ELT RTK Base

Step 1: Open Settings

To detect a GNSS receiver, you need to perform the “Detect” operation in the settings. Go to the Settings page, and to the right of “Main service”, click the Options button.

Step 2: Start Detection

Click the “Detect/Configure” button and select “Detect” from the drop-down menu.

Step 3: Detection Process

The detection process will begin automatically. Once completed, the receiver is detected.

Once completed, the receiver is detected.

Step 4: Save Receiver Settings

You can then click the Apply button to save the detected receiver's settings, including:

• Port
• Speed
• Receiver name
• Protocol type

These four settings will be used later during the receiver configuration.

Step 5: Select Protocol

Septentrio receivers can operate using either the rtcm3 protocol (default) or the sbf protocol — with the exception of Mosaic T, which supports only sbf. u‑blox receivers, in addition to the default rtcm3 protocol, can also use their proprietary ubx protocol. Details about the effect of protocol selection are described in the section “RTCM3 Proposals”. To switch to the sbf or ubx protocol, change the protocol in the “Receiver format” field after detection and then proceed with the configuration. Please note: When the selected receiver protocol differs from rtcm3, communication via NTRIP v2 becomes unavailable.

Configuration

To configure the receiver, do as described in the “Detection” section, but click the “Configure” button.

After configuration is complete, click the “Close” button.

During configuration, the receiver speed is reset to 115200, and all services are disabled. If the receiver was not at 115200 speed and the configuration ended with an error, the receiver speed will not match the speed specified in the settings. In this situation, you need to perform detection as described in the “Detection” section. In general, detection is a universal way to fix various issues.

Timeout Configuration

For maximum reliability, it is important to monitor whether the receiver is actually transmitting data. This is handled by the «Receiver inactivity timeout» setting. If no data is received for more than the number of seconds specified in this setting, the main service is automatically restarted. On advanced base stations ELT0231, ELT0431, ELT0731 the receiver itself is also rebooted in addition to restarting the main service. The default timeout value is 60 seconds. You can change this value at any time and then click Save.

If you power on the base station without an antenna connected, the receiver will not receive any satellites and therefore will not transmit data. The same situation occurs if the antenna does not have a clear view of the sky, for example when it is located indoors. In such cases, the main service will continuously restart. To disable automatic restarts in this situation, set the «Receiver inactivity timeout» value to 0.

Changing the Speed

To reduce the delay time between measurements and data transmission, it can be helpful to increase the speed to 921600. However, equipment from some manufacturers may work unstably at this speed.

If you want to change the speed, simply adjust it in the settings and click the Save button. During saving, the receiver is reconfigured to the required speed. However, although you can enter any speed, only the speeds 115200:8:n:1, 230400:8:n:1, 460800:8:n:1, 921600:8:n:1 are allowed. All other speeds are not allowed.

Manually changing other parameters (except for speed, timeout, coordinates, and antenna name) is strictly not recommended.

When the Save button is clicked, all services are stopped. If the main service was running at the time of clicking Save, it will restart, but the other services will remain stopped.

Septentrio Mosaic Website

Find the button to open the mosaic receiver's website on the Settings page and click it.

When you log in for the first time with firmware version 4.15 or later, username and password prompt appears. Enter admin as the username and admin as the password.

On the website that opens, you can configure the receiver.

RxTools

You can use RxTools utilities (such as RxControl) to configure the Mosaic X5 receiver. To do this, connect via TCP/IP, using rtkbase.local or the Raspberry Pi's IP address as the address, and port 28784 as the port number.

Internet Access

The Mosaic X5 receiver is connected to the Raspberry Pi via USB. This means the receiver has the address 192.168.3.1, and the Raspberry Pi performs NAT functions for it. The Mosaic X5 receiver has nearly full internet access with a few exceptions:

• For incoming connections (IPR or the receiver's built-in NTRIP caster), only ports 3000-3009 (both TCP and UDP) are available.
• FTP access is not functional. Since the Mosaic X5 does not have its own SD card, FTP is unnecessary.
• The Mosaic X5 acts as the time server (NTP and PTP protocols), not the Raspberry Pi.
• Access to the Mosaic X5's web interface is through port 9090, while ports 80 and 443 are routed to the Raspberry Pi.
• DNS servers 8.8.8.8 and 1.1.1.1 are used for the Mosaic X5.
• The setting “Outgoing Internet Access Over USB” must not be disabled.
• The setting “Ethernet Interface Mode” must not be enabled.
• The “TCP/IP Settings” must be set to DHCP.

