Abstract:
A gas detecting apparatus and method for detecting gas leaks are disclosed. The gas detecting apparatus includes an infrared (IR) detector configured to monitor a presence of one or more gases in a field-of-interest (FOI), wherein the IR detector generates IR light distribution information within the FOI; a controller configured to analyze the IR light distribution information to identify one or more locations of one or more gases in the FOI; and a visible light projector configured to project a visible image in the FOI based on the analysis by the controller, wherein the visible image depicts the one or more locations of the one or more gases in the FOI.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 62/316,448, filed on Mar. 31, 2016, and U.S. Provisional Patent Application Ser. No. 62/329,948, filed on Apr. 29, 2016, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present disclosure relates to a laser scanning detection and visualization apparatus, and more particularly, to a laser scanning detection and gas leak visualization apparatus that can aid the user to quickly identify leaks within a field-of-interest (FOI) within a laser scanning window which is the actual/real scene field-of-view (or field of projection). 
       BACKGROUND OF THE INVENTION 
       [0003]    Current competing solutions on the market today are hand-held remote methane leak detectors (RMLD) which detect gases by shooting stationary beams of both IR and visible laser light into a sampling space for the purpose of gas detection and device aiming, respectively. The visible laser in today&#39;s RMLD&#39;s output a single stationary beam, which results in a single visible dot into the sampling space. 
         [0004]    A detecting light beam source (IR laser) when intersecting a gas leak, a RMLD audibly signals to the user that a gas has been detected. At this point, the user can move closer to a leak but the single detecting light beam must continue to intersect the gas plume cloud. One problem with this solution is that gas plume clouds can dissipate making the RMLD appear to give unstable intermittent results. In addition, the RMLD must continuously be moved back and forth by hand in order to hunt for the leak. The RMLD readings that are provided to the user of the RMLD is gas concentration detected but the actual location of the leak, demarcation of leaks in-field sample space, shape of the gas plume, quantity of gas (rate of leakage) is not provided to the user as could be achieved by a scanning laser (and other “rastering” techniques, including, for example, solid state LiDAR and polygon mirrors). 
         [0005]    For example, known RMLD products emit one IR (Infrared) beam and can only detect a gas along the IR beam path. 
       SUMMARY OF THE INVENTION 
       [0006]    In consideration of the above issue, it would be desirable to have a gas leak visualization apparatus that can aid the user to quickly identify leaks within a field-of-interest (FOI) within a laser scanning window which is the actual/real scene field-of-view (or field of projection), and reduces the cycle time and the costs associated with identifying gas leaks which could pose a danger to surrounding people and assets. 
         [0007]    A gas detecting apparatus is disclosed, comprising: an infrared (IR) detector configured to monitor a presence of one or more gases in a field-of-interest (FOI), wherein the IR detector generates IR light distribution information within the FOI; a controller configured to analyze the IR light distribution information to identify one or more locations of one or more gases in the FOI; and a visible light projector configured to project a visible image in the FOI based on the analysis by the controller, wherein the visible image depicts the one or more locations of the one or more gases in the FOI. 
         [0008]    A method is disclosed for detecting gas leaks, comprising: generating Infrared (IR) light distribution information within a field-of-interest (FOI); analyzing the IR light distribution information to identify one or more locations of one or more gases in the FOI; and projecting with a visible light a visible image in the FOI based on the analyzed result, wherein the visible image depicts the one or more locations of the one or more gases in the FOI. 
         [0009]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
           [0011]      FIG. 1  is an illustration of a gas detection apparatus with an integrated pointer in accordance with an exemplary embodiment. 
           [0012]      FIG. 2  is an illustration of a gas detection apparatus with an integrated pointer in accordance with another exemplary embodiment. 
           [0013]      FIG. 3  is an illustration of a gas detection apparatus with an integrated pointer in use in accordance with a further exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
         [0015]    In accordance with an exemplary embodiment, a laser scanning gas leak detector and visualization apparatus is disclosed, which is able to “frame” the actual field-of-interest (FOI), and project onto the field-of-interest for the purpose locating the apparatus field-of-view and for projecting annotations/markings/highlights to assist the user in locating gas leaks. In this exemplary embodiment, the laser scanning gas leak detector is preferably a hand-held type, which a user can easily carry around the field to be inspected. However, the gas leak detector can be mounted on an automobile, a plane, or even a building, which is stationary. 
