AUV Abyss workflow: autonomous deep sea exploration for ocean research

Autonomous underwater vehicles (AUVs) equipped with multibeam echosounders (MBES) are essential for collecting high-resolution bathymetric data in the deep sea. Navigation of AUVs and accuracy of acquired MBES data is challenging, especially in deep water or rough terrain. Here, we present the AUV Abyss operational workflow that uses mission planning together with a long baseline (LBL) positioning network, and systematic post-processing of the MBES data using feature matching. The workflow enables autonomous exploration even in difficult terrain, makes ultrashort baseline navigation during the AUV survey obsolete and with this, increases the efficiency of ship time. It provides an efficient workflow for multi-survey mapping campaigns to produce high-resolution, large-coverage seafloor maps. Automated documentation of post-processing steps enhances the archiving of produced results, facilitates knowledge transfer, adaptation to other systems and management of large datasets. Comprehensive documentation allows developing routines that provide a first step towards automatization of AUV operations and MBES data processing

Active exploration and identification of kinematic devices

As an important part of solving the lockbox problem, this thesis deals with the problem of identifying kinematic devices based on data generated using an Active Learning strategy. We model the belief over different device types and parameters using a discrete multinomial distribution. We discretize directions as a Geodesic sphere. This allows an isotropic distribution without being biased towards certain directions. The belief update is based on experience using a Bayes Filter. This allows to localize the correct states, even if an action fails to generate movement. Our action selection strategy aims to minimize the number of actions necessary to identify devices by considering the expected future belief. We evaluate the effectiveness of different information measures and compare them with a random strategy within a simulation. Our experiments show that the use of the MaxCE strategy creates the best results. We were able to correctly identify prismatic, revolute, and fixed devices in 3D space

Multibeam bathymetry processed data (Reson SeaBat T50-P working area dataset) of RV Littorina during cruise L13-20

Multibeam bathymetry raw and processed data (RESON Seabat T50Extended Range) of Research Vessel Littorina at Fehmarn Belt in the western part of the Baltic Sea. The raw data were processed using QPS Qimera software (v 1.7), based on the following workflow: 0.Raw data -> 1.Apply correct Sound Velocity Profiles -> 2. correct lever arm offsets -> 3. Finalize with manual 2D and 3D point editing. The corrected soundings were used to create a GeoTIFF in the UTM32 coordinate system (FCC_ETRS89_UNIVERSAL_TRANSVERSE_MERCATOR_NORTH_HEMISPHERE_+_EGG2008)

AUV navigation correction based on automated Multibeam Tile Matching

Ocean science and hydroacoustic seafloor mapping rely on accurate navigation underwater. By exploiting terrain information provided by a multibeam echosounder system, it is possible to significantly improve map quality. This article presents an algorithm capable of improving map quality and accuracy by aligning consecutive pings to tiles that are matched pairwise. A globally consistent solution is calculated from these matches. The proposed method has the potential to be used online in addition to other navigation solutions, but is mainly targeted for post processing. The algorithm was tested using different parameter settings on an AUV and a ship-based dataset. The ship-based dataset is publicly available as a benchmark. The original accurate navigation serving as a ground truth, alongside trajectories that include an artificial drift, are available. This allows quantitative comparisons between algorithms and parameter settings

Multibeam bathymetry processed data (Reson SeaBat T50-P working area dataset) of RV Littorina during cruise L13-20 including navigation files and python scripts for automated terrain based navigation correction

Multibeam bathymetry raw and processed data (RESON Seabat T50Extended Range) of Research Vessel Littorina at Fehmarn Belt in the western part of the Baltic Sea. The raw data (.db format) were processed using QPS Qimera software (v 1.7), based on the following workflow: 0.Raw data -> 1.Apply correct Sound Velocity Profiles -> 2. correct lever arm offsets -> 3. Finalize with manual 2D and 3D point editing. The corrected soundings were used to create a GeoTIFF in the UTM32 coordinate system (FCC_ETRS89_UNIVERSAL_TRANSVERSE_MERCATOR_NORTH_HEMISPHERE_+_EGG2008) .gsf data and GeoTIFF are provided. In addition software is provided with the aim of establishing a benchmark for terrain based navigation correction software using mutlibeam data. A) A script that allows to alter navigation solutions B) A script that allows to compare navigation solutions By altering the original and correct navigation and using the product as a basis for a terrain based navigation correction algorithm, the quality of such an algorithm can be measured by comparing its output to the original navigation. This in turn allows quantitative comparisons between different algorithms or settings. In addition to the original navigation some altered navigation files are provided (in .csv file format)

