APPARATUS FOR INDICATING THE DIRECTION TO A SOUND PULSE SOURCE

• US 3,723,962 A
• Filed: 10/09/1970
• Issued: 03/27/1973
• Est. Priority Date: 10/09/1970
• Status: Expired due to Term

• Current Assignee: Fred Hotchner
• Original Assignee: Fred Hotchner
• Inventors: Hotchner, Fred
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US05/079,493
• Time in Patent Office: 900 Days
• Field of Search: 340/8FT,8L,6R,16R 181/.5ED,.5R,26,27R
• US Class Current: 181/125
• CPC Class Codes: G01S 3/8055 adjusting orientation of a single directivity characteristic to produce maximum or minimum signal

Abstract

Apparatus including a reflector constituting a part of a spherical, cylindrical or other concave reflecting surface and a thin film detector of concentric or flat planar shape located in the focusing zone of the reflector between the center of curvature and the reflecting surface. The detector is provided with means, such as a high cracking lacquer coating which will be fractured in the focal zone of the sound pulse, to provide a line-of-sight locating point which, in a three-element device, is combined with the center of curvature of the reflector to give the line-of-sight direction to the source of the sound pulse, the focal point for any sound source falling on a line drawn through the center of curvature of the reflector to that source. Instead of the center of curvature, means indicating a line or plane therethrough may be used with the lacquer fracture point to determine the direction to the sound source. In a two-element device the detector may comprise a photographic film on which there appears an inverted image of the field of view whereby the location of the fracture point on the image indicates the direction to the sound source, in which case the center of curvature and the line or plane therethrough are unnecessary.

Claims

1. Apparatus for detecting an acoustic pulse originating within an elected field of view and for indicating the line-of-sight direction from the apparatus to the source of the pulse, said apparatus comprising:

a reflector having a reflecting surface concave toward the field of view, and adapted to collect energy from the wave front of an oncoming pulse and reflect the collected energy from said reflecting surface to converge toward a focal area transverse to the axis of the projected energy and general to all such energy;

a thin diaphragm detector disposed in said general focal area and adapted to render intelligent response to the incidence thereon of any such convergent energy thereby to indicate the direction to the source within the field of view by the position of the area of such incidence on said detector; and

a pressure sensitive surface on said diaphragm markable by the incidence thereon of said convergent energy, said pressure sensitive surface being formed of a low-adhesion, high cracking lacquer on a supporting film, said lacquer off-flaking at the focal area of the reflected energy to mark the area of said incidence.

2. The apparatus defined in claim 1 including:

an image of at least a portion of the field of view on said supporting film and correlated to said reflector and receptor means so that the position of the off-flake area on the image directly indicates the direction to the pulse source.

3. The apparatus defined in claim 1 including:

an indicator of the center of curvature of said reflector whereby alignment of the off-flake area with the indicator gives the line-of-sight to the pulse source.

4. The apparatus defined in claim 3 in which:

said reflector and said detector means are transparent to permit alignment of the off-flake area with the indicator by direct visual observation from the convex side of the reflector.

5. The apparatus defined in claim 1 in which:

said lacquer is substantially opaque;

means on said lacquer which is luminescent under light which is invisible to the human eye; and

means for illuminating said luminescent means, whereby said off-flaking removes the luminescent means thereat to make the area of said incidence appear as a hole through the luminescent means.

6. Apparatus for detecting the occurence of an acoustic pulse within an elected field of view and for indicating the line-of-sight direction from the apparatus to the source of the pulse, said apparatus comprising:

an acoustic reflector having an arcuate concave surface fixed in a direction facing the elected field, and adapted to collect energy from the acoustic pulse and reflect and converge said collected energy toward a focal area lying along a straight line which extends through the center of curvature of said arcuate surface and the source of the pulse; and

a detector in said focal area and having means responsive to the incidence of said converged energy reflected from said arcuate surface to provide a visual indication on said detector of the location of said focal area, whereby an observer can locate the line-of-sight direction from the apparatus to the pulse source by visually aligning the center of curvature of the arcuate surface with the indicated focal area on said detector.

7. The apparatus defined in claim 6 in which:

said detector comprises a thin diaphragm having a pressure sensitive surface which is marked by the incidence thereon of the convergent energy.

8. The apparatus defined in claim 7 in which:

said pressure sensitive surface is composed of a low-adhesion, high cracking lacquer on a supporting film, said lacquer off-flaking at the focal area of the reflected energy to mark the area of said incidence.

9. The apparatus defined in claim 8 including:

an inDicator of the center of curvature of said reflector whereby alignment of the off-flake area with the indicator gives the line-of-sight to the pulse source.

10. The apparatus defined in claim 9 in which:

said reflector and said detector means are transparent to permit alignment of the off-flake area with the indicator by direct visual observation from the convex side of the reflector.

