A system comprising an imaging device and a passive-optical range-finder to focus, on the imaging device, a magnified image of a target positioned in a focal plane of the passive-optical range-finder. The system receives information indicative of a target type and generates information indicative of an absolute geographic location for the target based on at least the target type and information output by the imaging device.

BACKGROUND

During some military operations, one or more soldiers locate targets to be fired upon by, for example, indirect fire systems or air support and transmit a geographic location for the target to a fire control center or to an integrated tactical network. The fire control center or integrated tactical network then deploys a strike on the target using the target geographic location. Target designators are used by military personnel to determine the geographical coordinates of a target. One type of target designator is designed so that an operator is able to shine a laser at a target and to receive light scattered and/or reflected from the target in order to determine the geographical coordinates of the target.

Such lasers, however, are typically detectable by enemy sensors, which detect the laser light and set off alarms. In some cases, once the enemy realizes the target geographic location is being determined, the target is moved, hidden and/or hardened. Additionally, the enemy can sometimes trace the optical beam back to the operator of the target designator. In this case, the operator can become a target of the enemy.

Moreover, the divergence of the laser beam used in such target designators limits the range of such target designators. If the range is too large, the spot size of the laser becomes too large for range determination. Thus, with some such target designators, the operator must be within 10,000 meters for ranging, and 5000 meters for proper designation of the target, which can place the operator in tactical danger. Timing, coordination and lethality are of the essence for combined arms operations, particularly for non-organic fire support/air operations. It is highly desirable for the combat team to engage targets at the farthest practical range possible.

Furthermore, there are safety issues associated with target designators that use lasers in this way. If the operator or other soldiers near the target designator look directly into the laser, their retina can be burned and/or their vision otherwise impaired.

SUMMARY

A system comprising an imaging device and a passive-optical range-finder to focus, on the imaging device, a magnified image of a target positioned in a focal plane of the passive-optical range-finder. The system receives information indicative of a target type and generates information indicative of an absolute geographic location for the target based on at least the target type and information output by the imaging device.

The various described features are not drawn to scale but are drawn to emphasize features relevant to the subject matter described. Reference characters denote like elements throughout the figures and text.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments in which the claimed invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the claimed invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, and electrical changes may be made without departing from the scope of the claimed invention. The following detailed description is, therefore, not to be taken in a limiting sense.

FIG. 1is a block diagram of one embodiment of a system100that uses a passive-optical locator132and an imaging device110to determine a distance R to a target50. The passive-optical locator132includes a passive-optical range-finder85, sensors60, a display75, an operator input interface (I/F)111, a communication interface (CI)33, a programmable processor90, a memory91and software120stored or otherwise embodied in or on a storage medium130.

In the embodiment shown inFIG. 1, the passive-optical locator132is deployed in a military application in which the passive-optical locator132operates in conjunction with the imaging device110as a laser-free passive-optical locator to determine the geographic location of a target50. The passive-optical range-finder85focuses a magnified image of the target50on the imaging device110that is positioned in the image plane (i) (not shown inFIG. 1) also referred to here as the focal plane, of the passive-optical range-finder85(as is described in more detail below in connection withFIG. 2). The focal plane of the passive-optical range-finder85is the plane that is perpendicular to the optical axis35of the passive-optical range-finder85and passes through its focus. The target50is located in the object plane (o) (not shown inFIG. 1) of the passive-optical range-finder85. If the object is effectively an infinite distance from the passive-optical range-finder85, then the focal length is equal to the image distance, which is the distance between the front element surface of the lens system and the image plane. An object is effectively an infinite distance from the passive-optical range-finder85when the light rays reflected or emitted from the target50are approximately parallel to each other at the passive-optical range-finder85.

As shown inFIG. 1, the sensors60include a global positioning system/gyroscope (GPS/GYRO) device or subsystem62and other sensors61. The GPS/GYRO device62comprises one or more gyroscopic devices (GYRO)73integrated with a global positioning system (GPS)65. The other sensors61include sensors to sense the relative positions of lenses in an imaging system of the passive-optical range-finder85. In one embodiment, the other sensors61implement position, attitude, and pointing sensor suites that include magnetic compasses, level detectors, accelerometers, pointing feedback loops, odometers, and the like to perform the function of the GPS/GYRO device62in directly coupled system configurations, loosely coupled system configurations, or non-coupled system configurations.

