The accuracy of Unicore GNSS receivers ranges all the way from meter, though sub-meter and centimeter, down to the millimeter level.

Using our own unique technology Unicore has successfully developed and fielded series of multi-system, multi-frequency, high-performance System on a Chip (SoC), and a range of high-precision, board-level GNSS receivers and navigation/timing modules.

Applications include Continuously Operating Reference System (CORS) reference stations, survey & mapping, precision agriculture, positioning & heading, vehicle monitoring, autonomous vehicle navigation, and precision timing – along with a number of other

Unicore is a one-stop provider of GNSS SoC chips and GNSS receivers, with extensive experience in the design, verification, development, implementation and production of highly integrated ICs, along with multi-system high-performance GNSS baseband algorit

Unicore Communications, Inc. is a technology company focused on the design & development of highly integrated ICs, algorithms and GNSS receivers.

Home > Product Center > UB4B0M 


BDS/GPS/GLONASS/Galileo Multi-system Multi-frequency Compact High Precision Board

Brief Introduction

Unicore UB4B0M is a compact RTK board particularly suitable for high precision positioning and navigation. Based on a proprietary Nebulas-II GNSS System-on-a-Chip (SoC), the board delivers low power consumption, millimeter-level carrier phase observations, centimeter-level RTK positioning and supports multi-path mitigation.
Multi-system and Multi-frequency Signal Processing
UB4B0M simultaneously tracks signals from BDS,GPS, GLONASS, Galileo and QZSS and supports tri-band signals from BDS, GPS and Galileo,delivering“ instantaneous” RTK initialization and achieving 1-2 cm positioning accuracy. Even in shades or from a long distance, the board still obtains RTK positioning results quickly and reliably.
Nebulas-II GNSS SoC
UB4B0M is based on Unicore’s Nebulas-II multi-system, multi-core, high precision SoC. The SoC supports 432 channels, includes a built-in high performance ADC, an anti-interference unit, two 600MHz ARM processors and two precision floating-point processing units, providing powerful GNSS signal processing capability.
Adaptive Anti-interference
Thanks to powerful Nebulas-II chip and high linearity, wide dynamic RF front-end design,UB4B0M can effectively suppress narrow band and single-tone radio interference in the GNSS signals.Thus, the customers obtain accurate positioning results even in complex electromagnetic environments.
Integrated MEMS Navigation
The UB4B0M integrates 6-axis on-board MEMS chip and U-Fusion INS algorithm, resulting in optimized continuity and reliability of accurate heading and positioning output in tough environments such as city canyons, tunnels and overpasses. The board also supports odometer inputs to provide better navigation and positioning performance.

Product Characteristics

 Supports BDS B1/B2/B3; GPS L1/L2/L5; GLONASS L1/L2; Galileo E1/E5a/E5b; QZSS L1/L2/L5
• mainsteam board
• Better than 1 mm carrier phase observation
• Centimeter-level RTK positioning

• Integrated MEMS navigation

• MEMS navigation

Basic Features

• Multi system and multi-channel high performance SoC chip based on Nebulas-IItm
• Supporting single system independent location and multi system joint location.
• Support advanced multi-path mitigation technology.
• Support 3 serial ports, one 1PPS

Data Manual

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Technical Index

Performance Specifications


432 channels, based on Nebulas-II GNSS SoC

Velocity Accuracy (RMS)



BDS B1/B2/B3

Time Accuracy (RMS)

20 ns
GPS L1/L2/L5 Initialization time 5 s (typical)
GLONASS L1/L2 Cold Start <25 s
Galileo E1/E5a/E5b Initialization Time <5 s(typical)
QZSS L1/L2/L5 Initialization reliability > 99.9%


< 1s

Single point positioning (RMS)

Horizontal:1.5 m


RTCM 2.3/3.0/3.2

Vertical:3 m

Data Output



Horizontal:0.4 m

Vertical:0.8 m

Update Rate

20 Hz


Horizontal:1 cm + 1 ppm

Inertial Navigation Accuracy < 5%x droving distance(No GNSS signal,within 30s)

Vertical:1.5 cm + 1 ppm

Network Protocol


Observation Accuracy(RMS) BDS GPS GLONASS Galileo
B1/L1 C/A/E1 Code 10cm 10cm 10cm 10cm
B1/L1/E1 Carrier Phase 1mm 1mm 1mm 1mm
B2/L2P(Y)/L2C/E5b Code 10cm 10cm 10cm 10cm
B2/L2p(Y)/L2C/E5b Carrier Phase 1mm 1mm 1mm 1mm

Physical Specifications

Dimensions 46 × 71 × 9 mm
Weight 21 g
I/O Connectors 2 x 10 pin
Antenna Input
2 × MMCX

Environmental Specifications

-40°C ~ +85°C
Storage -55°C ~ +95°C
Humidity 95% non-condensing
Vibration GJB150.16-2009,
Shock GJB150.18-2009,

Electrical Specifications

Voltage 3 VDC + 5 %
LNA 4.75 ~ 5.10 V, 0 ~ 100 mA
Ripple Voltage 100mV p-p(max)
Power Dissipation 2.4 W (Typical)

Functional Ports

1 × Event 1 × LAN

Application Area