HB21 GNSS Box Receiver
The HB21 GNSS RTK Receiver is a new-generation, all-in-one GNSS positioning and orientation solution powered by Septentrio’s Mosaic X5 — a new-generation RF baseband and high-precision algorithm integrated GNSS SoC high-performance positioning engine. Designed for intelligent lawn mowers, unmanned aerial vehicles, low-speed unmanned ground vehicles, and unmanned ships, the HB21 integrates centimeter-level RTK accuracy, dual-antenna heading output, 1408 super-channel satellite tracking, integrated 4G LTE, Bluetooth, DTU data communication radio, TF card raw data logging, and SIM card slot — all in a single compact 50 × 75 × 18.2mm enclosure connected directly to a controller via RTGV / PEGR / LHGV interfaces.
The HB21’s dual working mode architecture — supporting both mobile station (rover) and base station operation — enables fully self-contained RTK network deployment. Operating as a rover, the HB21 receives RTCM differential corrections from a CORS base station via integrated 4G LTE and outputs RTK position and heading to the connected controller. Operating as a base station, it broadcasts corrections to rover units via integrated DTU data radio — providing complete RTK infrastructure independence for sites without existing CORS coverage.
Description
Product Overview – HB21 GNSS RTK Receiver
GNSS Positioning & Orientation RTK Receiver | 1408 Super Channels | 0.8cm RTK | 4G / BT / DTU Radio | Dual-Antenna Heading | Mobile & Base Station | Intelligent Lawn Mower · UAV · USV · Autonomous Vehicles
The HB21 GNSS RTK Receiver — powered by Septentrio Mosaic X5 — is a compact, connected, all-in-one RTK positioning and heading solution built on a new-generation RF baseband GNSS SoC engine that delivers the performance, connectivity, and operational flexibility demanded by next-generation autonomous outdoor platforms. With 1408 super-channels simultaneously tracking BeiDou B1I/B2I/B3I, GLONASS L1/L2, GPS/QZSS L1/L2/L5, and Galileo E1/E5a/E5b — and receiving RTCM differential corrections from CORS base stations via integrated 4G LTE — the HB21 delivers centimeter-level RTK accuracy and real-time heading to any autonomous platform with cellular coverage, anywhere in the world.
RTK horizontal accuracy of 0.8cm + 1ppm and vertical accuracy of 1.5cm + 1ppm, combined with RTK initialization time under 5 seconds at greater than 99.9% initialization reliability, make the HB21 one of the fastest and most reliable RTK GNSS receivers for real-world autonomous outdoor operations. For intelligent lawn mowers executing boundary-precise mowing patterns, USVs maintaining course accuracy on open water, and UAVs performing precision payload operations, the combination of fast initialization, high reliability, and 20Hz positioning and direction-finding update rate provides the real-time data quality needed for safety-critical autonomous guidance.
The Septentrio Mosaic X5 engine’s new-generation RF baseband architecture combined with intelligent anti-interference suppression technology delivers robust satellite signal tracking through the electromagnetic complexity of suburban and urban autonomous outdoor environments — including RF emissions from power tools, garden equipment, cellular infrastructure, WiFi networks, and Bluetooth devices that surround intelligent lawn mower and autonomous vehicle operating zones. The 1408 super-channel parallel tracking architecture maximizes satellite geometry by simultaneously tracking all visible satellites, maintaining optimal DOP values and RTK fix reliability even in partially obstructed garden and field environments.
Multiple wireless communication integration — 4G LTE with SIM card, Bluetooth, and DTU data communication radio — provides three independent data paths for RTCM correction reception, controller data streaming, device configuration, and local radio RTK correction broadcasting. The TF card slot enables onboard GNSS raw data logging for PPK post-processing and mission recording. AGPS-assisted cold start in under 10 seconds and hot start in under 1 second minimize deployment delay and recovery time for the high-frequency start-stop operational cycles of intelligent lawn mower and short-mission UAV applications.
