Patent Publication Number: US-2015062568-A1

Title: Reference systems for indicating slope and alignment and related devices, systems, and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 14/019,459 filed Sep. 5, 2013, which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present technology is related to reference systems for indicating slope and alignment. In particular, at least some embodiments are related to reference systems including light emitters that project light onto surfaces to create visible references for use in construction, surveying, and other applications. 
     BACKGROUND 
     In many construction, surveying, and other applications it can be useful to create a visible reference that has a selected deviation from horizontal (i.e., “slope” or “grade”) and a selected horizontal orientation off a vertical axis (i.e., “alignment,” “line,” or “heading”). For example, in tunneling applications, individual tunnel sections are often formed with a selected slope and alignment so that an overall run of tunnel will follow a desired course. Similarly, individual pipe sections in pipe-ramming applications are often formed with a selected slope and alignment. During construction of a tunnel, a pipe, or a similar structure, a visible reference can be used to guide certain operations (e.g., steering a tunnel-boring machine, aiming a pipe-ramming assembly, etc.) so as to maintain a selected slope and alignment. One conventional approach to creating this visible reference includes positioning a light emitter directly above or below a first alignment reference point, manually adjusting the alignment of a light beam generated by the light emitter so that the light beam intersects a second alignment reference point corresponding to a given alignment relative to the first alignment reference point, and then manually adjusting the slope of the light beam to a selected slope. Thereafter, the light emitter automatically maintains the light beam at the selected slope, but operates independently of the alignment of the light beam. Based on the initial calibration, the light beam is assumed to represent the given alignment. This approach and other conventional approaches to indicating slope and alignment have certain limitations and/or disadvantages. Accordingly, there is a need for further innovation in this field. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on clearly illustrating the principles of the present technology. For ease of reference, throughout this disclosure identical reference numbers may be used to identify identical or at least generally similar or analogous components or features. 
         FIG. 1  is a perspective view from the top and one side illustrating a light-emitting device of a reference system configured in accordance with an embodiment of the present technology. 
         FIG. 2  is a perspective view from the bottom and one side of the light-emitting device shown in  FIG. 1 . 
         FIG. 3  is a plan view of the light-emitting device shown in  FIG. 1 . 
         FIG. 4  is a front profile view of the light-emitting device shown in  FIG. 1 . 
         FIG. 5  is an inverse plan view of the light-emitting device shown in  FIG. 1 . 
         FIG. 6  is a rear profile view of the light-emitting device shown in  FIG. 1 . 
         FIG. 7  is a perspective view from the top and one side of an assembly of internal components of the light-emitting device shown in  FIG. 1 . 
         FIG. 8  is a rear profile view of the assembly shown in  FIG. 7 . 
         FIGS. 9 and 10  are plan and side profile views, respectively, of the light-emitting device shown in  FIG. 1  simultaneously emitting a planar light region and an indicator light beam. 
         FIG. 11  is a profile view of the planar light region and the indicator light beam shown in  FIGS. 9 and 10  projected onto a surface. 
         FIG. 12  is a plan view of a light-emitting device of a reference system configured in accordance with an embodiment of the present technology simultaneously emitting a planar light region horizontally offset from an indicator light beam. 
         FIGS. 13 and 14  are plan and side profile views, respectively, of a light-emitting device of a reference system configured in accordance with an embodiment of the present technology simultaneously emitting a planar light region and an intersecting planar light region. 
         FIG. 15  is a profile view of the planar light region and the intersecting planar light region shown in  FIGS. 13 and 14  projected onto a surface. 
         FIG. 16  is a perspective cut-away view from the top and one side of a subterranean pit in which a reference system configured in accordance with an embodiment of the present technology is guiding installation of pipe sections. 
         FIG. 17  is a flow chart illustrating a method for indicating slope and alignment in accordance with an embodiment of the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     Specific details of several embodiments of the present technology are disclosed herein with reference to  FIGS. 1-17 . Although the embodiments are disclosed herein primarily with respect to tunneling and pipe-ramming applications, other applications and other embodiments in addition to those disclosed herein are within the scope of the present technology. For example, reference systems configured in accordance with at least some embodiments of the present technology can be used for building layout or for positioning elevated structures (e.g., elevated tracks or pipes) along specific courses above grade. It should be noted that embodiments of the present technology can have different configurations, components, features, or procedures than those shown or described herein. Moreover, a person of ordinary skill in the art will understand that embodiments of the present technology can have configurations, components, features, or procedures in addition to those shown or described herein and that these and other embodiments can be without several of the configurations, components, features, or procedures shown or described herein without deviating from the present technology. 