         [0016]    In accordance with an exemplary embodiment, the gas detection apparatus may perform gas leak detection, discern gas type, provide local gas leak location and distance from the laser apparatus, and provide geo-location when GPS enabled, and create 3D (three-dimensional) point cloud data. For example, the system may use laser(s), sensor(s) (APD), camera(s), and optics to identify the gas(es), and visible lasers to annotate/mark/point to gas leak sources and seepage locations, as well as framing the laser scan field-of-interest for ease of precise pointing of the apparatus. Utilizing the system capabilities for distance ranging, for example, time of flight, and/or a distance measurement system using the triangulation principle, the apparatus can be configured to precisely geo-locate gas leaks within the actual FOI (field-of-interest). 
         [0017]    In accordance with an exemplary embodiment, imaging and point cloud data captured can be obtained about the gas leak and the surrounding scene, which can be processed algorithmically to annotate the actual field of projection in real-time. Thus, allowing the user, for example, to see the gas leak locations with a visible laser by projecting annotations, marks, and/or highlights onto adjacent surfaces and/or objects in actual field-of-interest. Additionally, leak location can be shown concurrently on a display as part of the apparatus with same in-field notations overlaid about the leak. For example, in accordance with an exemplary embodiment, the user with visual and stored gas leak information (in-field photo, leak rate, gas concentration, gas type, GPS (global positioning system) location, etc.) could grade the leak, report, and schedule appropriate follow-up action. 
         [0018]    In accordance with an exemplary embodiment, the laser scanning device as disclosed herein can include features such as the “framing” of the field-of-interest being sampled for gas leaks, and the “projection” of in-field-of-interest annotations, marking, highlighting, etc. In accordance with an exemplary embodiment, the apparatus  100  as shown in  FIG. 1  can provide simultaneous “projection” and “scanning” utilizing a light engine containing a micro-electrical-mechanical system (or MEMs), and a rastering system such as a micro-electrical-mechanical system (MEMs), which can enable the scanning of lasers (including, for example, Visible &amp; IR Lasers). In combination with, for example, IR (Infrared) &amp; RGB cameras, the apparatus  100  can enable a user to sense gas leaks, and create 3D point clouds of gas leaks and surrounding objects to determine the exact location of gas leakage points and/or areas. 
         [0019]      FIG. 1  is an illustration of a gas detection apparatus  100  with an integrated pointer in accordance with an exemplary embodiment. As shown in  FIG. 1 , the gas detection apparatus  100  can include an IR Laser  110 , one or more cameras  120 , at least one visible laser  130  (for example, green, red, blue, yellow, white, or any combination, for example, of green, red, blue, yellow, and/or white) for highlighting/annotating/marking leaks in the field-of-interest (FOI), a laser controller  140 , for example, a MEMs or laser actuation device, an optics module  150 , for example, a scanning MEMs mirror, and a micro processing unit (MPU or microprocessor)  160 . In accordance with an exemplary embodiment, the field-of-view of the one or more cameras  120  can coincide with the laser scanning window of the IR laser  110  and the at least one visible laser  130  as generated by the scanning MEMS mirror of the laser controller  140 . 
         [0020]    In accordance with an exemplary embodiment, the MPU  160  preferably is capable of storing frames of data and editing the frames of data algorithmically to support an accurate assessment of gas leaks and projection of lasers onto the field-of-interest. For example, in accordance with an exemplary embodiment, the MPU  160  can include a graphical processing unit (GPU) with an integrated or a separate frame buffer. 
         [0021]    In accordance with an exemplary embodiment, the one or more cameras  120  can include, for example, multi-spectral cameras, hyperspectral cameras, RGB cameras, black and white (B&amp;W) cameras, IR cameras, thermal cameras, and photodiodes. In addition, the one or more cameras  120  can have various types of sensors and/or arrays of sensors. In accordance with an exemplary embodiment, the apparatus  100  can include an optics module  127  ( FIG. 2 ) that can include optical filters including band-pass filters, taking optics and opto-mechanics. 
         [0022]    In accordance with an exemplary embodiment, the IR laser  110  includes an IR source  112 . The IR source  112  is configured to generate a pulsating or solid beam of IR light, which is received by the laser controller (or laser controller module)  140 , which is configured to direct or steer the light sources in a raster pattern. In accordance with an exemplary embodiment, the laser controller  140  comprises a driver of the visible light source. 
         [0023]    In accordance with an exemplary embodiment, the optics module  150  as disclosed herein can be referred to as a “combiner”. After pulsed light packets exit the optics module  150 , the laser controller (or MEMs module)  140  will continuously raster IR light and selectively place visible light to create notations and other graphics into the scene field-of-interest. In accordance with an exemplary embodiment, the laser controller (or MEMS)  140  directs the IR and visible light in a 2D (two-dimensional) raster pattern comprised of pulsed packets of light for each and every raster element in the scanning field-of-interest. 
         [0024]    In accordance with an exemplary embodiment, the optics module  150  can be configured to perform beam shaping, collimating, combining, and light mixing along a common path, for example, into a two-dimensional pattern, which can be comprised of a raster or matrix of individual beams of light, which are scanned across the defined two-dimensional pattern. The optics module  150  can also be configured to direct the pulsating or solid train of visible light into a visible frame (or light frame), which frames the two-dimensional pattern of IR light on the field-of-interest during gas leak detection. For example, the two-dimensional pattern can be a defined shape, such as a rectangle, ellipse, oval, square, or other suitable shape. In accordance with an exemplary embodiment, the projected pattern can be projected as a two-dimensional pattern, however, upon reaching the field-of-interest, a three-dimensional (3D) pattern can be formed (X, Y, Z). Accordingly, in accordance with an exemplary embodiment, the apparatus  100  can have the capability to adjust projection shapes, images, and video to correct for surfaces specific to the scanned scene. In accordance with an exemplary embodiment, this adjustment can be enabled via the IR point cloud information that is captured by the returning IR signal from the field-of-interest or scene. 
         [0025]    In accordance with an exemplary embodiment, rather than the laser controller (or module)  140  generating the pulsating beam or IR light, the pulsating effect can be generated by the IR source  112 , which can be configured to project a plurality of beams of radiation (or pulses) in the defined pattern at a pre-determined repetitive rate or timing sequence. 
         [0026]    In accordance with an exemplary embodiment, the plurality of emitted beams of radiation or light in the defined pattern pass through a volume of gas within the field-of-interest, and energy in the form of light from the laser beams is absorbed at certain wavelengths, depending on the properties of the detected gas. The light from the apparatus  100  is scattered from the target, and returns to the at least one camera  120 , more specifically, the IR camera  122 , where the light or energy is collected and focused onto the IR camera  122  where the light or energy can be analyzed to identify the presence of one or more gas or gas-like substances in the field-of-interest. For example, carbon monoxide absorbs light or energy at a wavelength of about 4.2 μm to 4.5 μm. The energy in the wavelength can be compared to a wavelength outside of the absorption range, and the difference in energy between the two wavelengths is proportional to the concentration of gas present. The gas concentration information obtained from the field-of-interest can be used to identify an outline shape of the gas plume by thresholding the concentration data, and this outline shape can be projected by the visible laser light or superimposed on the display. In addition, the distribution of the gas concentrations in the field-of-interest can be used to identify the location of the leakage source in the scene, which is usually a crack on the ground or a seam between pipes, and the identified source location can be marked in the field by the visible laser or by the display. 
         [0027]    In accordance with an exemplary embodiment, the apparatus  100  can include at least one camera  120 , for example an IR camera  122 , an optional RGB camera  124 , and an optional thermal camera  126  ( FIG. 2 ). In accordance with an exemplary embodiment, the IR  122  camera can be configured to capture the infrared (IR) light or energy returning from the defined pattern, which can be depicted on a display to assist the operator with identifying the location of the detected gas. In accordance with an alternative embodiment, the IR camera  122  can be a multi-spectral camera, a hyper-spectral camera, a RGB camera, and/or a black &amp; white (B/W) camera. 
         [0028]    The MPU  160  is preferably a microprocessor, which includes a central processing unit (CPU) on a single integrated circuit (IC), or at most a few integrated circuits. The microprocessor is a preferably a multipurpose, clock driven, register based, programmable device that accepts digital data or binary data as input, processes it according to instructions stored in its memory, and provides results as output. In accordance with an exemplary embodiment, the MPU  160  is configured to receive and compute information received from the IR laser  110 , the one or more cameras  120 , the plurality of visible lasers  130 , the laser controller or laser actuation module  140 , and the optics module  150 . In accordance with an exemplary embodiment, the MPU  160  accesses to a memory (not shown) to refer spectral information of multiple characterized gases of interest against which the signal from the gas can be compared against in order to determine the gas type. In accordance with an exemplary embodiment, the MPU  160  communicates with a display  262  ( FIG. 2 ). 
         [0029]    In accordance with an exemplary embodiment, the apparatus  100  includes at least one visible color laser  130 , which is projected onto the field-of-interest (FOI) in the form of a frame or framing feature, for example, a light frame. The at least one visible light color laser  130  can be, for example, a green, red, blue, yellow, white or any combination of visible for highlighting/annotating/marking leaks in the field-of-interest. In accordance with an exemplary embodiment, the at least one visible color laser  130  is sent through the laser controller module  140  and the optics module  150  such the at least one visible light is projected in a pattern, which frames an outer edge of the defined area of the pulsating IR laser  112 , which allows an operator and/or user of the laser to visually observe the area in which the apparatus  100  is searching. 
         [0030]      FIG. 2  is an illustration of a gas detection apparatus  100  with an integrated pointer in use in accordance with another exemplary embodiment. As shown in  FIG. 2 , the gas detection apparatus  100  can include an IR Laser and IR camera/detector  110 , one or more cameras  120 , at least one visible laser  130  (for example, green, red, blue, yellow, white or any combination) for highlighting/annotating/marking leaks in the field-of-interest (FOI), a laser controller (or control module)  140 , for example, a MEMs or laser actuation device, an optics module  150 , for example, a scanning MEMs mirror, and a core unit  200 . 
         [0031]    In accordance with an exemplary embodiment, the core unit  200  can include a pulsed laser controller  210 , a VPU (Vision Processing Unit)  220 , a MPU (or CPU)  160 , a GPS module (global positioning system)  230 , one or more memories  240 , and a network interface (I/F)  250 , such as a network connection, a battery  258 , and peripherals  260 . In accordance with an exemplary embodiment, the battery  258  can be a rechargeable battery source. In addition, the gas detection apparatus  100  can include a GPU (graphics processing unit)  251  with frame buffers for processing camera data in real time, and a video overlay  253  configured to support overlay of gas leak information/imagery onto not only the real (or actual) scene but onto the display screen or display  262 . In accordance with an exemplary embodiment, the gas detection apparatus  100  can be Bluetooth®  252  enabled, such that the apparatus  100  can have wireless connectivity with other local devices and/or computers  270 . 
         [0032]    In accordance with an exemplary embodiment, the one or more cameras  120  can include, for example, an IR camera  122 , a RGB camera  124 , and other cameras, for example, a thermal camera, a multi-spectral camera, a hyper-spectral camera, and photodiodes  126 . 
         [0033]    In accordance with an exemplary embodiment, the core unit  200  can include a pulsed laser controller  210  for controlling the laser power, timing, and pulse, the VPU (vision processing unit)  220  configured to support computer vision on board algorithms, the MPU  160 , the GPS module (global positioning system)  230  for providing location and time information during use of the apparatus  100 . The apparatus  100  can also include the MPU  160  and one or more memories  240  for storing software programs and data. In accordance with an exemplary embodiment, the processor or MPU  160  carries out the instructions of a computer program, which operates and/or controls at least a portion of the functionality of the apparatus  100 . The apparatus  100  can also include an operating system (OS), which manages the computer hardware and provides common services for efficient execution of various software programs. 
         [0034]    The apparatus  100  can also include peripherals  260  such as a display unit or graphical user interface (GUI)  262 , and/or an audio speaker  264 . In accordance with an exemplary embodiment, the apparatus  100  can be configured to provide an audible sound from the speaker  264  when a gas leak is detected. In accordance with an exemplary embodiment, for example, the network interface (I/F)  250  is preferably provided for communication with a display unit or graphical user interface (GUI)  262  via a connection, such as a cable, for example, a USB port, or a wireless connection, for example, Wi-Fi  250 , for example, using radio frequency (RF) and/or infrared (IR) transmission. 
         [0035]    In accordance with an exemplary embodiment, the apparatus  100 , for example, can include an RGB camera  123 , a display screen  262  to support actual image overlaid with digital leak marking &amp; leak data superimposed, a GPS module  230  for precise leak geo-location, Wi-Fi  250  to support wireless transmission of leak detection data, and a vision processing unit (VPU)  220  to manage, for example, point cloud data and computer vision onboard algorithms. 
         [0036]    In accordance with an exemplary embodiment, the peripherals  260  can include a display  262 , which can be a touch screen display, such that the user can press on (or touch) an identified gas leak on the touch screen display  262  to capture an image of the leak along with the geo-location data. 
         [0037]    In accordance with an exemplary embodiment, a remote peripheral or device  270  can be, for example, a tablet, a mobile device, a personal computer (PC) and/or other suitable device, which can be connected via, for example, Wi-Fi  250  or Bluetooth  252  to the apparatus  100 . In accordance with an exemplary embodiment, the remote peripheral or PC  270  can receive and store data detected by the apparatus  100  relating to leaks and pertinent and/or relevant data in real-time. For example, in accordance with an exemplary embodiment, the user using the display  262  on the apparatus  100  and/or the remote peripheral  270  can immediately grade the leak or review each of the leak images to grade the leak at a later time (for example, after further measurements). 
         [0038]    In accordance with an exemplary embodiment, the on-board algorithms of the apparatus  100  may also provide automatic decision making regarding leak grading, safety threat assessment levels considering gas leak attributes, and the geographic location determined via GPS and maps (for example, Google Maps®) of the leak in relation to public buildings, homes, commercial buildings, critical infrastructure or other). In accordance with an exemplary embodiment, the automatic determination can enable consistent assessment of gas leak. In accordance with an exemplary embodiment, the apparatus  100  can be configured to allow the user and/or operator the ability to input data into the data in real-time onto the apparatus  200 , for example, the display  262 , or via remote peripherals  270  and to tag this information for each detected gas leak. In addition, with the built-in Wi-Fi  250  or Bluetooth  252  modules, the apparatus can allow the user and/or operator to upload data onto a remote database (for example, vehicle based or cloud). 
         [0039]    In accordance with an exemplary embodiment, a variation of this disclosure is to use only camera technology to identify a gas leak (not IR laser with IR Camera combo), and to incorporate a separate laser pointer, which can for example, can compute or calculate distance to leaks in the field-of-interest. In accordance with an exemplary embodiment, for example, the separate laser pointer can be a motorized or other mechanical means laser pointer. In addition, the apparatus  100  may use a solid state LiDAR, for example, to help measure distances and for imaging of detected gases and other means to perform rastering. 
         [0040]    In accordance with an exemplary embodiment, the apparatus  100  can be configured to employ “active” gas detection scanning (for example, laser scanning), which can increase, for example, the contrast of the gas(es) within the scene (for example, thermal contrast). In accordance with exemplary embodiment, the laser  112  within the apparatus  100  can be used to increase the temperature of the detected field-of-interest (for example, above ambient temperature) to aid in the detection, for example, of a specific type of gas and/or the identification of one or more different types of gases by actively adding a thermal element to the field-of-interest and through use of not only the IR camera, but also a thermal camera  126 . 
