NOAA’s Facts About Hydrography

https://oceanservice.noaa.gov/facts/hydrography.html

How & Why NOAA Uses Hydrographic Surveying

https://oceanservice.noaa.gov/navigation/hydro/

What is a Hydrographic Survey?

https://en.wikipedia.org/wiki/Hydrographic_survey

What is Bathymetry?

https://www.nationalgeographic.org/encyclopedia/bathymetry/

https://en.wikipedia.org/wiki/Bathymetry

https://oceanservice.noaa.gov/facts/bathymetry.html

Applications for Bathymetry

https://www.usgs.gov/centers/whcmsc/science/sea-floor-mapping-group?qt-science_center_objects=0#qt-science_center_objects

What are Bathymetric Surveys Used For?

https://www.usgs.gov/centers/oki-water/science/bathymetric-surveys?qt-science_center_objects=0#qt-science_center_objects

What is Echo Sounding?

https://en.wikipedia.org/wiki/Echo_sounding

What is Sonar?

https://oceanservice.noaa.gov/facts/sonar.html

https://en.wikipedia.org/wiki/Sonar

Multibeam Sonar Theory of Operation

https://www3.mbari.org/data/mbsystem/sonarfunction/SeaBeamMultibeamTheoryOperation.pdf

What is a Multibeam Echosounder?

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/echo-sounder

https://en.wikipedia.org/wiki/Multibeam_echosounder