     Any given slope has a fixed angle relative to a level plane. Thus, a reference system including a light emitter that generates a light beam at a selected slope can automatically maintain the light beam at the selected slope by automatically leveling the light emitter. In this way, many conventional reference systems are capable of reliably indicating slope without the need for frequent monitoring or adjustment. Unfortunately, reliably indicating alignment is not as straightforward. A variety of factors can cause alignment to shift after a light emitter is initially calibrated. These factors include thermal expansion or contraction of a mount to which a light emitter is attached, thermal expansion or contraction of internal components of a light emitter, vibration of a light emitter, impact against a light emitter, and handling of a light emitter, among other examples. 
     Uncertainty regarding the accuracy of a reference indicating slope and alignment can reduce productivity, cause costly errors, or have other disadvantages. For example, when this accuracy is in doubt, personnel may find it prudent to manually recalibrate the reference just before key measurements are taken. In addition to being impractical, this still does not assure that alignment errors will not occur, since alignment shifts can occur after recalibration. Furthermore, manual recalibrations may be executed in haste, which may lead to calibration errors. In at least some cases, calibration errors tend to be magnified over long distances. For example, when a conventional light emitter is positioned in a subterranean pit (e.g., in a tunneling or pipe-ramming application), the length of the pit may limit the available distance between alignment reference points. Extrapolating an alignment calibrated using the alignment reference points to the end of a run of tunnel or pipe magnifies any calibration errors. Even a relatively small calibration error that may be difficult to detect at an alignment reference point may translate into a relatively large error at the end of a run of tunnel or pipe. In a particular example, a 0.5 inch calibration error at 50 feet near the top edge of a pit is magnified ten times along a 500 foot run of tunnel or pipe to cause a 5 inch misalignment at the end of the run of tunnel or pipe. This level of inaccuracy is often unacceptable or at least highly undesirable in modern construction applications. 
     Reference systems configured in accordance with at least some embodiments of the present technology can at least partially address one or more of the problems discussed above and/or other problems associated with conventional technologies whether or not stated herein. For example, reference systems configured in accordance with at least some embodiments of the present technology can have one or more features that reduce or eliminate inaccurate indications of alignment without necessitating frequent monitoring and/or manual adjustment. In a particular example, a reference system configured in accordance with an embodiment of the present technology includes a light-emitting device configured to communicate with a detector positioned at an alignment reference point. A light emitter of the light-emitting device can be configured to emit a planar light region having a vertical orientation or a scanning light beam having a vertical scanning field. The planar light region or the scanning light beam can interact with the detector. For example, when the planar light region or the vertical scanning field is shifted out of alignment (e.g., due to one of the factors discussed above), the detector can transmit a signal to the light-emitting device (e.g., via a controller) that causes the light-emitting device to automatically make one or more suitable adjustments to at least partially compensate for the shift. Accordingly, once the light-emitting device and the detector are initially positioned and activated, the reference system can be safely relied upon to accurately indicate alignment. This advantage and others are further discussed below with reference to  FIGS. 1-17 . 
     Selected Examples of Light-Emitting Devices 
       FIGS. 1 and 2  are perspective views illustrating a light-emitting device  100  of a reference system configured in accordance with an embodiment of the present technology.  FIGS. 3 ,  4 ,  5  and  6  are a plan view, a front elevation view, an inverse plan view, and a rear elevation view, respectively, of the light-emitting device  100 . With reference to  FIGS. 1-6  together, the light-emitting device  100  can include a housing  102  and a battery compartment  104  extending rearwardly from the housing  102 . An interior of the battery compartment  104  can be accessed, for example, by removing a circular cap  105  positioned at a rear surface  104   a  of the battery compartment  104 . The housing  102  can include a base  106  configured for attachment to a tripod (not shown) or another suitable support structure. For example, the base  106  can include a threaded recess  108  configured to receive a threaded protrusion of a tripod mounting head. 
     Along an upper surface  104   b  of the battery compartment  104 , the light-emitting device  100  can include buttons  112  (individually identified  112   a - 112   e ) or other suitable user-interface elements configured to allow a user to control certain operations of the light-emitting device  100 . In addition or alternatively, one of more of the buttons  112  can be configured to allow a user to control certain operations of one or more other components of the system, such as via a wireless or wired connection between the light-emitting device  100  and the one or more other components. The light-emitting device  100  can further include a handle  114  extending rearwardly from a rear surface  102   a  of the housing  102  such that the handle  114  has a position above and vertically spaced apart from the battery compartment  104 . Below the handle  114  and above the battery compartment  104 , the light-emitting device  100  can include a rearwardly facing display  116  configured to convey settings, status indicators, and/or other information to a user. 