The programmable processor90executes software120and/or firmware that causes the programmable processor90to perform at least some of the processing described here as being performed by the passive-optical locator132. At least a portion of such software120and/or firmware executed by the programmable processor90and any related data structures are stored in memory91during execution. Memory91comprises any suitable memory now known or later developed such as, for example, random access memory (RAM), read only memory (ROM), and/or registers within the programmable processor90. In one implementation, the programmable processor90comprises a microprocessor or microcontroller. Moreover, although the programmable processor90and memory91are shown as separate elements inFIG. 1, in one implementation, the programmable processor90and memory91are implemented in a single device (for example, a single integrated-circuit device). The software120and/or firmware executed by the programmable processor90comprises a plurality of program instructions that are stored or otherwise embodied on a storage medium130from which at least a portion of such program instructions are read for execution by the programmable processor90. In one implementation, the programmable processor90comprises processor support chips and/or system support chips such as ASICs.

The various components of the passive-optical locator132are communicatively coupled to one another as needed using appropriate interfaces (for example, using buses, traces, cables, wires, ports, wireless transceivers and the like). The imaging device10is communicatively coupled to the programmable processor90in the passive-optical locator132using appropriate interfaces (for example, using buses, traces, cables, wires, ports, wireless transceivers and the like).

In one implementation of the passive-optical locator132, imaging device110is an electronic imaging device and comprises a charge-coupled-devices (CCD) or active imaging element sensors (APS). Both APS and CCD technologies input entire frame images to processing electronics so the process is very fast. Available detectors arrays in CCDs and APSs are capable of detecting a broadband spectrum including visible light, the near infrared (NIR), and near ultraviolet. In one implementation of this embodiment, the imaging device110comprises a plurality of detector arrays that in combination cover all of the above spectral ranges. CCD detectors include Intensified CCD (ICCD), Electron Multiplying CCD (EMCCD), and other associated technologies, such as light intensification and infra-red imagery. Light intensification and infra-red imagery allow for night vision.

Examples of a commercially available imaging device110are the Sony ICX428AKL CCD Image Sensor, the MT9D112 SOC COMS Image Sensor, and the CIDTEC Spectra CAM.

The imaging device110is located in the focal plane of the passive-optical range-finder85to generate information indicative of the distance R from the passive-optical locator132to the target50(for example, as described below in connection withFIG. 2). This information is also referred to here as “distance information.”

Distance information is generated in part from information indicative of the focal length of the passive-optical range-finder85when the image of the target50, located at the object distance from the passive-optical range-finder85is focused on the imaging device110. This information is also referred to here as “focal length information.” As used herein, the passive-optical range-finder85is referred to as being “focused” or “in focus” when the passive-optical range-finder85is adjusted so as to focus the magnified image of the target50on the imaging device110. The programmable processor90executes software120to analyze information indicative of the configuration of the passive-optical range-finder85in order to determine the focal length information.

The imaging device110generates or otherwise outputs image signals associated with the target when the passive-optical range-finder85is focused. The distance information is generated in part from information indicative of a target type that is associated with the imaged target50. This additional information is also referred to here as “target-type information.”

The programmable processor90executes software120to determine target dimensions based on the target-type. In one implementation of this embodiment, pattern matching software executed by the programmable processor90generates the target-type information. In another implementation of this embodiment, the programmable processor90outputs the image signals to the display75for viewing of the target image by a user of the passive-optical locator132. In this case, an operator of the passive-optical locator132views the image of the target50displayed on the display75and inputs target-type information via the operator input interface111based on the viewed image.

Additionally, the imaging device110generates or otherwise outputs information indicative of the imaging elements or a subset of the imaging elements on which the target50is imaged when the passive-optical range-finder85is focused. Such additional information is also referred to here as “imaging-element information.” The distance information is generated in part from information indicative of at least one image dimension of the focused magnified image of the target50. This additional information is also referred to here as “image dimension information.”

The programmable processor90executes software120to generate the image dimension information from the imaging-element information. In one implementation of this embodiment, the programmable processor90analyzes the imaging-element information to determine an outline of the image of the target in order to generate the image dimension information.

