Troubleshooting RTK

Use this article to diagnose and resolve common issues with RTK setup and data processing. Find the symptom in the quick reference table and follow the link to the matching resolution.

Quick reference

Before you start

• Confirm the GNSS receiver is powered on before Hovermap.

• Confirm all cables are fully inserted.

• Confirm Emesent Cortex and Emesent Commander are on supported versions (Cortex 3.3 or later, Commander 1.5 or later).

RTK setup

Issue 1: GNSS receiver not receiving corrections

Symptom: The GNSS receiver is not receiving corrections in the Emlid Flow app.

Cause: The GNSS receiver settings are misconfigured, or the NTRIP details are incorrect.

Resolution:

1. Confirm the receiver is configured with the correct settings.

2. Check that the NTRIP details (IP address, username, and password) are entered correctly.

3. If using a SIM card, power off the device, remove and re-insert the SIM card, then restart.

4. Restart the device.

5. If the issue persists, contact Emesent support.

Issue 2: No GPS after connecting receiver

Symptom: Web UI / Commander shows "No GPS" after the GNSS receiver is plugged into Hovermap.

Cause: Hovermap was powered on before the GNSS receiver.

Resolution:

1. Remove the GNSS receiver cable and re-insert it.

Issue 3: No GPS

Symptom: Web UI / Commander shows "No GPS".

Cause: The GNSS receiver is not powered on, or the Emlid cable is not fully inserted.

Resolution:

1. Confirm the GNSS receiver is powered on and configured with the correct settings.

2. Reboot the GNSS receiver.

3. Reboot Hovermap.

Issue 4: RTK Error

Symptom: Web UI / Commander shows "RTK Error".

Cause: The GNSS receiver settings are misconfigured.

Resolution:

1. Confirm the GNSS receiver is configured with the correct settings.

Issue 5: No RTK Fix

Symptom: The system is not achieving RTK Fix.

Cause: Correction settings are not configured correctly, the baseline length exceeds 15 km, or environmental conditions are affecting signal quality.

Resolution:

1. If the baseline length exceeds 15 km, select a closer CORS base station or set up a local base station to reduce the baseline length. Georeferencing accuracy decreases by approximately 1 mm per kilometer of baseline length.

Issue 6: RTK status not visible in Commander

Symptom: The RTK status is not visible in Emesent Commander.

Cause: Incompatible software versions.

Resolution:

1. Confirm Emesent Cortex is version 3.3 or later and Emesent Commander is version 1.5 or later.

2. If a software update is not possible, use the Web UI to view RTK status. Note that the Web UI does not display the number of satellites, precision, or coordinates.

Issue 7: Vacuum mounts difficult to attach

Symptom: The vacuum mounts are difficult to attach to the vehicle.

Cause: The mount legs are not loose enough.

Resolution:

1. Gently loosen the mount legs until they move freely.

2. Place the mount on the vehicle.

3. Tighten the mount.

RTK data processing

Issue 8: Scan splitting during processing

Symptom: Processing the scan causes it to split.

Cause: The Advanced feature matching with RTK setting is disabled, or the GNSS receiver is returning high-confidence incorrect GPS data due to an urban canyon or other environmental interference.

Resolution:

1. Go to Processing Settings (General tab) and enable Advanced feature matching.

2. Review the site to determine whether tall or reflective buildings may be interfering with the GPS signal.

Issue 9: RTK data in wrong coordinate system

Symptom: RTK data is not in the desired coordinate system.

Cause: The scan has not been reprojected.

Resolution:

1. Reproject the scan into the desired coordinate system. See Reproject your Point Cloud.

Issue 10: Low-quality colorization

Symptom: Colorization is low quality.

Cause: Low point density, or a mask is applied to the area requiring colorization.

Resolution:

1. For Vehicle RTK: drive more slowly or do multiple passes over the scan area to increase point density.

2. For Vehicle or Backpack RTK: review the extracted frames to determine whether the desired area has been masked, and update the mask if necessary.

3. Adjust the orientation of Hovermap during scanning to ensure the GoPro MAX 360 camera has a sufficient view of the area.

Issue 11: Areas not colorized

Symptom: Areas of the point cloud that are expected to be colorized are not colorized.

Cause: A mask is applied to the area, or the area is too far from the camera.

Resolution:

1. Review the extracted frames to determine whether the desired area has been masked, and update the mask if necessary.

2. Adjust the orientation of Hovermap during scanning to ensure the GoPro MAX 360 camera has a sufficient view of the area.

3. Go to Processing Settings (Colorize tab). Under Processing Quality, increase the Colorization Distance value.

Issue 12: Operator visible in point cloud

Symptom: The operator appears throughout the point cloud during a backpack scan.

Cause: The exclusion zone bounding box is not large enough to exclude the operator.

Resolution:

1. Go to Processing Settings (General tab).

2. Under Exclusion Zone, set Mode to Bounding Box.

3. Adjust the bounding box values as needed.

Issue 13: Vehicle visible in point cloud

Symptom: The vehicle appears throughout the point cloud.

Cause: The exclusion zone bounding box is not large enough to exclude the vehicle.

Resolution:

1. Go to Processing Settings (General tab).

2. Under Exclusion Zone, set Mode to Bounding Box.

3. Adjust the bounding box values to match the size of the vehicle.

Issue 14: Slips or drifts in scan

Symptom: Slips or drifts are visible in the scan.

Cause: The vehicle is travelling faster than 60 kph.

Resolution:

1. Reduce driving speed if operationally appropriate.

Issue 15: Banding in point cloud

Symptom: The point cloud shows banding, with some areas having high point density and others having very few points.

Cause: Driving too fast does not allow Hovermap sufficient time to scan the area.

Resolution:

1. Reduce driving speed to allow Hovermap to collect more data, if operationally appropriate.

2. Do additional passes over the scan area to increase point density.

Issue 16: Moving object removal removing too much

Symptom: Moving object removal is removing too much of the point cloud.

Cause: When travelling quickly, stationary points in the point cloud can appear to move, triggering the Moving Object Removal filter.

Still not resolved?

If the issue persists after following the steps above, contact Client Support with the following information:

• Product and version

• Steps already tried

• Any error messages or logs