US3610798A
Expired / Lapsed
US
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Sonar echo simulator
Assignee: United States Department of the Navy
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Filing: 1969-09-17
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Granted: 1971-10-05
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Expires: 1989-09-17
Abstract
Abstract A sonar echo simulator utilizes analog and digital means to generate a series of highlight trigger signals the timing of which is related to simulated target length, length of insonifying pulse, and target aspect angle. The highlight trigger pulses are applied to pulse function generator means which produces a plurality of highlight echo signals. The highlight echo signals are variably attenuated and added to provide a composite echo signal which is further attenuated in accordance with insonifying pulse length and aspect angle to provide a realistic simulated echo signal.
Inventors
- 👤 Francis J Murphree
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:38
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/56; G01; G01S; G01S7/00; G01S7/52; G01S7/52004
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
228 words
Apparatus for generating electrical signals simulative of sonar echoes for example in a sonar simulator capable of providing inputs representing keying, insonification frequency f1, and insonification pulse length T, and target aspect angle theta , said apparatus comprising: pulse function generator means (14) comprising a plurality of pulse function generators (160-161) each operative to provide a pulsed CW output of frequency f1 and length T in response to a trigger pulse, a first (160) of said pulse function generators being adapted to receive a start trigger pulse representing keying; 2s/C cos theta and highlight generator means (12) responsive to said pulsed CW output of said first pulse function generator (160) and to an input representative of theta to provide as a plurality of outputs highlight trigger pulses each representing the time of occurrence of a highlight echo; said pulse function generators (161-165) other than said first function generator each being responsive to one of said highlight trigger pulses to provide an output signal of length T and frequency f1, each starting at a time appropriate to an assigned highlight; attenuator means (191-195) for effecting predetermined attenuation of each of the outputs of said other pulse function generators, and summing means 196. 198) for combining the attenuated outputs of said other pulse function generators into a composite signal having an envelope which is representative of highlight amplitude and distribution.
Claim 2
Dependent Claim
228 words
Apparatus for generating electrical signals simulative of sonar echoes for example in a sonar simulator capable of providing inputs representing keying, insonification frequency f1, and insonification pulse length T, and target aspect angle theta , said apparatus comprising: pulse function generator means (14) comprising a plurality of pulse function generators (160-161) each operative to provide a pulsed CW output of frequency f1 and length T in response to a trigger pulse, a first (160) of said pulse function generators being adapted to receive a start trigger pulse representing keying; 2s/C cos theta and highlight generator means (12) responsive to said pulsed CW output of said first pulse function generator (160) and to an input representative of theta to provide as a plurality of outputs highlight trigger pulses each representing the time of occurrence of a highlight echo; said pulse function generators (161-165) other than said first function generator each being responsive to one of said highlight trigger pulses to provide an output signal of length T and frequency f1, each starting at a time appropriate to an assigned highlight; attenuator means (191-195) for effecting predetermined attenuation of each of the outputs of said other pulse function generators, and summing means 196. 198) for combining the attenuated outputs of said other pulse function generators into a composite signal having an envelope which is representative of highlight amplitude and distribution.
Claim 3
Dependent Claim
249 words
Apparatus as defined in claim 1, and wherein said 2s/C cos theta and highlight generator means comprises: single-shot multivibrator means (52) responsive to said pulsed CW output of said first pulse function generator (160) to provide an output pulse for each cycle of said pulsed CW and having a width proportional to cos theta ; first gate means (64) responsive to the output pulses of said multivibrator means and to counting means (74), to pass a number proportional to cos theta , of cycles of a frequency f2 to a count and hold means (72); means (112) responsive to said start trigger signals to provide readout trigger pulses having a predetermined time delay with respect to said start trigger signals; gate pulse generator means (106) for initiating gate pulses in response to said readout trigger pulses; counter means (86); second gate means (90) responsive to said gate pulses from gate pulse generator means (106) to pass cycles of frequency f1 to said counter means (86); comparator means (82) connected to said count and hold means (72) and said counter means (86), said comparator means being operative to provide an output signal each time the count in said counter means (86) equals a count being held in said count and hold means (72); shift register means (98) having a plurality of output stages and responsive to said output signals of said comparator means (82) to provide as output signals on predetermined successive ones of said stages said highlight trigger signals.
