Step-by-Step Guide: Configuring Trimble SPS-855 and Echotrack E20 with HYPACK

 ### Real-time Survey Monitoring

Hydrographic surveying requires extreme precision, and the synchronization between your GPS and Echo Sounder is the most critical part of the job. In this professional guide, I will share my step-by-step field experience on how to interface the Trimble SPS-855 GNSS receiver and the Echotrack E20 echosounder using HYPACK software.

Whether you are a beginner or a seasoned hydrographer, this 21-step visual manual will help you configure your hardware and software correctly to ensure high-quality bathymetric data collection. Let’s dive into the technical configuration.

1. Hardware connection/Equipment overview

Technical Note: "The primary step involves a robust physical connection between the Trimble SPS-855 and the data acquisition laptop. Ensure all serial or Ethernet cables are industrial-grade to prevent data loss during rough sea conditions."

Establishing physical hardware connection between Trimble SPS-855 and the laptop.

 2. Device Manager/COM Port identification

Expert Tip: "Always verify your COM Port assignments in Windows Device Manager before launching HYPACK. A common troubleshooting error is a port conflict—ensure your RS-232 to USB converters are assigned to consistent ports."

Verifying COM Port assignments in Windows Device Manager for sensor stability.

 3. HYPACK Hardware Configuration (Initial setup)

Configuration: "Inside the HYPACK Hardware module, adding the 'Trimble.dll' or 'Generic.dll' is crucial. Here, we define the device as our primary positioning sensor to sync with the survey vessel's motion."

Initializing the Hardware Configuration module in HYPACK.

 4. Setting up the Baud Rate & Parity

Precision Setting: "For the Trimble SPS-855, I typically set the Baud Rate to 38400 or 115200 depending on the update frequency. Remember: the settings in HYPACK must be an exact mirror of the receiver's internal output settings."

Configuring Baud Rate and Parity settings for the GPS receiver.

5.  Interfacing with Echotrack E20 (Depth sensor)

Bathymetry Sync: "Now we integrate the Echotrack E20. This dual-frequency echosounder must be synced via the same time-tagging protocol as the GPS to ensure that every depth point is mapped to the exact geographical coordinate."

Integrating the Echotrack E20 Echo Sounder into the HYPACK system.

6. Setting up the Input/Output (I/O) Messages

Technical Detail: "Configuring the NMEA messages (like GGA, VTG, and ZDA) is vital. In this step, we ensure the Trimble receiver is pumping out the right data strings so HYPACK can interpret the latitude, longitude, and precise time."

Setting up I/O messages for depth and positioning data synchronization.

7. Echo Sounder Calibration & Draft Settings

Expert Adjustment: "Before you hit the water, the 'Draft' value—the distance from the water surface to the transducer—must be entered accurately. A 5cm error here means a 5cm error in your entire bathymetric chart."

Configuring NMEA string formats and signal update rates.

8. Testing the Communication Link (Testing Tab)

Live Verification: "Use the 'Test' button in HYPACK Hardware. If you see scrolling green text, your communication is successful. If it's blank or red, go back and check your wiring and COM port parity."

Adjusting Echo Sounder Draft and Sound Velocity calibration settings.

Defining Vessel Offsets and sensor positioning relative to the COG.

9. Configuring the Offsets (Vessel Geometry)

Vessel Setup: "Every sensor has a position relative to the vessel's center of gravity. Here, we define the 'Offsets' for the GPS antenna and the Transducer. Precision in measurement here prevents 'smearing' of data during turns."

Defining Vessel Offsets and sensor positioning relative to the COG.

### Navigation and Survey Monitoring

10. Finalizing the Hardware Tree

Summary: "Once all sensors (GPS, Echosounder, Motion Sensor) are added, the hardware tree should look like this. This structure ensures that HYPACK knows exactly which device is providing which piece of information."

Synchronizing Time-Tagging between the GPS and the Echo Sounder.

11. Opening the HYPACK Survey Module

Process: "Once the hardware is configured, we launch the 'Survey' module. This is the heart of the operation where the vessel's movement, planned lines, and real-time depths are visualized on the screen."

Launching the HYPACK Survey Module for real-time monitoring.

12. Project Geodesy & Coordinate System

Geodetic Setup: "Accuracy depends on the correct Geodetic parameters. Ensure your UTM zone, datum (usually WGS-84), and units (Meters/Feet) are perfectly aligned with your project requirements to avoid positioning shifts."

Setting up Geodetic parameters and the project coordinate system.

 13. Setting up Planned Lines (LNW Files)

Navigation: "Survey lines (LNW files) are our guide. In this step, we load the pre-designed lines to ensure the vessel covers the entire survey area systematically without leaving any 'holidays' or gaps in the data."

Navigation view showing real-time tracklines and vessel position.

14. Real-time Data Visualization (The Matrix)

Monitoring: "This screen shows the real-time matrix being filled with depth data. Watching the color-coded depth points helps the surveyor identify any anomalous spikes or signal losses instantly."

Real-time digital depth output display on the HYPACK screen.

15. Checking GPS Quality Indicators (HDOP/RTK Status)

Quality Control: "Always keep an eye on your GPS status. For high-precision work, we aim for RTK Fixed status with a low HDOP. If the status drops to Float or DGPS, the vertical accuracy of your bathymetry may be compromised."

Monitoring GPS signal quality (HDOP) during active data collection.

16. Operation: "Timing is everything. In this window, we manage the 'Log' files. Starting the logging exactly at the beginning of a line and stopping it at the end ensures clean raw data for post-processing."

Controlling the start and stop of raw data logging for survey lines.

17. Viewing the Raw Data Files (RAW & HSX)

Storage: "HYPACK generates RAW or HSX files during the survey. These files contain all the sensor information, including timestamps, depth, and positioning strings, which will be used later in the Single Beam Editor."

Verifying RAW and HSX data files in the designated project folder.

18. Cross-line Verification

Quality Assurance: "Conducting cross-lines is a standard practice to verify the repeatability of our data. Any significant discrepancies at the intersections indicate potential issues with the tide or sound velocity settings."

Cross-line verification for bathymetric data quality assurance.

19. Real-time Depth Profile and Echogram

Sub-bottom Insight: "This echogram view from the Echotrack E20 helps us distinguish between the actual seabed and soft mud or suspended sediment. It’s a vital tool for ensuring the 'true bottom' is being tracked."

Real-time Echogram display from the Echotrack E20 for bottom tracking.

20. Backing Up the Project Data

Expert Habit: "Never risk your day's work. At the end of each session, back up your 'Raw' and 'Project' folders to an external drive. In the field, data redundancy is your best friend."

Procedure for backing up raw project data to an external drive.

21. Survey Completion & System Shutdown

"Once the area coverage is verified, we safely shut down the HYPACK modules and the Trimble receiver. Proper shutdown procedures prevent corruption of the final data files."

Proper system shutdown and safe closure of all survey modules.

Achieving Precision in the Field

"Setting up a hydrographic survey system like the Trimble SPS-855 with HYPACK requires both technical knowledge and attention to detail. Throughout my 26 years of experience in the field, I have learned that the success of a bathymetric survey depends 90% on the initial hardware and software configuration.

A single wrong offset or an incorrect baud rate can lead to hours of wasted effort. I hope this step-by-step visual guide helps young surveyors and engineers to streamline their workflow and achieve centimeter-level accuracy in their projects.

If you encounter any specific errors during your setup or have questions regarding the Echotrack E20 integration, feel free to leave a comment below. Let’s keep exploring the depths of engineering together!"