Abstract:
There is described a method and a system for providing a sighting reticle oriented to aim at a target from a vehicle within an environment of the target. The method improves the situational awareness of the operator regardless of the orientation and motion of the aiming instrument and thus finds applications for the control of Unmanned Aerial Vehicle (UAV). The method comprises providing a graphical image representing the environment as seen from the vehicle when aiming at the target; determining a state of the vehicle with respect to a spatial reference point; overlaying the sighting reticle onto the graphical image, the sighting reticle indicating the target on the graphical image with respect to the spatial reference point, the sighting reticle comprising a marking defining the spatial reference point; positioning the sighting reticle to orient the marking based on the state of the vehicle; and displaying on a display device the sighting reticle positioned on the graphical image to enable aiming at the target.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of U.S. Provisional Patent Application No. 60/910,806 filed on Apr. 9, 2007, the contents of which are hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This application relates generally to aiming devices to display device for displaying vehicle state information. 
       BACKGROUND OF THE ART 
       [0003]    Typical sighting or targeting reticles generally comprise a circular sighting ring with a central cross-hair or “pipper” which marks the exact aiming-point or target at within the field of view of the sighting ring.  FIG. 1  illustrates a simple example of the basic reticle symbology of the prior art. 
         [0004]    Sighting reticles may be adequate for gun sighting or camera-aiming purposes, particularly when the associated device (e.g. the gun or the camera) maintains a fixed orientation with respect to an operator. The situation becomes more complex however, when the frame of reference is no longer fixed. This situation occurs for example with a turret-mounted device which incorporates two or more axes of rotational freedom compared to a position of the operator. The most complex level of abstraction arises when the operator is no longer located in an aiming vehicle, as is the case for example with Unmanned Aerial Vehicles (UAVs). 
         [0005]    In controlling UAVs for example, the operator lacks all non-instrument cues regarding the orientation and flight path of the vehicle, which makes it extremely challenging for a sensor operator to remain oriented in space. When a target of interest (TOI) or a “threat” is identified on the camera image, it is extremely difficult for the operator to determine which direction the vehicle should be turned to intercept, photograph, or evade the “threat”. Some systems use auto-stabilization and auto-tracking devices to diminish the adverse effects by maintaining a “lock” on the target using gimballing techniques. These techniques however add yet another level of abstraction outside the operator&#39;s control loop for the vehicle and its sighting system. 
         [0006]    There is therefore a need to provide a sighting reticle which aids an operator in controlling the vehicle. 
       SUMMARY OF THE INVENTION 
       [0007]    The present application therefore addresses issues associated with the prior art. 
         [0008]    In accordance with one of multiple embodiments, there is described a method for providing a sighting reticle oriented to aim at a target from a vehicle within an environment of the target. The method comprises: providing a graphical image representing the environment as seen from the vehicle when aiming at the target; determining a state of the vehicle with respect to a spatial reference point; overlaying the sighting reticle onto the graphical image, the sighting reticle indicating the target on the graphical image with respect to the spatial reference point, the sighting reticle comprising a marking defining the spatial reference point; positioning the sighting reticle to orient the marking based on the state of the vehicle; and displaying on a display device the sighting reticle positioned on the graphical image to enable aiming at the target. 
         [0009]    In accordance with another one of multiple embodiments, there is provided a system which provides a sighting reticle oriented to aim at a target from a vehicle within an environment of the target. The system comprises: a processing module; a database accessible by the processing module; an application coupled to the processing module; and a display unit. The application is configured for: receiving vehicle state information from the vehicle; receiving a graphical image, the graphical image representing the environment as seen from the vehicle when aiming at the target; determining a state of the vehicle with respect to a spatial reference point using the vehicle state information received; overlaying the sighting reticle onto the graphical image received, the sighting reticle indicating the target on the graphical image with respect to the spatial reference point, the sighting reticle comprising a marking defining the spatial reference point; and positioning the sighting reticle to orient the marking based on the state of the vehicle. The display unit is for displaying the sighting reticle positioned on the graphical image to enable aiming at the target. 
         [0010]    Further details of these and other aspects of the present invention will be apparent from the detailed description and Figures included below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Reference is now made to the accompanying Figures depicting aspects of the present invention, in which: 
           [0012]      FIG. 1  is a schematic illustration of a simple example of the basic reticle symbology according to the prior art; 
           [0013]      FIG. 2   a  is a schematic illustration of an oriented sighting reticle overlaid on an image with a horizon line in accordance with an embodiment; 
           [0014]      FIG. 2   b  is an exemplary display of an oriented reticle overlaid on an image with a runway; 
           [0015]      FIG. 2   c  is another exemplary display of an oriented reticle overlaid on an image with a body of water and a pier; 
           [0016]      FIG. 3  is a flow chart of a method for providing an oriented sighting reticle for aiming at a target, in accordance with an embodiment; and 
           [0017]      FIG. 4  is a schematic illustration of a system for aiming at a target, in accordance with an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The sighting reticle thus provided and displayed in accordance with the present description modifies the traditional reticle symbology by using vehicle information and spatial referencing. 