11. Apparatus for detecting an acoustic pulse originating within an elected field of view and for indicating the direction to the source thereof, said apparatus comprising:

transparent receptor means having a reflecting surface concave toward the field of view and adapted to collect acoustic energy from the wave front of an opening pulse and to project such energy in a beam convergent to an individual focal region contained within a general focal region positioned between the center of reflector curvature and the reflector and extending transverse to the axes of all such so focused beams;

transparent pressure sensitive detector means positioned within and coextensive with said general focal region and adapted to render visual response to the incidence thereon of any such so focused beam, said response corresponding inversely in position to the position of the pulse source within the field of view;

an indicator at the center of curvature of said reflector visible through both said detector and said receptor;

said detector being positioned in the pathway of direct pulses from the source and being of such permeability thereto as to transmit a high percentage of the energy thereof to said reflector; and

said detector being of relatively low marking response characteristic to such direct pulses, and high marking response characteristic to the focused beams from the reflector, whereby upon the reception of a pulse from the field of view a distinct visible mark is produced thereby on said detector which mark is in the line of sight through said receptor, said detector, and through the center of curvature of said reflector directly to the position of the source of the pulse.

12. Apparatus for detecting an acoustic pulse originating within an elected field of view, and for indicating the direction to the source thereof, said apparatus comprising:

receptor means having a reflecting surface concave toward the field of view and adapted to collect acoustic energy from the wave front of an oncoming pulse and to project such energy into a beam convergent toward an individual focal region contained within a general focal region located between the center of curvature of said reflector and said reflecting surface, and extending transverse to the axes of all such so focused beams;

detector means positioned within and coextensive with said general focal region and comprising a thin diaphragm having a pressure sensitive surface adapted to display a visible marking over the area of incidence thereon of any such so convergent beam, said marking corresponding inversely in position on said detector to the field position of the source within the field of view;

said detector being positioned in the pathway of direct pulses from the source and being of such characteristic thereto as to pass a high percentage of the energy thereof to said reflector;

said detector being of relatively low marking response characteristic to such direct pulses from the source and high marking response characteristic to such so focused beams from said reflector; and

sighting means establishing a line of sight through any such marking on said detector and through the center of curvature of said reflector, whereby upon the reception of an acoustic pulse from the field of view, an operator of the apparatus can obtain a direct line-of-sight to the field position of the source by aligning said marking on said detector and the center of curvature of said reflector.

13. The apparatus defined in claim 12 in which:

said pressure sensitive surface is composed of a low-adheSion, high-cracking lacquer on a supporting film, said lacquer being adapted to off-flake at the focal area of said convergent beam to mark the area of such incidence.

14. The apparatus defined in claim 13 including:

an image of at least a portion of the field of view on said supporting film which image is correlated to said reflector and said center of curvature of said reflector so that the position of the off-flake area on the image directly indicates the direction to the pulse source.

15. The apparatus defined in claim 13 in which:

said receptor and said detector means are transparent to permit alignment of the off-flake area of said diaphragm with said indicator by direct visual observation from the convex side of said reflector.

16. The apparatus defined in claim 13 in which:

said lacquer is substantially opaque;

means on said lacquer which is luminescent under light which is invisible to the human eye; and

means for illuminating said luminescent means;

whereby said off-flaking removes the luminescent means thereat to make the area of said incidence appear as a hole through the luminescent means.

17. The apparatus defined in claim 12 in which:

the reflecting surface of said receptor is of cylindrical contour concave toward the field of view and said sighting means comprises an indicator positioned at the axis of curvature thereof thereby to establish a plane of sight through said detector marking to, and cutting, the field position of the source of the pulse.

18. Apparatus for detecting an acoustic pulse originating within an elected field of view and for determining a lineation across the field cutting the position of the source of the pulse, said apparatus comprising:

receptor means having a substantially cylindrical reflecting surface concave toward the field of view and adapted to collect acoustic energy from the wave front of an oncoming pulse and to project such energy in a beam convergent to a linear focal region contained within a general focal region positioned between the axis of curvature of said reflector and said reflecting surface, and extending transverse to all such so focused beams;

pressure sensitive detector means positioned within and coextensive with said general focal region and adapted to exhibit a visible linear response to the incidence thereon of any such so focused beam;

said lineation being parallel to the axis of curvature of said reflector and inversely corresponding in transverse position to the transverse position of the source within the field of view; and

sighting means having a linear ocular element and a linear objective element movable together between said detector and said reflector and angularly variable with respect to the instrument general axis, said optical elements being parallel to each other and to the axis of curvature of said reflector in any position, and all thereof are contained within a reference plane which extends radially from the axis of curvature of said reflector to said reflector surface, whereby upon the reception of an acoustic pulse from the field of view and the consequent appearance of such lineation on said detector, an operator of the apparatus can adjust said sighting means to align said optical elements with each other and with such lineation on said detector, thereby to attain a plane of sight direction to and cutting the field position of the source of the pulse.