     A row of windows  118  (individually identified as  118   a - d ) and intervening bridges  120  (individually identified as  120   a - c ) can extend along the rear surface  102   a  of the housing  102  above the handle  114 , along an upper surface  102   b  of the housing  102 , and along a front surface  102   c  of the housing  102 . In some embodiments, a single window  118   d  extends from a bridge  120   c  at a corner between the upper surface  102   b  of the housing  102  and the front surface  102   c  of the housing  102  to a portion of the front surface  102   c  of the housing  102  at least proximate to the base  106 . In other embodiments, the window  118   d  can extend to another suitable portion of the front surface  102   c  of the housing  102 . The light-emitting device  100  can further include an antenna  122  and a groove  124  configured to receive the antenna  122  when the antenna  122  is in a stowed state. The groove  124  can be laterally spaced apart from and longitudinally aligned with a portion of the row of windows  118  and intervening bridges  120  extending along the upper surface  102   b  of the housing  102 . The antenna  122  can be hingedly connected to the housing  102  at a forwardmost portion of the groove  124 . 
       FIG. 7  is a perspective view from the top and one side of an assembly of internal components of the light-emitting device  100 .  FIG. 8  is a rear profile view of the assembly shown in  FIG. 7 . Many internal components of the light-emitting device  100  are not shown in  FIGS. 7 and 8  for clarity of illustration. With reference to  FIGS. 1-8  together, the light-emitting device  100  can include a first light emitter  126 , a second light emitter  127 , and a third light emitter  128  positioned within the housing  102  and operably connected to the base  106 . In the illustrated embodiment, the first light emitter  126 , the second light emitter  127 , and the third light emitter  128  include a first light source  129  (e.g., including a first laser driver operably connected to one or more first light-emitting diodes), a second light source  130  (e.g., including a second laser driver operably connected to one or more second light-emitting diodes), and a third light source  131  (e.g., including a third laser driver operably connected to one or more third light-emitting diodes), respectively. In other embodiments, some or all of the first, second, and third light emitters  126 ,  127 ,  128  can include a shared light source, such as a shared light source including laser driver operably connected to one or more light-emitting diodes and a beam splitter configured to receive light from the one or more light-emitting diodes and to distribute the light to some or all of the first, second, and third light emitters  126 ,  127 ,  128 . 
     The first light emitter  126  can be partially or entirely dedicated to maintaining and/or indicating alignment. In contrast, the second light emitter  127  can be partially or entirely dedicated to indicating slope. Accordingly, the first and second light emitters  126 ,  127  can be configured to emit light having different characteristics (e.g., with respect to shape, intensity, and/or orientation) associated with these different purposes. In one example, the first light emitter  126  is configured to emit a planar light region (not shown) having a vertical orientation and the second light emitter  127  is configured to emit an indicator light beam (not shown) having an adjustable slope. Adjusting the slope of the indicator light beam can change a position of the indicator light beam within a vertical adjustment field. In another example, instead of being configured to emit a planar light region, the first light emitter  126  is configured to emit a scanning light beam having a vertical scanning field. In yet another example, the first light emitter  126  is configured to emit a planar light region and the second light emitter  127  is configured to emit an intersecting planar light region (not shown) perpendicular to the planar light region and having an adjustable slope. The third light emitter  128  can be configured to emit a plummet light beam via the threaded recess  108 . The plummet light beam can have a vertical orientation and can be useful for positioning the light-emitting device  100  relative to a reference (e.g., a stake or another suitable marker) in the field. Other types and combinations of light from the first, second, and third light emitters  126 ,  127 ,  128  are also possible. 
     The first, second, and third light emitters  126 ,  127 ,  128  can be carried by one or more gimbals. In the illustrated embodiment, the light-emitting device  100  is configured to level the first, second, and third light emitters  126 ,  127 ,  128  electronically. For example, the light-emitting device  100  can include an x-axis leveling mechanism  132  configured to rotate the first, second, and third light emitters  126 ,  127 ,  128  front-to-back about an x-axis  136 . Similarly, the light-emitting device  100  can include a y-axis leveling mechanism  134  configured to rotate the first, second, and third light emitters  126 ,  127 ,  128  left-to-right about a y-axis  138 . The x-axis leveling mechanism  132  can include a first motor  140  and a first set of motion-transmitting components  142  operably connected to the first motor  140 . Similarly, the y-axis leveling mechanism  134  can include a second motor  144  and a second set of motion-transmitting components  146  operably connected to the second motor  144 . 
