EchoNIMBUS-SSS Calculator

The EchoNIMBUS-SSS Calculator helps you determine optimal survey parameters for your side-scan sonar missions.

System Configuration

The EchoNIMBUS-SSS system features:

  • Dual side-scan sonars: Port and starboard sensors for complete coverage
  • Beam angle: 50° beam width per sensor (±25° from centerline)
  • Mounting angle: 20° down from horizontal (sensor tilt)
  • Beam edges: -5° (upper edge, near horizontal) to 45° (lower edge, forms dead zone)
  • Dead zone geometry: Lower beam edges meet at 90° total angle (45° from vertical on each side)
  • Sensor position: Mounted at water surface level
  • Coverage: Both sides of the survey path simultaneously

Interactive tool — open this page in the online manual to use it.

Usage

This calculator will help you:

  • Calculate swath width based on water depth and range setting
  • Visualize the sonar beam footprint on the bottom
  • Determine the dead zone directly below the sensor
  • Calculate optimal survey line spacing (profile width)
  • Understand how range settings affect coverage
  • Plan efficient survey patterns for complete coverage

Input Parameters

Water Depth (h)

The depth from the water surface to the bottom. This determines the geometry of the sonar beams and affects the coverage area.

Range (R)

The maximum beam path length (hypotenuse) of the side-scan sonar in meters. This is the actual distance the acoustic signal travels from the sensor to the target, not the horizontal distance on the bottom.

Overlap Percentage

The desired overlap between adjacent survey lines (0-90%). Higher overlap ensures better coverage but requires more survey time. Typical values are 20-30%.

Understanding the Results

The calculator uses these formulas to determine coverage:

Minimum Range Required

To reach the bottom at the dead zone edge (45° beam): R_min = h × √2

Dead Zone Width

Horizontal distance on bottom where neither sensor can detect: 2h (when R ≥ h√2)

Near Range

Horizontal distance to dead zone edge: h (where 45° beam hits bottom)

Far Range

Maximum horizontal reach on bottom: √(R² - h²)

Swath Width (one side)

Coverage from dead zone edge to far range: √(R² - h²) - h

Total Swath Width

Combined coverage both sides: 2 × (√(R² - h²) - h)

Recommended Profile Width

Survey line spacing with overlap: Total Swath × (1 - Overlap%)

Note

If R < h√2, the beam cannot reach the bottom and no footprint is recorded.

Understanding the Diagram

The diagram visualizes the side-scan sonar geometry:

  • Sensor: Orange rectangle at the water surface
  • Water Surface: Blue dashed line
  • Bottom: Brown line (seafloor/lakebed)
  • Sonar Beams: Yellow/orange cones showing coverage on both sides
  • Dead Zone: Red line with width label showing uncovered area below sensor
  • Coverage Footprint: Green lines with width labels showing effective scanning area
  • Water Depth: Vertical dimension line on the right edge

Width labels are displayed directly on the footprint lines for easy reading.