Spherefix SP30 SE RTK GNSS Rover and Base Set

Complete RTK base and rover system

The Spherefix SP30 SE Rover & Base Set provides the main equipment required to operate an independent local RTK GNSS system. It combines two SP30 SE receivers with the C100T Android field controller and the accessories needed to establish a base station and work with a mobile rover.

One receiver is positioned over a known or assigned base point and transmits correction data through its integrated UHF radio. The second receiver uses those corrections as the rover, allowing the operator to measure or stake out points with centimetre-level positioning. This setup is useful on construction sites, remote projects and large outdoor areas where mobile coverage or access to a regional correction service cannot be relied upon.

Two identical multi-purpose GNSS receivers

Because the set uses two SP30 SE receivers, either unit can be configured for base or rover work. This provides more flexibility than a system with a dedicated base-only receiver. Crews can adapt the configuration between projects, use either receiver as the rover or operate one receiver separately with a compatible NTRIP correction service.

Each SP30 SE contains a 1,408-channel GNSS board that tracks signals from GPS, GLONASS, Galileo, BeiDou, QZSS, SBAS and NavIC. Multi-constellation and multi-frequency tracking gives the receiver access to a broad range of satellite observations, helping maintain positioning performance when parts of the sky are obstructed by trees, buildings, machinery or terrain.

Centimetre-level RTK positioning

Under suitable RTK operating conditions, the SP30 SE has a specified horizontal accuracy of ±(8 mm + 1 ppm) and vertical accuracy of ±(15 mm + 1 ppm). This makes the set suitable for construction stakeout, topographic surveying, utility mapping, site documentation, ground-control measurement and other work where standard handheld GPS accuracy is insufficient.

The final accuracy achieved in the field depends on factors such as satellite visibility, multipath, base coordinates, correction age, radio reception, pole setup and the distance between the base and rover. Correct base placement and project configuration remain important when working to engineering or survey tolerances.

IMU tilt compensation for difficult points

The integrated IMU allows the rover pole to be tilted by up to 60 degrees while the system calculates the position of the pole tip. The specified tilt compensation accuracy is below 2 cm within the supported tilt range.

This makes it easier to measure beside walls, underneath vegetation, around parked machinery, near excavations and at building corners. Instead of forcing the complete pole into a vertical position, the operator can place the pole tip on the required point and lean the receiver away from the obstruction.

Tilt compensation can also speed up routine point collection because the operator does not need to centre the pole bubble for every observation. This is particularly useful during high-volume topographic surveys, utility inventories and construction as-built work.

Local UHF radio corrections

Both SP30 SE receivers include an integrated 410–470 MHz UHF radio with selectable output power up to 5 W. In a base-and-rover workflow, the base receiver broadcasts correction data directly to the rover without requiring internet access at each measured point.

The product is specified for long-range radio communication in open terrain. Actual working range depends on the selected power, antenna installation, base height, local interference, obstacles, terrain and national radio regulations. A base positioned on elevated, open ground will generally provide better coverage than one placed beside buildings, vehicles or earthworks.

Radio frequencies and permitted transmission powers vary between countries. The system should be configured for the locally authorised frequency range before use.

Network RTK when a local base is not required

The integrated 4G modem also allows either receiver to work with compatible NTRIP correction services. This gives users the choice between operating their own base station and connecting the rover to an existing RTK network.

Network RTK can be convenient for projects spread across a wide region because no physical base receiver needs to be guarded or moved. A local base may be more suitable in remote areas, on controlled construction sites or where the team needs an independent correction source. Having two multi-purpose receivers allows the same set to support both approaches.

C100T Android survey controller

The included C100T controller provides a rugged interface for configuring the receivers, recording survey points and carrying out stakeout. It uses Android 11, an eight-core processor and a 5.45-inch high-resolution display designed for outdoor visibility.

The combination of a touchscreen and physical keypad gives operators practical control while wearing gloves or working in wet and dusty environments. Dual-SIM 4G connectivity supports internet-based corrections, project communication and data transfer where compatible mobile service is available.

The controller is specified for up to 18 hours of operation, making it suitable for extended field sessions. Compatible surveying software can be used for point coding, line collection, coordinate entry, stakeout and exporting measurements for CAD or GIS workflows.

Built for outdoor survey conditions

The SP30 SE receiver housing is rated IP68 for resistance to dust and water ingress. Each receiver is also specified to withstand a 1.5 m pole drop and operate between −20°C and +60°C.

At approximately 1 kg per receiver, the system remains manageable for daily field use. The relatively low rover weight reduces the load at the top of the survey pole, while the compact base receiver is easy to transport and install on the included tripod setup.

Battery capacity for extended projects

Each SP30 SE contains a 7.4 V 10,000 mAh rechargeable battery. The receiver is specified for more than 24 hours of rover operation and more than 10 hours in base mode under stated test conditions.

Base operation normally consumes more power because the integrated radio is continuously transmitting correction data. Actual operating time will vary with transmission power, mobile connectivity, temperature, satellite conditions and battery age. External power can be considered for projects that require the base to operate continuously for longer periods.

Construction layout and site measurement

Construction teams can use the system to stake out foundations, building grids, roads, drainage, utilities and earthwork designs. The rover can also record completed work for progress measurement and as-built documentation.

A local base-and-rover setup is especially useful on larger construction sites where the same correction source needs to serve repeated measurements throughout the project. The base can be established over a stable control point while the rover moves between different work areas.

Topographic and engineering surveys

Surveyors and engineers can use the SP30 SE set to collect terrain points, breaklines, boundaries, site features and control information. The receiver’s IMU supports efficient measurement on slopes and around obstacles, while multi-constellation tracking helps in locations with partly restricted sky visibility.

The set can also support road surveys, quantity calculations, earthwork checks and preliminary engineering surveys. Project coordinate systems, transformations and base coordinates should be configured carefully when measurements need to match existing design or control data.

GIS utility and asset mapping

GIS teams can record accurate positions for inspection chambers, pipes, valves, cables, signs, trees, street furniture and other assets. Attributes and point codes can be entered through compatible field software, reducing the amount of manual processing required after returning to the office.

Operating a local base can be helpful in rural areas, industrial sites or private facilities where access to a public RTK network is limited. The rover can continue receiving corrections over the local radio link without depending on mobile coverage at every asset location.

Drone ground control and checkpoints

Drone operators can use the rover to measure ground control points and independent checkpoints for photogrammetry and mapping projects. Accurate ground coordinates help georeference aerial models and provide reference points for checking the horizontal and vertical quality of the final dataset.

A self-contained base-and-rover system is particularly practical for drone projects in remote areas. The base can remain on a stable point during the flight and ground survey while the rover is used to measure control targets throughout the site.

Choosing and configuring the system

Before using the set, consider how the base coordinates will be established, which radio frequencies are permitted locally, which coordinate reference system the project requires and which data formats need to be delivered. These choices directly affect whether the collected measurements align correctly with existing drawings, GIS databases or survey control.

Global GPS Systems can assist with receiver configuration, radio settings, controller software, coordinate systems and accessories for the intended workflow. Support is also useful when the equipment must communicate with an existing receiver, third-party radio or external NTRIP service.