Improving Quality for Onocoy Through Receiver Settings

The Onocoy quality scale is influenced not only by antenna placement but also by various receiver characteristics. While antenna positioning, multipath effects, Axial Ratio, and other RF-related factors are covered in detail in our blog, this section focuses on the simpler adjustments—receiver settings. For deeper context, we recommend reading the “Quality Scale” section in the Onocoy documentation.

Board Design

Poor PCB design can significantly degrade performance. Fortunately, this is rare and typically limited to DIY projects or boards from unknown manufacturers. So far, none of Onocoy’s partners have supplied poor-quality boards. For DIY builds, it’s recommended to carefully inspect the quality of the trace leading to the antenna input, and to check for possible interference entering via the antenna input or receiver power supply—especially noise from the processor or its clock circuitry.

Receiver Type

This plays a crucial role in performance. It’s not only about the number of satellite systems or signal bands supported. Onocoy’s Phase RMS scale directly correlates with the receiver's ADC resolution. Firmware updates can add signal support, but cannot change ADC bit depth.

Receiver Options

Septentrio refers to them as Permissions, while uBlox calls them Fuses. These are feature sets configured at the time of sale. For example, a cheap board with a Mosaic-X5 chip may lack base station mode. Always verify available permissions before purchase.

Receiver Firmware

Firmware can have a minor or major impact. It might enable new signals, fix bugs, or add features. Minimum and recommended versions are listed in “Checking the Receiver Firmware Version”. It's highly recommended to use the latest firmware, especially for Mosaic X5 and Bynav M10/M20, where firmware has significant influence.

Signal Support

Many base stations aren’t fully configured for CORS-level output. Surveying stations often limit signal output to save bandwidth, and the Mosaic-X5 is similarly conservative by default. Enable all signals using the commands:

setSignalTracking, all
setRTCMv3Formatting, 1, all

This can improve the quality score by as much as 0.200. One Onocoy partner failed to apply both commands, which led to severely degraded scores. If you hear claims that Mosaic-X5 is worse than UM980, it's likely due to incomplete configuration.

SBAS Signals

SBAS corrections are not considered by Onocoy, so on many receivers it’s sufficient to simply disable SBAS corrections. However, the Mosaic-X5 receiver has only 62 channels, and SBAS satellites can occupy up to 9 of them, which significantly limits the number of tracked satellites. Therefore, on the Mosaic-X5, it’s recommended to use the command setSatelliteTracking, -SBAS to disable SBAS satellites. On the Unicore UM980 receiver, we use the command CONFIG SBAS DISABLE for the same purpose

GPS L5 Signal

Until at least 24 GPS satellites transmitting the L5 signal are fully deployed in orbit (expected around 2027), this signal is typically marked as “unhealthy.” Single-frequency receivers relying solely on L5 will perform poorly. However, Onocoy still considers this signal valid in multi-frequency configurations.

Some receivers offer specific settings to enable or disable the use of the L5 signal. One Onocoy partner recommends enabling GPS L5 on Mosaic X5 using:

setHealthMask, Tracking, off

However, with the latest Mosaic X5 firmware, this step is unnecessary.

Unhealthy Satellites

Mosaic-X5’s setHealthMask, Tracking, off enables tracking of “unhealthy” satellites/signals. Onocoy excludes these from the quality score but includes them in “Sky Visibility” and “Code RMS” graphs. To avoid skewed metrics, disable Beidou-3 experimental satellites with:

setSatelliteTracking, -C56-C57-C58

Dynamics Mode

Surprisingly, not all receivers automatically adjust their dynamic behavior—such as tightening code and phase tracking loops—when set to base station mode or assigned fixed coordinates. In the Mosaic X5 receiver, this behavior must be configured explicitly using the following command:

• setReceiverDynamics, Low, Static

This improves “Code RMS” and “Phase RMS”."

