This guide explains how to use the Emlid Reach RX or RX2 with Mobile 3D Scan in the DroneDeploy Ground app. With RTK, each scan is placed in your project's coordinate system, so it lines up with drone maps and design files without ground control or manual alignment.
In our testing, scans that followed the capture best practices landed a median 1.3 in (3.3 cm) horizontally and 1.0 in (2.6 cm) vertically from surveyed control.
What You'll Need
- The Ground Pro add-on. Mobile 3D Scan, including RTK, is available with Ground Pro.
- An iOS device with LiDAR: iPhone 12 Pro or newer, or an iPad Pro with LiDAR (2020 onward). See Supported Devices for Mobile 3D Scan.
- DroneDeploy Ground App version 2.208.0 or later.
- RTK receiver: Emlid Reach RX or Reach RX2.
- Mount: the Emlid Scanning Handle with an SP Connect phone case for iPhone, or a custom mount for iPad and other setups (see Mounting and Offset).
- Internet on the device. The app connects to DroneDeploy's RTK network automatically, so no NTRIP credentials are needed.
Before You Begin
- RTK works on the project's Exterior only, and it needs a clear view of the sky.
- Only the Emlid Reach RX and RX2 are currently supported. Other receivers won't connect.
- Using a custom mount? Enter its measured camera-to-antenna offset in the app's settings before your first scan.
Mounting and Offset
The app corrects for the distance between the device camera and the receiver antenna, called the camera-to-antenna offset or lever arm.
- iPhone with the Emlid Scanning Handle: no setup needed. The app already accounts for the offset.
- iPad or a custom mount: the Handle does not fit iPads. Measure the offset and enter it in the app's settings.
- Without the correct offset, every frame carries a constant shift. The scan looks clean but sits in the wrong place.
Step-by-Step: Connect Reach RX/RX2 to Mobile 3D Scan
- Power on your Reach RX or RX2.
- In the DroneDeploy Ground App, open your project's Exterior and select Scan mode.
- Tap the connection bar and select Emlid Reach RX/RX2 from the list.
- The light ring on the receiver flashes to show it's connected. Wait for the green "RTK Fixed" status in the app, or a green light on the receiver, before you start scanning. If you see white or yellow, move to open sky and allow up to a minute.
The app shows live RTK status while you scan:
- Fixed: centimeter-level positioning.
- Float: positions are typically off by decimeters.
- Single: positions are typically off by meters.
Field Best Practices for Accurate Scans
- Wait for RTK Fixed before you start, and hold it for the whole scan. If the status drops to Float or Single, pause until Fixed returns.
- Stay out from under roofs, canopies and covered trenches.
- Loop back or cross your own path so every stretch is seen from two directions. Avoid a single straight pass. In our testing, single straight passes caused the largest misses.
- Capture with heavy overlap: at least 50 frames per scan, more for larger areas.
- Walk at a steady pace and move slowly when turning.
- Cover featureless surfaces from more than one direction.
- Before measuring, rotate the finished scan in 3D and confirm flat ground reads flat.
For full guidance, see Mobile 3D Scan Best Practices.
Pro tip: to check accuracy on your own site, survey one or two checkpoints and compare them with the scan.
Processing and Where to Find Results
- Scans captured with RTK connected are automatically georeferenced.
- Find your scans under 3D Scans in the Media menu on the left sidebar. RTK scans are also processed as a georeferenced map, but you'll find them under 3D Scans, not in the Maps dropdown, which is for drone maps.
Known Limitations
- Any stretch captured on Float or Single is placed on that less accurate position, and the finished scan does not yet show which frames were captured on Fixed.
- RTK positions can drift a few centimeters over a session, which matters most when comparing elevations between sessions.
- Ground control is not yet supported in the 3D scan workflow.
Troubleshooting
- Cannot connect to the receiver: restart the device, check the receiver's battery, and make sure no other app is paired over Bluetooth.
- Status stuck on Single or Float: move to open sky and wait 30 to 60 seconds.
- Scan shifted by a constant amount: check the camera-to-antenna offset for your mount.
- Scan not uploading: reconnect to a stable network.
FAQs
Do I need my own NTRIP credentials?
No. The app connects to DroneDeploy's RTK network automatically.
Can I use an iPad?
Yes. The Emlid Scanning Handle doesn't fit iPads, so use a custom mount and enter its measured offset in the app's settings.
Where do my RTK scans appear?
Under 3D Scans in the Media menu on the left sidebar, not in the Maps dropdown, which is for drone maps.
Can I use ground control points?
Not yet. Ground control isn't supported in the 3D scan workflow. To validate a scan, survey one or two checkpoints and compare them with the scan.