--- title: "Explained by Offshore Sensing: Scientific echosounder: what it is and why it’s used?" description: "Scientific echosounder explained: what it measures, how pings become echograms and biomass indicators, and why fisheries rely on calibrated acoustic surveys." image: https://sailbuoy.no/hubfs/Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png --- [Skip to main content](https://sailbuoy.no/news/explained-by-offshore-sensing-scientific-echosounder-what-it-is-and-why-its-used#main-content) [![Offshore Sensing_original_logo_fixed](https://sailbuoy.no/hubfs/Logo%20and%20Icons/Offshore%20Sensing_original_logo_fixed.svg) ![Offshore Sensing_original_logo_fixed](https://sailbuoy.no/hubfs/Logo%20and%20Icons/Offshore%20Sensing_original_logo_fixed.svg) ![Offshore Sensing_original_logo_fixed](https://sailbuoy.no/hubfs/Logo%20and%20Icons/Offshore%20Sensing_original_logo_fixed.svg) ![Offshore Sensing_original_logo_fixed](https://sailbuoy.no/hubfs/Logo%20and%20Icons/Offshore%20Sensing_original_logo_fixed.svg)](https://sailbuoy.no) - [Show submenu for USV USV](https://sailbuoy.no/unmanned-surface-vessels) - [SB Bio](https://sailbuoy.no/sb-bio-unmanned-surface-vessel) - [SB Comms](https://sailbuoy.no/sb-comms-unmanned-surface-vessel) - [SB Echo](https://sailbuoy.no/sb-echo-unmanned-surface-vessel) - [SB eEDNA](https://sailbuoy.no/sb-edna-unmanned-surface-vessel) - [SB Met](https://sailbuoy.no/sb-met-unmanned-surface-vessel) - [Fisheries](https://sailbuoy.no/commercial-fish-scouting) - [Build your own](https://sailbuoy.no/unmanned-surface-vessels#byo) - [Technology](https://sailbuoy.no/the-sailbuoy-technology) - [Missions](https://sailbuoy.no/missions) - [News](https://sailbuoy.no/news) - [Show submenu for Company Company](https://sailbuoy.no/company) - [Join our team](https://sailbuoy.no/career) - [Our partners](https://sailbuoy.no/our-partners) Open main navigation Close main navigation - Show submenu for USV USV - USV - [USV](https://sailbuoy.no/unmanned-surface-vessels) - [SB Bio](https://sailbuoy.no/sb-bio-unmanned-surface-vessel) - [SB Comms](https://sailbuoy.no/sb-comms-unmanned-surface-vessel) - [SB Echo](https://sailbuoy.no/sb-echo-unmanned-surface-vessel) - [SB eEDNA](https://sailbuoy.no/sb-edna-unmanned-surface-vessel) - [SB Met](https://sailbuoy.no/sb-met-unmanned-surface-vessel) - [Fisheries](https://sailbuoy.no/commercial-fish-scouting) - [Build your own](https://sailbuoy.no/unmanned-surface-vessels#byo) - [Technology](https://sailbuoy.no/the-sailbuoy-technology) - [Missions](https://sailbuoy.no/missions) - [News](https://sailbuoy.no/news) - Show submenu for Company Company - Company - [Company](https://sailbuoy.no/company) - [Join our team](https://sailbuoy.no/career) - [Our partners](https://sailbuoy.no/our-partners) - Search - [Contact us](https://sailbuoy.no/contact) [Contact us](https://sailbuoy.no/contact) Search # Explained by Offshore Sensing: Scientific echosounder: what it is and why it’s used? **Quick answer:** A **scientific echosounder** is an acoustic instrument that sends sound pulses (“pings”) into the sea and measures the returning echoes to quantify **biomass in the water column**. It’s used in fisheries and ocean science because it can provide repeatable, calibrated measurements of fish and plankton distribution over distance and time—often as echograms and derived indicators. ## Key facts | Term | Meaning | Why it matters | | --- | --- | --- | | Ping | A transmitted sound pulse | The basic unit of measurement | | Echo / backscatter | Returned energy from targets | Relates to biomass presence and structure | | Water column | The full depth range below the surface | Enables depth-resolved mapping | | Frequency | The “pitch” of the sound (kHz) | Different targets respond differently | | Calibration | Reference procedure to validate measurements | Needed for quantitative comparisons | --- ## What makes an echosounder “scientific” A “scientific” echosounder is designed for **repeatable, quantitative work**—not just detecting a bottom depth or showing fish marks. In practice, that usually means: - Stable transmit/receive control and consistent logging - Metadata that