The distance information is generated in part from information indicative of a magnification of the image of the focused target50. This additional information is also referred to here as “magnification information.” The programmable processor90executes software120to analyze of information indicative of the configuration of the passive-optical range-finder85to determine the magnification information.

The focal length information, the magnification information, the target-type information, the image dimension information comprise the input required for a determination of the distance information.

The one or more gyroscopic devices73in the GPS/GYRO device62generate information indicative of an azimuth θ and an elevation φ of an optical axis35of the passive-optical range-finder85. Such information is also referred to here as “azimuth and elevation information.” InFIG. 1, only one such gyroscopic device73is shown though it is to be understood that one or more gyroscopic devices73are used in various implementations of such an embodiment. In one implementation of such an embodiment, gyroscopic device73comprises an inertial navigation system that generates the azimuth and elevation information. In another implementation of such an embodiment, the gyroscopic device73comprises an accelerometer.

The GPS65in the GPS/GYRO device62generates or otherwise outputs information indicative of an absolute location associated with the passive-optical locator132. Such information is also referred to here as “GPS information.” In one implementation of such an embodiment, the GPS information associated with the passive-optical locator132comprises the latitude LatL, the longitude LongL, and the attitude AltLof the passive-optical locator132. The GPS65comprises various GPS implementations such as Differential GPS (DGPS). Although the gyroscopic device73and the global positioning system65are shown inFIG. 1as a single, integrated device GPS/Gyro device62, in other implementations the global positioning system65and the gyroscopic device73are implemented using two more separate devices. The software120and/or firmware executing on the programmable processor90processes the GPS information, the distance information, and the azimuth and elevation information in order to determine information indicative of an absolute location associated with the target50(also referred to here as the “target location information”). The target location information is defined by a latitude LatT, a longitude LongT, and an altitude AltTof the target50. The target location information is generated using one or more trigonometric relationships between the distance R between the passive-optical range-finder85and the target50, the azimuth θ, and the elevation φ of the optical axis35of the passive-optical range-finder85, and the absolute location of the passive-optical locator132. In one implementation, such trigonometric relationships are established and/or corrected using the calibration techniques described in the '938 Application.

The imaging device110outputs image signals associated with the focused magnified target to the programmable processor90. In one implementation of this embodiment, the programmable processor90outputs the image signals to the display75for viewing of the target image by an operator of the passive-optical locator132. In another implementation of this embodiment, the display75additionally provides a visual indication of the absolute location of the target50for the operator of the passive-optical locator132. In one implementation of such an embodiment, the display75shows the values for the target latitude LatT, target longitude LongT, and target altitude AltT. In another implementation, the display75shows the values for the distance R, the azimuth θ and the elevation φ from the passive-optical locator132. In other implementations, information indicative of the absolute location of the target50is displayed in other ways.

The passive-optical locator132comprises a communication interface (CI)33that communicates at least a portion of the information indicative of the absolute location of the target50from the passive-optical locator132to a remote device20over a communication link71. In one implementation of such an embodiment, the target location information is communicated from the passive-optical locator132to the remote device20by having the operator read such the target location information off the display75and describe the target (for example, “Dismounted troops in the open at this grid coordinate”). The operator announces the target location information and the target description into a microphone coupled to the communication interface33so that the voice of the operator is communicated over the communication link71to the remote device20. In another implementation, the target location information is communicated in digital form from the programmable processor90over the communication link71. In such an implementation, a processor21included in the remote device20executes software to process such target location information.

In an alternative embodiment, the target location information is not generated at the passive-optical locator132and, instead, focal length information, magnification information, target-type information, image dimension information, azimuth and elevation information, and GPS information is communicated from the passive-optical locator132to the remote device20and the remote device20generates the absolute geographic location associated with the target50using such focal length information, magnification information, target-type information, image dimension information, azimuth and elevation information, and GPS information (for example, using software executing on the processor21of the remote device20).

In another embodiment, the distance information is generated at the passive-optical locator132from the focal length information, magnification information, target-type information, image dimension information and then the distance information, azimuth and elevation information, and GPS information is communicated from the passive-optical locator132to the remote device20and the remote device20generates the absolute geographic location associated with the target50using such distance information, azimuth and elevation information, and GPS information (for example, using software executing on the processor21of the remote device20).

