How Auto Spray Systems Work and Where They Are Used

Understanding RTK GNSS: How It Works
RTK is a technique that enhances GNSS positioning accuracy by using carrier-phase measurements from satellites and real-time correction data from a reference base station.
Core Components:
1.Rover: The mobile receiver (e.g., in a vehicle tablet or tractor).
2.Base Station: A stationary GNSS receiver installed at a known, fixed location.
3.Communication Link: Transmits real-time correction data from the base to the rover (via radio, 4G/NTRIP, or proprietary channels).
The Technical Process:
- Both the base station and rover receive signals from GNSS satellites (GPS, GLONASS, BeiDou, etc.).
- The base station knows its exact position and compares it to the position calculated from satellite data—allowing it to compute the error in real-time.
- These correction values are transmitted to the rover.
- The rover then adjusts its own satellite data, reducing positional error from 2–10 meters (standard GPS) to ±2 centimeters.
Unlike standalone GPS, which only processes timing and pseudo-range data, RTK processes carrier phase information, which is far more precise but sensitive to signal noise and obstructions. This is why line-of-sight to satellites and base stations is crucial for RTK to function optimally.
RTK VS Standard GPS: A Precision Leap

Why RTK GNSS is Perfect for Agriculture?
1. Unmatched Field Accuracy
Whether plowing, planting, or spraying, precision matters. RTK ensures every pass of the tractor follows the exact line needed—reducing overlap and missed areas, saving input costs and time.
2. Consistent Repeatability
Farmers can return to the exact same rows or plots season after season. This is especially important in:
- Row crops like corn, cotton, and soybeans
- Orchards and vineyards
- Controlled-traffic farming (CTF) systems
3. Supports Auto-Steering and Autonomy
RTK GNSS enables automated vehicle steering and lays the foundation for autonomous machinery. With minimal human intervention, tractors can perform complex tasks with surgical precision—even at night or in poor visibility.
4. Efficient Input Management
Precision allows targeted application of:
- Fertilizer
- Pesticides
- Seeds
- Water
This leads to:
- Reduced environmental impact 
- Better yield outcomes 
- Lower operating costs 
5. Integration with Vehicle Tablets
RTK-enabled vehicle tablets serve as the command center for smart tractors:
- Display real-time GNSS positioning
- Sync with farm management systems (FMS)
- Integrate with CAN Bus, auto-steer, and implement control systems
- Offer user-friendly touchscreen interfaces for operators

The RTK Network Infrastructure: Options for Farmers
Farmers can receive RTK correction signals via:
1. Local Base Station
- Installed on-site
- Most accurate and reliable
- One-time investment for long-term use
2. CORS/VRS (Virtual Reference Station)
- Subscription-based via 4G/NTRIP
- Convenient with wider coverage
- Useful for mobile operations across large areas
3. RTK Bridge Devices
- Bridge between GNSS rover and correction source
- Used when cellular connectivity is spotty or unavailable

The Science Behind the Accuracy
RTK’s high accuracy is due to its use of carrier-phase positioning:
- GNSS satellites transmit signals on carrier waves (~1.5 GHz)
- RTK measures the phase of these waves rather than just the travel time
- Because the wavelength is very short (~19–24 cm), phase errors can be resolved to fractions of a centimeter
However, carrier-phase ambiguities must be resolved in real time—this is the most complex part of RTK, requiring advanced algorithms and often taking a few seconds to initialize.

Looking Ahead: RTK and the Future of Agriculture
As agriculture becomes more data-driven, RTK is central to emerging technologies:
- Autonomous tractors and robots
- Drones with RTK landing and spraying capabilities
- Precision seeding and variable-rate application
- Farm-wide GNSS sensor networks
Combined with AI, IoT, and cloud platforms, RTK enables truly connected, intelligent farms.

RTK GNSS is not just an upgrade—it's a foundational technology that brings millimeter-level intelligence to the farm. When embedded in rugged vehicle tablets, RTK empowers farmers to grow more with less, reduce waste, and embrace automation.
With climate challenges rising and margins tightening, the adoption of RTK represents a strategic move toward sustainability, profitability, and agricultural innovation.

1. Why am I not getting centimeter-level accuracy?
- Possible causes:
Poor signal reception due to obstructions (trees, buildings, hills).
Base station or correction service not properly set up or out of range.
Interference from nearby electronic equipment.
- Solutions:
Ensure clear sky view for the GNSS antenna.
Check connection to the RTK correction source (base station or NTRIP).
Move away from potential interference sources.

2. How do I set up the base station or connect to correction services?
- For local base stations:
Install the base at a surveyed fixed point.
Ensure power supply and proper antenna placement.
Verify radio or network link to the rover device.
- For online services (NTRIP):
Subscribe to a regional correction service.
Configure the tablet with correct credentials and server info.
Test connection before heading to the field.

3. Why does my vehicle tablet lose RTK correction during work?
- Weak cellular or radio signal in certain areas.
- Hardware antenna or cable issues.
- Power interruptions or device overheating.
- Tips:
   Use signal boosters or external antennas.
   Check hardware connections and power supply.
   Operate the device in shaded areas if overheating occurs.

4. Can I use the vehicle tablet without RTK corrections?
- Yes, it will function using standard GNSS positioning with lower accuracy (2–10 meters).
- However, precise tasks like auto-steering or variable-rate applications require RTK-level accuracy.

5. How do I maintain and care for my vehicle tablet?
- Keep it clean and dry; wipe dust and dirt regularly.
- Use protective cases or mounts designed for agricultural vehicles.
- Avoid extreme temperatures or direct sunlight when not in use.
- Update firmware/software regularly to ensure compatibility and performance.

6. Can multiple tractors use the same RTK correction service?
- Yes, many correction services (especially network-based NTRIP) support multiple users simultaneously.
- Local base stations typically serve a limited radius; network services offer broader coverage.

7. How do I integrate the vehicle tablet data with farm management software?
- Use compatible Farm Management Systems (FMS) that support RTK data import/export.
- Sync data via Wi-Fi, cellular network, or USB.
- Consult tablet and FMS documentation for supported data formats and procedures.

8. What should I do if the vehicle tablet screen is hard to read in sunlight?
- Adjust brightness settings to maximum.
- Use anti-glare screen protectors.
- Position the tablet mount to avoid direct sunlight reflection.

9. Is training required to operate RTK GNSS vehicle tablets?
- Basic operation is designed to be user-friendly.
- Some training recommended for advanced functions (auto-steering setup, data management).
- Many manufacturers provide tutorials, manuals, and customer support.

10. Who can I contact for technical support?
- Reach out to your tablet or RTK device provider.
- Contact PDS Technology support at:
- Email: [email protected]
- WeChat/WhatsApp: +86 18823731364
- www.szpdss.com