APEKS FAQ | Understanding RTK Status: What Do Single, DGNSS, Float, and Fixed Really Mean?
Before starting any GNSS RTK survey, it’s essential to know what your current RTK status means. Different statuses reflect different levels of positioning accuracy and stability. If you’re unsure when to begin your survey or what each status really indicates, this guide will walk you through the four common RTK statuses and how they affect your measurements.
1. Single — Standalone Positioning
What it means:
"Single” is the most basic RTK status. It means the receiver is not receiving any correction data and is relying solely on satellite signals for positioning.
When it happens:
·When the device is first powered on.
·If the SIM card isn’t inserted or the mobile network isn’t available.
·When not connected to a base station or CORS network.
Accuracy level:
·Typically a few meters, with relatively low precision.
Is it suitable for surveying?
No. Measurements taken under Single status are not accurate enough for professional surveying tasks.
2. DGNSS — Differential GNSS
What it means:
“DGNSS” indicates that the receiver has started receiving correction data, but due to signal quality or environmental interference, it hasn't yet reached high-precision positioning.
When it happens:
·Right after connecting to a correction source.
·In areas with weak or unstable signals.
·When operating near tall buildings or tree cover.
Accuracy level:
·Sub-meter level, better than Single but still not suitable for precise work.
Is it suitable for surveying?
Not recommended. While improved, this level of accuracy is still unreliable for high-precision applications.
3. Float — Floating Solution
What it means:
“Float” status means the receiver is receiving correction data and has started processing it. The position accuracy is close to the centimeter level, but the signal is not yet stable enough for a fixed solution.
When it happens:
·When satellite signals are partially blocked.
·While the receiver is moving or the network is slightly unstable.
·During the transition toward Fixed status
Accuracy level:
·Typically several centimeters. Sufficient for some applications.
Is it suitable for surveying?
Depends. You can proceed for low-precision tasks, but it’s better to wait for a Fixed solution for consistent results.
4. Fixed — Fixed Solution
What it means:
“Fixed” is the most accurate and stable RTK status. It indicates the receiver is receiving stable correction data and has resolved all ambiguities in satellite signals.
When it happens:
·In open areas with no obstructions.
·When using a stable CORS or radio connection.
·After the receiver has been stationary for a short time.
Accuracy level:
·High centimeter-level precision, ideal for professional-grade surveying.
Is it suitable for surveying?
Absolutely. This is the optimal status for collecting highly accurate GNSS data.
Bonus Tip | What Does “Age” Mean?
On your controller screen, you may notice a value called “Age.” This indicates the delay (in seconds) since the last correction data was received.
In Fixed status:
·With CORS/GSM, Age should be between 1–2 seconds.
·With radio mode, Age between 2–4 seconds is acceptable.
Keeping the Age value low ensures your correction data is fresh and reliable.
By understanding these four RTK statuses, you'll know when it’s safe to start measuring, and when to wait or troubleshoot. It also gives you confidence in assessing your device’s performance on the field.
Want to learn more about APEKS RTK and GNSS surveying? Keep following our APEKS FAQ video series for more tutorials and insights.
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