Dataset Properties

Detailed specifications and characteristics of the UXO Dataset 2024

Dataset Characteristics

The UXO Dataset 2024 provides comprehensive multimodal data with synchronized acoustic and optical sensing capabilities. All data was recorded in a controlled experimental environment to ensure accuracy and repeatability.

Included Data Types

The dataset includes the following data formats and types:

Sonar Data

Raw and polar-transformed ARIS frames

Optical Data

Annotated GoPro camera frames

Pose Information

Sonar and target pose data

3D Models

Textured 3D models of UXO targets

Additional Resources

• Calibration matrices for both sensors
• Known transforms between sonar and targets
• Trajectory data from gantry crane system
• Target dimensions and munition type specifications

ARIS Explorer 3000 Sonar Specifications

The dataset uses an ARIS Explorer 3000 imaging sonar for acoustic data collection.

Sonar Data Formats

Raw Format

• Format: .pgm files
• Content: Individual sonar frames with full resolution
• Metadata: Accompanying .csv files with frame information

Polar Transform

• Format: .png images
• Resolution: 1000 pixels per meter (configurable)
• Compression: PNG compression level 9
• Method: Polar2 transformation (recommended)

Point Cloud

• Format: .csv files
• Accuracy: 64-bit floating point
• Size: ~12MB per frame
• Use: High-precision analysis

Transform Chain

The sonar positioning follows this transform hierarchy:

setup/portal_crane
  └─ setup/ar3
      └─ setup/aris
          └─ setup/sonar (acoustic origin)

The sonar origin is offset from the ARIS mounting point by 108.725mm in the X direction.

GoPro Hero 8 Camera Specifications

Video Recording

• Maximum Resolution: Ultra HD (5.3k, 5312x2988)
• Export Resolutions Available:
  • UHD: 5312x2988 (full resolution)
  • FHD: 1920x1080 (Full HD)
  • SD: 640x360 (preview quality)

Frame Annotations

When using GoPro frame labels, multiply coordinates by 3 to account for the resolution scaling.

Exported Frame Format

• Format: .jpg (JPEG)
• Default Export Resolution: FHD (1920x1080)
• Frame Extraction: Individual frames exported from video

Camera Transform Chain

setup/ar3
  └─ setup/gopro_mounting_hole
      └─ setup/gopro_mounting_axis
          └─ setup/camera (optical origin)

UXO Target Types

The dataset includes recordings of 3 distinct types of unexploded ordnance:

100lbs Bomb

Standard aircraft bomb replica

Mortar Shell

Artillery mortar shell

Incendiary Device

Incendiary munition type

Target Data Provided

• Munition type specifications
• Physical dimensions
• Textured 3D models
• Fixed world coordinates in the tank
• Ground truth pose for each frame

Trajectory Patterns

The dataset contains close to 100 trajectories recorded using a custom gantry crane system.

Trajectory Characteristics

Trajectories are designed to be typical and achievable for non-experimental environments, making them suitable for training real-world AUV systems.

• Recording Method: Controlled gantry crane with ROS tracking
• Data Format: .csv files with timestamped positions
• Synchronization: Matched with sonar and camera data
• Motion Profiles: Various approach angles and speeds

Trajectory Data

timestamp, x, y, z, qx, qy, qz, qw

Each trajectory includes:

• 6DOF pose information (position + orientation)
• Precise timestamps
• Motion onset and end markers

Recording Conditions

Environment

• Setting: Controlled underwater tank
• Lighting: Consistent for optical recording
• Water Conditions: Stable, controlled environment
• Target Placement: Fixed positions with known coordinates

Synchronization

The dataset provides multi-sensor synchronization:

1. ARIS Sonar: Primary timing reference
2. GoPro Camera: Motion-matched to sonar data
3. Gantry Crane: ROS timestamps aligned with sensors

Optical flow analysis was used to match GoPro footage with ARIS data, as the GoPro does not provide synchronized timestamps.

Data Formats

The dataset uses simple, well-established formats for maximum compatibility:

Images

.pgm, .png, .jpg

Tabular Data

.csv

Metadata

.yaml, .json, .txt

Calibration Data

The dataset includes comprehensive calibration information:

Camera Calibration

Multiple camera parameter sets for different field-of-view modes:

• Wide angle
• Superview
• Linear
• Narrow

Transform Calibration

Accurate transforms between:

• Sonar and camera
• Sensors and mounting points
• Gantry crane and world frame
• All UXO targets and world frame

All calibration matrices and transform trees are provided in standard .yaml format.