Figure 4 shows example plot of the fathometer
data collected for bed elevations during the period of March 25, 2005, to April 14, 2005, on the nose of the front pier columns at a bridge over Flint River, May 5, 2003, to May 12, 2003, on the nose of central pier bent in Chattahoochee River, and February 15,2003, to March 2, 2003, on the left side of pier bent in Ocmulgee River, respectively.
Heezen had been collecting fathometer
records (or echo soundings) since he began voyages on the Laboratory ship in 1947.
Mean water depth (in meters) was recorded by a fathometer
at the start and end of each trawling event, after which the relative change (in percentage) between the start and end locations was recorded.
A Raytheon DE-719 recording fathometer
was used in 2004 to create depth profiles for each leader in the study.
To produce a detailed topographic map, three data sets were combined: (1) 9,283 ground elevation points on the surrounding hills digitized from 2-foot (0.67-meter) contour lines mapped in 1999 by the Army Corps of Engineers, (2) a terrestrial land survey inside the Englebright Dam Reach canyon using real-time kinematic global positioning system (RTK-GPS) and Robotic Total Station technology and (3) a boat-based fathometer
survey of the submerged riverbed (Pasternack 2008).
"You might be operating in a milewide river with an easily discernible 20-foot-deep channel at one point," he told the "Professional Mariner" one recent season, "and then when you get into a tributary, you might be operating at dead slow in a channel less than 4-feet deep, that changes on a daily basis, with a small boat out ahead of you taking soundings with a fathometer
and a marked stick."
As the court said: "It is obvious that under these circumstances and at this time, the Miss Esmeralda required a three-man crew, two to raise the nets at the stern and one to check the compass and fathometer
in the wheelhouse.
Further examples of through-the-sensor data acquisition are the extraction of bathymetry and surficial seafloor sediment types from the UQN-4 fathometer
on mine countermeasures (MCM) ships, the BQN-17 submarine fathometer
and the AN/AQS-20A mine-hunting system (which also yields multibeam bathymetry).
Willis: The technology exists within the system to accept and record input from the ship's position and fathometer
After one of the Soviet boats hit the bottom near the banks of Phoenix, we were required to cross the strait with the fathometer
on, so as to have constant control over the depth under the keel.
Comparison of near-shore (walking) survey data with offshore (boat) data at overlap points was used to calibrate digitized fathometer
strip chart data in the Y and Z coordinates.
We were taking on water and, what's more, our depth-finding fathometer
was on the fritz, making our proximity to that coral a troubling mystery.