Claim 4
Dependent Claim
107 words
Apparatus as defined in claim 2, and wherein: said 2s/C cos theta and highlight generator further comprises additional shift register means (100) having a plurality of output stages and responsive to said output signals of said comparator means (82) to provide as output signals on predetermined successive ones of said output stages of said additional shift register means additional highlight trigger signals; and said pulse function generator means further comprises logic means (170) responsive to inputs indicative of bow or stern aspect to apply said highlight trigger signals from said shift register means (98) or said highlight trigger signals from said additional shift register means (100), respectively.
Claim 5
Dependent Claim
35 words
Apparatus as defined in claim 3, and further comprising echo amplitude adjustment means (18) for attenuating said composite signal output of said summing means in accordance with insonifying pulse length and aspect angle theta .
Claim 6
Dependent Claim
177 words
Apparatus as defined in claim 4, and wherein said amplitude adjustment means comprises: first divider means (230) connected to receive the pulsed CW output of said first pulse function generator and operative to divide the number of cycles therein by an integer M to provide output pulses at a frequency proportional to the insonification pulse length T; a T shift register and logic means (234) connected to receive as an input the output of said first frequency divider means and operative to provide a first output when said input thereto bears a first predetermined relation to an integer p and a second output when said input bears a second predetermined relation to said integer p; second and third attenuator means (R1-R4, R5-R8); third and fourth gate means (Q1, Q2) connected to the output of said pulse function generator means (14), said third and fourth gate means being responsive to said first and second outputs, respectively, of said T shift register and logic means (234) to pass said composite signal alternatively to said second and third attenuator means.
Claim 7
Dependent Claim
191 words
Apparatus as defined in claim 5, and wherein said amplitude adjustment means further comprises: second divider means (246) connected to receive said output of said i count gate 64 and operative to effect division thereof by an integer N to provide output pulses at a frequency proportional to cos theta ; a cos theta shift register and logic means (252) connected to receive as an input the output of said second divider means and operative to provide a plurality of outputs each representative of theta being in a different predetermined sector; each of said second and third attenuator means comprising a plurality of resistors equal in number to the plurality of outputs of said cos theta shift register and logic means; a plurality of additional gate means (Q3-Q10) each connected in series with one of said resistors said additional gate means being responsive to said plurality of outputs of said cos theta shift register and logic means (252) to connect selected ones of said resistors to a final output line whereby said composite signal is attenuated in accordance with the aspect angle theta as well as with the pulse length T.
Claim 8
Dependent Claim
35 words
Apparatus as defined in claim 2, and further comprising echo amplitude adjustment means (18) for attenuating said composite signal output of said summing means in accordance with insonifying pulse length and aspect angle theta .
Claim 9
Dependent Claim
177 words
Apparatus as defined in claim 7, and wherein said amplitude adjustment means comprises: first divider means (230) connected to receive the pulsed CW output of said first pulse function generator and operative to divide the number of cycles therein by an integer M to provide output pulses at a frequency proportional to the insonification pulse length T; a T shift register and logic means (234) connected to receive as an input the output of said first frequency divider means and operative to provide a first output when said input thereto bears a first predetermined relation to an integer p and a second output when said input bears a second predetermined relation to said integer p; second and third attenuator means (R1-R4, R5-R8); third and fourth gate means (Q1, Q2) connected to the output of said pulse function generator means (14), said third and fourth gate means being responsive to said first and second outputs, respectively, of said T shift register and logic means (234) to pass said composite signal alternatively to said second and third attenuator means.
Claim 10
Dependent Claim
190 words
Apparatus as defined in claim 8, and wherein said amplitude adjustment means further comprises: second divider means (246) connected to receive said output of said i count gate 64 and operative to effect division thereof by an integer N to provide output pulses at a frequency proportional to cos theta ; a cos theta shift register and logic means (252) connected to receive as an input the output of second divider means and operative to provide a plurality of outputs each representative of theta being in a different predetermined sector; each of said second and third attenuator means comprising a plurality of resistors equal in number to the plurality of outputs of said cos theta shift register and logic means; a plurality of additIonal gate means (Q3-Q10) each connected in series with one of said resistors said additional gate means being responsive to said plurality of outputs of said cos theta shift register and logic means (252) to connect selected ones of said resistors to a final output line whereby said composite signal is attenuated in accordance with the aspect angle theta as well as with the pulse length T.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |