文档介绍：PROCEEDINGS OF THE IEEE, VOL. 69, NO. 11, NOVEMBER 1981 1451
Digital Signal Processing for Sonar
Abstmct-This pnper is a tutorkl which describes “main stream” sonar SEASURFACE
digital signal processing functions along with the nasocipted implemen-
tation considerrtiona The attempt b to promote further crolrr-fertilize-
tion of ideas among digital signd processing npplicptioas m “pt, radar,
speech, ltions, seismdogy, and other related fields.
as
HE TERM “SONAR” is defined by Winder [ 1091 the ACTIVE SONAR
T “method or equipment for determining by underwater
sound the presence, location or nature of objects in the
sea.” It is an acronymn for “SXJund Uvigation and Eanging.”
turn
Sonar has been in practical use since the of the century; Fig. 1. Active sonar.
but references to undersea sound propagation date back much
further, as described in Urick [ 1071.
SEASURFACE
Active sonar, as illustrated in Fig. 1, involves the transmis-
sion of an acoustic signal which, when reflected from a target,
provides the sonar receiver with a basis for detection and esti- /TOW CABLE
mation. Besides the loss in signal strength due to propagation
through the medium, the reflectionloss at the target, and addi-
tive noise at the receiver; a major limiting factor foractive so-
nar is reverberation which results fromreflections of the
transmitted signal from scatterers-the sea surface, the sea bot-
tom, biologics, inhomogeneities within the oceanvolume.
Passive sonar, as illustrated in Fig. 2, bases its detection and
estimation on sounds which emanate from the target itself-
machinery noise, flow noise, transmissions fromits active
sonar. Performance limitations arise as a result of propagation Fig. 2. Passive sonar.
loss and additive noise at thereceiver: but major limitations re-
sult from imprecise knowledge of the characteristics of the tar- Some of the applications of underwater sound are as follows.