19. The apparatus defined in claim 18 in which:

said receptor is configurated to afford an operator of the device an optically open region therepast through which region he may visually align said optical elements with each other and with any such marking on said detector from a position behind the convex side of said reflector.

20. Apparatus for detecting an acoustic pulse originating within an elected field of view and for rendering a graphic representation of the field position of the source thereof, said apparatus comprising:

receptor means having a reflecting surface concave toward the field of view and adapted to collect acoustic energy from the wave front of an oncoming pulse and to project such energy into a beam convergent toward an individual focal region contained within a general focal region positioned between the center of curvature of said reflector and said reflecting surface, and extending transverse to the axes of all such so focused beams;

pressure sensitive detector means disposed within and coextensive with said general focal region and adapted to exhibit a visual marking at the area of impingement thereon of any such so focused beams;

said detector being positioned in the pathway of oncoming pulses, and being of such high permeability thereto as to transmit a high percentage of the energy of pulses so intercepted directly to the reflector;

said detector being of relatively low mark-producing sensitivity to pulses oncoming from the source as compared to a high mark-producing sensitivity to the beams focused by the reflector; and

a graphic representation on said detector, each feature of which representation is inversely positioned thereon relative to the corresponding feature of the field of view by a reference line therebetween passing through the center of curvature of said reflector, whereby a pulse originating within the field of view produces a visible marking on said detector inversely related on said graphic representation to the field position of the pulse origin.

21. Apparatus for detecting an acoustic pulse originating within an elected field of view and for exhibiting a representation of the position of the source of such pulse on a photographic image of such field, said apparatus comprising:

receptor means having a reflecting surface concave toward the field of view and adapted to collect acoustic energy from the wave front of an oncoming pulse and to project such energy into a beam convergent toward an individual focal region contained within a general focal region positioned between the center of reflector curvature and the reflector and extending transverse to the axes of all such so focused beams;

pressure sensitive detector means positioned within and coextensive with said general focal region and bearing an inverted photographic image of the field of view to which the apparatus is aimed;

each feature of which photographic image is in alignment through the center of curvature of said reflector with the corresponding feature of the field of view;

said detector being adapted to exhibit a distinct marking at the area of impingement thereon of any beam so focused by said reflector, which marking is indicative in position on said image of the field position of the source of the acoustic pulse;

said detector being positioned within the pathway of direct pulses from the source and being of such permeability thereto as to transmit a high percentage of the energy thereof to said detector; and

said detector being of relatively low marking response characteristic to such direct pulses from the source and high marking response characteristic to the focused beams from the reflector.

22. Apparatus for detecting an acoustic pulse originating within an elected field of view and for indicating the direction to the source thereof, said apparatus comprising:

transparent receptor means having a reflecting surface concave toward the field of view and adapted to collect acoustic energy from the wave front of an oncoming pulse and to project such energy into a beam convergent toward an individual focal region contained within a general focal region positioned between the center of curvature of said reflector and reflector surface, and extending transverse to the axes of all such so focused beams;

transparent pressure sensitive detector means positioned within and coextensive with said general focal region and adapted to render visible marking response to the incidence thereon of any such so focused beam, said marking correspondinG inversely in detector position to the field position of the causative source thereof; and

sighting means bearing an ocular element and an objective element movable together between said reflector and said detector, and angularly variable with respect to the instrument general axis, said optical elements being in alignment with each other on a line from the center of curvature of said reflector radially to said reflector surface in any position, whereby, upon the reception of a pulse from the field of view, an operator of the apparatus can obtain a direct line of sight to the field position of the source of the pulse by sighting through the receptor and manually aligning said optical elements with each other and with the resultant marking on said detector.

23. Apparatus for detecting the occurrence, and for locating the position, of the source of an acoustic pulse originating within an elected field of view, said apparatus comprising:

an acoustic reflector of substantially spherical contour positioned with its concave surface toward said field and projective of the energy of a received pulse into a beam convergent toward a focal region residing along a line-of-sight extending through the center of curvature of said reflector directly to the position of the source for all source positions within said field; and

means enabling an operator of the apparatus to locate said line-of-sight without moving the position of said reflector.

24. Apparatus for detecting the occurrence, and for locating the position, of the source of an acoustic pulse originating within an elected field of view, said apparatus comprising:

an acoustic reflector of substantially cylindrical contour positioned with its concave surface toward said field and projective of the energy of a received pulse into a beam convergent toward a linear focal region residing along a plane of sight extending through the axis of curvature of said reflector to and cutting the position of the source for all source positions within said field; and

means enabling an operator of the apparatus to locate said plane of sight without moving the position of said reflector.