Patent Publication Number: US-2013241762-A1

Title: Light-beam scanning for laser radar and other uses

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of U.S. Provisional Application No. 61/612,027, filed on Mar. 16, 2012, and U.S. Provisional Application No. 61/659,798, filed on Jun. 14, 2012, both of which are incorporated herein by reference in their respective entireties. This application is also related to U.S. patent application Ser. No. 13/840,093, entitled “Beam Steering for Laser Radar and Other Uses,” filed concurrently with the present application and incorporated herein by reference. 
    
    
     FIELD 
     The disclosure pertains to, inter alia, imparting a scanning or sweeping motion to a beam of light, particularly to a substantially collimated beam such as a laser beam. The devices and methods disclosed herein can be used, for example, to impart a scanning or sweeping motion to an interrogation beam produced by a laser radar system. 
     BACKGROUND 
     Various applications have been developed for using substantially collimated beams of light that are directed onto the surface of a object. One application, called laser radar, involves directing a laser beam to an object or site called a “target” herein. Laser radar (also called “LIDAR” or “LADAR”) is a remote-sensing technique used for measuring distance to and/or surface properties of a target by illuminating the target surface with light pulses produced by a laser. Laser radar systems are particularly useful for inspection applications in which large objects or complex surfaces are to be measured such as in the manufacture and assessment of aircraft, automobile, wind turbine, satellite, marine, and other oversized parts. Some conventional laser radar systems are described in the following U.S. Pat. Nos. 4,733,609; 4,824,251; 4,830,486; 4,969,736; 5,114,226; 7,139,446; and 7,925,134; and in Japan Patent No. 2,664,399, all of which are incorporated herein by reference to the fullest extent allowed by law. In these conventional laser radar systems, a laser beam (called an “interrogation beam”) is directed to and scanned over a region of the target surface. Portions of the interrogation beam that are reflected or scattered back from the target to the laser radar system are detected, and the resulting signals are processed to produce usable information about the target. 
     Referring to  FIG. 11 , a conventional laser radar system  250  typically comprises the following subsystems: (a) a source  252  of a laser beam  253  or other substantially collimated light beam, (b) a beam-shaping optical system  254  that receives the beam  253  from the source and directs, shapes, and focuses the beam into an interrogation beam  255 , (c) a sending optical system  256  that directs the interrogation beam  255  to a target  258 , (d) a scanning device  260  that imparts motion to the beam-shaping optical system  254  and sending optical system  256  so as to scan the interrogation beam over a selected region on the target surface (beam scanning is usually one or both of azimuth and elevation), (e) a receiving optical system  262  that receives light  257  (from the interrogation beam  255 ) reflected from the target back to the system  250  (the receiving optical system  262  includes a photodetector, not detailed, that produces an electronic signal corresponding to the received light  257 ), and (f) a signal-processing system that converts the signal from the photodetector into usable data concerning the scanned region of the target. The beam-shaping optical system  254  and sending optical system  256  collectively have large mass, which limits the rate at which the scanning device  260  can move them, particularly if the motion is a periodic motion. I.e., the maximum achievable beam-scanning rate is adversely affected by the mass that must be moved by the scanning device  260 . The resulting compromised scanning rate can limit the rate at which the system  250  produces information about the target. 
     Therefore, there is a need for beam-scanning systems of which the mass that is actually moved to achieve scanning of the beam is substantially less than in conventional systems, and hence are less limited in the rates at which the beam can be moved in a scanning manner. 
     SUMMARY 
     A first aspect of this disclosure pertains to optical systems that impart a scanning motion to a light beam. An exemplary embodiment of such a system comprises a beam-shaping optical system including a first movable optical element and a second movable optical element. The first optical element forms and directs an optical beam along a nominal propagation axis from the beam-shaping optical system to a target. The second optical element includes a respective actuator by which the second optical element is movable relative to the first optical element. A controller is coupled at least to the actuator of the second optical element and is configured to induce the actuator to move the second optical element. This motion of the second optical element moves the optical beam, as incident on the target, relative to the nominal propagation axis. This particular configuration allows the second optical element to be moved by itself, as induced by its actuator, to produce, for example, a fine scanning motion of the light beam relative to the nominal propagation axis. Meanwhile, the first optical element can be moved by a separate actuator to change the focus of the optical beam. 
     The optical system may also be coupled to one or more additional actuators that are energized as required to set the nominal propagation axis with desired elevation and/or azimuth. The additional actuator(s) can be operated to provide time-variant elevation and/or azimuth, thereby producing, for example, a large-scale scanning motion of the nominal propagation axis (and thus of the optical beam). Meanwhile, the second optical element can be moved by its actuator to produce a fine-scan motion of the optical beam relative to the nominal propagation axis. Further meanwhile, the first optical element can be moved by its actuator as required for beam shaping during all these scanning motions of the optical beam. These motions desirably are controlled by a controller to ensure their good coordination. The additional actuator(s) providing azimuth and/or elevation can operate separately from operation of the actuator of the first optical element and from operation of the actuator of the second optical element. These coordinated motions of the optical beam are particularly applicable to laser radar systems. 
     With these systems, the first optical element directs the beam to the target but does not need to be moved to produce scanning motions of the beam on the target. Rather, scanning motions are achieved by moving the second optical element. This movement of the second optical element is independent of motion of the first optical element. 
     In some embodiments the first and second optical elements are respective reflective optical elements. The first optical element can comprise a corner cube situated to receive the optical beam from a light source. Meanwhile, the second optical element can be situated to receive the optical beam from the corner cube and can be configured to return the beam to the corner cube as the second optical element is being moved by its actuator relative to the corner cube. 
     In other embodiments, the first optical element is a reflective optical element and the second optical element is a refractive optical element. For example, the first optical element can comprise a corner cube situated to receive the optical beam from a light source. Meanwhile, the second optical element is situated to receive the optical beam from the corner cube and configured to direct the beam to the target, even as the second optical element is being moved by its actuator relative to the corner cube to move the beam relative to the nominal propagation axis. This motion of the optical beam imparted by corresponding motion of the second optical element can be effectively a fine-scanning motion of the optical beam in a designated region of a target. 
     In yet other embodiments the first optical element comprises a corner cube situated to receive the optical beam from a light source. Meanwhile, the second optical element is situated to receive the optical beam from the corner cube and is configured to return the beam to the corner cube as the second optical element is being moved by its actuator relative to the corner cube to move the beam relative to the nominal propagation axis. For example, the actuator of the second optical element can be configured to move the beam by correspondingly tilting the second optical element relative to the corner cube. 