     The light-emitting device  100  can further include an x-axis level sensor  148 , a y-axis level sensor  149 , and a controller  150  (shown schematically) operably associated with the x-axis leveling mechanism  132 , the y-axis leveling mechanism  134 , the x-axis level sensor  148 , and the y-axis level sensor  149 . The controller  150  can include memory  151  (shown schematically) and processing circuitry  152  (shown schematically). Wires (not shown) or other suitable electrical connectors can operably connect the controller  150  to the x-axis leveling mechanism  132 , the y-axis leveling mechanism  134 , the x-axis level sensor  148 , and the y-axis level sensor  149 . The memory  151  can store instructions (e.g., non-transitory instructions) that, when executed by the controller  150  using the processing circuitry  152 , cause the x-axis leveling mechanism  132  to level the first, second, and third light emitters  126 ,  127 ,  128  based on input from the x-axis level sensor  148 . Similarly, the memory  151  can store instructions that, when executed by the controller  150  using the processing circuitry  152 , cause the y-axis leveling mechanism  134  to level the first, second, and third light emitters  126 ,  127 ,  128  based on input from the y-axis level sensor  149 . In other embodiments, the light-emitting device  100  can be configured to level the first, second, and third light emitters  126 ,  127 ,  128  in another suitable manner, such as by gravity. 
     In the illustrated embodiment, the first light emitter  126  includes a reflector  153  (e.g., a pentamirror or a pentaprism) operably connected to a reflector-rotating mechanism  154  configured to rotate the reflector  153  about a horizontal axis parallel to the x-axis  136 . The reflector-rotating mechanism  154  can include a third motor  155  and a third set of motion-transmitting components  156  operably connected to the third motor  155 . The reflector  153  can be configured to receive light from the first light source  129  and to emit the light away from the light-emitting device  100  via one, some, or all of the windows  118 . The speed at which the reflector  153  rotates can determine whether the emitted light forms a planar light region having a vertical orientation or a scanning light beam having a vertical scanning field. In other embodiments, the light-emitting device  100  can include a lens, a filter, or another suitable rotating or non-rotating component configured to convert light from the first light source  129  into a planar light region having a vertical orientation, a scanning light beam having a vertical scanning field, or another suitable form. 
     The second light emitter  127  can include a cylinder  158  defining a passage (not shown) through which light from the second light source  130  can be transmitted. For example, a first end portion of the passage can be positioned to receive light from the second light source  130 . A collimating lens (not shown) disposed within the cylinder  158  at a second end portion of the passage opposite to the first end portion of the passage can be configured to convert the light from the second light source  130  into an indicator light beam. In at least some embodiments in which the second light emitter  127  is configured to emit an intersecting planar light region, the collimating lens can be replaced with a rotatable reflector or another suitable component for generating planar light regions. The angle of at least a portion of the second light emitter  127  can be adjustable to change the slope of an indicator light beam or an intersecting planar light region from the second light emitter  127 . For example, the light-emitting device  100  can include a slope-adjusting mechanism  162  configured to rotate the second light emitter  127  about a horizontal axis parallel to the x-axis  136  to change the slope of an indicator light beam or an intersecting planar light region from the second light emitter  127 . The slope-adjusting mechanism  162  can include a fourth motor  164  and a fourth set of motion-transmitting components  166  operably connected to the fourth motor  164 . In the illustrated embodiment, the fourth set of motion-transmitting components  166  includes a vertical lead screw  168  and a yoke  170  configured to lift and lower one end of an arm  172  having an opposite end operably connected to the cylinder  158  at least proximate to the second end portion of the passage. In other embodiments, the fourth set of motion-transmitting components  166  can have another suitable configuration. 
     In addition to controlling automatic leveling of the first, second, and third light emitters  126 ,  127 ,  128  via the x-axis leveling mechanism  132  and the y-axis leveling mechanism  134 , the controller  150  can be configured to control automatic alignment of the first, second, and third light emitters  126 ,  127 ,  128 . For example, the controller  150  can be configured to receive one or more signals from a remotely positioned detector (not shown) via the antenna  122  and to control automatic alignment of the first, second, and third light emitters  126 ,  127 ,  128  based on the one or more signals. Although in the illustrated embodiment the controller  150  is configured to receive the one or more signals wirelessly, in other embodiments, the controller  150  can be configured to receive the one or more signals via a wired connection with the detector. Furthermore, although in the illustrated embodiment the controller  150  is configured to control both automatic leveling and automatic alignment of the first, second, and third light emitters  126 ,  127 ,  128 , in other embodiments the controller  150  can be configured to control one of automatic leveling and automatic alignment with the other being controlled in another suitable manner. 
     The light-emitting device  100  can include an alignment-adjusting mechanism  174  configured to rotate the first, second, and third light emitters  126 ,  127 ,  128  in concert relative to the base  106  about a vertical axis  176 . In this way, the light-emitting device  100  can rotationally reposition a planar light region from the first light emitter  126  or a vertical scanning field of a scanning light beam from the first light emitter  126  in concert with an indicator light beam or an intersecting planar light region from the second light emitter  127 . The alignment-adjusting mechanism  174  can include a fifth motor  178  and a fifth set of motion-transmitting components  180  operably connected to the fifth motor  178 . In the illustrated embodiment, the fifth set of motion-transmitting components  180  includes a horizontal lead screw  182  extending though a threaded passage (not shown) defined by a rotationally constrained nut  184 . In other embodiments, the fifth set of motion-transmitting components  180  can have another suitable configuration. 