In the embodiment shown inFIG. 1, the remote device20is part of an integrated tactical network. The integrated tactical network comprises a wide area network (WAN) used for communications, command, control and intelligence functions for military operations. The integrated tactical network integrates the indirect fire control centers and-forward air controllers to direct fire missions and air strikes. As shown inFIG. 1, the remote device20is part of an integrated tactical network. The remote device20communicates the target location information for the target50to a fire control center25over a communication link72. A target description is also communicated. The fire control center25is operable to deploy a weapon (not shown) on a trajectory26towards the target50. In one implementation, the passive-optical locator132is packaged in a bipod/shoulder unit that can be carried by a soldier. In another implementation, the passive-optical locator132is packaged in a tripod unit that can be carried by a soldier. In yet another implementation, the passive-optical locator132is mounted on a vehicle.

The communication links71and72comprise one or more of a wireless communication link (for example, a radio-frequency (RF) communication link) and/or a wired communication link (for example, an optical fiber or copper wire communication link). For applications of such an embodiment in which secure communication is desired, one or more appropriate protocols for automation, encryption, frequency hopping, and spread-spectrum concealment are used in communicating such information from the remote device20to the fire control center25.

Although a military application is described here in connection withFIG. 1, it is to be understood that the passive-optical locator132can be used in other applications, including commercial applications. Generally, the target50is an object to be located at an absolute geographic location. In one exemplary usage scenario, the object to be located is a person stranded on a side of a mountain. In this usage scenario, a person in a search and rescue party uses the passive-optical range-finder85of the passive-optical locator132to focus on an image of the stranded person and the target location information of the stranded person is communicated to a rescue helicopter. Other applications include geographical surveying, civil engineering and navigation.

In one implementation of this embodiment, the passive-optical locator132and the imaging device110are implemented with a remotely controlled actuator (as described in application Ser. No. 11/482,468) to remotely determine the geographic location of a target50.

One embodiment in which the programmable processor receives the focal length information, the magnification information, the target-type information, the image dimension information needed to determine the distance information is described with reference toFIG. 2andFIG. 3.FIG. 2shows a block diagram of an embodiment of the passive-optical locator132. As shown inFIG. 2, an exemplary passive-optical range-finder85comprises a plurality of lenses represented generally by the numeral86that are aligned along a shared optical axis35to focus and magnify an object, such as the target50(FIG. 1), positioned along the line of sight of the optical axis35. The relative positions of the lenses86shift as the focal length of the passive-optical range-finder85is adjusted to focus on the distant target50and/or to zoom in or out on the target50. The programmable processor90is communicatively coupled to other sensors61that sense the relative positions of the lenses86and send the information indicative of the relative positions to the programmable processor90. The programmable processor90executes software120to generate the focal length information from the relative positions of the lenses86.

In one implementation of this embodiment, the programmable processor90executes software120to generate the magnification information and the focal length information from the relative positions of the lenses86. For example, the operator can rotate one or more knobs (not shown) on the barrel133of the passive-optical locator132to modify the focusing and magnifying of the passive-optical range-finder85. In another implementation of this embodiment, the operator can rotate one or more knobs (not shown) on the barrel133of the passive-optical locator132to modify the field of view of the passive-optical range-finder85.

The imaging device110is positioned at the focal plane116, also referred to as the “image plane116,” of the passive-optical range-finder85. In one implementation of this embodiment, as the relative positions of the lenses86shift, the position of the imaging device110also shifts relative to the lenses86.

The operator views an image of the target50(FIG. 1) that is displayed on the display75, through the viewfinder115.FIG. 3shows an embodiment of an imaging device110on which the magnified image of a target50is focused within a subset of the field of view of the plurality of lenses86. The field of view is generally represented by the numeral235.

The imaging device110comprises an array of imaging elements, for example, pixels, represented generally by the numeral210. The focused magnified image of the target50is incident on a set230of the imaging elements210internal the field of view235in order to generate at least a portion of the information output by the imaging device110. The set230of the imaging elements210includes less than all of the imaging elements210within the field of view235of the passive-optical locator132. The passive-optical locator132in system10(shown inFIG. 1) determines at least one of an image height, an image width, and an image depth of the focused magnified image based on the information output by the imaging device110.

