Carlson Viking RTK GNSS Rover and Base Set with RT4 Plus and SurvPC

Complete RTK base and rover system for professional fieldwork

The Carlson Viking RTK Base and Rover Set with RT4+ provides a complete professional positioning system for teams that want to operate their own GNSS base and rover. Two Carlson Viking receivers form the GNSS system: one receiver is established over the project reference point as the RTK base station, while the second Viking receives correction data and is used as the mobile rover. The Carlson RT4+ running SurvPC provides the field interface for configuring the equipment, collecting survey data and carrying out stakeout.

This type of setup is particularly useful for land surveying, construction, earthworks, civil engineering and other projects where crews want direct control over their RTK corrections rather than relying entirely on a third-party correction network. Once the base is established correctly, the rover can work throughout the site using real-time correction information transmitted from the base.

Two Carlson Viking receivers with interchangeable roles

Both GNSS receivers in the system are Carlson Viking units. Each Viking can operate as either an RTK base or rover, so the hardware is not permanently restricted to one role. This provides useful flexibility for survey companies and construction teams because either receiver can be configured for the required job.

On a normal base and rover project, one Viking remains stationary over the control point while the second moves around the site. For other projects, either receiver can also be used independently as a rover with a suitable external correction service or configured as a base for another compatible RTK receiver.

Direct RTK corrections from base to rover

The Viking includes an integrated UHF radio, allowing the base receiver to transmit RTK corrections directly to the Viking rover when both radios are configured with compatible settings. This creates a self-contained local RTK system that does not require a mobile internet connection between the two receivers.

This is useful on construction sites, rural projects, earthworks jobs and survey locations where cellular reception is limited or where a direct radio connection is preferred. Actual radio performance depends on terrain, buildings, vegetation, antenna setup, radio configuration and local radio regulations.

The Viking also provides cellular, Wi-Fi, Bluetooth and other communication options, allowing the receivers to be integrated into different correction workflows when required.

Triple Fix technology for demanding GNSS environments

The Carlson Viking uses two GNSS RTK modules together with three independent RTK engines. Carlson’s Triple-Fix architecture allows the receiver to calculate and compare multiple RTK solutions rather than depending on a single positioning engine.

For the rover operator, this is especially valuable when working in real field conditions where satellite reception can be affected by buildings, machinery, fences, vehicles or vegetation. Reflected and partially obstructed satellite signals can make GNSS positioning more difficult, so having independent RTK calculations available provides another level of information when evaluating the solution.

Triple-Fix does not replace normal survey control procedures or independent checks, but it is designed to reduce the risk associated with relying on a single RTK calculation in challenging locations.

Centimetre level RTK positioning

The Viking is specified for RTK horizontal accuracy of 0.6 cm + 0.5 ppm and vertical accuracy of 1 cm + 1 ppm under appropriate operating conditions. For everyday fieldwork, this makes the base and rover system suitable for accurate coordinate collection, construction layout, topographic surveying, control work and many other professional GNSS applications.

As with any RTK system, final accuracy depends on factors including the quality of the base coordinate, satellite conditions, correction link, baseline length and the surveying procedures being used. Establishing the base correctly is therefore just as important as achieving an RTK fixed solution at the rover.

632 channel multi-constellation GNSS

Each Viking receiver supports 632 GNSS channels and tracks GPS, GLONASS, Galileo, BeiDou, QZSS and NavIC. Multi-frequency and multi-constellation tracking gives both the base and rover access to observations from a large number of available satellites.

For the rover, this helps maintain useful satellite geometry as the surveyor moves around buildings, equipment and other obstacles. At the base, broad satellite support provides the observations needed to generate modern multi-constellation RTK corrections for the rover.

Survey with the rover pole tilted up to 60 degrees

When a Viking is used as the rover, its integrated IMU provides calibration-free pole tilt compensation up to 60°. The receiver calculates the position of the pole tip even when the GNSS antenna is not directly above it, allowing the operator to measure without carefully levelling the pole for every point.

This can save significant time when collecting large numbers of points and makes difficult features easier to reach. Building corners, kerbs, trenches, fences, drainage features, utilities and points beside machinery can often be measured by placing the pole tip directly on the required position and allowing the IMU to compensate for the pole angle.

Establish the base over project control

The accuracy of the complete base and rover system depends on the coordinate assigned to the base station. For professional survey work, the base is normally established over a known control point whenever suitable project control is available. SurvPC provides dedicated GPS Base tools for entering and configuring the base position.

Depending on the project, a base can be established from known geographic or grid coordinates, an existing surveyed point, local coordinates or a newly determined position. Previously established base information can also be reused when returning to a project.

This is especially useful on construction sites that run for weeks or months. The base receiver can be installed over the same surveyed control point on each visit so the rover continues working within the established project coordinate system.

Carlson RT4 Plus rugged survey data collector

The Carlson RT4+ is the field controller for the system. It runs Microsoft Windows 11 and uses an Intel N200 processor with 16 GB RAM and a 256 GB PCIe SSD. This provides the performance required for SurvPC, survey coordinate files, drawings, maps, surfaces and other project information used during fieldwork.

