RADIO ACOUSTIC RANGING—ADAMS 223 
observed at two or more receiving stations at known positions, these 
time intervals may be used to determine the position of the sound 
source. 
(c) All operations may be controlled and all measurements made 
at the sound source. A subaqueous sound signal is made near a 
survey vessel and its time recorded. The instants of arrival of the 
subaqueous sound at two or more receiving stations are then signaled 
> ngitnntaeestntannttodt sn maMLtnyyynyy ‘i & —_—-—-L 
\b 
=e 
Monta Fige 
WMibynyy eng 
rae, Way 
Udy 
— 
— 
Figure 1.—Radio acoustic ranging. In hydrographic surveying the ship’s position 
is determined by subaqueous sound travel to sono-radio buoys anchored at 
known positions. A, the bomber throws a small TNT bomb overboard from the 
moving ship. B, the bomb explodes and the resulting sound wave travels 
toward the sono-radio buoys (g and h) via paths (C—C) and toward the 
hydrophone (e) in the bottom of the ship via the path (D—D). The sound 
wave (F) travels in all directions at a velocity of about 1.5 km. per Sec. 
Instantly on arrival at a sono-radio buoy (g) a radio signal (R) is transmitted 
which is received at the ship. In the figure the sound wave has not yet arrived 
at sono-radio buoy (h). 
automatically by radio, and received and recorded on board the 
survey ship. From these data, the elapsed time between the origin 
of the sound and its receipt at each station is known and the position 
of the survey ship may be determined. 
This is the method used by the Coast and Geodetic Survey, and 
is considered the most practicable for use in hydrographic surveying 
because all operations are controlled from the survey ship and all 