     In yet other embodiments the first optical element comprises a corner cube situated to receive the optical beam from a light source. Meanwhile, the second optical element comprises a refractive optical element that is situated to receive the light beam from the corner cube and is configured to direct the beam toward the target as the second optical element is being moved by its actuator relative to the corner cube to move the beam relative to the propagation axis. By way of example, the second optical element can be configured by its actuator to move substantially laterally to the nominal propagation axis. 
     In yet other embodiments the first optical element comprises a reflective optical element that receives the optical beam and reflects the beam toward the target. Meanwhile, the second optical element comprises a terminus of a flexible light conduit, such as an optical fiber, directing the optical beam to the first optical element. The terminus is coupled to the actuator, which is configured to move the terminus relative to the first optical element to move the beam relative to the nominal propagation axis. 
     Various embodiments summarized above can further comprise a transmitting system and a receiving system. The transmitting system is coupled to the processor and includes a light source, wherein the transmitting system produces and delivers at least one optical beam to the beam-shaping optical system. The receiving system is coupled to the processor and is configured to receive light, of the light beam, reflected from the target, and to determine a characteristic of the target based on the received light. 
     The system can further comprise a primary beam scanner and a secondary beam scanner. The primary beam scanner directs the optical beam, from the beam-shaping optical system, toward the target. Meanwhile, the secondary beam scanner comprises the beam-shaping optical system summarized above. 
     In these various embodiments the beam-scanning device can have as few as one movable optical element, which can be refractive or reflective optical element. The single optical element can be moved more quickly, more reliably, more accurately, and more efficiently to produce a desired scanning motion of the interrogation beam, compared to conventional systems. 
     Another aspect of this disclosure is directed to devices for scanning a substantially coherent light beam, as an interrogation beam, over a region of a target. An embodiment of such a device comprises a beam-shaping optical system configured to direct the interrogation beam along a nominal propagation axis to the region. The beam-shaping optical system comprises at least one adjustably situated optical element configured to vary a direction of the nominal propagation axis. A controller, coupled to the first adjustably situated optical element, is configured to establish an interrogation-beam scan path based upon an adjustment of the adjustably situated optical element. The beam-shaping optical system can further comprise a multiple-element lens configured to focus the interrogation beam in the region. The adjustable optical element comprises a lens element of the multiple-element lens, wherein the lens element is displaceable relative to an axis of the multiple-element lens. 
     The beam-shaping optical system can further comprise a lens configured to focus the interrogation beam in the region, and a return-reflective surface situated on a lens axis and configured to direct a light beam to the lens, wherein the return-reflective surface comprises the adjustable optical element. By way of example, the return reflective surface is tiltable with respect to the lens axis. The return reflective surface can be, for example, a mirror surface. 
     In other embodiments the beam-shaping optical system comprises a lens configured to focus the interrogation beam in the region and an optical fiber situated and configured to conduct light to the lens. In these configurations the adjustable optical element can be a terminus of the optical fiber, wherein adjustment of the fiber terminus end is a displacement of the fiber terminus relative to the lens axis. 
     Some embodiments further comprise an optical receiving system situated and configured to receive at least portions of the interrogation beam from the target. A processor can be coupled to the optical receiving system and configured to estimate at least one target range based on the received portions and the interrogation beam scan path. 
     In embodiments in which the beam-shaping optical system includes a beam-focusing lens, the adjustable optical element can comprise a prism situated to transmit the interrogation beam along the varying axis. 
     A beam-shaping optical system can include at least one adjustably situated optical element configured to vary the direction of the nominal propagation axis. A beam-scan controller can be coupled to the at least one adjustably situated optical element and be configured to establish a scan path for the interrogation beam based on the orientation of the beam-shaping optical system and on an adjustment of the at least one adjustably situated optical element. In some examples, the beam-shaping optical system includes a multi-element lens configured to focus the interrogation beam, wherein the adjustably situated optical element is an adjustable lens element of the multi-element lens. In representative examples, adjustment of the adjustably situated optical element includes displacing the adjustable lens element of the multi-element lens relative to a lens axis. 
     The beam-shaping optical system in various embodiments includes: (a) a lens configured to focus the interrogation beam and (b) a return-reflective surface situated on a lens axis and used so to direct an optical flux to the lens. In these embodiments the adjustably situated optical element can be the return-reflective surface (e.g., a mirror surface or a prism surface). Adjustment of the return-reflective surface can comprise tilting the surface relative to the lens axis. In other examples, the beam-shaping optical system includes: (a) a lens configured to focus the interrogation beam, and (b) an optical fiber coupling optical radiation to the lens. In these embodiments the adjustably situated optical element can be an optical-fiber end, wherein adjustment of the fiber end produces a displacement of the fiber end relative to the lens axis. In further examples, an optical receiver is configured to receive, from the target, at least portions of the interrogation optical beam. A processor coupled to the optical receiver estimates at least one target range or other target characteristic based on the received portions and on the scan path of the interrogation beam. 
     Another aspect of this disclosure is directed to methods, of which representative embodiments comprise establishing a scan direction of the interrogation beam using a primary scanner configured to selectively orient a beam-shaping optical system. The established beam-scan direction can be varied based on an adjustment of at least one optical element of the beam-shaping optical system so as to establish a scan path. In some embodiments, adjustment of the at least one optical element of the beam-shaping optical system comprises displacing a lens element of a lens configured to focus the shaped optical beam. Adjusting the at least one optical element of the beam-shaping optical system can comprise tilting a reflective surface that directs the shaped interrogation beam along a lens axis. In other examples, adjusting the at least one optical element of the beam-shaping optical system comprises displacing a fiber end associated with a fiber portion that routes optical radiation into the beam-shaping optical system. In further representative embodiments, the shaped optical beam is directed to a target. One or more characteristics of the target surface are determined based on a portion of the shaped interrogation beam that reflects from the target along a scan path. At least one of target distance or other target characteristic is associated with the scan path. 
     In some examples, an image of at least a portion of the target is formed based on a plurality of distances determined along the scan path of the interrogation beam. The distances correspond to a respective plurality of target locations. In still other examples, the beam-scan direction produced by the primary scanner is based on portions of the shaped interrogation beam received along the scan path from the target. 