Key Applications
- Intelligent Lawn Mower RTK Guidance & Boundary Navigation
- Unmanned Aerial Vehicle (UAV / Drone) Precision Positioning
- Low-Speed Unmanned Ground Vehicle Navigation
- Unmanned Surface Vessel (USV) Positioning & Heading
- Autonomous Outdoor Robot Guidance
- Precision Agriculture Autonomous Equipment
- Golf Course & Sports Field Autonomous Maintenance
- RTK Base Station & CORS Rover Deployment
- Autonomous Outdoor Equipment Guidance
Key Features
GNSS Performance
| Feature | Detail |
|---|---|
| GNSS Engine | Septentrio Mosaic X5 — New generation RF baseband & high-precision algorithm GNSS SoC |
| Tracking Channels | 1408 super channels — simultaneous all-visible satellite tracking |
| Positioning Update Rate | 20 Hz (positioning & direction finding) |
| Raw Observations Rate | 20 Hz |
| Cold Start TTFF | 30 seconds or less |
| Cold Start with AGNSS | 10 seconds or less |
| Hot Start TTFF | 1 second or less |
| RTK Initialization Time | Less than 5 seconds (typical) |
| Initialization Reliability | Greater than 99.9% of the time |
| Sensitivity | -130 dBm at 12 or more available satellites |
Positioning Accuracy
| Mode | Horizontal | Vertical / Elevation |
|---|---|---|
| Single Point (RMS) | 1.5 m CEP | 2.5 m CEP |
| RTK | 0.8 cm + 1 ppm | 1.5 cm + 1 ppm |
| Velocity Accuracy | 0.03 m/s CEP | — |
Heading & Orientation Accuracy
| Antenna Baseline | Orientation Accuracy |
|---|---|
| 1 meter baseline | 0.1° |
Satellite System Support
| Satellite System | Supported Signals |
|---|---|
| BeiDou (BDS) | B1I, B2I, B3I |
| GLONASS | L1, L2 |
| GPS / QZSS | L1, L2, L5 |
| Galileo | E1, E5a, E5b |
Detailed Technical Specifications
Communication & Connectivity
| Interface | Specification |
|---|---|
| 4G LTE | Integrated — CORS RTCM correction reception, data streaming |
| Bluetooth | Integrated — device configuration and short-range data transfer |
| DTU Data Radio | Integrated — local differential data transmission for base station mode |
| SIM Card | Integrated SIM slot |
| USB | Type-C |
| TF Card | Integrated TF card slot — GNSS raw data logging |
Working Modes
| Mode | Description |
|---|---|
| Mobile Station (Rover) | Receives RTCM corrections from CORS base station via 4G LTE — outputs RTK position and heading to controller via RTGV / PEGR / LHGV interfaces |
| Base Station | Broadcasts RTCM differential corrections to rover units via integrated DTU data radio — enables independent RTK deployment without CORS infrastructure |
LED Status Indicators
| Indicator | Function |
|---|---|
| PPS | Pulse-per-second timing signal status |
| RTK | RTK fix status — fixed / float / no fix |
| 4G | 4G LTE cellular network connection status |
| BT | Bluetooth connection status |
| DTU | Data radio transmission status |
| PWR | Power on status |
Physical Dimensions
| Dimension | Value |
|---|---|
| Width | 50 mm |
| Height | 75 mm |
| Depth | 18.2 mm |
| Antenna Ports | DIRECTIONAL (heading antenna) + GNSS + 4G — dedicated connectors |
| Output Connectors | PEGR, RTGV, LHGV, RTGN |
Working Diagram — CORS to Controller Architecture
- CORS base station transmits satellite signals and RTCM differential correction data
- HB21 (mobile station mode) receives RTCM corrections via integrated 4G LTE from CORS infrastructure
- Septentrio Mosaic X5 engine computes centimeter-level RTK position and 0.1° heading solution in real time
- RTK position, heading, and raw observation data output to connected autonomous vehicle or drone controller via RTGV / PEGR / LHGV interfaces
- Alternatively: HB21 in base station mode broadcasts RTCM corrections to multiple rover units via DTU data radio — independent of CORS network
Competitive Advantages
- Septentrio Mosaic X5 new-generation RF baseband GNSS SoC — industry-proven signal processing in intelligent lawn mower and autonomous vehicle form factor
- 1408 super channels — massively parallel satellite tracking for maximum signal availability and RTK fix reliability in partially obstructed garden and field environments
- RTK initialization under 5 seconds at greater than 99.9% reliability — fastest and most dependable fix for intelligent lawn mower and UAV applications
- 0.1° heading accuracy at 1m baseline — precision compass-free orientation for intelligent lawn mowers, USVs, and UAVs
- Three integrated communication paths — 4G LTE, Bluetooth, DTU radio — eliminates need for separate communication modules
- Dual mobile station and base station modes — complete RTK infrastructure self-sufficiency for sites without CORS coverage
- AGNSS cold start in under 10 seconds, hot start in under 1 second — minimal delay for intelligent lawn mower daily start cycles
- TF card raw GNSS data logging — PPK post-processing and mission recording capability
- Compact 50×75×18.2mm with three dedicated antenna ports — optimized for intelligent lawn mower top-plate and USV deck integration
- Intelligent anti-interference suppression — reliable positioning through suburban RF environments surrounding autonomous outdoor equipment
Standards & Compatibility
- Differential Input: RTCM — received via integrated 4G LTE from CORS base stations
- Connectivity: 4G LTE (integrated SIM), Bluetooth, DTU data radio
- Interface: Type-C USB, TF card slot, RTGV / PEGR / LHGV / RTGN output connectors
- Working Modes: Mobile station (rover) and base station — user selectable
- Platform Integration: Intelligent lawn mowers, UAV autopilots, USV navigation systems, low-speed AGV controllers, autonomous outdoor equipment
Disclaimer
Specifications subject to change without notice. Positioning accuracy values are nominal under open-sky unobstructed conditions at 99% static. Test results may be affected by atmospheric conditions, baseline length, GNSS antenna type, multipath, number of visible satellites, and satellite geometric configuration.






