is extremely easy to use, has a relatively low weight and shockproof complex for all devices included in the set.The unique design of the antenna allows for ultra-accurate measurements in both static and real-time modes. The design of the device is an example of ergonomics, and the control interface is simple and intuitive. Most often used for landscape architecture.

• Actual value for money;
• Ergonomic design
• Supports all known satellite constellations (civilian, of course).

• The modem only works in 2G / 3G networks.

3rd place: SOUTH Galaxy G1 set

This unit represents a new generation of receivers with small size and enhanced functionality. The receiver is equipped with automatic adjustment of the reception levels, which uniquely increases the measurement accuracy. Also, a special tilt sensor is included in the design, which allows you to eliminate centering errors and automates communications along the route. The kit won the 2015 Surveyor's Best Friend at the Reddot Design Award.

• Almost fully automated model - in some cases you don't even need to press a button to take measurements;
• Honored brand with an international award;
• Works under all existing operating systems from Microsoft (except for the 10th version).

• Not found (for its segment).

2nd place: LEICA GS18T LTE

This model is equipped with a special compensator that smooths out inaccuracies in measurements when the angle of inclination of the pole occurs. Thus, constant leveling of the device is not required. It is highly resistant to electromagnetic influences, which makes it possible to ensure stable communication with the satellite even near power lines. The case has an increased level of dust and moisture protection (IP68). Extremely unpretentious to weather conditions.

• Works with all satellite systems;
• No need for additional calibration;
• Data can be stored on external media (up to 8 GB).

• High price for an incomplete set.

1st place: GPS Leica GR50

This receiver can be called a "server from the world of GNSS equipment". It can work both as a permanent stationary station, and as a reference (reference) model. The exceptional accuracy of the device allows it to be used in extremely precise areas, for example, when monitoring deformations of the earth's surface. Has its own software "SmartWorks", focused on performing special tasks. It can work with many client rovers.

• Multifunctionality;
• Own software;
• Support for a large number of rovers;
• Works with all satellite systems.

• Extremely high price (available only to large buyers for specific applications).

Instead of an epilogue

Due to the fact that the described equipment is technically complex, it should be purchased only from trusted suppliers. Moreover, professionals advise making purchases on Internet sites, because there it will be possible to save on the difference in retail cost. This circumstance is most relevant, because the price of the devices is extremely high.