The display75is communicatively coupled to imaging device110to display the magnified image of the target50. The user input interface111receives the information indicative of the target type. The system correlates the information indicative of the target type to one of the plurality of target types in the lookup table and uses at least one of the height, the width, and the depth associated with the correlated target type. The system determines a distance to the target50based on the focal length of the passive-optical range-finder85and at least one of a ratio of the height associated with the correlated target type to the image height, a ratio of the width associated with the correlated target type to the image width, and a ratio of the depth associated with the correlated target type to the image depth. The information indicative of the absolute geographic location for the target is generated, at least in part, based on the distance.

The height of each imaging element is measured along the X-direction and is represented generally by the letter “H.” The width of each imaging element is measured along the Y-direction and is represented generally by the letter “W.” The imaging elements are positioned in a rectangular array of rows and columns. Rows extend in the X-direction and columns extend in the Y-direction. The exemplary imaging device110ofFIG. 3includes six rows and seven columns to form a 6×7 rectangular matrix. The right-most edges of imaging elements210in a shared row have a spacing represented as “SC” that is slightly larger than “W.” Likewise, the bottom-most edges of imaging elements210in a shared column have a spacing represented as “SR” that is slightly larger than “H.”

A processing unit190in the imaging device110is communicatively coupled to each of the imaging elements. The processing unit190sends the image signals from the imaging device110to the programmable processor90. In one implementation of this embodiment, the image signals are sent directly from the imaging elements210to the programmable processor90in the passive-optical locator132.

In this exemplary case, the target50is a heavy armor tank (also referred to here as a “tank”). The magnified image of the tank is focused on a set of the imaging elements that are a subset230of all the imaging elements210within the field of view235of the passive-optical locator132. As shown inFIG. 3, the target image is formed on six adjacent imaging elements210that form a 2×3 rectangular matrix referred to here as subset230. The image height, which is the height of the image of the tank, is represented generally by the numeral220and has a linear dimension of about2SR. The linear dimension2SRis a first portion of the imaging-element information. The image of the tank is seen from the side inFIG. 3. The image length, which is the length of the image of the tank, is represented generally by the numeral225and has a linear dimension of about3SC. The linear dimension3SCis a second portion of the imaging-element information. In one implementation of this embodiment, the subset230of imaging elements210is outlined by input received from the operator of the passive-optical locator132via the operator input interface111.

The processing unit190sends both portions of the imaging-element information to the programmable processor90. The programmable processor90calculates values (in dimensions of length) for the imaging-element information2SRand3SCusing the dimensions SCand SRstored in the memory91. The calculated values are the image dimension information or information indicative of the image height and the image depth. In one implementation of this embodiment, the processing unit190calculates values (in dimensions of length) for the imaging-element information2SRand3SCand sends the image dimension information to the programmable processor90.

If the image of the tank is seen from the front or back, the image width is visible. In that case, the image width replaces the image depth as the second portion of the imaging-element information. In that case, the processing unit190sends the information indicative of the image height and the image width to the programmable processor90as the image dimension information.

The programmable processor90receives the target-type information from the operator of the passive-optical locator132. The operator views the target image, such as the tank image shown inFIG. 2, as it is displayed on the display75. In one implementation of this embodiment, the operator inputs target-type information code via the operator input interface111to the programmable processor90.

In another implementation of this embodiment, the operator views the target image and then selects the associated target-type information from a lookup table stored in the memory91, such as the TABLE 1 shown below. The programmable processor90retrieves a target-type table, such as TABLE 1 which shows dimensions for exemplary target types, from the memory91to obtain the target dimensions for the target. The lookup table comprises information indicative of at least one of a height, a width, and a depth of a respective one of the plurality of target types. In this case, after the operator selects the target-type information, the target-type information is sent to the programmable processor90.

For the exemplary heavy armor tank viewed inFIG. 3, the programmable processor90received the target type of “HEAVY ARMOR TANK” from the operator.