         [0041]    In accordance with another exemplary embodiment, the laser  112  can be configured to emit one or more types of lights having one or more different band widths or wavelengths to aid in the detection of the one or more gases. For example, the laser  112  can be configured to emit one or more different bandwidths or wavelengths, for example, IR 1 , IR 2 , IR 3 , (e.g., IR lambda1, IR lambda2, IR lambda3), in a series of pulsed packets of light, which can be detected by the cameras  120 , for example, the IR camera  122 , for improved detection or distinguishing of the one or more gas(es) within the field-of-interest by providing additional contrast in an active process. In accordance with an exemplary embodiment, the one or more different bandwidths or wavelengths of IR lights can be produced using the optics  150  within the apparatus  100 , for example, a combiner. 
         [0042]    In accordance with an exemplary embodiment, once a gas is detected via the apparatus&#39; algorithms and image processing, the rastering of the laser(s) used for gas detection the field-of-interest can be reduced and the laser scanning over the gas leak plume can be intensified to increase the local contrast (for example, thermal) of the gas and the signal intensity received by the apparatus camera and or sensors, which can be called “Hyper IR” or “Hyper IR Scanning”. For example, two or more bandwidths or wavelengths can be used to speciate (inform or identify the specific gas) gases. In accordance with an exemplary embodiment, by the increasing number of bandwidths or wavelengths for scanning, for example, an apparatus  100  can be produced, which can be identified as “Dual Band Hyper IR Scanning” (two bandwidths or wavelengths), “Tri Band Hyper IR Scanning” (three bandwidths or wavelengths), and/or “Quad Band Hyper IR Scanning” (four bandwidths or wavelengths). 
         [0043]    In accordance with an exemplary embodiment, with the use of a single or a multiple band hyper scanning, the apparatus  100  can be configured to increases the local contrast signal of the gas(es) to be received by the camera  120  and increase the number of return signal data points from the gas leak plume for algorithmic computation accuracy. In addition, the apparatus  100  can be configured to support multi bands of laser light along the same light path which may return to the camera(s), for example, for the direct comparison of a reference signal vs. second band along the same light path. In accordance with an exemplary embodiment, hyper scanning of a gas leak plume can enable multiple readings from within a gas plume with each and every pulsed point projection of the laser(s). 
         [0044]    In addition, with the visible lasers, and different colors, the apparatus  100  can be configured to produce different colors of light, for each type of gas detected and/or different patterns of light for different types of gases. For example, in addition to producing a visible light frame, which is projected and frames the two-dimensional projecting pattern of IR light on a field-of-interest during gas leak detection, the detected gases can include for example, a red image or outline for methane, a blue image or outline for H 2 S (hydrogen sulfide), and a green image or outline for a third type of gas, or indication that a dangerous situation has been encountered. In addition, different patterns, cross-hatchings, arrays of dots and symbols, and/or text messages can be projected onto the detected gases in a single color and/or multi-colors. The apparatus  100  can also be programmed to provide detected leak concentrations, leak rates, and/or the ability to focus or be concentrated onto one or more sections or areas of the detected gas(es). 
         [0045]    In accordance with an exemplary embodiment, as shown in  FIG. 3 , a user can point the hand-held laser scanning gas leak detector apparatus  100 , which emits a pulsating beam of short duration of IR light in a two-dimension pattern  330  onto a field-of-interest (FOI)  300  by hand and moves the apparatus  100  to and around the field-of-interest  300  and begins to search for gas leaks  310 , which can include, for example, a ground crack  312  releasing a gaseous material. In accordance with an exemplary embodiment, the apparatus  100  will project markings  320  (for example, a visible light frame  322 , which frames the pulsating beam of IR light, and/or visible light outlines and marking depicting detected gas leaks  324 ) onto objects in the field-of-interest  300  to assist the user to visually identify the area being analyzed. 
         [0046]    In accordance with an exemplary embodiment, once a leak is identified and the notation is projected, the user in practice may move the apparatus  100  but the projection will stay on the encountered gas leaks (via internal tracking algorithm of the leak features). In accordance with an exemplary embodiment, should the leak move out of the scanning and gas detection field of view, the apparatus  100  can provide audible signals, projected visual signals, or notations on the display  262  to help the user or operator to return to the encountered leak(s). 
