The New Era of High-Precision Positioning: Deep Integration of RTK Technology and the I3700 Dual-Antenna GNSS/INS System

Centimeter-level real-time positioning is crucial in fields like autonomous driving, precision agriculture, and drone surveying. Micro-Magic's I3700 Dual-Antenna GNSS/INS system enhances RTK technology by overcoming limitations like signal occlusion, enabling accurate and reliable navigation in complex environments. This system powers next-gen applications with robust positioning.

In digitally driven fields like autonomous driving, precision agriculture, and drone surveying, centimeter-level real-time positioning has become a core requirement. Real-Time Kinematic (RTK) technology reduces traditional GPS positioning errors from meters to centimeters through base station-rover collaboration. The emergence of Micro-Magic’s I3700 High-Performance Dual-Antenna GNSS/INS Integrated Navigation System empowers RTK with enhanced environmental adaptability and reliability, ushering in a new era of high-precision positioning.

I. Core Breakthroughs of RTK Technology

The RTK system achieves precision positioning through base station-rover collaboration:

1. Base Station: Positioned at known coordinates, it calculates real-time satellite signal errors (e.g., atmospheric delay, clock drift)

2. Rover: Receives error-correction data from the base station and fuses it with its own observations for centimeter-level positioning

3. Real-Time Performance: Data transmission via 4G/NTRIP protocols with <20ms latency

Technical Bottleneck: Traditional RTK fails under signal occlusion (tunnels, urban canyons) and cannot provide carrier attitude data.

II. I3700 System: The Enhanced Engine for RTK

As a high-performance module integrating dual-antenna GNSS + Inertial Navigation (INS), the I3700 overcomes RTK limitations through three innovations:

1. Dual-Antenna Heading Enhancement

• Baseline Orientation: A/B antenna spacing: 0.8–1.5m; calibrated against the carrier’s Y-axis using the SETBASELINE command

• Heading Accuracy: 0.2° (under RTK fixed solution), far exceeding single-antenna GPS (2°–5° error)

• Anti-Occlusion Capability: Maintains heading during GNSS signal loss using a gyroscope with 2.5°/hr bias stability

2. Multi-Source Fusion Algorithm

# Extended Kalman Filter (EKF) Workflow  
while True:  
   gnss_data = get_rtk_position()  # Acquire RTK position  
   imu_data = read_mems()          # Read MEMS angular velocity/acceleration  
   wheel_speed = can_obd2_decode() # Decode CAN bus vehicle speed  
   fused_position = ekf_fusion(gnss_data, imu_data, wheel_speed)  

• Supported Peripherals: Odometers, DVL (Doppler Velocity Log), vision sensors

• Continuous Navigation: Horizontal positioning error <6m within 60s of GNSS loss (with odometer input)

3. Industrial-Grade Reliability Design

III. Scenario-Based Application Cases

1. Autonomous Agricultural Machinery

Challenge: Signal occlusion in farmlands causes path deviation during automated operations
I3700 Solution:

• Dual antennas provide stable heading, achieving ±2.5cm inter-row navigation with RTK

• INS maintains <1m error for 10s under tree occlusion
  Command: CONFIG MODEL CAR activates vehicle motion constraints

2. Urban Autonomous Driving

• Key Config: Output 20Hz fused navigation data via LOG INSPVAXB ONTIME 0.05

3. Drone Power Grid Inspection

• Precision Hovering: 0.8cm+1ppm position accuracy under RTK fixed solution

• Wind-Resistant Attitude: 150Hz accelerometer compensates crosswind disturbances

• Data Transmission: RS-422 interface streams binary RAWIMUXB (raw IMU data)

IV. Technical Extension: From Positioning to Spatiotemporal Networks

I3700’s multi-protocol interfaces enable limitless system integration:

1. Cloud Collaboration: Access Qianxun/China Mobile CORS via 4G DTU

   CONFIG NTRIP rtk.ntrip.qxwz.com 8002 AUTO qxx 123456 # Qianxun account setup 

2. Automotive-Grade Comms: SAE J1939 outputs PGN65341 (attitude)/PGN65345 (heading)

3. Synchronized Triggering: PPS pulse + SYNC_IN pin synchronizes LiDAR scanning

Conclusion: The "Dual-Core Era" of Precision Positioning

RTK solves absolute positioning accuracy, while GNSS/INS systems like I3700 deliver environmental robustness and attitude dimensionality. Together, they form a "spatiotemporal dual-core," bridging the "last centimeter" gap for autonomous driving, smart agriculture, and robotics.