USS Greeneville's fire control station. The four display screens at the fire control station, looking left to right, are (1) line-of-sight, (2) time-bearing, (3) TMA, and (4) op-summary. (1) Line-of-sight: shows bearing as a vertical line, contact as a vector at the top of the screen, and own ship as a vector at the bottom of the screen. (2) Time-bearing: plots contact bearing against time.

(3) TMA: compares incoming sonar bearings, shown as dots, with the bearing generated by the fire control computer for the parameters of course, speed, and range in the computer. Incoming dots appear above the previous dots to form a line of dots. To achieve a tracking solution, the FTOW varies course, speed, and range settings to eliminate the difference between the generated bearings and the actual bearings coming from sonar.

(4) Op-summary: shows position of all contacts and land with respect to position of own ship.

(U.S. Navy photo)

Source: http://www.ntsb.gov/publictn/2005/MAB0501.htm

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