UM981/UM981S GPS/BDS/GLONASS/Galileo/QZSSAll-constellation Multi-frequency RTK/INS Integrated Positioning Module

UM981/UM981S is Unicore's new-generation proprietary RTK and INS integrated navigation module. It can simultaneously track multiple satellite systems and frequencies, including GPS, BDS, GLONASS, Galileo, QZSS, NavIC and SBAS. The module integrates a high-speed floating point processor and an RTK dedicated coprocessor, being able to output positioning data at 100Hz. The on-board MEMS chip and U-Fusion integrated navigation algorithm ensure continuous positioning when loss of lock on GNSS signals occurs, providing high-quality positioning results in complex environments such as building blocks, tunnels, overpasses and tree shades. UM981 and UM981S are designed for high-precision navigation and positioning application, with UM981 for precision agriculture and UM981S for surveying and mapping, respectively.

Features

• Based on Unicore's proprietary GNSS SoC NebulasIV that integrates RF, baseband and high-precision algorithm

• All-constellation multi-frequency RTK engine and advanced RTK technology

• Instant RTK initialization technology

• 60 dB narrowband anti-jamming and jamming detection

• Heading2 technology to provide heading information

• STANDALONE single-station high-precision positioning technology

• Supports B2b-PPP and E6-HAS

• On-board MEMS integrated positioning technology and tilt compensation capability
   

  M981 vs. UM981S: Key Differences

  While both modules share the same compact footprint and high-precision GNSS performance, they are optimized for different professional industries:

  Feature	UM981 (Agri-Version)	UM981S (Survey-Version)
  Primary Target	Precision Agriculture	Surveying & Mapping
  Interface	Dual CAN Bus (ISOBUS compatible)	Standard High-speed Serial Ports
  IMU Optimization	Vibration filtering for tractors/machinery	Walk-and-Go rapid initialization
  Tilt Compensation	Standard	Professional Grade (30° error < 2.5cm)
  Core Advantage	Seamless integration with vehicle Bus	Instant leveling-free surveying

   

BDRTK-981S High-Precision RTK/INS GNSS Board

Professional RTK + INS Positioning Solution

The BDRTK-981S is a high-performance RTK/INS GNSS board based on the latest Unicore UM981S module. It integrates full-constellation multi-frequency GNSS positioning with an industrial-grade MEMS IMU, providing reliable centimeter-level positioning, precise heading, and continuous navigation even in challenging environments.

Designed for UAVs, autonomous robots, precision agriculture,  surveying & mapping , machine control, and structural monitoring applications.

Key Features

RTK + INS Navigation

Integrated high-performance MEMS IMU enables continuous positioning during temporary GNSS signal interruptions.

• RTK Positioning up to 50Hz
• IMU Data Output up to 100Hz
• Stable positioning in urban canyons, forests, tunnels, and challenging environments

Professional Tilt Measurement

Built-in tilt compensation algorithm allows accurate survey measurements without keeping the pole perfectly vertical.

Tilt Accuracy:

• 10 mm + 0.7 mm/° Tilt
• Less than 2.5 cm error within 30° tilt range

Integrated Heading2 Technology

Provides accurate heading and orientation information for:

• UAV Navigation
• Autonomous Vehicles
• Agricultural Machinery
• Marine Applications
• Robotics

No magnetic interference issues compared to traditional electronic compasses.

Global Multi-Constellation Tracking

Supports all major GNSS constellations:

• GPS
• BeiDou (BDS)
• GLONASS
• Galileo
• QZSS
• NavIC
• SBAS

Tracks multiple frequencies simultaneously for maximum availability and reliability.

Triple PPP Service Support

Supports advanced PPP correction services:

• B2b-PPP
• Galileo E6-HAS
• QZSS L6E (MADOCA)

Achieve centimeter-level positioning even without local RTK base stations.

Advanced Anti-Jamming & Anti-Spoofing

JamShield technology provides:

• Multi-frequency interference suppression
• Signal quality enhancement
• Anti-spoofing protection
• Improved performance in complex environments