UM981
UM981
GPS/BDS/GLONASS/Galileo/QZSS All-constellation Multi-frequency RTK/INS Integrated Positioning Module
Unicore’s new-generation proprietary RTK/INS integrated navigation module. The module integrates a high-speed floating-point processor and an RTK-dedicated coprocessor, enabling it to output IMU raw data at 100Hz and RTK data at 50Hz, respectively. The on-board MEMS chip and algorithm ensure continuous, high-quality positioning results in GNSS denied environments such as buildings, tunnels, overpasses, and shaded areas. With its high precision and performance, the UM981 is well-suited for surveying and precision agriculture, among other applications.
Features
Based on the new generation GNSS SoC – NebulasIV, which integrates RF, baseband, and high precision algorithm
All-constellation multi-frequency RTK engine and advanced RTK technology
Instant RTK initialization technology
60 dB narrowband interference suppression and interference detection
Heading2 technology to provide orientation information
STANDALONE single-station high-precision positioning technology
Supports B2b-PPP and E6-HAS
On-board MEMS integrated navigation and U-Fusion technology to ensure continuous positioning when loss of lock on GNSS signals
Technical Specifications
Performance Specifications
Channel
1408 channels, based on NebulasIV
Frequency
GPS L1C/A, L1C, L2C, L2P(Y), L5
BDS B1I, B2I, B3I, B1C, B2a, B2b
GLONASS G1, G2, G3
Galileo E1, E5a, E5b, E6
QZSS L1C/A, L1C, L2C, L5
NavIC L5
SBAS L1C/A
Single Point Positioning(RMS)
Horizontal: 1.5m
Vertical: 2.5m
DGPS (RMS)
Horizontal: 0.4m
Vertical: 0.8m
RTK (RMS)
Horizontal: 0.8cm+1ppm
Vertical: 1.5cm+1ppm
PPP（RMS）
Horizontal: 5cm
Vertical: 10 cm
Tilt Measurement
10 mm + 0.7 mm/°tilt
(accuracy < 2.5 cm within 30°)
Positioning Error of INS only
< 5 % of the distance traveled without GNSS signals
Observation Accuracy (RMS)
BDS
GPS
GLONASS
Galileo
B1I/B1C/L1 C/A/G1/E1 Code
10 cm
10 cm
10 cm
10 cm
B1I/B1C/L1C/A/G1/E1 Carrier Phase
1 mm
1 mm
1 mm
1 mm
B2I/B2a/B2b/L5/E5a/E5b Code
10 cm
10 cm
10 cm
10 cm
B2I/L2P(Y)/L2C/G2/E5b Carrier Phase
1 mm
1 mm
1 mm
1 mm
B3I/B2a/E5a/L5 Code
10 cm
10 cm
10 cm
10 cm
B3I/B2a/E5a/L5 Carrier Phase
1 mm
1 mm
1 mm
1 mm
Time Accuracy (RMS)
20 ns
Velocity Accuracy (RMS)
0.03 m/s
Cold start
< 12 s
Initialization Time
< 5 s (typical)
Initialization Reliability
> 99.9%
Data Update Rate
100 Hz (IMU RAW Data)
50 Hz* (RTK)
Differential Data
RTCM V3.X
Data Format
NMEA-0183, Unicore
Physical Characteristics
Packaging
54 pin LGA
Dimension
17.0 × 22.0 × 2.6 mm
Weight
1.91 g ± 0.03 g
Environmental Specifications
Working temperature
-40 °C ~ +85 °C
Storage Temperature
-55 °C ~ +95 °C
Humidity
95% No condensation
Vibration
GJB150.16A-2009, MIL-STD-810F
Shock
GJB150.18A-2009, MIL-STD-810F
Communication Interface
3 x UART (LVTTL)
1 x I2C*
1 x SPI*
1 × CAN* (shared with UART3)
Note: Items marked with * are only supported by specific firmware.
