Each object card shows the object's geometry, a synthetic aperture sonar image tile of it at 50 m range formed with one fixed sonar preset (36 channels, 300 kHz, 60 kHz bandwidth, a straight pass at 5 m altitude, 20,000 scatterers per square metre), and a size-reference plot whose axes are 1.1 times the object's bounding box. The sonar tiles use the standard display chain (magnitude, Schlick tone curve, SAS colormap); along-track is up, range is to the right.
The seabed under the objects is an idealized flat sand bed: the measured sand height-roughness spectrum (Lyons, Olson & Hansen 2022) is suppressed so each object stands out. This is a reference catalog, not a representative at-sea scene; on real sand the bed carries roughness that competes with the target. Feature relief such as trawl grooves, outcrops, boulder fields and mounds is explicit and is shown as it is. The Procedural seafloor types section at the end is different; each bed there carries its own calibrated roughness, shown as a heightmap beside a SAS tile, including the sand roughness the object cards suppress.
Mesh assets 73
Mesh asset, 0.09 x 2.00 x 0.09 m.
Mesh asset, 0.58 x 0.58 x 0.88 m.
Mesh asset, 0.06 x 0.26 x 0.06 m.
Mesh asset, 4.47 x 1.51 x 1.01 m.
Mesh asset, 1.00 x 1.14 x 0.97 m.
Mesh asset, 0.36 x 0.03 x 0.07 m.
Mesh asset, 0.27 x 0.02 x 0.06 m.
Mesh asset, 3.69 x 4.50 x 1.03 m.
Mesh asset, 0.28 x 0.03 x 0.08 m.
Mesh asset, 0.37 x 0.07 x 0.20 m.
Mesh asset, 5.75 x 2.43 x 2.44 m.
Mesh asset, 1.50 x 0.50 x 0.50 m.
Mesh asset, 2.23 x 2.67 x 0.92 m.
Mesh asset, 9.86 x 10.72 x 1.36 m.
Mesh asset, 1.20 x 0.80 x 0.14 m.
Mesh asset, 1.50 x 1.37 x 0.66 m.
Mesh asset, 51.06 x 50.62 x 11.99 m.
Mesh asset, 0.13 x 0.04 x 0.13 m.
Mesh asset, 0.06 x 0.03 x 0.06 m.
Mesh asset, 13.00 x 11.30 x 5.59 m.
Mesh asset, 0.99 x 1.75 x 0.32 m.
Mesh asset, 2.77 x 4.39 x 8.91 m.
Mesh asset, 0.51 x 0.59 x 0.51 m.
Mesh asset, 3.00 x 0.65 x 0.52 m.
Mesh asset, 3.47 x 1.72 x 4.09 m.
Mesh asset, 2.65 x 2.40 x 5.36 m.
Mesh asset, 2.65 x 2.40 x 5.36 m.
Mesh asset, 3.53 x 11.85 x 3.06 m.
Mesh asset, 0.21 x 0.75 x 0.21 m.
Mesh asset, 0.34 x 0.50 x 0.20 m.
Mesh asset, 0.47 x 0.50 x 0.20 m.
Mesh asset, 0.35 x 0.50 x 0.20 m.
Mesh asset, 0.50 x 0.50 x 0.20 m.
Mesh asset, 0.21 x 0.50 x 0.21 m.
Mesh asset, 0.46 x 0.46 x 0.20 m.
Mesh asset, 0.26 x 0.26 x 0.20 m.
Mesh asset, 2.39 x 2.64 x 3.14 m.
Mesh asset, 0.21 x 0.02 x 0.21 m.
Mesh asset, 24.31 x 9.36 x 1.71 m.
Mesh asset, 26.21 x 9.97 x 1.71 m.
Mesh asset, 4.74 x 2.73 x 3.58 m.
Mesh asset, 4.74 x 2.73 x 3.58 m.
Mesh asset, 4.74 x 2.73 x 3.58 m.