The 7-inch high-visibility display is designed for outdoor operation. Its capacitive touchscreen can be used with gloves and a compatible stylus and is designed to remain practical in wet field conditions. Physical navigation controls and programmable buttons provide additional input options when using a touchscreen is less convenient.

Carlson SurvPC connects the complete workflow

Carlson SurvPC provides dedicated configuration tools for both the GNSS base and rover. The base setup allows the operator to connect to the first Viking, define its position, enter antenna information and configure the method used to transmit RTK corrections. The rover configuration is then used to connect the second Viking and define how it receives those corrections.

When using the integrated UHF radios, the base and rover need compatible radio parameters. Once communication is established and the rover achieves a suitable RTK fixed solution, the same SurvPC environment can be used for normal survey and stakeout operations.

Current Carlson Viking receivers require SurvPC 7.12 or higher. Using a supported software version ensures that the correct Viking drivers and configuration options are available on the RT4+.

Topographic and detail surveying

For land surveyors, the base and rover system provides a practical setup for collecting large numbers of accurately positioned points throughout a project. The rover can be used for topographic measurements, boundary-related field observations where GNSS methodology is appropriate, site detail, terrain surveys and general coordinate collection.

Tilt compensation is especially helpful during detail surveys because the pole can be positioned against features that would otherwise be awkward to occupy while maintaining a perfectly vertical antenna.

Construction setting out and as built measurements

Construction professionals can use the rover to take digital design information directly into the field. SurvPC supports point, line and other stakeout routines that guide the operator toward the required project position and provide information such as horizontal differences and cut or fill.

The same equipment can then be used to record completed work for as-built documentation. Keeping both layout and measurement within the same base reference helps crews maintain a consistent coordinate framework throughout the project.

A self contained system for sites without RTK network coverage

One of the main reasons to use a dedicated base and rover is independence from external RTK correction networks. When the two Viking receivers communicate directly by UHF, the field team can operate in locations where mobile data is unavailable or unreliable, provided the radio link between base and rover remains suitable.

This can be valuable for rural surveys, new developments, road construction, large earthworks sites and remote engineering projects. It also gives the survey team direct control over the physical base point used as the reference for the job.

Flexible enough to use with network RTK

Owning a base and rover system does not prevent the Viking rover from being used with network corrections. The Viking supports several RTK correction input methods, including UHF and NTRIP-based workflows. This means the rover can be used with the local Viking base on one project and with a suitable RTK network on another.

Likewise, the second Viking remains a fully capable GNSS receiver rather than hardware that can only operate as a dedicated base. This flexibility is valuable for companies whose survey requirements change from project to project.

GIS and infrastructure mapping

The Viking rover can also be used for accurate GIS and asset data collection. Utilities, drainage systems, road furniture, inspection points and other infrastructure can be positioned with the GNSS rover while project information is handled through the RT4+ and compatible field software workflows.

A local base can be particularly useful on large sites where repeated asset surveys need to remain within the same project coordinate reference over an extended period.

Ground control for drone mapping

Drone survey teams can use the rover to measure ground control points and independent checkpoints for photogrammetry projects. Accurately surveyed points provide a coordinate reference for the aerial dataset and can be used to independently check the resulting model or orthophoto.

The ability to operate one Viking as a base also makes the system useful to teams that combine conventional ground surveying with compatible RTK drone workflows.

Designed for long days in the field

Each Viking uses dual hot-swappable batteries and is designed for more than 12 hours of operation under specified conditions. A depleted battery can be replaced while the other remains installed, helping avoid unnecessary interruption to a long base or rover session.

The Viking receivers have an IP67-rated enclosure and are designed for professional outdoor use. The RT4+ has an IP68 rating and a removable battery rated for up to 15 hours under specified operating conditions. Together, the equipment is suited to the dust, rain and changing conditions encountered on active survey and construction sites.

One system for survey construction engineering and GIS teams

A complete base and rover set is useful for organisations that carry out different types of positioning work. A surveyor can collect topographic data in the morning, a construction crew can use the same system for layout, and the rover can later be used for as-built measurements, utility mapping or ground control.

Because both Viking receivers can be configured as either a base or rover, the equipment can also be reorganised as project requirements change. This makes the set more flexible than a system where the base hardware has only one dedicated function.

Carlson Viking base and rover set from Global GPS Systems

Global GPS Systems can help configure the Carlson Viking RTK Base and Rover Set around your project requirements and existing equipment. Important considerations include the correct regional UHF configuration, coordinate system, base setup method, RTK correction workflow, SurvPC configuration and any accessories required for mounting the base and rover in the field.

For surveyors, construction professionals, engineers and GIS teams looking for their own complete RTK system, two Carlson Viking receivers combined with the RT4+ and SurvPC provide a flexible solution that covers the full workflow from establishing the base station to measuring and staking centimetre-level positions with the rover.