Multipath Mitigation

Multipath is one of the key factors that reduces a station’s reward by degrading the “Code RMS” and “Phase RMS” metrics. In Mosaic X5 receivers, the APME+ multipath mitigation technology is enabled by default. While effective, this feature may introduce a small amount of noise. For base stations with an excellent antenna placement—clear of reflective surfaces—you can disable this function using:

setMultipathMitigation, off, off

Unicore UM980 receivers feature a similar multipath mitigation system, which can be enabled with::

CONFIG MMP ENABLE

As with the Mosaic X5, this function can also be disabled in high-quality installations to reduce any unnecessary processing

Code Smoothing Using Carrier Phase

This improves the Code RMS metric. On Mosaic X5, we currently apply:

setSmoothingInterval, all, 60, 60

But using:

setSmoothingInterval, all, 300, 30

may yield better results. For other receivers, this function is planned to be implemented via software in future versions of ELT_RTKBase

Measurement Resync

Disabling this slightly improves measurement quality on UM980:

CONFIG RTCMCLOCKOFFSET DISABLE

Elevation Mask

One limitation of the Mosaic X5 receiver is its relatively small number of tracking channels. To prevent satellites from competing for limited channels, we reduce the elevation mask using the command:

• setElevationMask, Tracking, 5

This setting filters out low-elevation satellites, prioritizing those with higher elevation angles. If your receiver has enough available channels, you can lower the elevation mask to 1 or even 0.

According to Onocoy information, only satellites with an elevation above 10° are considered in the quality score calculation. However, it seems that all tracked satellites are shown in the visualization. Interestingly, tests show that reducing the mask can actually increase reward scores.

For receivers with a higher number of channels, it’s recommended to set the elevation mask to 0.

Unicore UM980: MASK 0

Bynav M20: ECUTOFF 0

Signal Strength Mask

According to Onocoy, GNSS signals with an SNR below 34 are excluded from quality scoring. However, limiting the minimum SNR threshold to 32+ has been shown to increase the quality score—possibly because weak signals are excluded in some metrics but still impact others. To set an SNR mask:

Mosaic X5:

setCN0Mask, all, 32

UM980:

MASK RTCMCN0 32

Bynav M20:

SNRCUTOFF 32

In addition, it’s recommended to raise the threshold for GLONASS signals on the Unicore UM980 to 36+, since weak GLONASS signals tend to degrade both the “Code RMS” and “Phase RMS” metrics. For this, use:

MASK RTCMCN0 36 GLO

Whether the Mosaic X5 would also benefit from a similar adjustment is currently unknown.

Credits

These recommendations are informed by documentation from ArduSimple and SparkFun. If you use this guide, please credit our efforts.

Settings updates during firmware upgrades

If a new version of ELT_RTKBase includes improved configuration defaults, the receivers are automatically updated with the new settings during the upgrade process. As a result, modifying receiver settings manually is generally only necessary if you want to go beyond the standard optimization and implement something not yet included in the firmware.

Modifying Settings via SSH

The most reliable method for customizing receiver settings on ELT_RTKBase stations is through SSH access. Log in via SSH, then use sudo to edit the configuration files located in:

/usr/local/rtkbase/rtkbase/receiver_cfg

After editing the necessary settings files, apply the configuration as described in the section titled “Configuration”.

Receiver (Configuration file path)

• Mosaic X5: Septentrio_RTCM3_OUT.txt
• Unicore UM980: UM980_RTCM3_OUT.txt
• Unicore UM982: UM982_RTCM3_OUT.txt
• Bynav M20: Bynav_RTCM3_OUT.txt
• U-blox ZED-X20P X20P_RTCM3_OUT.txt

Modifying Settings via TCP

To configure a receiver on ELT_RTKBase over TCP, first enable the “Rtcm TCP service”. Then open a command prompt on a Windows machine and run the following command:

NmeaConf +rtkbase.local:5016 andlt;fileandgt;

Here, andlt;fileandgt; refers to one of the configuration files listed in the table above. The NmeaConf utility and its documentation are available on GitHub.

Modifying Settings via USB

For budget ELT_RTKBase stations, receiver settings can be configured via the USB Type-C port on the enclosure. Open a Windows command prompt and run:

NmeaConf COM11 andlt;fileandgt;

Replace COM11 with the actual COM port assigned to the USB-serial interface by Windows, and andlt;fileandgt; with the appropriate configuration file. Again, the NmeaConf utility and its documentation are available on GitHub.

Modifying Settings on Receivers in Third-Party Miners

If your Unicore UM980 receiver is installed in a miner from another manufacturer, configuration is also done via USB as described above. Surprisingly, some such devices require opening the enclosure and moving a jumper using a screwdriver before configuration is possible.

Modifying Mosaic X5 Settings via its Web Interface

Download the configuration file from GitHub. Then open the web interface of your Mosaic X5 receiver and navigate to Admin → Configuration. Copy the RxDefault configuration into User2 to clear it. Click the blue-circled arrow to upload the downloaded configuration file into User2. Once loaded, copy it into both the Current and Boot configurations.