Mesh asset, 0.20 x 2.00 x 0.20 m.
Mesh asset, 0.10 x 2.00 x 0.10 m.
Mesh asset, 0.26 x 0.24 x 0.08 m.
Mesh asset, 0.39 x 0.38 x 0.08 m.
Mesh asset, 0.16 x 0.24 x 0.08 m.
Mesh asset, 0.65 x 9.36 x 1.17 m.
Mesh asset, 0.40 x 0.08 x 0.08 m.
Mesh asset, 0.21 x 0.24 x 0.08 m.
Mesh asset, 23.85 x 14.07 x 2.07 m.
Mesh asset, 0.12 x 0.12 x 5.00 m.
Mesh asset, 7.59 x 1.38 x 7.20 m.
Mesh asset, 5.11 x 5.24 x 1.27 m.
Mesh asset, 0.21 x 0.11 x 0.21 m.
Mesh asset, 2.56 x 2.36 x 4.95 m.
Mesh asset, 2.67 x 2.67 x 4.47 m.
Mesh asset, 2.05 x 4.70 x 1.47 m.
Mesh asset, 0.04 x 0.10 x 0.10 m.
Mesh asset, 0.15 x 0.16 x 0.11 m.
Mesh asset, 2.29 x 3.00 x 1.51 m.
Mesh asset, 1.25 x 0.29 x 0.29 m.
Mesh asset, 7.50 x 2.45 x 2.58 m.
Mesh asset, 17.00 x 1.83 x 5.34 m.
Mesh asset, 1.59 x 2.50 x 1.25 m.
Mesh asset, 0.35 x 0.69 x 0.52 m.
Mesh asset, 0.64 x 0.64 x 0.78 m.
Mesh asset, 7.64 x 0.71 x 0.71 m.
Mesh asset, 2.43 x 5.30 x 1.81 m.
Mesh asset, 0.80 x 0.80 x 0.34 m.
Mesh asset, 0.71 x 1.01 x 0.19 m.
Mesh asset, 0.71 x 1.01 x 0.34 m.
Primitive object kinds 7
Rectangular block, 2.0 x 1.0 m footprint, 0.5 m high.
Smooth horizontal cylinder, 3.0 m long, 0.5 m diameter.
Trihedral corner reflector; a calibrated bright return.
Wedge body, 1.02 m long, 0.80 m wide at the tail, 0.385 m high.
Truncated cone, 0.98 m base diameter, 0.30 m top, 0.44 m high.
Thin armored fiber-optic cable laid on the bed, 3.5 cm diameter.
Large-diameter subsea pipeline, 0.6 m OD, rigid concrete-coated.
Procedural primitives 16
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.70 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.80 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.60 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.40 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 1.50 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.60 x 1.00 m, height 0.12 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 0.87 m, height 0.50 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.80 x 1.00 m, height 0.50 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.30 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.50 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.15 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.00 x 1.00 m, height 0.40 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 8.00 x 1.40 m, height 1.00 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 6.00 x 1.00 m, height 1.00 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 2.00 x 1.00 m, height 0.06 m).
Parametric 2.5-D clutter primitive, size 1.0 m (footprint 1.50 x 1.00 m, height 0.45 m).
Protection structures 3
Articulated concrete mattress draped over a pipeline (3 m mat).
Cluster of grout ballast bags.
Cluster of rock ballast bags (larger, brighter pillows).
Seabed features 8
Engineered quarry-rock ridge laid along a cable route, 0.8 m crest.
Wide flat-floored meandering channel with raised levees, 1.2 m deep.
Narrow sinuous V-section gully, 2.5 m wide, 1.6 m deep.
Seeded scatter of mixed clutter primitives over an organic footprint.
Low rubble mound topped with dense fines, reading as dumped spoil.
Paired otter-board grooves with flanking berms, cut into the bed by bottom trawling.
Bedrock outcrops: gently dipping rock plateaus with steep edges and a talus apron, painted as rock.
