Chasing M2 Pro/M2 Pro Max Cerulean USBL ROV Locator Mark II - Autosync

Chasing Cerulean USBL ROV Locator Mark II – Autosync real-time tracking on QGroundControl

The Chasing Cerulean USBL ROV Locator Mark II uses an Autosync feature to provide real-time ROV position tracking on the QGroundControl map display. The system ships as a bundle with a transmitter mounted on the ROV, a receiver module for surface use, and a mounting ring and adapter for installation.

Quick start and connectivity

Power up the transmitter and receiver, start the dive, and track the ROV location in real time via QGroundControl. The unit supports serial communication and provides an API for integration into custom workflows. This allows you to view position data live while operating the ROV.

How Autosync works

Autosync synchronizes the Receiver and Transmitter by exposing both to GPS or GNSS signals at mission start and, optionally, at intervals during the mission. Satellite acquisition typically completes within 30 seconds of power-up. In the typical deployment—receiver located near the ROV operator and transmitter mounted on the ROV—satellite acquisition generally happens in the background while the ROV is being prepared for launch and while Receiver IMU calibration is performed.

Performance considerations and recommendations

Chasing has implemented several optimizations to the USBL system that address configuration and synchronization. However, real-world positioning accuracy depends on environmental conditions, operational scenarios, and potential signal interference. Expect these external factors to influence absolute performance.

Measured positional error for horizontal ROV positioning is approximately 0–8.5 meters when the distance between receiver and transmitter is 50 meters. This horizontal offset is caused in part by changes in receiver attitude and orientation, and the offset distance increases as the receiver–transmitter separation increases.

To improve practical accuracy during operations, we recommend securing the USBL receiver to prevent rotation caused by seawater movement. Also, keep a reasonable distance between the USBL receiver and pool walls or the vessel hull to reduce interference and improve signal quality.

Included items

• Transmitter mounted on the ROV
• Receiver module for surface deployment
• Mounting ring and adapter

Software and firmware

For best results, upgrade to the latest versions of the APP, ROV, and Dock firmware. The latest releases add new features and fix known issues to improve overall usability and data handling.

Recent APP and firmware updates

1. Fixed issues reported in the APP version 4.9.9.
2. New: USBL Trajectory Recording and Import.
3. New: USBL Interest Point Marking & Split-Screen Map/Video Transmission Display.
4. New: Automatic Storage of Water Quality Sensor Data to ROV Memory Card.
5. New: Two ROV Operating Modes.
6. New: Mechanical Arm/Water Quality Sampler Control Method - Short Press Right Shoulder Button to Open/Close, Long Press for Right Dial Control.
7. New: Manual Configuration Mode for Accessory Dock.

Technical specifications

FAQ

Question: How do I start tracking the ROV with the Locator Mark II?
Answer: Power up the transmitter and receiver, open QGroundControl, start the dive, and the ROV position will appear on the map display. Serial communication and the API are available if you want to integrate the data into other systems.

Question: What does Autosync do and when does it run?
Answer: Autosync exposes both Receiver and Transmitter to GPS/GNSS signals at mission start and optionally at intervals. This enables satellite acquisition—typically within 30 seconds of power-up—often occurring while you prepare the ROV for launch and perform Receiver IMU calibration.

Question: What accuracy can I expect from the USBL Locator Mark II?
Answer: Horizontal positional error is approximately 0–8.5 meters at a 50 meter separation between receiver and transmitter. Keep in mind environmental conditions, orientation changes, and interference can affect accuracy, and error tends to increase with distance.

Question: How can I improve positioning accuracy in practice?
Answer: Secure the USBL receiver to prevent rotation in seawater and maintain a reasonable distance from pool walls or the vessel hull to reduce interference. Also ensure the APP, ROV, and Dock firmware are updated to the latest versions.

Question: What new features are included in recent updates?
Answer: Recent updates include USBL trajectory recording and import, interest point marking with split-screen map/video display, automatic water quality data storage to the ROV memory card, two ROV operating modes, new control methods for mechanical arm/water quality sampler, and a manual configuration mode for the accessory dock. The updates also address fixes reported in APP version 4.9.9.