     Exemplary apparatus comprise a beam-forming optical system configured to produce an interrogation beam that is focused at a target. A primary scanner determines a primary path of the interrogation beam based on the pointing direction of the beam-forming optical system. A secondary scanner can be configured to produce a scan path relative to the pointing direction. In some representative embodiments, the beam-shaping optical system includes a multi-element lens for focusing the interrogation beam. A secondary scanner can be configured to establish a scan path by displacing at least one element of the multi-element lens relative to a lens axis. In other examples, the beam-shaping optical system includes a beam-focusing lens and an optical fiber. The optical fiber is situated to deliver optical radiation from a radiation source to the beam-focusing lens to produce the focused interrogation beam. The secondary scanner displaces an end of the optical fiber relative to a lens axis of the beam-focusing lens to establish the scan path of the interrogation beam. In other examples, the beam-shaping optical system includes a beam-focusing lens and a return reflector. The beam-focusing lens and return reflector reflect a beam of optical radiation from a radiation source to the beam-focusing lens to produce the focused optical beam. The secondary scanner tilts the return reflector relative to a lens axis of the beam-focusing lens to establish the scan path of the interrogation beam. The beam-shaping optical system can include a beam-focusing lens and a wedge prism situated along an axis of the beam-focusing lens. In these examples the secondary scanner is configured to rotate the wedge prism relative to the lens axis to establish the scan path. A processor can be used to produce a surface map or determine other characteristics of a target based on portions of the focused interrogation beam that return along the scan path and are analyzed by the processor. 
     The foregoing and other features and aspects of the disclosed technology are set forth below with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a portion of laser radar system that includes an optical system configured to scan a laser beam (interrogation beam) over a region of interest on a target object (“target”). 
         FIGS. 2A-2B  illustrate a mirror configured to perform scanning of the interrogation beam. 
         FIG. 3  is a schematic diagram illustrating a fiber support that scans the interrogation beam by displacing a fiber held by the fiber support. 
         FIG. 4  is a block diagram of a laser radar system that includes a lens element that can be displaced to produce a corresponding scan of the interrogation beam. 
         FIG. 5  is a block diagram of a method for evaluating a target using a scanned interrogation beam. 
         FIG. 6  is a schematic diagram of an optical radar or optical tracking system that includes a primary beam scanner and a secondary beam scanner. 
         FIG. 7  illustrates a secondary beam scanner that scans a beam based on a corresponding displacement of a holographic optical element or a Fresnel lens. 
         FIG. 8  is a block diagram of a representative method for tracking a tooling ball that is secured to a substrate or target. 
         FIG. 9  is a block diagram of a representative manufacturing system that includes a laser radar or other profile-measurement system, wherein the manufacturing system is used for manufacturing workpieces and for assessing whether the manufactured workpieces are defective or acceptable. 
         FIG. 10  is a block diagram of a representative manufacturing method that includes profile measurement for determining whether manufactured workpieces are acceptable, and if the manufactured workpieces are unacceptable whether any of them can be repaired. 
         FIG. 11  is a schematic diagram of a conventional laser radar system. 
     
    
    
     DETAILED DESCRIPTION 
     The invention is described below in the context of representative embodiments that are not intended to be limiting in any way. 
     As used in this application and in the claims, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the term “includes” means “comprises.” Further, the term “coupled” does not exclude the presence of intermediate elements between the coupled items. 
     The systems, apparatus, and methods described herein should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and non-obvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The disclosed systems, apparatus, and methods are not limited to any specific aspect or feature or combinations thereof, nor do the disclosed systems, apparatus, and methods require that any one or more specific advantages be present or problems be solved. Any theories of operation are to facilitate explanation, but the disclosed systems, methods, and apparatus are not limited to such theories of operation. 
     Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed systems, methods, and apparatus can be used in conjunction with other systems, methods, and apparatus. Additionally, the description sometimes uses terms like “produce” and “provide” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms will vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art. 
     In the following description, certain terms may be used such as “up,” “down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to a target or other object, an “upper” surface can become a “lower” surface simply by turning the target over. Nevertheless, it is still the same object. 
     The systems, apparatus, and methods described herein should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and non-obvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The disclosed systems, methods, and apparatus are not limited to any specific aspect or feature or combinations thereof, nor do the disclosed systems, methods, and apparatus require that any one or more specific advantages be present or problems be solved. Any theories of operation set forth herein are to facilitate explanation; but, the disclosed systems, methods, and apparatus are not limited to such theories of operation. 
     Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed systems, methods, and apparatus can be used in conjunction with other systems, methods, and apparatus. Additionally, the description sometimes uses terms like “produce” and “provide” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms will vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art. 
     For convenience in the following description, the terms “light” and “optical radiation” refer to propagating electromagnetic radiation that is directed to one or more targets or other loci to be profiled, detected, or otherwise investigated. Such radiation can be referred to as propagating in one or more “beams” that typically are based on optical radiation produced by a laser. In addition, such beams can have a spatial extent associated with one or more laser transverse modes, and can be substantially collimated and/or focused. As used herein, a beam having a wavelength λ is “substantially collimated” if an associated beam divergence (or convergence) angular diameter β is less than about 0.05, 0.01, or 0.005. In some examples, a substantially collimated beam has a divergence or convergence such that a ratio of a beam diameter at a target to a beam diameter as emitted to the target is less than 2:1, 1.5:1 or 1.2:1. Alternatively, collimation can be associated with beams such that a source-to-target distance is less than about 0.5, 1.0, 2.0, or 4.0 times a Rayleigh range associated with the beam. 
     For convenience, beams are described as propagating along one or more axes. Such axes generally are based on one or more line segments so that an axis can include a number of non-colinear segments as the axis is bent or folded or otherwise responsive to mirrors, prisms, lenses, and other optical elements. The term “lens” is used herein to refer to a single refractive optical element (a singlet) or a compound lens that includes one or more singlets, doublets, or other elements. In some examples, beams are shaped or directed by refractive optical elements; but, in other examples, reflective optical elements such as mirrors are used, or combinations of refractive and reflective elements are used. Such optical systems can be referred to as dioptric, catoptric, and catadioptric, respectively. Other types of refractive, reflective, diffractive, holographic and other optical elements can be used as may be convenient. 
     Some described embodiments include a corner cube used as part of the beam-shaping system. For convenient illustration, such corner cubes are shown in some figures as two reflectors having reflective surfaces oriented at 90° to each other. 
     Relevant portions of a first representative embodiment of an optical system  100  particularly suitable for use as a laser radar system are illustrated in  FIG. 1 . The denotation “laser radar system” will be understood to encompass not only laser radar systems per se but also any of various other optical systems that project one or more optical beams to a target while providing scanning motion to the projected beam(s). An optical fiber  102  includes an emitter surface  104  that emits an optical beam  106  to a corner cube  108 . The optical beam  106  is substantially collimated and destined to become a laser-radar “interrogation beam.” The optical fiber  102  is typically coupled to a transmitting (TX) system  103  via a beam splitter  105 . The transmitting system  103  typically includes one or more lasers or other suitable light sources (not shown in  FIG. 1 ). The corner cube  108  is mounted on a movable translation device, described below, for purposes of shaping and focusing the beam into an interrogation beam. Scanning motion of the interrogation beam is achieved by a scanning device that is separate from the corner cube and from the translation device and that does not rely upon movement of the corner cube to achieve beam scanning. 
     It is generally convenient to select the optical fiber  102  and the wavelength of the light beam such that the beam emitted by the optical fiber  102  propagates in a lowest-order mode of the fiber. Alternatively, in some embodiments, higher-order modes can be used. 
     The optical system of  FIG. 1  can also be configured to produce an alignment beam in a similar manner as the interrogation beam. By way of example, the optical fiber  102  can be single-mode at about 1550 nm so that a 1550-nm beam destined to be the interrogation beam propagates through the optical fiber in a single, lowest-order mode, while a visible-wavelength beam destined to be the alignment beam propagates through the optical fiber in multiple (but nevertheless few) modes. A receiving (RX) system  107  is coupled to the optical fiber  102  via the beam splitter  105 . The beam splitter  105  as shown is configured as a cubic beam splitter; alternatively, beam splitting can be achieved using one or more other components such as, but not limited to, fiber couplers. 
     The optical beam  106  emitted from the optical fiber  102  propagates to the corner cube  108 , diverging at an angle that is based on approximately the numerical aperture of the optical fiber. The corner cube  108  directs the optical beam  106  to a return reflector  110 , which produces therefrom a reflected beam  109   a  destined to be the interrogation beam  109   b . The reflected beam  109   a  exits the corner cube  108  and propagates (as the interrogation beam  109   b ) along a nominal propagation axis  112  (parallel to, for example, a Cartesian z-axis) to a beam-shaping lens  114 . The nominal propagation axis  112  can be bent or folded and hence is generally not a single straight line. 
     As noted, the corner cube  108  is mounted on a translation device (e.g., a stage or the like)  118  that is movable under the control of a focus controller (“focus adjust”)  120 . By way of example, the translation device  118  in  FIG. 1  is movable in at least the z-direction (i.e., direction of the nominal propagation axis  112 ; see arrows  111 ). Such motion of the translation device  118  is as directed by the focus controller  120  and serves to focus the interrogation beam  109   b  onto a target  133 . 
     A controller (“control logic”)  101  is coupled to the transmitting system  103 , the receiving system  107 , the focus controller  120 , and a tilt controller  128  (described below). The controller  101  is configured (e.g., by software programming) to perform various functions, such as but not necessarily limited to: (a) correcting certain optical characteristics of the interrogation beam  109   b ; (b) processing signals from one or more of the transmitting system  103 , the receiving system  107 , the focus controller  120 , and the tilt controller  128 ; (c) adjusting focus of the interrogation beam  109   b ; and (d) tilting the return reflector  110  as required to impart a scanning motion of the interrogation beam. The tilt controller  128  is discussed later below. 
     In this embodiment the return reflector  110  is a portion of a beam-scanning device that scans or sweeps the interrogation beam independently of any motion of the translation device  118 . This scanning or sweeping of the beam is the result of correspondingly tilting the beam, wherein beam tilting is achieved by correspondingly controlled tilting motions of the return reflector  110 . Tilting the return reflector  110  in a controlled manner produces a scanned interrogation beam  109   b  as follows: As shown in  FIG. 1 , actuators  124 ,  125  are situated relative to the return reflector  110  so as, when the actuators are energized, to tilt the reflector  110  in a controlled manner about one or more tilt axes (not shown). The tilt axes are typically perpendicular to the nominal propagation axis  112 . For example, in some embodiments, if the translation device  118  is movable along the z-axis, the tilt axes are the x-axis and y-axis. The actuators  124 ,  125 , are coupled to the tilt controller  128  which is coupled to and under the control of the controller  101 . The tilt controller  128  produces actuator-energization impulses according to control signals produced by the controller  101 . Thus, the return reflector  110  is controllably tilted about its tilt axis (or axes) as required to direct the interrogation beam  109   b  to propagate along tilt propagation axes  129  (one such axis is shown). During beam scanning the tilt propagation axis  129  correspondingly changes relative to the nominal propagation axis  112 . As a result, the interrogation beam  109   b  assumes a scanning displacement according to a selected scan pattern SP as the interrogation beam is incident on the target  133 . Light returning from the target propagates through the lens  114  and optical fiber  102  to the beam splitter  105  to the receiving system  107 , which includes at least one detector. 
     In this embodiment the transmitting system  103 , optical fiber  102 , corner cube  108 , and beam splitter  105  are components of a “beam-producing system.” The corner cube  108 , focus controller  120 , and beam-shaping lens  114  are components of a “beam-shaping system.” The return reflector  110 , actuated by the actuators  124 ,  125 , constitutes a “beam-steering device” (also called a “beam-scanning device”). Whereas the beam-shaping system forms, shapes, and sends the interrogation beam to the target  133 , the beam-steering device moves the beam in a scanning or sweeping manner as required for interacting with a target  133 . The beam-steering device and beam-shaping system typically operate concurrently, but they can operate separately. 
     One or more encoders such as encoder  126  can be provided for measuring the tilt of the return reflector  110 . By coupling the encoder(s)  126  to the controller  101 , closed-loop adjustments of tilt of the return reflector  110  can be performed, as controlled by the controller  101 . In some embodiments only a single actuator (e.g., item  124 ) is provided, rather than both actuators  124 ,  125 , wherein a single actuator tilts the interrogation beam  109   b  on only a single axis rather than on two axes. Two actuators  124 ,  125  produce scanning of the interrogation beam  109   b  on two axes (e.g., x- and y-axes). 
     The actuators  124 ,  125 , depending upon their configurations, tilt the reflector  110  in various respective ways. In some embodiments the actuators are configured as respective galvanometers that, when energized by the tilt controller  128 , cause the return reflector  110  to tilt at periodic respective repetition rates (which can be the same or different). In other embodiments the tilt controller  128  commands the actuators  124 ,  125  to produce aperiodic scanning tilts of the return reflector  110 . In yet other embodiments the return reflector  110  is tilted according to a raster, a spiral, or a W-shaped scan pattern SP. In any event, the return reflector  110  and its actuators  124 ,  125  are components of a beam-steering device. 