         [0047]    In accordance with an exemplary embodiment, the apparatus  100  can have a display  262  ( FIG. 2 ) that shows the field-of-interest  300  including the projected laser markings  322  that frames the emitted pulsating beam of short duration of IR light in the two-dimension pattern  300  and visible laser markings  324  of detected gases  310 . In accordance with an exemplary embodiment, as the user searches for gases, in the condition where gas is not detected, the display unit  262  of the apparatus  100  displays only the projected frame  322  and the scene being analyzed. 
         [0048]    In the situation in which, for example, a gas leak  310  is detected within the field-of-interest  300  during the searching for gas, the apparatus  100  may sound an audible confirmation. In addition, at that instant in time in which gas is detected, the apparatus  100  can project marking features, for example, visible light of a different color from the light frame, onto the surroundings nearest the leak to show area of high gas concentration relative to surroundings. For example, the projected marking features can include any shape to mark the location of the leak or seepage locations. In addition, different line types, or colors can be projected by the apparatus  100  to demarcate variations in gas concentration or different gas types encounter by the apparatus  100 . In addition, distance information may be supplementary projected to the field-of-interest  300 . Other examples of such supplemental information would be a kind of gas (in case the detector can detect multiple kinds), a concentration, and/or a warning level. 
         [0049]    In accordance with an exemplary embodiment, multiple leaks or seepage points may be encountered within the field-of-interest  300  and in this case the laser markings can designate the location of each of such leakage points within the field-of-interest (FOI)  300 . In addition, using laser-ranging techniques coupled with GPS, each leak geo-location can be stored on the apparatus  100  in one or more of the memories  240  along with a picture (or image) of the leak location (for example, utilizing B/W or RGB Image sensor array). Since the laser scanning also creates a point-cloud the gas leak locations can be rectified with features within the scene, for example, sidewalks, rocks, trees, buildings, street curbs, etc. 
         [0050]    In accordance with an exemplary embodiment, for example, using point cloud distance data and geo-location, a leak&#39;s location may be rectified with any and all industrial plant components (for example, valves, pumps, equipment, pipes, etc.) within, for example, oil &amp; gas and/or petrochemical plants. This type of functionality can benefit both hand held and permanent installation of this apparatus  100  in support of leak detection activities such as leak detection and repair (LDAR) monitoring. 
         [0051]    In addition, the apparatus  100  can be configured to be mounted to vehicles (manned or unmanned), mounted to stationary objects such as infrastructure, poles, buildings, or whether it is actuated by hand or by motors for rotation, pan and tilt. For example, in accordance with an exemplary embodiment, the apparatus  100  as shown in  FIGS. 1 and 2  can be mounted, for example, to aerial vehicles, for example, unmanned aerial vehicles and/or drones. 
         [0052]    For instance, although the above-mentioned exemplary embodiments use an IR laser  110  to actively detect gas leakage, the present invention may be achieved with using a passive way (or approach) for the gas leakage detection. In other words, the gas detection by the IR camera  122  can be achieved with using IR light in the environment, without actively shooting the IR laser dots into the field-of-interest  300 . In such case, the frame projection by the visible laser  130  is carried out so that the projected frame agrees to the viewing angle (or the detection angle) of the IR camera, which is known. 
         [0053]    In addition, the area of the field-of-interest  300  may be reduced once a gas leakage is detected. By increasing the intensity or resolution of the IR laser dots in the reduced field-of-interest  300 , the local thermal contrast can be increased and thereby the signal intensities from the field-of-interest can increase. This also can be achieved by supporting multi bands of laser lights along the same light path which may return to the camera(s), for example, for the direct comparison of a reference signal vs. second band along the same light path. In addition, multiple IR lasers may be used to recognize the kinds of the detected gases in the same reduced field-of interest, or multiple discrete reduced field-of-interests. 
         [0054]    It will be apparent to those skilled in the art that various modifications and variation can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.