supports traceability (time, position, settings) - Calibration workflows to support comparisons across time and platforms - Outputs that can be processed into biomass indicators and maps --- ## What a scientific echosounder measures (in plain language) It does not “see fish.” It measures **echo strength** from the sea. Echoes come from: - Fish (including swimbladders, which can be strong reflectors) - Zooplankton and micronekton layers - Seabed and hard structures - Bubbles and turbulence (sometimes noise, sometimes signal) Those returns are recorded along depth and time to create an **echogram** and derived metrics. --- ## Why it’s used in fisheries Scientific echosounders are used because they can produce: - **Distribution maps** (where biomass is in space and depth) - **Density indicators** (how strong the backscatter is over time/area) - **Repeatable transect datasets** (comparisons week-to-week or year-to-year) - **Operational awareness** (where patterns shift during a campaign) This becomes especially useful when paired with long-duration platforms (for example a USV – unmanned surface vessel) that can repeat routes over days/weeks. --- ## Typical outputs - Echograms (depth vs time/distance) - Depth-binned backscatter summaries - Trackline gridded products (e.g., per km) - Quality flags (motion, dropouts, settings changes) --- ## FAQ **Is a scientific echosounder the same as a “fish finder”?** Not exactly. A fish finder is typically optimized for real-time viewing; a scientific echosounder is designed for traceable logging and quantitative analysis. **Does it identify species?** Not on its own. Acoustics can suggest target types and layers, but species ID usually needs additional context (frequency response patterns, biology, sampling, or models). **Why is calibration mentioned so often?** Because calibration is what makes datasets comparable across time, platforms, and campaigns. ### Related Articles ##### [![Explained by Offshore Sensing: Autonomous platform emissions and sustainability in marine research](https://sailbuoy.no/hs-fs/hubfs/Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png?width=520&height=294&name=Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png) Explained • June 2, 2026 Explained by Offshore Sensing: Autonomous platform emissions and sustainability in marine research](https://sailbuoy.no/news/explained-by-offshore-sensing-autonomous-platform-emissions-and-sustainability-in-marine-research) ##### [![Explained by Offshore Sensing: Arctic and polar ocean monitoring with autonomous platforms](https://sailbuoy.no/hs-fs/hubfs/Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png?width=520&height=294&name=Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png) Explained • June 2, 2026 Explained by Offshore Sensing: Arctic and polar ocean monitoring with autonomous platforms](https://sailbuoy.no/news/explained-by-offshore-sensing-arctic-and-polar-ocean-monitoring-with-autonomous-platforms) ##### [![Explained by Offshore Sensing: Continuous ocean time-series data: why gaps in observation cost science](https://sailbuoy.no/hs-fs/hubfs/Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png?width=520&height=294&name=Hubspot%20blog%20feature%20image%20explained%20by%20offshore%20sensing%20(1).png) Explained • June 2, 2026 Explained by Offshore Sensing: Continuous ocean time-series data: why gaps in observation cost science](https://sailbuoy.no/news/explained-by-offshore-sensing-continuous-ocean-time-series-data-why-gaps-in-observation-cost-science) [![Offshore Sensing_original_logo_fixed](https://sailbuoy.no/hubfs/Logo%20and%20Icons/Offshore%20Sensing_original_logo_fixed.svg)](https://sailbuoy.no) - [Book meeting](https://sailbuoy.no/contact) - [Build your Sailbuoy](https://sailbuoy.no/unmanned-surface-vessels) - [Explained by Offshore Sensing](https://sailbuoy.no/explained-by-offshore-sensing) - [Resources](https://sailbuoy.no/resources) Offshore Sensing AS Sandslimarken 31 5254 Sandsli, Norway   [Crowdworks Company Profile](https://app.crowdworks.it/companies/offshore-sensing/update) ©2026 Offshore Sensing AS. 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