Spherefix SP20 GNSS RTK Receiver with IMU Tilt

Portable RTK GNSS Surveying for Everyday Fieldwork

The Spherefix SP20 GNSS RTK Receiver combines multi-constellation satellite tracking, IMU tilt measurement and several correction-data options in a portable 740 g receiver. It is suitable for surveyors, construction teams, civil engineers, GIS professionals and drone operators who need accurate coordinates without carrying an unnecessarily heavy field setup.

The receiver can be configured for rover, base or static data collection. This gives one system the flexibility to handle construction stakeout, topographic surveys, boundary and cadastral work, control-point observations, utility mapping, as-built measurements and ground-control-point collection for photogrammetry.

Reliable Multi-Constellation GNSS Tracking

A 1,408-channel GNSS engine tracks signals from GPS, GLONASS, BeiDou, Galileo, QZSS, SBAS and NavIC. Access to multiple constellations gives the receiver more satellites from which to calculate a position. In practical fieldwork, this can help maintain a usable solution when part of the sky is obstructed by buildings, machinery or vegetation.

When used with suitable RTK corrections, the SP20 provides horizontal accuracy of ±(8 mm + 1 ppm) and vertical accuracy of ±(15 mm + 1 ppm). Static observations offer horizontal accuracy of ±(2.5 mm + 0.5 ppm) and vertical accuracy of ±(5 mm + 0.5 ppm). Actual results will depend on satellite geometry, correction quality, baseline length, atmospheric conditions and the surrounding environment.

Measure Difficult Points with IMU Tilt Compensation

The integrated IMU supports tilt measurement through an inclination of up to 60°, with positioning accuracy within 2 cm across the supported tilt range. The system uses seamless inertial navigation and does not require a separate calibration routine before normal measurement.

This allows the survey pole to be tilted while the receiver calculates the position at the pole tip. It is particularly useful beside walls, underneath overhangs, at building corners, near fences or around excavations where a vertical pole is difficult or unsafe to hold. Construction workers can capture points with less time spent levelling the pole, while surveyors can reach details that would otherwise require an offset measurement.

Flexible Correction Links for Base and Rover Work

The SP20 includes an internal 4G modem for connecting to network RTK correction services. It also provides an integrated 410–470 MHz UHF radio with selectable transmit power, allowing the receiver to work in a local base-and-rover configuration where mobile coverage or an NTRIP service is unavailable.

Bluetooth connects the receiver to a compatible field controller, while Wi-Fi provides access to its browser-based management interface. NFC is available for simplified device interaction. These communication options give crews the flexibility to choose a correction method that suits the project location and existing equipment.

Survey, Stakeout and Static Data Collection

Supported field workflows include point surveying, tilt surveying, point stakeout, coordinate localisation and control-point calibration. In rover mode, the receiver can accept real-time corrections for measuring or setting out points. Base mode allows it to transmit correction data through its radio, while static mode records observations for post-processing and high-accuracy control work.

For construction teams, point stakeout helps transfer design coordinates to the ground for foundations, utilities, roads and structural elements. Surveyors can use the same receiver for detail surveys and control observations. GIS crews can capture accurate asset positions, and drone operators can measure ground control and checkpoints for mapping projects.

Designed for Long Days Outdoors

The magnesium-alloy main body provides a strong but lightweight structure, while the IP68 rating protects the receiver against dust and water ingress. It is designed to withstand a 1.5 m pole drop at room temperature and operate between -20°C and +60°C, making it suitable for demanding construction sites and regular outdoor surveying.

A 9,600 mAh internal battery provides more than 16 hours of typical rover operation using a mobile data connection. Static mode can support up to 24 hours of continuous data collection under the stated operating conditions. Fast-charging support helps crews prepare the receiver between field sessions.

Simple Data Management

The Linux-based system includes 32 GB of internal storage and supports standard NMEA output and RTCM 3.x correction formats. Status indicators show battery condition, satellite positioning and the differential-data link, allowing operators to check essential receiver functions without opening the field software.

The web interface provides access to the satellite sky plot, data streams, operating modes, recorded files and receiver settings. This helps experienced surveyors configure detailed parameters while keeping everyday operation straightforward for construction and GIS crews.

Buying and Support from Global GPS Systems

Global GPS Systems supplies the Spherefix SP20 for organisations that need a practical RTK GNSS solution for accurate field measurement. Our team can help buyers choose a suitable rover, base-and-rover or network RTK configuration and match the receiver with an appropriate data controller, survey pole and field software.

Choosing the correct setup depends on the required accuracy, available correction service, radio compatibility and intended workflow. Professional setup and support help ensure that the receiver, coordinate system and correction source are configured correctly for the work being carried out.