Dual head swath width calculator

Advanced swath-width calculator for dual head multibeam systems with asymmetric swaths. Enter each sonar’s mount tilt, lateral offset, altitude, and outer/inner beam angles. Outputs total swath width, overlap, minimum range settings, and the inner swath angles required for beams to touch below the vessel centre.

Select the type of setup for the appropriate diagram Dual Head on a Single Pole Dual Head on Two Poles

Sonar Installation Parameters

Physical mounting values — Negative = Port of Centre of Vessel / Positive = Starboard of Centre of Vessel

Port mount tilt — τ (°)

Clockwise = Positive when viewed from aft

Starboard mount tilt — τ (°)

Clockwise = Positive when viewed from aft

Port sonar altitude

Acoustic centre to bottom (positive down)

Starboard sonar altitude

Acoustic centre to bottom (positive down)

Lateral offset — vessel centre to port sonar

Negative = Port of Centre of Vessel

Lateral offset — vessel centre to starboard sonar

Positive = Starboard of Centre of Vessel

Sonar Swath Parameters

Relative to sonar — Clockwise = Positive / Counter-clockwise = Negative when viewed from aft

Port outer swath angle — α (°)

Clockwise = Positive when viewed from aft

Starboard outer swath angle — α (°)

Clockwise = Positive when viewed from aft

Total: port outer angle from sonar centre (°)

τ + α

Total: starboard outer angle from sonar centre (°)

τ + α

Port inner swath angle — β (°)

Clockwise = Positive when viewed from aft

Starboard inner swath angle — β (°)

Clockwise = Positive when viewed from aft

Total: port inner angle from sonar centre (°)

τ + β

Total: starboard inner angle from sonar centre (°)

τ + β

Results — Negative = Port / Positive = Starboard of vessel centre

Port outer distance from vessel centre

—

Starboard outer distance from vessel centre

—

Port inner distance from vessel centre

—

Positive = starboard of vessel centre

Starboard inner distance from vessel centre

—

Negative = port of vessel centre

Total swath width

—

Port outer to starboard outer

× Altitude

—

Using average altitude

Overlap

—

Negative = NO overlap

Minimum Range Settings

Sonar range settings required to reach outer swath limits

Port sonar — minimum range setting

—

Starboard sonar — minimum range setting

—

Inner Swath Angles

Angles required to touch the bottom directly below the centre of the vessel

Port inner swath — β (°)

—

Relative to sonar face. Clockwise = Positive when viewed from aft

Starboard inner swath — β (°)

—

Relative to sonar face. Clockwise = Positive when viewed from aft

These calculators are informational tools provided without warranty or cost. All calculations are theoretical and cannot account for sonar performance or specific water conditions. Do not rely on this tool when planning any survey where financial or safety factors are present. MosaicHydro is not responsible for any errors, omissions, or decisions made in reliance on these results.