     The controller  150  can be operably associated with the alignment-adjusting mechanism  174 . For example, the memory  151  can store instructions (e.g., non-transitory instructions) that, when executed by the controller  150  using the processing circuitry  152 , cause the alignment-adjusting mechanism  174  to rotate the first, second, and third light emitters  126 ,  127 ,  128  in concert relative to the base  106  about the vertical axis  176  in response to the one or more signals or an absence of the one or more signals from the detector. As further discussed below, the one or more signals or an absence of the one or more signals can indicate a misaligned state of a planar light region from the first light emitter  126  or of a vertical scanning field of a scanning light beam from the first light emitter  126 . Thus, based on the one or more signals or an absence of the one or more signals, the controller  150  can be configured to move a planar light region from the first light emitter  126  or a vertical scanning field of a scanning light beam from the first light emitter  126  from a misaligned state toward an aligned state. An indicator light beam or an intersecting planar light region from the second light emitter  127  can move with the planar light region from the first light emitter  126  or with the vertical scanning field of the scanning light beam from the first light emitter  126  such that the indicator light beam or the intersecting planar light region is correspondingly repositioned. 
     The controller  150  also can be operably associated with the buttons  112  and the display  116 . For example, pressing the button  112   a  can cause the controller  150  to open one or more switches (not shown) and thereby allow electricity from batteries (not shown) within the battery compartment  104  to flow to the first, second, and third light emitters  126 ,  127 ,  128 . Pressing the button  112   e  can manually change a slope of an indicator light beam or an intersecting planar light region from the second light emitter  127  to a selected slope. For example, the slope-adjusting mechanism  162  can include an encoder  186  operably connected to the controller  150 . The controller  150  can be configured to cause the display  116  to indicate a slope of the second light emitter  127  based one or more signals from the encoder  186 . The display  116  can be a touchscreen that allows a user to control additional operations of the light-emitting device  100  and/or other components of the system. Furthermore, instead of or in addition to being positioned on the light-emitting device  100 , the buttons  112  and/or the display  116  can be positioned on a remote control (not shown) configured to communicate with the light-emitting device  100  via a wired or wireless connection. 
     Pressing the button  112   c  can cause the controller  150  to switch control of the alignment-adjusting mechanism  174  between a manual state (e.g., a calibration state) and an automatic state (e.g., a locked state). In the manual state, the controller  150  can be configured to rotate the first, second, and third light emitters  126 ,  127 ,  128  right or left via the alignment-adjusting mechanism  174  in response to pressing the button  112   b  or the button  112   d,  respectively. Once a selected alignment is achieved, the button  112   c  can be pressed to cause the controller  150  to switch control of the alignment-adjusting mechanism  174  to the automatic state. In the automatic state, the controller  150  can be configured to automatically maintain the selected alignment by controlling the alignment-adjusting mechanism  174  based on the one or more signals or an absence of the one or more signals from the detector. For example, in the automatic state, the controller  150  can be configured to make small or large adjustments as needed to maintain the selected alignment. At least some adjustments may occur relatively frequently to compensate for factors (e.g., thermal expansion and contraction of components of the light-emitting device  100 ) with relatively minor, but persistent effects on alignment. Other adjustments may occur relatively infrequently to compensate for factors (e.g., impact against the light-emitting device  100 ) with relatively major effects on alignment. 
       FIGS. 9 and 10  are plan and side profile views, respectively, of the light-emitting device  100  simultaneously emitting a planar light region  188  and an indicator light beam  189 .  FIG. 11  is a profile view of the planar light region  188  and the indicator light beam  189  projected onto a surface  190 . The planar light region  188  can have a vertical orientation and the indicator light beam  189  can have an adjustable slope. For example, the indicator light beam  189  can have a radial direction  191  away from the base  106  within a vertical adjustment field (represented by arrow  192 ) extending from an uppermost radial direction  193  away from the base  106  to a lowermost radial direction  194  away from the base  106 . In some embodiments, the uppermost radial direction  193  has an angle within a range from about 10 degrees to about 90 degrees off a horizontal plane and the lowermost radial direction  194  has an angle within a range from about −5 degrees to about −90 degrees off the horizontal plane. In a particular embodiment, the uppermost radial direction  193  has an angle of about 17 degrees off the horizontal plane and the lowermost radial direction  194  has an angle of about −6 degrees off the horizontal plane. In other embodiments, the uppermost and lowermost radial directions  193 ,  194  can have other suitable positions relative to the horizontal plane. 