         [0019]    Reference is made to  FIG. 2   a , which illustrates an exemplary display of an oriented reticle as per the method and system described hereinbelow. In  FIG. 2   a , there is shown a graphical image  30  having a sighting reticle  32  overlaid thereon. The graphical image  30  shows a horizon line  34  along with geographical features (not shown). 
         [0020]    The sighting reticle  32  has a sighting ring  38  (also referred to as a sighting circle) and a central reference symbol  40  such as that defining central cross hairs for example, therein aimed at a target. Marking  42  on the sighting ring  38  represents a spatial reference point. Additional optional indices  44  (annotated or not) can be added to the sighting reticle  32  to add reference points. These can be spaced by varying angles “a” as desired around the sighting ring  38  and can form, with the spatial reference point at  42 , a spatial reference frame for indicating a state of the vehicle. Other vehicle heading indices such as index  46  can be added to the sighting reticle to indicate a heading direction of the vehicle. In addition, the central reference symbol  40  can be adapted to represent a shape of the vehicle from which an orientation of the vehicle can be inferred. In addition to the above, vehicle state information  48  can be overlaid on the graphical image, as illustrated. 
         [0021]      FIGS. 2   b  and  2   c  both provide examples based on electronic imagery obtained from a UAV aiming or sensor equipment ( 76  or  78 ) having a spatial reference point  42  defined as True North. The aiming equipment system in  FIG. 2   b  is oriented in an approximately Northeasterly direction, as depicted by the top-centre of the sighting ring  38 , close to the horizon line  34 . In contrast, the vehicle  74  is heading in a Southeasterly direction as indicated by the vehicle heading orientation index  46 , almost parallel to the runway  92 . The target at central reference symbol  40  is shown to be at the intersection of the taxiway, on the other side of the runway  92 , with the short cutoff leading to the runway  92 . 
         [0022]    In  FIG. 2   c , the target as seen by the aiming equipment  76  and the vehicle  74  are almost aligned. The vehicle  74  is heading slightly West of South, toward the far point of the bay  100 , and the aiming equipment is aiming slightly East of south. The pier  102  runs Northeast-Southwest, and the target at central reference symbol  40  is directly on the pier  102 , slightly off-shore from the beach  104 . 
         [0023]    Referring now to  FIG. 3 , there is described a method for providing a sighting reticle oriented to aim at a target. In step  50 , a graphical image representing the environment as seen from the vehicle when aiming at the target is provided. At step  52 , a state of the vehicle is determined. The state is relative to a spatial reference point. Step  54  involves overlaying the sighting reticle onto the graphical image. The sighting reticle indicates the target on the graphical image with respect to the spatial reference point and the sighting reticle comprises a marking defining the spatial reference point. At step  56 , the sighting reticle is positioned to orient the marking based on the state of the vehicle. In step  58 , a display device displays the sighting reticle positioned on the graphical image to enable aiming at the target. Step  60  is optional and involves the display of the state of the vehicle on the graphical image with the sighting reticle. Any display unit can be used to accomplish this display, as for step  58 . 
         [0024]    The graphical imagery includes, but is not limited to, photographic imagery from a camera, radar, infra-red, synthetic imagery, or vision systems where the graphical imagery is formed from graphical data derived from databases. Any type of sensor can be used to acquired the graphical imagery. 
         [0025]    Although the above method applies to any type of vehicle, the examples provided herein are generally based on a UAV because this type of platform tends to pose more severe challenges to an operator than surface-based vehicles. Other possible types of vehicles are for example helicopters, tanks, cars or various aircraft. 
         [0026]    If the vehicle is an aircraft, the vehicle state information may be received from the aircraft&#39;s primary instrumentation systems and may include such information as, but not limited to, aircraft altitude, heading direction, and ground track. This overlaid information is exemplified by  FIGS. 2   b  and  2   c.    
         [0027]    In the present method, further steps can be optionally included to overlay annotated angular markings, such as cardinal bearing indices, on the aiming circle of the sighting reticle. The annotated angular markings are oriented to a selected reference point which can optionally be chosen to be a True, a Magnetic North, a Grid North or any other suitable Grid reference appropriate to the operation of the vehicle. These annotated indices may also be supplemented by additional indices, as desired. Such annotated indices can form together a fully annotated compass rose of 360 degrees although adequate orientation of the reticle can be achieved by the use of a single spatial reference point or a frame formed by the cardinal markings as shown in  FIG. 2   b  or  2   c.    
