Follow the Diver

Last week we took a look at the UWIS dive logs. With the diver or ROV in the water UWIS starts recording the position on either a 2 or 4 second cycle, capturing latitude, longitude and depth.

UWIS Tracker feeding back ROV or diver position. Long/Lat/Depth are written to the log file

The actual track log can be downloaded as a geoJSON file and loaded into GIS applications such as our own favourite Global Mapper. We can visualise the track in the context of the rest of the planet, and in glorious 3D too:

Global Mapper can add a wide range of geospatial data in both 2D and 3D environment

The 3D view caught the attention of UWIS CEO Pertti Arvonen. We have a few georeferenced models and UWIS tracks from Vobster. Could we combine the two?

The models were exported from Metashape Professional with WGS84 reference. Although each chunk is separate their geolocation is recorded and allows us to view the 3D content in context of not only each other, but the rest of the planet.

Building the Scene

The UWIS track log was loaded first and then each 3D model in turn:

The track log with 3D content

The track log needed a little work to tidy it up with Global Mapper’s editing tools, deleting a few unwanted vertices and using the smooth tool to refine the track and soften some of the harsher changes in position.

Models and track loaded with Open StreetMap map service layer added

With the track log trimmed and refined the next step was to generate the fly through data:

Generating the fly through path data in Global Mapper

Export the Video

With the fly through path sorted the final step is to export the video. In this example the World Imagery satellite overlay has been deliberately left on, representing the surface of the quarry:

The video isn’t perfect but as a proof of concept give us a clear direction in merging 3D data with diver telemetry

The final video isn’t going to win awards anytime soon but that’s not the point here. As a proof of concept it has started to open up a few ideas of how geo referenced 3D photogrammetry can be merged with ROV or diver telemetry.

If you are interested in knowing more about underwater GPS & UWIS, photogrammetry with Metashape, or GIS with Global Mapper then please use the contact us page to get in touch.