TABLE 1Exemplary target-type table.Exemplary Target typeHeightWidthDepthArmored Personnel Carrier2.3 m2.8 m5.8 mBuilding: Single story6 m8 m9 mBuilding: Two story12 m12 m12 mHeavy Armor Tank4 m4 m7 mTruck (2.5 Ton)5 m4 m9 mPersonnel2 m0.2 m0.5 m
In one implementation of this embodiment, the operator inputs information indicative of the view of the target50via the operator input interface110. In the exemplary case ofFIG. 3, the operator inputs “SIDE VIEW” and the programmable processor recognizes that the depth dimension is required for the tank (for example, 7 meters) from TABLE 1. In another implementation of this embodiment, the operator inputs view and a viewing angle. In this case, the programmable processor90takes the cosine of the viewing angle to translate the view image dimension of width or depth to a front view or side view, respectively. In yet another implementation of this embodiment, the programmable processor uses the elevation information to provide the required cosine factor to the imaged height, if the target50is at an elevation that differs from the elevation of the passive-optical locator132. The programmable processor90retrieves the dimensions for the tank height, tank width, and tank depth of the heavy armor tank from TABLE 1 based one the viewing angle of the target50.

Since the magnification of a lens system is the ratio of the target image/target, the programmable processor90calculates the ratio of the tank image height/tank height, and the ratio of the tank image depth/tank depth to calculate the magnification of the passive-optical range-finder85. The magnification is also the ratio of the focal length of the imaging system of passive-optical range-finder85to the distance R to the target50(shown inFIG. 1). The programmable processor90generates the value of the distance R to the target50by calculating R=focal length/magnification. The passive-optical locator132then determines the absolute location associated with the target50as described in the '938 Application.

In one implementation of this embodiment, the programmable processor90executes software120to generate both magnification information and focal length information from the relative positions of the lenses86. In this implementation, the programmable processor90does not use the target-type information but determines the distance information from the equation M=i/o, where M is the magnification, o is the object distance that equals the focal length, and i is the image distance that equals the distance R to the target50. In one implementation of this embodiment, the generated magnification information provides a confirmation to the ratios of the calculated image height/tank height and the image depth/tank depth.

The passive-optical locator132as shown inFIG. 2can be carried by the operator to a remote location and set up on a tripod when the operator uses the passive-optical locator132. In another implementation of this embodiment, the passive-optical locator132shown inFIG. 2is carried in a land vehicle to a remote location. Thus, system10includes an imaging device110and a passive-optical range-finder85to focus, on the imaging device110, a magnified image of a target50that is positioned in an object plane of the passive-optical range-finder. The system10receives information indicative of a target type and generates information indicative of an absolute geographic location for the target50based on at least the target type and information output by the imaging device110.

Additionally, at least one sensor60generates information indicative of an azimuth and an elevation of an optical axis35of the passive optical range-finder85, and the information indicative of the azimuth and the elevation are additionally used to generate the information indicative of the absolute geographic location for the target50. The information indicative of the absolute geographic location for the target is generated, at least in part, based on at least one of: information indicative of a magnification of the magnified image, information indicative of a focal length of the passive-optical range-finder, and information indicative of a geographic location associated with the passive-optical locator. In one implementation of this embodiment, the information indicative of the absolute geographic location for the target is generated, at least in part, using at least some of the information included in the lookup table. In another implementation of this embodiment, pattern-recognition software120determines the target type for the target50.

FIG. 4shows an embodiment of an imaging device on which the magnified image of a target50is focused within the complete field of view235of the passive-optical locator132. As shown inFIG. 4, the target image is formed on twenty adjacent imaging elements210that form a 4×5 rectangular matrix referred to as “subset240,” and also referred to as the “set of the imaging elements240.” The image height, which is the height of the image of the tank, is represented generally by the numeral250and has a linear dimension of about4SR. The linear dimension4SRis a first portion of the imaging-element information. The image of the tank is seen from the side inFIG. 4. The image length, which is the length of the image of the tank, is represented generally by the numeral255and has a linear dimension of about5SC. The linear dimension5SCis a second portion of the imaging-element information.

