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OFOP - Ocean Floor Observation Protocol

Over the last 11 years the software package OFOP has been developed to deploy ROVs, Epibenthic Sledges, TV-Sled tows, Lander or Multiparameter Probes at the best possible sampling position.


OFOP reads a wide variety of position data and formats (NMEA-0183, NMEA-equivalent serial strings like SAG from Posidonia or GAPS underwater navigation systems, HRP and camera view direction from ROV's, …). Setting way points, creating routes and plotting of digitally recorded seafloor observations helps to define targets for the next deployments and makes later GIS-based data analysis possible. Writing Ocean Floor Observation Protocols in OFOP simply demands clicking buttons that record all input parameters (GPS-position, underwater position of the deployed gear, and other connected data streams) and station actions, when e.g. the device has reached the seafloor or crosses a seep site with tubeworms. All actions are stored locally in simple-to-read text files and can be broadcast to the local network via UDP at the same time. Detailed post processing is possible by replaying the recorded seafloor video which is linked to the recorded navigation and position data.

The post processed observation files can be merged with previous ones and additional sensor data can be integrated, corrected for time offsets and finally splined to get a complete data set for each individual deployment. Seafloor observation items are retrieved from an editable item list that gives each item an individual ID number. Each of the 28 buttons can be linked to a specific observation item (e.g. bacterial mat, bubbles, seep, soft sediment, etc.) and 6 different lists of up to 100 entries can be used to categorize the more specific observations (e.g. Ascidina (solitary), Orange Roughy, Pebbles, …). All data from previous observation tracks can be plotted online with the current deployment and thus help tremendously to find and re-find a particular spot at the seafloor. Special requirements can be accomodated by adding features in new windows and input/output capabilities can be adapted to individual needs.

Control over the positioning of devices that are deployed (coring or lander systems), towed over (TV-sleds, toyo CTDs) or work at the seafloor (ROVs) is essential for the success of the deployment. Easy online logging of sea floor observations helps to decide where additional deployments should be undertaken and is the basis for later GIS-based spatial analyses.

Background maps are loaded as images (jpg, bmp, wmf). Once calibrated, they can be reloaded easily. Various tools for distance measurement, multi beam planning, offset calculation for e.g. moored equipment help during the navigation. Several data sets of waypoints and routes can be loaded, manipulated and exported. The post-processing options in OFOP allow to:

  • edit, smooth and spline navigation data (e.g. needed for underwater positions)
  • replay the seafloor video and display the linked position data information on the map at the same time
  • perform detailed digitising (logging) of seafloor observations with the replay option
  • merge other data with the processed navigation data (e.g. memory CTD data) and seafloor observations carried out by different specialists

All logged data are saved as "easy-to-read and import" ASCII-text files to allow maximum compati-bility with other software (e.g. EXCEL, ACCESS, SURFER, ARC GIS, data bases in general). OFOP allows input and output via serial and / or network connections (UDP). Three different positions can be displayed and logged simultaneously (normally the ship and two underwater positions, e.g ROV and ROV-cage). More positions (e.g. air gun-arrays at the sea surface) can be implemented. Input support:

  • NMEA style inputs (e.g. VTG, GGA, HDT, WPL, …)
  • Underwater navigation input (e.g. iXSea SAG string; HPR calculation of the absolute position is carried out in OFOP)
  • Heave, roll, pitch, depth, camera viewdirection output from ROV systems (e.g. sub-Atlantic overlay output)
  • Special input formats as direct export from data bases (e.g. Werum DVS, RV Tangaroa DAS)
  • Other input formats can be easily implemented

Output support:

  • Export of all incoming strings via serial and/or network connection
  • OFOP data string for broadcasting to other OFOP-computers in the local network
  • Fledermaus-compatible string to visualize the ship, ROV and cage position in 3D Writing and logging individual protocols for each deployment is made easy.

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