ACTIVE SUBMARINE TARGET ECHO SYNTHESIZER

• US 3,609,671 A
• Filed: 03/23/1970
• Issued: 09/28/1971
• Est. Priority Date: 03/23/1970
• Status: Expired due to Term

• Current Assignee: Michael T. Marrero, Richard B. Webster
• Original Assignee: Michael T. Marrero, Richard B. Webster
• Inventors: Webster, Richard B., Marrero, Michael T.
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US05/021,899
• Time in Patent Office: 554 Days
• Field of Search: 340/2,3,3E,5,5D 35/10.4
• US Class Current: 367/1
• CPC Class Codes: G01S 7/52004 Means for monitoring or calibrating short-range imaging G01S7/5205

Abstract

Apparatus wherein an active incoming sonar signal is synthesized by means including a spaced array of receiver transducers to provide a carrier frequency and a digital signal, said digital signal being applied to address a memory means including a core memory in which submarine signatures are stored for retrieval in relation to the type of submarine and aspect angle thereof and which also includes a digital to analog converter means. The outputs of said analog converter means being applied to modulate a carrier wave signal derived from a tone burst to carrier wave converter and further modulated by range data from a range translator to activate transducer means to provide a reflected submarine target sonar signal representative of a selected type submarine at an aspect angle and range corresponding to said incoming active sonar signal.

Claims

1. An active submarine target echo synthesizer comprising:

a. a receiver and aspect encoder circuit including an array of spaced receiver transducers, amplifying means and an aspect encoder for receiving active input sonar signals and providing a digital output signal representative of the aspect angle of said target from the source of said active sonar signal;

b. memory means including a core memory and a digital to analog converter means;

c. said core memory having a matrix of cells, each of specific output signal characteristics for a range of types of submarine targets and for specific aspect angle of the target;

d. said core memory including manual means for preprogramming said core memory for a specific type of submarine and being connected to said aspect encoder for addressing said core memory for a specific aspect angle derived from said active sonar input signal;

e. sequential pulse time gating means for said core memory for sequential activation of the cell addressed portions of said core memory to provide digital output signals from said cells to said digital to analog converter means;

f. a carrier wave generator means connected to said receiving circuit amplifier means to provide a carrier wave of frequency corresponding to the frequency of said incoming active sonar signal;

g. an amplitude modulator connected to said carrier wave generator and to the analog output of said digital to analog converter to modulate said carrier wave in accordance with the aspect angle of said target;

h. range translation and modulator means connected to said amplitude modulator and to said receiver circuit to further modulate said carrier wave in accordance with the range of said target, derived from said active sonar signal input; and

i. a reflective wave transducer means connected to said range modulator to provide a return sonar signal representative of the type of submarine target, its aspect angle and range.

2. Apparatus according to claim 1, a. said array of spaced receiver transducers consisting of a pair of transducers.

3. Apparatus according to claim 1, a. said sequential pulse time gating means including a pulse width encoder having inputs connected to the outputs of said aspect encoder and said receiver circuit amplifying means to provide a sequential series of output digital number signals, and b. an address sequence generator for receiving said series of output digital number signals for sequential pulse gating a cell of said core memory corresponding to said digital number.

4. Apparatus according to claim 1, a. said carrier wave generator means including a tone burst to frequency generator.

5. Apparatus according to claim 2, a. said sequential pulse time gating means including a pulse width encoder having inputs connected to the outputs of said aspect encoder and said receiver circuit amplifying means to provide a sequential series of output digital number signals, and b. an address sequence generator for receiving said series of output digital number signals for sequential pulse gating a cell of said core memory corresponding to said digital number.

6. Apparatus according to claim 5, a. said carrier wave generator means including a tone burst to frequency generator.