     The degree of scanning deflection of the return reflector  110  desirably is limited in one, two, or three dimensions. For example, in certain embodiments the return reflector  110  is located in a gap between opposing front and rear stops, as depicted generally in  FIGS. 2A and 2B . In such embodiments the return reflector  110  can be mounted in a three-point manner, for example, wherein each of three mounting points is independently positionable at or between corresponding “front” and “rear” stops, thereby allowing the return reflector to be moved repeatedly to any of multiple 3-D orientations. In these and other embodiments the positions of the return reflector  110  can be predetermined and the maximum tilts can be fixed, thereby possibly eliminating the need for position-sensor(s) for determining and/or monitoring scan positions of the return reflector  110 . The return reflector  110  can selectively be, at any moment in time, in one of a finite number of fixed positions that are measured and calibrated in advance. 
       FIG. 2A  illustrates a representative example of a return reflector  200  configured to be tilted, by an actuator  124 ,  125 , by any of various tilt angles (arrows  203 ) within predetermined tilt limits. The return reflector  200  has a reflective surface  202  and is secured by mounting points  204 ,  206  that are displaceable between a front stops  208   a ,  208   b  and rear stops  210   a ,  210   b . Scanning motion of the return reflector  200  is controlled so that, at a first tilt maximum (shown in  FIG. 2B ), the mounting point  204  contacts the front stop  208   a  as the mounting point  206  contacts the rear stop  210   b , while at a second tilt maximum the mounting point  204  contacts the front stop  208   b  as the mounting point  206  contacts the rear stop  210   a . Periodic scanning of the beam is achieved by moving the return reflector in a correspondingly periodic manner between the first and second tilt maxima.  FIG. 2A  depicts the return reflector  200  situated mid-way between the stops  208 ,  210  and thus midway between corresponding tilt maxima.  FIG. 2B  depicts the return reflector  200  at maximum “downward” tilt (arrow  203 ). This embodiment is simple and reliable for producing regular, periodic tilting motions of the reflector  200  upward and downward (in the figure) between the stops  208 ,  210 . A possible disadvantage is that the return reflector  200  is maximally tilted only to fixed, predetermined angles. (However, the distance between the stops  208 ,  210  can be made infinitely adjustable up to a maximum at which the mounting points  204 ,  206  no longer contact the stops  208 ,  210 . A key advantage of these embodiments is that, for producing a scanned interrogation beam, moving the return reflector  200  involves moving much less mass than moved in conventional laser radar systems. Hence, this embodiment achieves more rapid and more accurate beam scanning than a conventional laser radar system. 
     In an alternative embodiment, scanning motion of the interrogation beam is achieved by correspondingly displacing the end of an optical fiber conducting a laser beam destined to be the interrogation beam. In other words, this alternative embodiment does not require scanning motion of a return reflector to produce a scanned interrogation beam. If a return reflector (similar to item  110 ) is used together with a corner cube (similar to item  108 ), the return reflector can be stationary. 
     More specifically, the embodiment  300  shown in  FIG. 3  includes an optical fiber  302  (viewed end-wise). A first end (not visible) of the optical fiber  302  is coupled to receive a laser beam from a source (not shown, but see item  102  in  FIG. 1 ). Light of the laser beam propagates through the optical fiber  302  to the second end  302   a  of the optical fiber. From the second end  302   a , the beam enters the corner cube (not shown). The second end  302   a  (seen in the figure) of the optical fiber is mounted, relative to the first end, in a manner by which beam-scan-producing motions of the second end can be produced. The motion of the second end of the optical fiber changes the angle of the beam leaving the optical system, which changes the angle of the focus axis. This change in angle changes the location of the focused spot on the target, allowing the focused spot to be scanned across a target. The resulting interrogation beam propagating from the corner cube to the target exhibits corresponding scanning motion. Hence, the second end  302   a  effectively serves as an optical element, distinct from the corner cube, that is movable to produce scanning motions of the interrogation beam. 
     The second end  302   a  of the optical fiber  302  is secured by supports  304 ,  306 ,  308  to a support member  310 . In  FIG. 3  the supports extend radially relative to the second end  302   a , but this arrangement is not intended to be limiting. To produce motion of the second end  302   a  of the optical fiber  302 , sufficient for producing corresponding scanning motion of the interrogation beam as focused onto the target, respective piezoelectric actuators  314 ,  316 ,  318  are situated between the support member  310  and the respective supports  304 ,  306 ,  308 . The piezoelectric actuators  314 ,  316 ,  318  are coupled to a scan controller  320  configured (e.g., programmed) to deliver respective actuation potentials to the actuators  314 ,  316 ,  318 . The actuation potentials cause respective dimensional changes in the respective actuators. The net result of the dimensional changes is a corresponding displacement of the second end  302   a  as required to achieve the desired scanning motion of the interrogation beam exiting the second end  302   a . If desired, one or more displacement sensors (not shown) can be placed and utilized to produce data from which actual displacement of the second end  302   a  and/or of the interrogation beam can be calculated. The scan controller  320  can be configured to provide closed-loop control of interrogation-beam displacement, based on corresponding measured displacements of the optical fiber. 
     In the embodiment of  FIG. 3 , the second end  302   a  of the optical fiber as well as the actuators  314 ,  316 ,  318  controlling its position are components of a beam-steering device. 
     Turning now to  FIG. 4 , an optical system  400  is shown that is similar in some aspects to the embodiment shown in  FIG. 1 . Both embodiments deliver a beam of light via an optical fiber  102 ,  402 , respectively, from a respective beam splitter  105 ,  405 . The optical fiber  102 ,  402 , respectively, in each embodiment includes an emitter surface  104 ,  417 , respectively, that directs an optical beam  106 ,  419 , respectively, to a respective corner cube  108 ,  408 . In each embodiment the optical beam  106 ,  419 , respectively, is destined to become an interrogation beam. The optical fiber  102 ,  402 , respectively, in each embodiment is coupled to a respective transmitting (TX) system  103 ,  409  via the respective beam splitter  105 ,  405 . The transmit system  103 ,  409  typically includes one or more lasers or other suitable light sources (not shown) that produce respective one or more interrogation beams. 