     The vertical adjustment field can at least partially overlap a first vertical arc area (represented by arrow  196 ) extending from a first horizontal direction  198  away from the base  106  to an upward vertical direction  200  away from the base  106 . In some embodiments, the planar light region  188  at least partially overlaps a second vertical arc area (represented by arrow  202 ) extending from a second horizontal direction  204  away from the base  106  opposite to the first horizontal direction  198  to the upward vertical direction  200 . Similarly, when the first light emitter  126  is configured to emit a scanning light beam having a vertical scanning field instead of the planar light region  188 , the vertical scanning field can at least partially overlap the second vertical arc area. It can be useful for the planar light region  188  or a vertical scanning field to at least partially overlap the second vertical arc area, for example, to allow the planar light region  188  or the vertical scanning field to interact with a detector positioned behind the light-emitting device  100  rather than in front of the light-emitting device  100 . In some cases, positioning a detector behind the light-emitting device  100  rather than in front of the light-emitting device  100  can be advantageous, such as to reduce interference between the detector and an operation (e.g., a tunneling operation) occurring in front of the light-emitting device  100  or when suitable mounting positions for the detector in front of the light-emitting device  100  are less available or desirable than suitable mounting positions for the detector behind the light-emitting device  100 . 
     In the illustrated embodiment the planar light region  188  is within the same plane as the indicator light beam  189  and the vertical adjustment field. Similarly, when the first light emitter  126  is configured to emit a scanning light beam having a vertical scanning field instead of the planar light region  188 , the vertical scanning field can be within the same plane as the indicator light beam  189  and the vertical adjustment field. In other embodiments, at least a portion of the planar light region  188  or a vertical scanning field can be circumferentially offset relative to the vertical adjustment field by a non-zero fixed angle within a horizontal plane. For example,  FIG. 12  is a plan view of a light-emitting device  206  in which the row of windows  118  and intervening bridges  120  and internal components associated with emitting the planar light region  188  are rotated 90 degrees about the vertical axis  176  relative to their positions in the light-emitting device  100 . Similar to the advantages discussed above with reference to  FIGS. 9 and 10  regarding overlapping the second vertical arc area, horizontally offsetting the planar light region  188  or a vertical scanning field relative to the vertical adjustment field can be advantageous, such as to reduce interference between the detector and an operation (e.g., a tunneling operation) occurring in front of the light-emitting device  206  or when suitable mounting positions for the detector in front of the light-emitting device  206  are less available or desirable than suitable mounting positions to the side of the light-emitting device  206  or otherwise horizontally offset from being directly in front of the light-emitting device  206 . 
     Instead emitting an indicator light beam having an adjustable slope, light-emitting devices of reference systems configured in according with some embodiments of the present technology can emit a planar light region (not shown) that has an adjustable slope and intersects a vertical planar light region. For example,  FIGS. 13 and 14  are plan and side profile views, respectively, of a light-emitting device  208  of a reference system configured in accordance with an embodiment of the present technology simultaneously emitting a vertical planar light region  210  and an intersecting planar light region  212 . Similar to the indicator light beam  189  shown in  FIGS. 9-11 , the intersecting planar light region  212  can have a planar radial direction  213  away from the base  106  within the vertical adjustment field (represented by arrow  192 ) extending from an uppermost planar radial direction  214  away from the base  106  to a lowermost planar radial direction  216  away from the base  106 . The angles of the uppermost and lowermost planar radial directions  214 ,  216  relative to the first horizontal direction  198  can correspond to those of the uppermost and lowermost radial directions  193 ,  194 , respectively. 
     The planar light region  188  shown in  FIGS. 9-11  can be visible or invisible to the naked eye. For example, the planar light region  188  can be intense enough to be detected by a detector, but not intense enough to be visibly located. When a planar light region is only used for maintaining alignment, there is typically no need for it to be visible. For example, a dot, crosshair, or other discrete projection (not shown) of the indicator light beam  189  onto a surface (not shown) can visibly indicate a selected slope at a selected alignment. In contrast, with reference again to  FIGS. 13 and 14 , the vertical planar light region  210  can be used to visibly indicate alignment and used in conjunction with the intersecting planar light region  212  to visibly indicate slope. The vertical planar light region  210  shown in  FIG. 14  extends over a smaller arc than does the planar light region  188  shown in  FIG. 10 . In some cases, reducing the arc of the vertical planar light region  210  can enhance visibility by allowing for greater light output over a smaller space. 