The set of the imaging elements240includes all of the imaging elements210within a field of view235of the passive-optical locator132. The imaging elements210have the shape and spacing along the two dimensions X and Y as described above with reference toFIG. 3. The set of the imaging elements240on which the focused magnified image of the target50is incident defines a target outline. The focused magnified image of the target is incident on all the imaging elements in at least one row256of the target outline and all the imaging elements210in at least one column257of the target outline. The row256provides information indicative of the image depth, shown as the length of the tank, and the column257provides information indicative of the image height. If the tank were imaged from the front or back, then row256provides information indicative of the image width.

FIG. 5is a flowchart of one embodiment of a method500of generating information indicative of an absolute geographic location for a target. The embodiment of method500can be implemented using the passive-optical locator132ofFIG. 1. In such an embodiment, at least a portion of the processing of method500is performed by software120executing on the programmable processor90of the passive-optical locator132. Other embodiments are implemented in other ways.

At block502, a passive-optical range-finder is focused to form a magnified image of a target on an imaging device positioned in a focal plane of the passive-optical range-finder (for example, as described above in connection withFIGS. 1 and 2). At block504, information indicative of a target type is received at the passive-optical locator that comprises the passive-optical range-finder (for example, by having a user input such information and/or via the execution of pattern-recognition software). At block506, a lookup table is stored in a memory. The lookup table comprises information about a plurality of target types. In one implementation, the lookup table is created “offline” and stored in a memory (or on or in a storage medium) included in the passive optical locator. The information indicative of the absolute geographic location for the target is generated, at least in part, using at some of the information included in the lookup table. In one implementation, the lookup table comprises information indicative of at least one of a height, a width, and a depth of a respective one of the plurality of target types and the information indicative of the absolute geographic location for the target is generated, at least in part, in the manner described above in connection with TABLE 1 andFIG. 3.

The imaging device comprises an array of imaging elements. The focused magnified image of the target is incident on a set of the imaging elements in order to generate at least a portion of the information output by the imaging device. At least one of an image height, an image width, and an image depth of the focused magnified image is determined based on the information output by the imaging device. In one implementation of this embodiment, the set of the imaging elements includes all of the imaging elements within a field of view of the passive-optical locator (for example, as shown inFIG. 4). In another implementation of this embodiment, the set of the imaging elements is less than all of the imaging elements within the field of view of the passive-optical locator (for example, as shown inFIG. 3). At block508, the information indicative of the target type is correlated to one of the plurality of target types in the lookup table (for example, as described above in connection with TABLE 1).

At block510, a distance to the target is determined based on the focal length of the passive-optical range-finder and at least one of a ratio of the height associated with the correlated target type to the image height, a ratio of the width associated with the correlated target type to the image width, and a ratio of the depth associated with the correlated target type to the image depth (for example, as described above in connection withFIG. 2and TABLE 1). The information indicative of the absolute geographic location for the target is generated, at least in part, based on the distance.

At block512, information indicative of an azimuth and an elevation of an optical axis of the passive optical range-finder is received at the passive-optical locator. The information indicative of the azimuth and the elevation are used to generate the information indicative of the absolute geographic location for the target as described in the '938 Application.

At block514, information indicative of an absolute geographic location for the target is generated based on at least the target type and information output by the imaging device. The information indicative of the absolute geographic location for the target is generated, at least in part, based on at least one of: information indicative of a magnification of the magnified image, information indicative of a focal length of the passive-optical range-finder, and information indicative of a geographic location associated with the passive-optical locator. The information indicative of the absolute geographic location is generated as described above with reference to the '938 application using the information indicative of a magnification of the magnified image and/or the information indicative of a focal length of the passive-optical range-finder in conjunction with the information indicative of a geographic location associated with the passive-optical locator. The information indicative of a magnification of the magnified image and/or the information indicative of a focal length of the passive-optical range-finder are obtained as described above with reference toFIG. 2and the information indicative of a geographic location associated with the passive-optical locator is obtained from the GPS65shown in the sensors60ofFIG. 1.

FIG. 6is a flowchart of one embodiment of a method600of generating an absolute geographic location for a target. The embodiment of method600can be implemented using the passive-optical locator132ofFIG. 1. In such an embodiment, at least a portion of the processing of method500is performed by software executing on the programmable processor90of the passive-optical locator132and/or the GPS/GYRO device62or the passive-optical range-finder85. Other embodiments are implemented in other ways.