     Continuing further with  FIG. 4 , the optical system  400  includes a beam-focusing lens  406 , which (in this embodiment) includes a rear negative lens  406 A and a front positive lens  406 B. One or both of the lenses  406 A,  406 B can be compound lenses such as cemented doublets or air-spaced lenses, if preferred. For producing scanning motion of the interrogation beam, the rear lens  406 A is coupled to a displacement mechanism such as an actuator  403  (e.g., a piezoelectric device or other suitable device). The actuator  403  displaces the rear lens  406 A laterally (perpendicularly to the nominal propagation axis  412 ), as directed by a displacement controller  424  to which the actuator  403  is coupled. By displacing the rear lens  406 A using the actuator  403 , a corresponding deflection of the interrogation beam is produced that causes the beam to propagate along an axis  414  that is not coincident with the axis  412 . Repetitive, periodic displacement of the rear lens  406 A in this manner produces a corresponding periodic deflection of the beam relative to the nominal propagation axis, which causes the interrogation beam to be repetitively scanned along an arc  430 , or according to another desired scan pattern, on the target  411 . 
     The  FIG. 4  embodiment differs from the  FIG. 1  embodiment principally in the means for scanning the interrogation beam. Both embodiments utilize an optical element that interacts with a beam destined to be the interrogation beam. In the  FIG. 1  embodiment the optical element is reflective, namely the return reflector  110  that is caused to tilt by the tilt actuators  124 ,  125 . In the  FIG. 4  embodiment the optical element is refractive, namely the rear lens  406 A that is caused to shift laterally by the actuator  403 . Although the rear lens  406 A can comprise multiple elements (e.g., a doublet or triplet), it is usually advantageous to specify the rear lens  406 A as a singlet to reduce as much as possible the mass to be displaced for scanning the interrogation beam. 
     The scanning motion of the interrogation beam imparted by corresponding displacement of the rear lens  406 A can be repetitive or variable. As shown in  FIG. 4 , the actuator  403  allows the rear lens  406 A to be displaceable in one dimension orthogonal to the nominal axis  412 . By adding a second actuator (not shown) situated and configured to produce movement of the rear lens  406 A along a second axis orthogonally to the nominal axis  412 , the interrogation beam can be displaced in a two-dimensional manner relative to the nominal axis  412  to provide two-dimensional scanning of the target  411 . In any event, displacement of the rear lens  406 A for scanning purposes can be detected and measured using a position sensor or displacement sensor  404 . The rear lens  406 A is not limited to a negative lens as shown; it alternatively can be, for example, a parallel plate. The scanning lens or scanning optics may have small refractive power, especially when the magnitude of tilt of the propagation axis  129  relative to the nominal propagation axis  112  is small. 
     As in the  FIG. 1  embodiment, the embodiment of  FIG. 4  also includes a return reflector  410  situated relative to the corner cube  408 , a translation device  418 , and a focus controller  420 . The corner cube  408  is mounted on the translation device (e.g., a stage or the like)  418  that is movable under the control of the focus controller (“focus adjust”)  420 . By way of example, the translation device  418  is movable in the z-direction (i.e., direction of the nominal propagation axis  412 ; see arrows  421 ). Such motion of the translation device  418  is as directed by the focus controller  420 , serving to shape and focus the interrogation beam  423  onto a selected location on the target  411 . 
     In the  FIG. 4  embodiment the return reflector  410  can be stationary, in contrast to the return reflector  110  of the  FIG. 1  embodiment  100 , because the return reflector  410  is not used to produce scanning of the interrogation beam. The receiving system  407 , transmitting system  409 , focus controller adjuster  420 , and displacement controller  424  can be coupled to and under the control of a controller  401  similar in many ways to the controller  101  in  FIG. 1 . The receiving system  407  and transmitting system  409  are respective portions of a transmit/receive system  413 . 
     In the embodiment  400  as well as in other embodiments disclosed herein, scattered, reflected, or other light produced by interaction of the scanned interrogation beam with the target  411  is returned to the transmit/receive system  413 . Detected signals based on the portions of the interrogation beam that are returned from the target  411  are coupled to a signal processor  415  for use in forming surface images, contour maps, or other representations of the target  411  that can be provided to a display  416 . In some examples, the detected signals can be processed to provide assessments of the target surface without having to produce a displayed image. The scanning elements (e.g., optical fiber  402 , lenses  406 A,  406 B, return reflector  410 , and signal processor  415 ) can be coupled generally to a control interface  422  so that beam scanning can be correlated with a corresponding detected signal. The control interface  422  can also allow a user to input selected scan ranges, scan rates, surface data assessments, and/or other measurement configurations. For example, positions and tilts of the scanning elements and locations of the scanned interrogation beam can be monitored during scanning, wherein the monitoring is performed using one or more encoders or other appropriate monitoring devices (not shown). In other examples, detections of beam deflection or associated scan-element position are not needed because open-loop scan performance is stable and/or calibrations can be performed at occasional convenient intervals. Nevertheless, real-time tracking of beam scan and the associated scan elements can be advantageous. 
     In the embodiment of  FIG. 4 , the lens  406 A and actuator  403  are components of a beam-steering device. 
     Some advantages of the embodiments disclosed herein include scanning and/or sweeping of the interrogation beam in a manner that is independent of other motions. This allows the scanning and/or sweeping motions (i.e., scanning beam “steering” motions) of the interrogation beam to be performed without having to move the relatively large masses of other portions of the laser radar system. This does not mean that the laser radar system necessarily lacks respective subsystems for achieving motions other than beam-steering; rather, it simply means that the beam-steering motions are produced in a manner that is independent of those other motions. Consequently, component(s) responsible for beam steering can be made relatively small and low in mass, and beam-steering can be achieved more easily and more quickly than in conventional laser radar systems. For example, in the various embodiments the interrogation beam(s) can be rapidly scanned in the vicinity of a given measurement point on the surface of the target. The beam-steering device can be used to produce, for example, spiral or w-scans of the interrogation beam. Different measuring strategies can be implemented such as, for example, averaging a number of points around a selected measurement point on the target to obtain a better estimated value, or determining target-surface orientation on a small patch of the target. Monitoring return-signal intensity as the interrogation beam moves scanningly relative to the target can indicate, for example, centering of a tooling ball relative to the interrogation beam. These features can increase measurement quality, accuracy, and/or rate, and can be used as a tracking function. Consequently, a laser radar system including these features can mimic a laser tracker from a functionality perspective. 