       FIG. 15  is a profile view of a first line  218  corresponding to the vertical planar light region  210  and a second line  220  corresponding to the intersecting planar light region  212  projected onto a surface  222 . During use, the first line  218  can visibly indicate a selected alignment, the second line  220  can visibly indicate a selected slope, and an intersection  224  of the first and second lines  218 ,  220  can indicate the selected slope at the selected alignment. Indicating a selected slope and a selected alignment in this way can be useful, for example, when a vertical line, a horizontal line, or both at the selected slope and alignment are needed as a visible reference for positioning a piece of equipment or for another suitable aspect of an operation occurring at the selected slope and alignment. 
     Although the second line  220  is shown as a level line in  FIG. 15 , in other embodiments, the second line  220  can be non-level. For example, the intersecting planar light region  212  can have an adjustable slope in two perpendicular planes. In this way, the intersecting planar light region  212  can visibly or invisibly indicate a compound slope. When the intersecting planar light region  212  is used to indicate a compound slope, the accuracy of the entire plane may depend on the alignment of the light-emitting device  206 . The vertical planar light region  210 , another visible or invisible vertical planar light region, or a scanning light beam having a vertical scanning field can be emitted from the light-emitting device  206  to maintain this alignment. Planar light regions indicating compound slopes can be useful, for example, in earthwork applications calling for complex topography, among other examples. 
       FIG. 16  is a perspective cut-away view from the top and one side of a subterranean pit  226  in which a reference system  228  configured in accordance with an embodiment of the present technology is guiding installation of pipe sections  230  using a pipe-ramming assembly  231 . The reference system  228  includes the light-emitting device  100  and a detector  232  attached to a mount  234  positioned at an upper rim  236  of the subterranean pit  226 . After setup, the detector  232  can receive the planar light region  188  and to detect its presence and/or position (e.g., via optical transducers positioned behind a detection window). When the detected presence and/or position of the planar light region  188  is accurate and does not change, the detector  232  can be configured to transmit (e.g., wirelessly transmit) one or more signals indicating an aligned state of the planar light region  188 . When the detected presence and/or position of the planar light region  188  changes, the detector  232  can be configured to stop transmitting the one or more signals so as to indicate a misaligned state of the planar light region  188 . Alternatively, when the detected presence and/or position of the planar light region  188  changes, the detector  232  can be configured to start transmitting one or more signals so as to indicate a misaligned state of the planar light region  188  and when the detected presence and/or position of the planar light region  188  is accurate and does not change, the detector  232  can be configured to stop transmitting the one or more signals so as to indicate a misaligned state of the planar light region  188 . In some embodiments, the detector  232  is configured to emit one or more signals indicating a direction of misalignment of the planar light region  188 , such as a shift to the left or a shift to the right. In other embodiments, the detector  232  can be configured to only emit one or more signals that do not indicate a direction of misalignment of the planar light region  188 . 
     The light-emitting device  100  can be configured to receive one or more signals from the detector  232  and to adjust the position of the planar light region  188  accordingly. For example, the controller  150  shown in  FIGS. 7 and 8  can be operably connected to the detector  232  via a wired or wireless connection and the memory  151  of the controller  150  can store instructions that, when executed by the controller  150  using the processing circuitry  152  of the controller  150 , cause the alignment-adjusting mechanism  174  to rotationally reposition the planar light region  188  so as to move the planar light region  188  from the misaligned state toward an aligned state. When the detector  232  emits one or more signals indicating a misaligned state of the planar light region  188  without indicating a direction of the misalignment, the light-emitting device  100  can be configured to dither or otherwise suitably rotationally reposition the planar light region  188  until the detector  232  stops emitting the one or more signals and/or starts emitting one or more signals indicating an aligned state of the planar light region  188 . As another example, when the detector  232  emits one or more signals indicating a misaligned state of the planar light region  188  without indicating a direction of the misalignment, the light-emitting device  100  can be configured to purposefully rotationally reposition of the planar light region  188  until the detector  232  stops emitting the one or more signals and/or starts emitting one or more signals indicating an aligned state of the planar light region  188 . Although the planar light region  188  is shown in  FIG. 16 , the same or similar functionality can alternatively be achieved with a scanning light beam having a vertical scanning field. 
       FIG. 17  is a flow chart illustrating a method  238  for indicating slope and alignment in accordance with an embodiment of the present technology. With reference to  FIGS. 9-11  and  14 - 17  together, the method  238  can include emitting the planar light region  188 ,  210  or a scanning light beam using the first light emitter  126  (block  240 ). The method  238  can further include adjusting an alignment of the planar light region  188 ,  210  or of a vertical scanning field of the vertical scanning beam to move the planar light region  188 ,  210  or the vertical scanning field, respectively, to an aligned state (block  242 ). The method  238  can further include emitting the indicator light beam  189  or the intersecting planar light region  212  using the second light emitter  127  (block  244 ). The method  238  can further include adjusting a slope of the indicator light beam  189  or of the intersecting planar light region  212  to move the indicator light beam  189  or the intersecting planar light region  212 , respectively, to a selected slope (block  246 ). The method  238  can further include projecting a dot corresponding to the indicator light beam  189  or projecting a line corresponding to the intersecting planar light region  212  onto a surface (e.g., a working surface or the surface of a field receiver) to indicate the selected alignment and the selected slope (block  248 ). 
