RTK Receiver
Connecting a Receiver
Once your browser and receiver are ready (see Web Bluetooth Setup), connecting is a straightforward process. This page walks through scanning for devices, selecting your receiver, monitoring the connection, and handling disconnections.
![[Screenshot: SiteView header showing the RTK status chip displaying 'Connected' with a green indicator, next to the site name and navigation controls]](/images/placeholder.png)
Scanning for Devices
- Open a site in SiteView and ensure you are on the site detail or map view
- Click the RTK button in the SiteView toolbar or header
- Click Scan for Devices
Your browser opens a system Bluetooth device picker dialog. This dialog shows all nearby BLE devices that are advertising. Your RTK receiver should appear in the list, typically with a name like "ArduSimple", "SparkFun RTK", or the receiver's model number.
ℹ️ Did you know?
The device picker dialog is a browser-level dialog, not part of SiteView's interface. Its appearance varies between browsers and operating systems. You may need to wait a few seconds for all nearby devices to appear.
Selecting Your Receiver
Click on your receiver's name in the device picker to select it, then click Pair (or Connect, depending on your browser). The browser establishes a BLE connection to the receiver.
Once connected, SiteView:
- Discovers the NMEA data service on the receiver
- Subscribes to NMEA sentence notifications
- Begins parsing incoming GGA and RMC sentences
- Displays the current position on the CesiumJS map
First-Time Pairing
The first time you connect to a receiver, your device may ask you to confirm the pairing. Accept the pairing request. Subsequent connections to the same receiver are typically faster because the pairing is remembered.
The RTK Status Chip
Once connected, an RTK status chip appears in the SiteView header bar. This chip provides at-a-glance information about the connection:
| Chip State | Indicator | Meaning |
|---|---|---|
| Disconnected | Grey | No receiver connected |
| Connected (Single) | Red | Receiver connected, autonomous position only (no corrections) |
| Connected (Float) | Amber | Receiver connected, corrections received, solution converging |
| Connected (Fixed) | Green | Receiver connected, full RTK fix achieved |
Click the status chip to open a detail panel showing additional information:
- Receiver name and connection details
- Current position (latitude, longitude, elevation)
- Fix quality and accuracy estimate
- Satellite count
- NTRIP connection status (if configured)
- Disconnect button
See RTK Status & Accuracy for detailed information about fix quality levels.
NMEA Data Parsing
SiteView parses the following NMEA 0183 sentences from the receiver:
| Sentence | Data Extracted |
|---|---|
| GGA | Position (lat/lon), altitude, fix quality, satellite count, HDOP, age of differential corrections |
| RMC | Position (lat/lon), speed, course, date/time |
The position updates on the CesiumJS map in real time as new NMEA sentences arrive. A typical update rate is 1 to 5 times per second, depending on the receiver's configuration.
💡 Tip
If your receiver supports configurable NMEA output rates, set it to 1Hz (once per second) for a good balance between responsiveness and battery life. Higher rates (5Hz or 10Hz) provide smoother position updates but drain the receiver battery faster.
Handling Disconnections
BLE connections can drop for several reasons:
- The receiver moves out of BLE range (typically 10-30 metres)
- The receiver powers off or runs out of battery
- Bluetooth interference from other devices
- The device's Bluetooth is turned off
Auto-Reconnect
When a connection drops, SiteView automatically attempts to reconnect. The status chip changes to a "Reconnecting" state with a pulsing indicator. If the receiver comes back within range, the connection is typically re-established within a few seconds.
Manual Reconnect
If auto-reconnect fails (for example, the receiver was powered off and back on), click the status chip and then click Reconnect. This initiates a new scan and connection sequence.
Disconnecting Intentionally
To disconnect from the receiver, click the status chip and click Disconnect. This cleanly closes the BLE connection and stops NMEA parsing.
⚠️ Watch out!
If you close the browser tab or navigate away from SiteView, the BLE connection is terminated. You will need to reconnect when you return. There is no background BLE connection — the browser must be active on the SiteView page.
One Receiver at a Time
SiteView supports connecting to one RTK receiver at a time. If you want to switch to a different receiver:
- Disconnect the current receiver
- Scan for devices and select the new receiver
Connecting a second receiver without disconnecting the first is not supported.
What's Next?
- NTRIP Corrections — configure correction data for centimetre-level accuracy
- Capturing Points — use the connected receiver to capture survey points on the map
- RTK Status & Accuracy — understand fix quality and what affects accuracy
- Web Bluetooth Setup — review browser and hardware requirements