     A representative embodiment of a measurement method is illustrated in  FIG. 5 . At  502 , an interrogation beam is scanned along a pre-selected circular arc or other geometrical scan pattern on the target, as achieved by operation of the beam-steering device. At  504 , portions of the interrogation beam returning from the target (“returning beam”) are detected, and the respective magnitudes of one or more parameters of the returned beam are estimated for the entire selected scan pattern or for a selected portion thereof. At  506 , the magnitudes of the parameters are evaluated to determine possible corresponding features on the surface of the target. In some examples, spherical or circular target features are of interest, wherein the respective center locations of circular or spherical features on the target can be estimated, based on the signal magnitudes, using a circular scan pattern. If beam centration is determined to be of interest at  508 , the beam position (axis) is adjusted, as required, at  510 . Typically, beam adjustment is accomplished by moving components other than those of the beam-steering system. For example, if the laser radar system is mounted on one or more movable stages or analogous mountings, beam adjustment may be made by shifting one or more of such stages. As another example, beam adjustment may be achieved by adjusting the beam-shaping system. After beam adjustment, beam scanning continues at  502 . 
     Measurements produced by execution of the method  500  can be used to produce an average measurement over a region of a target surface. Alternatively or in addition, the measurements can be analyzed to determine surface-feature orientations at a measurement location. By monitoring the signal intensity of light returning from a scan of a region on the target, deviations from a center location or other particular location on the target can be estimated so that the interrogation beam can be maintained in alignment with a specific target-surface location. In other examples, beam scanning as disclosed above can be used to increase measurement quality, measurement accuracy, and/or measurement rate, or used to track particular surface features. In some examples, the disclosed fine-scanning can be used exclusively. 
       FIG. 6  depicts an embodiment of an optical system  600  that includes a primary beam scanner  601  and a secondary beam scanner  602 . The system  600  further includes an optical transmitting (“TX”) system  606  that typically comprises one or more laser sources (e.g., laser diodes), each producing a respective optical beam. The TX system  606  also includes respective laser-driver and laser-control circuitry for the laser sources. The TX system  606  directs an optical beam to an optical fiber  608 . A receiving (“RX”) system  607  receives, from the optical fiber  608 , portions of the interrogation beam returning from the target (target not shown). The RX system  607  typically includes one or more photodetectors. Exemplary photodetectors include but are not limited to photodiodes, avalanche photodiodes, and photomultipliers. As shown in  FIG. 6 , a beam splitter  605  couples optical radiation to the TX system  606  and RX system  607 . Alternatively to the beam splitter, another light-coupling device can be used, such as but not limited to a fiber splitter or other optical beam-routing device. 
     This embodiment includes a focus adjuster  620  serving as a respective portion of a beam-shaping system. The focus adjuster  620  includes a corner cube  622  that can be controllably translated along a nominal propagation axis  624  as commanded by a “focus adjust” controller  621 . The focus adjuster  620  also includes a return reflector  626  that is tiltable similarly to the return reflector  110  of the first embodiment. Tilt of the return reflector  626  is controllably achieved using a secondary beam scanner  602  coupled to one or more actuators  627 . The beam-shaping system also comprises a lens  630  including a first lens  632  and a second lens  634 . As shown in  FIG. 6 , the first lens  632  is coupled to an actuator  633  that selectively displaces the lens relative to the nominal propagation axis  624  in response to a command from the secondary beam scanner  602 . The secondary beam scanner  602  thus achieves scanning propagation of the interrogation beam along a scan path  636  or other trajectory by causing appropriate motion of the first lens  632 , the return reflector  626 , or both. Thus, the secondary beam scanner  602  together with the actuators  627 ,  633 , return reflector  626 , and lens  632  are components of a beam-steering system of this embodiment. 
     This embodiment also includes a primary beam scanner  601 . By way of example, the primary beam scanner  601  directs the interrogation beam to a selected region of the target. The secondary beam scanner  602  then causes the interrogation beam to move in a scanning manner, according to a selected beam-scanning trajectory, in the selected region. A scan-control system  640  is configured to provide scan instructions to the primary beam scanner  601  to direct the interrogation beam to the desired region on the target, and instructions to the secondary beam scanner  602  to scanningly move the interrogation beam according to a selected scan pattern. The control system  640  can also be coupled to the TX system  606  and to the RX system  607  to achieve regulation of, for example, interrogation-beam power, wavelength, and/or or other characteristic(s) and to process data associated with the returning beam to produce target-surface profiles and/or to track selected features of the target surface. In some embodiments a display  642  is coupled to the control system  640  so as to display the data (or display other information) for use by a user. 
     Although a particular arrangement of components is shown in  FIG. 6 , other arrangements alternatively can be used. For example, one or more components such as the TX system  606 , the RX system  607 , and/or the secondary beam scanner  602  can be mounted to a common mechanical support (not shown). Further alternatively, these components can be mechanically separated from each other and coupled together optically using flexible optical fibers and electrical cables so that the primary beam scanner  601  can control the orientations of beam-forming and beam-shaping components only while the secondary beam scanner  602  controls scanning motions of the interrogation beam. One or more encoders (e.g., an encoder  627  for the return reflector and/or an encoder  635  for the lens  632 ) can be provided and coupled so that beam tilts and/or other scanning displacements produced as instructed by the secondary beam scanner  602  can be sensed and used by the control system  640  for target characterization or for achieving closed-loop control of the secondary beam scanner. 
     The receiving system  607  detects light of the interrogation beam that is returning from the target. The receiving system  607  also can also be used to produce one or more optical reference beams (for simplicity of illustration, these features are not shown in  FIG. 6 ). 
       FIG. 7  depicts an exemplary embodiment of a laser-tracking system  700  configured as a beam-steering system. A beam-forming lens  737  is situated along a nominal propagation axis  724  to receive an optical light flux (one or more beams) from a laser diode (not shown) or the like via an optical fiber  708 . The light flux is directed by the optical fiber  708  to a corner cube  722  and to a return mirror  726 . From the return mirror  726  the light flux (in the form of an interrogation beam) passes from the corner cube  722  to an objective lens  732  that directs the beam onto a region of the target (not shown). To achieve scanning of the interrogation beam, a secondary scan controller  702  is coupled to an electromagnetic actuator such as a voice-coil motor or piezoelectric actuator  733 . One or more actuators  733  are used, each being configured to displace a central or other portion of the objective lens  732  relative to the axis  724 . In the embodiment shown in  FIG. 7 , the objective lens  732  can be a holographic optical element or a Fresnel lens, for example. The objective lens  732  is coupled to and responsive to the actuator(s)  733 . The actuator(s)  733  desirably displace the objective lens  732  in two directions that are orthogonal to the axis  724 , thereby achieving two-dimensional scanning of the interrogation beam. Encoder(s) or position sensor(s)  735  can be coupled to the objective lens  732  to assess displacements of the objective lens  732  as well as the resulting displacements of the interrogation beam. In some examples, the objective lens  732  can include a holographic, diffractive, or Fresnel lens. The objective lens  732  can comprise one or more refractive lens elements such as the lens element  737 . 
