An outdoor robot may need to know where it is, which way it faces, or both. These are separate requirements. A single-antenna RTK GNSS module can provide a precise global position when suitable correction data is available. A dual-antenna system can also determine heading from two antennas mounted on the robot.
The right choice depends on how your robot moves and whether its navigation system needs a heading reference while the platform is stopped or moving slowly.
When Is a Single Antenna Enough?
A single-antenna RTK module is a practical choice when global position is the main requirement. For example, an outdoor UGV may combine RTK position with wheel odometry and an IMU. A UAV may use RTK as a position reference for flight or mapping.
The LucSys G70 GNSS RTK module uses a compact, single-antenna architecture. It is suited to projects that need RTK positioning but do not require heading from a second GNSS antenna.
A single antenna does not directly measure the robot's orientation while it is stationary. If your system needs a heading estimate at standstill, account for that requirement when choosing the rest of the sensor system.
Why Use Two Antennas?
A dual-antenna receiver uses the relative positions of two antennas installed on the same platform to estimate heading. It can provide a GNSS-based heading reference without requiring the robot to move first.
This can be valuable for slow-moving UGVs, robotic mowers, agricultural vehicles and other platforms that must initialize or resume navigation from a stop. It can also provide an alternative heading reference where magnetic measurements are disturbed by motors, electrical equipment or nearby metal.
The LucSys G90 GNSS RTK module supports dual-antenna heading as well as RTK positioning. Its specified heading accuracy is 0.1° RMS with a 1 m antenna baseline. Antenna placement, baseline length and GNSS reception matter when designing the installation.
What Else Does an RTK Setup Need?
Centimeter-level RTK positioning requires suitable differential correction data, adequate satellite visibility and appropriate antenna installation. The correction data may come from a local RTK base station or a compatible network service, depending on the deployment.
The communication link should be planned as part of the system. Do not assume that the GNSS module itself includes a cellular modem or an RTK correction subscription. For a project involving a configurable base station, radio link or multiple rovers, read our guide to modular RTK GNSS for UAVs, UGVs and multi-robot systems.
G70 or G90: A Quick Decision Guide
| Requirement | G70 | G90 |
|---|---|---|
| RTK positioning | Yes, with suitable corrections | Yes, with suitable corrections |
| GNSS antenna configuration | Single antenna | Dual antenna |
| GNSS-based heading at standstill | No dual-antenna heading | Supported with suitable installation and reception |
| Typical selection reason | Compact RTK position is the main goal | Both RTK position and GNSS heading are needed |
For either module, check the available mounting space, antenna layout, correction-data source, power supply and data interface before ordering. If the robot also uses an IMU and wheel odometry, plan how these measurements will be combined in its localization system.
Compare the G70 and G90 specifications and available options →