     The method  238  can further include detecting a misaligned state of the planar light region  188 ,  210  or of the vertical scanning field using the detector  232  after the planar light region  188  or the vertical scanning field moves to the aligned state (block  250 ). The method  238  can further include automatically rotationally repositioning the planar light region  188 ,  210  or the vertical scanning field about the vertical axis  176  after detecting the misaligned state (block  252 ). When the indicator light beam  189  is used to indicate the selected slope and alignment, the indicator light beam  189  can be automatically rotationally repositioned in concert (e.g., equal in degree, direction, and time, equal in degree and direction, or coordinated in another suitable manner) with the planar light region  188 ,  210 . When the intersection  224  of the planar light region  188 ,  210  and the intersecting planar light region  212  is used to indicate the selected slope and alignment, the intersecting planar light region  212  may be automatically rotationally repositioned in concert with the planar light region  188 ,  210  or may remain stationary. The method  238  can further include detecting a return of the planar light region  188 ,  210  or vertical scanning field to the aligned state (block  254 ). The method  238  can further include automatically ceasing the rotational repositioning after detecting the return of the planar light region  188 ,  210  or of the vertical scanning field to the aligned state (block  256 ). The method  238  can also include other suitable operations. As an example, the method  238  can include automatically leveling the first and second light emitters  126 ,  127 . 
     Conclusion 
     This disclosure is not intended to be exhaustive or to limit the present technology to the precise forms disclosed herein. Although specific embodiments are disclosed herein for illustrative purposes, various equivalent modifications are possible without deviating from the present technology, as those of ordinary skill in the relevant art will recognize. In some cases, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the present technology. Although steps of methods may be presented herein in a particular order, in alternative embodiments the steps may have another suitable order. Similarly, certain aspects of the present technology disclosed in the context of particular embodiments can be combined or eliminated in other embodiments. Furthermore, while advantages associated with certain embodiments may have been disclosed in the context of those embodiments, other embodiments can also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages or other advantages disclosed herein to fall within the scope of the present technology. Accordingly, this disclosure and associated technology can encompass other embodiments not expressly shown or described herein. 
     Certain aspects of the present technology may take the form of computer-executable instructions, including routines executed by a controller or other data processor. In at least some embodiments, a controller or other data processor is specifically programmed, configured, and/or constructed to perform one or more of these computer-executable instructions. Furthermore, some aspects of the present technology may take the form of data (e.g., non-transitory data) stored or distributed on computer-readable media, including magnetic or optically readable and/or removable computer discs as well as media distributed electronically over networks. Accordingly, data structures and transmissions of data particular to aspects of the present technology are encompassed within the scope of the present technology. The present technology also encompasses methods of both programming computer-readable media to perform particular steps and executing the steps. 
     The methods disclosed herein include and encompass, in addition to methods of practicing the present technology (e.g., methods of making and using the disclosed devices and systems), methods of instructing others to practice the present technology. For example, a method in accordance with a particular embodiment includes emitting a planar light region from a light-emitting device, adjusting an alignment of the planar light region to move the planar light region to an aligned state, emitting an indicator light beam from the light-emitting device, adjusting a slope of the indicator light beam to move the indicator light beam to a selected slope, detecting a misaligned state of the planar light region using a detector after the planar light region moves to the aligned state, automatically rotationally repositioning the planar light region in concert with the indicator light beam about a vertical axis after detecting the misaligned state, detecting a return of the planar light region to the aligned state, and automatically ceasing the rotational repositioning after detecting the return of the planar light region to the aligned state. A method in accordance with another embodiment includes instructing such a method. 
     Throughout this disclosure, the singular terms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise. Similarly, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the terms “comprising” and the like are used throughout this disclosure to mean including at least the recited feature(s) such that any greater number of the same feature(s) and/or one or more additional types of features are not precluded. Directional terms, such as “upper,” “lower,” “front,” “back,” “vertical,” and “horizontal,” may be used herein to express and clarify the relationship between various elements. It should be understood that such terms do not denote absolute orientation. Reference herein to “one embodiment,” “an embodiment,” or similar formulations means that a particular feature, structure, operation, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present technology. Thus, the appearances of such phrases or formulations herein are not necessarily all referring to the same embodiment. Furthermore, various particular features, structures, operations, or characteristics may be combined in any suitable manner in one or more embodiments.