       FIG. 8  illustrates a representative method of tracking a tooling ball secured to a substrate or target. One or more tooling balls can be secured to a target to provide reference points for coordinate determinations. Tooling balls generally include a reflective ball-shaped surface to provide ample reflection of an interrogation beam of a laser-based measurement apparatus such as a laser radar system. 
     The system shown in  FIG. 7  can be used to determine the respective locations of one or more “tooling balls” on the surface of the target. This determination can be made according to the method diagrammed in  FIG. 8 . At  802  the location of a tooling ball on the target surface is identified and recorded, based on returned portions of a scanned interrogation beam reflected from the tooling ball. The beam can be scanned in any of a variety of patterns such as circles, spirals, w&#39;s, or zig-zags for tracking the tooling ball. 
     At  804 , the identified location of the tooling ball is evaluated to determine its position relative to a primary scan. The primary scan is adjusted at  806  so that the tooling-ball location is at a preferred location relative to the primary scan. (Typically, the primary scan is adjusted so that the tooling-ball location is approximately centered within the range of the primary scan.) At  808 , a determination is made of whether to perform additional scanning. 
       FIG. 9  illustrates a representative manufacturing system  900  suitable for producing one or more components of a ship, airplane, or other system or apparatus, and for evaluating and possibly reprocessing the components after manufacture. The system  900  typically includes a shape- or profile-measurement system  905  such as the laser radar system  100  discussed above. The manufacturing system  900  also includes a design system  910 , a shaping system  920 , a controller  930 , and a repair system  940 . The controller  930  includes coordinate storage  931  configured to store coordinates (coordinates obtained by measurements and/or established design coordinates) or other parametric characteristic(s) of the component(s). The coordinate storage  931  is generally a computer-readable medium such as a hard disk, a random access memory, or other memory device. Typically, the design system  910 , the shaping system  920 , the shape-measurement system  905 , and a repair system  940  communicate with each other via a communications bus  915  using a network protocol. 
     The design system  910  is configured to produce design information corresponding to shape, coordinates, dimensions, and/or other parametric features of a structure to be manufactured, and to communicate the produced design information to the shaping system  920 . The design system  910  can also communicate design information to the coordinate storage  931  of the controller  930  for storage. Design information typically includes data corresponding to the coordinates of at least some features of a structure to be manufactured. 
     The shaping system  920  is configured to produce a structure based on the design information from the design system  910 . The shaping processes performed by the shaping system  920  can include casting, forging, cutting, or other suitable process. The shape-measurement system  905  is configured to measure the coordinates of one or more features of the manufactured structure and to communicate the information (e.g., measured coordinates or other information related to the shape of the structure) to the controller  930 . 
     A manufacture inspector  932  of the controller  930  is configured to obtain design information from the coordinate storage  931 . The manufacture inspector  932  also compares information (e.g., coordinates or other shape information received from the profile-measuring system  100 ) with design information read out from the coordinate storage  931 . The manufacture inspector  932  is generally configured as a processor and a series of computer-executable instructions that are stored in a the controller  930  in a tangible computer-readable medium such as a random access memory, a flash drive, a hard disk, or other memory-storage device. Based on a comparison of design data versus actual structural data, the manufacture inspector  932  can determine whether the manufactured structure meets specification in terms of, for example, the design information. The determinations are generally based at least in part on one or more design tolerances that can be stored in the coordinate storage  931 . In other words, the manufacture inspector  932  can determine whether the manufactured structure is defective or non-defective. If the structure is not shaped in accordance with design specifications (and hence is defective), then the manufacture inspector  932  determines whether the structure is repairable. If the structure is repairable, then the manufacture inspector  932  identifies the defective portions or regions of the structure and provides suitable coordinates or other data by which to perform repair. The manufacture inspector  932  is also configured to produce repair instructions and/or repair data and to forward the instructions and/or data to the repair system  940 . The repair data can include locations requiring repair, extent of re-shaping required, or other repair data. The repair system  940  is configured to process defective portions of the manufactured structure based on the repair data. 
       FIG. 10  is a flowchart showing a representative manufacturing method  1000  incorporating a manufacturing system such as the embodiment shown in  FIG. 8 . At  1002 , design information is obtained or created corresponding to the shape or topography of a structure to be manufactured. At  1004 , the structure is manufactured or “shaped” based on the design information. At  1006 , coordinates, dimensions, or other features of the manufactured structure are measured using a profile-measurement system such as any of the laser radar embodiments described above to obtain shape or other profile information pertaining to the structure as manufactured. At  1008 , the structure is inspected based on a comparison of actual (as-manufactured) versus design (as-specified) dimensions, coordinates, manufacturing tolerances, or other structural parameters. At  1010 , if the manufactured structure is determined to be non-defective (within specification), the structure is regarded as “acceptable” and processing ends at  1014 . If the structure is determined to be defective (out of specification) at  1010  (by, for example, the manufacture inspector  932  of the controller  930  shown in  FIG. 8 ), then at  1012  a determination is made of whether the offending structure is repairable. If the structure is repairable, it is reprocessed or repaired at  1016 , and then measured, inspected, and reevaluated at  1006 ,  1008 ,  1010 , respectively. If the structure is determined to be non-repairable at  1012 , the process ends at  1014 . 
     According to the embodiment of  FIG. 10 , a manufactured structure can be evaluated using a profile-measurement system to measure or assess coordinates or other features of a manufactured structure. Thus, the structure can be evaluated to determine whether the structure is defective or not. If the structure is determined to be defective but repairable or reprocessable, a reprocessing process can be performed. By repeating measurement, inspection, and evaluation, defective parts can be readily identified and reprocessed, while structures that are defective and non-repairable can be set aside or discarded. The particular systems and methods of  FIGS. 9-10  are exemplary only, and other arrangements alternatively can be used. 
     In the embodiment of  FIG. 10 , the manufacturing system  1000  can include a profile-measurement system comprising a laser radar  100 , a design system  910 , a shaping system  920 , a controller  930  configured to determine whether a structure is acceptable (inspection apparatus), and a repair system  940 . However, other systems and methods can be used, and the exemplary embodiments of  FIGS. 9 and 10  are provided for convenient illustration and should not be regarded as limiting the scope of the this disclosure. We claim all that is encompassed by the appended claims. 
     Whereas the invention has been described in the context of multiple representative embodiments, it will be understood that it is not limited to those embodiments. On the contrary, it is intended to cover all modifications, alternatives, and equivalents as may be including within the spirit and scope of the invention, as defined by the appended claims.