Do you ever feel confused about how to achieve high-precision farming with F100 Auto Steer System for tractors? In fact, it mainly depends on Real Time Kinematics (RTK) technology. RTK is used to improve the accuracy of GPS positioning. It can provide users with high accuracy in centimeter precision. Using RTK technology for tractors reduces fuel costs and eliminates driver errors & fatigue. This article will explain how to receive RTK data for high-precision farming and provide some suggestions about how to choose RTK sources for reference.
How to Receive RTK Correction Data?
RTK correction data can come from local base stations, or it can be received from third-party correction services over the Internet using NTRIP. RTK base stations provide a stable signal with a range of up to 10 km. NTRIP correction services typically require a per-user subscription and Internet access.
NTRIP:
1. What is NTRIP and how it works
NTRIP (Networked Transport of RTCM via Internet Protocol) is a protocol for streaming corrections from a base station to a rover over the Internet to achieve centimeter-level accuracy.
It is an RTK positioning correction transmission protocol. The NTRIP system consists of three main software components: NTRIP server base, NTRIP caster, and NTRIP client rover.
NTRIP server base transmits GNSS data corrections from the NTRIP server to the NTRIP caster.
NTRIP caster is an HTTP Internet service that acts as a communication line between the NTRIP server and the NTRIP client.
NTRIP client rover accesses GNSS data from the NTRIP caster for RTK positioning by a single reference station or RTK network. In addition, it sends a request message to the caster to receive data.
To perform an accurate RTK measurement, the NTRIP server base continuously observes the satellites and calculates position corrections. Then it sends the data to the NTRIP client rover. The rover uses the position information from the satellite and the base correction data to calculate coordinates more accurately. Next, we will come to the connection of NTRIP network for specific use.
2. Are there NTRIP service providers in your area
The NTRIP service provides you with access to the NTRIP network to receive RTK corrections. This makes the rover and Internet connection sufficient to start measurements. Fees and coverage areas may be different, depending on the specific NTRIP service provider.
The list of NTRIP service providers in different areas is as below:
There is no need for a local base if with an Internet connection to NTRIP. So you can still perform an accurate task with just a rover. But if there is no available NTRIP service provider nearby, you may also consider purchasing the Sveaverken RTK base station to receive the signal with 2.5 cm accuracy.
3. How to connect to NTRIP Server
To access the NTRIP network, you will need to contact your local NTRIP service supplier to create an account. Some NTRIP networks are free and some are private with very expensive subscription fees.
Take Sveaverken F100 Auto Steer System as an example of NTRIP connection steps. You need to locate the nearest mount point and insert the network access credentials first. Once registered, you will be given a specific port and host to access the network and obtain network authorization.
Tap Get Source and the source node field will automatically show the port having the strongest signal strength, indicating that the NTRIP domain information is completed. Then enter an account and password to log in to the network. Next, you can successfully connect the rover to the NTRIP network.
* Please note that you need to find suppliers that support RTCM2.X and 3.X communication protocols for Sveaverken F100.
RTK Base Station:
1. How does an RTK base station work
RTK base station adopts advanced RTK technology and uses a high-performance antenna. It provides a fast and stable high-precision positioning correction service for precision agriculture users. To set up your own RTK base station, you just need three components: GNSS receiver, RTK base station software, and devices like mobile phones or iPad to run the software.
2. Why do you need a Sveaverken RTK base station
High Positioning Accuracy. By using this RTK base station, Sveaverken-related products can achieve centimeter-level high-precision positioning and operations.
Wide Range Coverage. In an environment without signal shielding and interference, the working range covered by this RTK base station is 5-10 km.
Global Constellation. Sveaverken RTK base station receives 965 channels of signals from 8 satellite navigation systems including GPS, GLONASS, GALILEO, Beidou, SBAS, IRNSS, L-band, and QZSS.
Multiple Application Scenarios. IP67 waterproof level, 1.5m drop-resistance, and 10 hours of lithium battery life allow this RTK base station to be used in a variety of environments and usage scenarios.
Smart Assistant APP. RTK Assistant APP can help us set Sveaverken as the base station conveniently. We can set the base station with the inner radio or external radio. It contains functions such as known coordinate base setting and user-defined radio frequency.
3. How to connect to Sveaverken RTK base station
To connect to a Sveaverken base station, enable it and tap Frequency Connecting. In the popup dialog, enter the frequency code. (For frequency codes, refer to Base Station User Manual.)
Establishing the Connection: Choose Communication first. The options are Bluetooth connection and demo mode. Select Bluetooth, and tap the device name beginning with "GNSS" from Bluetooth devices.
Set the base station. Select Inner Radio mode or External Radio mode. Then ensure the satellite signal is good.
Setting frequency, Over-the-air Baud Rate, and Radio Communication Protocol consistent with the base station.
Comparison of NTRIP and RTK Base Station
NTRIP and Base Station are two useful methods to implement when working in RTK. However, they have advantages and disadvantages. Your decision on which to use mostly depends on the specific conditions you’re going to work in.
1. Accuracy
RTK Base Station ≈ Ntrip
High absolute accuracy. With RTK correction data from NTRIP and Sveaverken Base Station, you can both obtain centimeter-level accuracy. So they can provide fast and stable high precision positioning correction service for farmers thanks to RTK technology.
2. Coverage
Ntrip > RTK Base Station
As for NTRIP, you can carry out measurement work only with one rover, avoiding distance limitation problems of traditional radio communication. But NTRIP is dependent on the Internet, cellular network coverage is necessary to use it. In the long term, it is better to have your own RTK base station. Because if you go offline, RTK Base Station can replace NTRIP to provide stable differential data services.
3. Stability
RTK Base Station > Ntrip
Sveaverken Base Station provides stable signals. High-quality internal hardware and module design can ensure its signal strength and high accuracy. But NTRIP is not as stable as your own RTK base station. Because the public casters will not be always available whenever and wherever you need them.
4. Fees
Ntrip > RTK Base Station
You may find some NTRIP networks are private or just for governmental use, so you need to pay if you want to use them. Fees may vary in different countries and regions. Sometimes it can get really expensive. The cost of RTK base stations is reasonable. After purchasing it, you can enjoy lifetime usage without extra subscription fees or other service charges.
5. Mobility
RTK Base Station > Ntrip
Before farming, you can set the coordinates of known points for the base station. After you finish your farming work for the day, you can take the GNSS receiver anywhere. After inputting the coordinates, the RTK base station will work the same route as yesterday, reducing the operation deviation for different locations. But NTRIP service can only work well when the local network is available.
