Using Reference Markers in Greensea

In situations where Geolocation is required, but a GPS signal is not available, the coordinates of a known landmark must be ascertained, the ROV moved to that location and the coordinates entered into the system.

The following step-by-step instructions are provided for Marker Reference. Instructions for creating georeferenced chart overlay files is provided separately.

Steps 1 - 6 can be completed in the office.

1. For Marker Reference navigation, the GPS coordinates of several landmarks must be collected from a mapping program such as browser based mapping application (Google, Yahoo, and other) or a dedicated application like Google Earth. For each point of interest, collect the latitude and longitude information from your chosen mapping application. One landmark should be the planned deployment location for the ROV.
2. In Greensea, display the Map (F1 or F5) and right click anywhere on the map and select Add Marker.
3. Below the map, select the Chart Items tab and then the Markers tab.
4. Export the markers to a file.
5. Using the created markers file as a template replace the information for the marker with the information collected for one of your landmarks and add additional lines for each additional landmark. This can be done in a standard text editor.
6. Save the marker file.
7. Return to Greensea and import the Markers file.
8. Launch the ROV.
9. Follow the steps in the Auto Flight and Course Following Checklist section but do NOT complete step 5.3, "Fuse GPS."
10. Move the ROV to the position of one of the landmarks (most likely the planned deployment location).
11. In Greensea, display the Map (F1 or F5).
12. Below the map, select the Set Up tab.
13. Enter the GPS coordinates of the landmark to which you moved the ROV (most likely the deployment location.
14. Click the Push to ROV button.
15. You are now ready to navigate to any of the markers you placed or record the coordinates of any other point of interest.