A rock ledge: a terraced step with a steep face and a gently back-dipping top.
Boulder fields 8
Unsorted glacial till: a broad mix of rounded clasts dropped by ice, poorly sorted.
Isolated dropstones scattered sparsely on an otherwise clear bed.
Talus apron: angular debris shed from a slope, graded coarser toward the source edge.
Rockfall deposit: coarse angular blocks fallen from a scarp.
Dense cobble bed: closely packed, rounded, well-sorted cobbles.
Slab field: flat, platy rock slabs lying on the bed.
Carbonate reef rubble: broken coral and limestone fragments.
Fractured basalt: blocky prismatic fragments from columnar jointing.
Biota 5
Branching (staghorn) coral: open, antler-like thickets.
Massive (boulder/brain) coral: rounded hemispherical heads.
Plate / table coral: broad flat horizontal foliose colonies.
Seagrass meadow (Zostera): ribbon-blade shoots bending with the current.
Seagrass meadow (Syringodium): cylindrical tube-blade shoots.
Procedural seafloor types
Each bed below carries one procedural pattern or one bottom material and no discrete object. The left panel is the seafloor heightmap (elevation in metres; reflectivity for the no-relief material patches); the right panel is a SAS tile of that bed at 50 m range. Unlike the object cards, these show each material's own calibrated roughness, including the sand roughness the object cards suppress.
sand ripples 3
Sand ripples (Tang skewed-ripple model) at 0.3 m wavelength; height and skewness are held fixed.
Sand ripples (Tang skewed-ripple model) at 0.75 m wavelength; height and skewness are held fixed.
Sand ripples (Tang skewed-ripple model) at 1.5 m wavelength; height and skewness are held fixed.
macro-roughness 3
Fractal sand macro-roughness at 0.01 m RMS height; a rougher bed scatters more and casts finer shadow texture.
Fractal sand macro-roughness at 0.05 m RMS height; a rougher bed scatters more and casts finer shadow texture.
Fractal sand macro-roughness at 0.15 m RMS height; a rougher bed scatters more and casts finer shadow texture.
pockmarks 3
Gas-escape pockmark field at 0.02 features/m^2; each pockmark is a Gaussian bowl with an annular rim.
Gas-escape pockmark field at 0.05 features/m^2; each pockmark is a Gaussian bowl with an annular rim.
Gas-escape pockmark field at 0.1 features/m^2; each pockmark is a Gaussian bowl with an annular rim.
material patches 3
Shell-hash lag patches: sand armoured with shell fragments, a few dB brighter than clean sand.
Gravel-lag patches: coarse clasts, markedly brighter than the surrounding sand.
Mud pockets: fine cohesive sediment, darker (lower backscatter) than sand.
bottom materials 31
Clean sand with its calibrated Goff-Jordan roughness (Lyons, Olson & Hansen 2022). This is the roughness the object cards suppress.
Rippled-sand class: a rougher sand spectrum than clean sand.
Mud: fine, cohesive, very smooth and weakly scattering.
Exposed rock bed: high backscatter and coarse relief.
Gravel bed: coarse clasts, bright, with moderate relief.
Silt: very smooth and weakly scattering.
Patchy sand: sand-class roughness imaged with the point-target angular law.
Shell-hash bed: granular, rougher than sand at the scatterer scale.
APL-UW TR9407 sediment 'rough rock', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'rock', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'cobble', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'sandy gravel', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'very coarse sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'muddy sandy gravel', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'coarse sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'gravelly muddy sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'medium sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'muddy gravel', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'fine sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'muddy sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'very fine sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'clayey sand', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'coarse silt', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'sandy silt', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'medium silt', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'sandy mud', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'fine silt', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'sandy clay', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'very fine silt', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'silty clay', imaged with the handbook's roughness spectrum and angular law.
APL-UW TR9407 sediment 'clay', imaged with the handbook's roughness spectrum and angular law.