Mutibeam data of Research Vessel Littorina at Fehmarn Belt as a benchmark dataset for automated terrain based navigation correction software

Multibeam bathymetry raw and processed data (RESON Seabat T50Extended Range) of Research Vessel Littorina at Fehmarn Belt in the western part of the Baltic Sea. The raw data (.db format) were processed using QPS Qimera software (v 1.7), based on the following workflow: 0.Raw data -> 1.Apply correct Sound Velocity Profiles -> 2. correct lever arm offsets -> 3. Finalize with manual 2D and 3D point editing. The corrected soundings were used to create a GeoTIFF in the UTM32 coordinate system (FCC_ETRS89_UNIVERSAL_TRANSVERSE_MERCATOR_NORTH_HEMISPHERE_+_EGG2008) .gsf data and GeoTIFF are provided. In addition software is provided with the aim of establishing a benchmark for terrain based navigation correction software using mutlibeam data. A) A script that allows to alter navigation solutions B) A script that allows to compare navigation solutions By altering the original and correct navigation and using the product as a basis for a terrain based navigation correction algorithm, the quality of such an algorithm can be measured by comparing its output to the original navigation. This in turn allows quantitative comparisons between different algorithms or settings. In addition to the original navigation some altered navigation files are provided (in .csv file format)

Sediment echosounder raw data (Atlas Parasound P70 echosounder entire dataset) of RV MARIA S. MERIAN during cruise MSM96

This dataset contains sediment profiling hydroacoustic data from RV MARIA S. MERIAN's Atlas PARASOUND P70 echosounder system. The data was recorded almost continuously during cruise MSM96 in the North-East Atlantic (2020-10-12 - 2020-11-09). This dataset contains the raw data files as created by the system along the cruise with Atlas PARASTORE software (.asd, .sgy, .ps3) and ancillary data. No data processing or quality control was conducted. The dataset additionally contains screenshots of selected parts of the recordings for visualization and data selection purposes. The PARASOUND data was recorded to complement the extensive multibeam data recordings of the cruise and to select sampling sites for the multicorer deployments. Data was recorded during multibeam stations and the vessel speed rarely reduced below 7 knots. Vessel speed varies throughout the dataset. This dataset does not contain any dedicated, slow-speed PARASOUND profiles. This publication is conducted within the efforts of the German Marine Research Alliance in the core area "Data management and Digitalization" (Deutsche Allianz Meeresforschung, DAM), MareHub (Helmholtz) & iAtlantic (EU) research projects

ADCP current measurements (38 kHz) during Maria S. Merian cruise MSM96

Upper-ocean velocities along the cruise track of Maria S. Merian cruise MSM96 were continuously collected by a vessel-mounted Teledyne RD Instruments 38 kHz Ocean Surveyor ADCP. The transducer was located at 6.5 m below the water line. The instrument was operated in narrowband mode with 32 m bins and a blanking distance of 16.0 m, while 50 bins were recorded using a pulse of 2.87 s. The ship's velocity was calculated from position fixes obtained by the Global Positioning System (GPS). Heading, pitch and roll data from the ship's gyro platforms and the navigation data were used by the data acquisition software VmDas internally to convert ADCP velocities into earth coordinates. Accuracy of the ADCP velocities mainly depends on the quality of the position fixes and the ship's heading data. Further errors stem from a misalignment of the transducer with the ship's centerline. The average interval was set to 60 s. Data post-processing included water track calibration of the misalignment angle (0.44° +/- 0.8536°) and scale factor (1.0015 +/- 0.0180) of the Ocean Surveyor signal