Editing Echo sounding (section)

===Standards for hydrographic echo sounding===

The required precision and accuracy of the hydrographic echo sounder is defined by the requirements of the [[International Hydrographic Organization]] (IHO) for surveys that are to be undertaken to IHO standards.<ref>{{cite journal|last=International Hydrographic Bureau|title=IHO Standards for Hydrographic Surveys|date=February 2008|issue=5th Edition|url=http://www.iho-ohi.net/iho_pubs/standard/S-44_5E.pdf|url-status=dead|archive-url=https://web.archive.org/web/20111008191705/http://www.iho-ohi.net/iho_pubs/standard/S-44_5E.pdf|archive-date=8 October 2011|df=dmy-all}}</ref>  These values are contained within IHO publication S44.

In order to meet these standards, the surveyor must consider not only the vertical and horizontal accuracy of the echo sounder and transducer, but the survey system as a whole.  A motion sensor may be used, specifically the heave component (in single beam echosounding) to reduce soundings for the motion of the vessel experienced on the water's surface.  Once all of the uncertainties of each sensor are established, the hydrographer will create an [[uncertainty budget]] to determine whether the survey system meets the requirements laid down by IHO.

Different hydrographic organisations will have their own set of field procedures and manuals to guide their surveyors to meet the required standards.  Two examples are the US Army Corps of Engineers publication EM110-2-1003,<ref name="USACE Hydrographic Manual">{{cite web |url=http://140.194.76.129/publications/eng-manuals/em1110-2-1003/toc.htm |title=EM 1110-2-1003 (01 Jan 02) |access-date=2011-06-09 |url-status=dead |archive-url=https://web.archive.org/web/20110720182750/http://140.194.76.129/publications/eng-manuals/em1110-2-1003/toc.htm |archive-date=20 July 2011 |df=dmy-all }}, USACE publication EM 1110-2-1003.</ref> and the NOAA 'Field Procedures Manual'.<ref name="NOAA Field Procedures Manual">[http://www.nauticalcharts.noaa.gov/hsd/docs/Field_Procedures_Manual_May_2011.pdf] {{Webarchive|url=https://web.archive.org/web/20110516143244/http://www.nauticalcharts.noaa.gov/hsd/docs/Field_Procedures_Manual_May_2011.pdf|date=16 May 2011}}, NOAA Field Procedures Manual.</ref>