         [0028]    The above method also optionally has additional vehicle state indices overlaid on the sighting circle of the sighting reticle. In  FIGS. 2   a  and  2   b , a single vehicle state index  46  is shown and aligned with the heading of the vehicle. These represent the vehicle&#39;s heading and/or track in reference to the spatial reference point of the annotated indices on the sighting ring. Two of these indices  46  are used in  FIG. 2   c.    
         [0029]    The central reference symbol  40  is also optionally modified to form a plan-view vehicle representation typical of navigation displays that are well known to one versed in the art. Such adapted central reference symbol has a head  64  and a tail  66  indicative of an orientation of the vehicle in space, while still defining an aiming point or target of the sighting reticle  32 . 
         [0030]    For example, in reference now with  FIGS. 2   b  and  2   c , the central reference symbol  40  is adapted to represent an aircraft by having the symbolic “wings” intersected by a “fuselage” at a centre of rotation of the symbol so as to simultaneously represent the target or aiming point. A symbolic “tail’  66  is also added to the reference symbol to assist in determining its orientation. The central reference symbol is rotatable and oriented in accordance with the vehicle state indices  46  or the vehicle state information. Accordingly, the operator can immediately gauge the direction of the vehicle&#39;s heading orientation (or track) in relation to the graphical imagery  30  and spatial reference point  42  for example. 
         [0031]    Now referring to  FIG. 4 , there is illustrated a system  70  for aiming at a target  72  from the vehicle  74  by implementing an embodiment of the above described method. The vehicle  74  has aiming equipment  76  which optionally has a sensor  78  recording graphical data for representing the environment of the vehicle  74  when aiming at the target  72 . 
         [0032]    The system  70  receives information from the vehicle  74 , including vehicle state information, graphical data and other optional aiming information from the aiming equipment  76 . 
         [0033]    The system  70  has a database  80  for recording information received from the vehicle  74 . This information is retrieved and processed for display by a sighting module  82 . In one embodiment, the database  80  can integrally form part of the sighting module  82 . 
         [0034]    The sighting module  82  has a processing module  84 , an application  86  and a display unit  88 . The processing module  84  has access to the database  80  and the application  86 . 
         [0035]    The system  70  optionally has a graphical database  89  which is dedicated to storing graphical data either as received from the sensor  78  or as compiled beforehand to provide synthetic imaging. Databases  80  and  89  may also be provided as a single database. The system  70  can also have an input device (not shown) allowing an operator to set various customization parameters of the system such as the setting of the spatial reference point or different display options which are then used to update any default parameters stored on database  80 . 
         [0036]    An optional user interface (not shown) can also form part of the system  70 , along with other input/output devices (not shown) allowing various forms of transmission and reception of information between the operator and the system  70 . These input/output devices include but are not limited to, mouse, joysticks, keyboard, touch screen, speaker, microphone and the like. 
         [0037]    The processing module  84  accesses the application  86  and the database  80  or  89  to retrieve vehicle state information as received from the vehicle  74 . In addition, graphical data is retrieved from either the database  89  or the sensor  78 . Such graphical data is used to display on the display unit  88  a graphical image representing the environment as seen from the vehicle  74  when aiming at the target  72 . 
         [0038]    The processing module  84  processes the vehicle state information to determine a state of the vehicle  74  with respect to a given spatial reference point. This state can include information such as a position, an orientation, heading or ground track information of the vehicle with respect to the spatial reference point. 
         [0039]    The processing module  84  overlays a sighting reticle for display on the graphical image to indicate where the target  72  is on the graphical image. The sighting reticle also has a marking placed so as to show the spatial reference point. The processing module  84  thus positions and orients the sighting reticle with its marking over the graphical image to enable a display indicating both the location of the target with respect to the vehicle and in turn the state of the vehicle with respect to the spatial reference point. 
         [0040]    The graphical image and properly overlaid and positioned sighting reticle is then sent to the display unit  88  for display to enable an operator or control equipment to aim the aiming equipment  76  at the target. 
         [0041]    The processing module  84  of the system  70  can implement the above optional actions described herein in relation to the method of  FIG. 3  and displays on the display unit  88  the sighting reticle in accordance with these options. The system  70  enables a control of the vehicle  74  and the aiming equipment  76  on the vehicle  74  by outputting the sighting reticle positioned on the graphical image. This output allows an aiming of the aiming equipment  76  at the target  72 . 
         [0042]    The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without department from the scope of the invention disclosed. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.