At block602, information indicative of a target type is received at a programmable processor (for example, by have a user input such information after viewing a selection menu and/or via the execution of pattern-recognition software). At block604, the programmable processor generates information indicative of a distance between a target and a passive-optical locator based on the target type. For example, the programmable processor90determines a distance R to the target50based on the focal length of the passive-optical range-finder85and a ratio of the height associated with the correlated target type to the image height and a ratio of the width associated with the correlated target type to the image width. In another implementation, the programmable processor90determines a distance R to the target50based on the focal length of the passive-optical range-finder85and a ratio of the height associated with the correlated target type to the image height and a ratio of the depth associated with the correlated target type to the image depth.

At block606, the programmable processor receives information indicative of an azimuth and an elevation of a direction to the target as described in the '938 application. At block608, the programmable processor receives information indicative of the geographic location of the passive-optical locator from the GPS65shown in the sensors60ofFIG. 1. At block610, the programmable processor generates an absolute geographic location of the target based on at least: the information indicative of the distance between the target and the passive-optical locator; the information indicative of an azimuth and an elevation of a direction to the target; and the information indicative of the geographic location of the passive-optical locator. With reference toFIG. 1and as described in the '938 Application, when the geographic location of the passive-optical locator132is known, an absolute geographic location of the target50is able to be generated using the distance R between the target50and the angle from the optical axis35of the passive-optical range-finder85when it is focused on the target50. The programmable processor90performs a trigonometric calculation to generate the absolute geographic location of the target50.

FIG. 7is a flowchart of one embodiment of a method700of generating information indicative of a distance to a target. The embodiment of method700can be implemented using the passive-optical locator132ofFIG. 1. In such an embodiment, at least a portion of the processing of method700is performed by software120executing on the programmable processor90of the passive-optical locator132. Other embodiments are implemented in other ways.

At block702, the optical axis of the passive-optical range-finder is aligned along a line of sight to the target. With reference toFIG. 1, the operator of the passive-optical locator132points the passive-optical range-finder85at the target50and when the image of the target50is visible at the passive-optical range-finder85, for example on the display75, the optical axis35of the passive-optical range-finder85is aligned along a line of sight to the target50. At block704, a magnified image of the target is focused on an imaging device located at an image plane of the passive optical range-finder. The operator of the passive-optical locator132adjusts the focusing elements of the passive-optical range-finder85to focus the magnified image of the target50on the imaging device110. At block706, information indicative of a focal length of the passive-optical range-finder is obtained. The relative positions of the lenses86shift as the focal length of the passive-optical range-finder85is adjusted to focus on the distant target50and/or to zoom in or out on the target50. In one implementation of this embodiment, the programmable processor90is communicatively coupled to other sensors61that sense the relative positions of the lenses86and send the information indicative of the relative positions to the programmable processor90. The programmable processor90executes software120to generate the focal length information from the relative positions of the lenses86. At block708, a target height, a target width, and a target depth associated with the target type are determined. In one implementation of this embodiment, the target height, target width, and target depth are determined from a lookup table. At block710, information indicative of a magnification is generated. The information indicative of the magnification is generated based on a ratio of at least one of: a ratio of the target height to an image height; a ratio of the target width to an image width; and a ratio of the target depth to an image depth. At block712, the information indicative of the distance is generated based on the information indicative of the magnification and the information indicative of the focal length. The ratio of the focal length to the distance (which is written as FL/R) is equal to the ratio of the image (i)/object (o), which equals the magnification (M) of the passive-optical range-finder85. Thus, the distance equals the magnification divided by the focal length (R=M/FL).

FIG. 8is a flowchart of one embodiment of a method800to receive the information indicative of the target type at a passive-optical locator. In one implementation of this embodiment, method800is implemented using the passive-optical locator132ofFIG. 1. Other embodiments are implemented in other ways.

At block802, a programmable processor compares an image of a target to a plurality of target images. In this case, a memory in a passive-optical locator includes the plurality of target images and the programmable processor in the passive-optical locator compares the images in the memory to a magnified image of a target from an imaging device executing software, such as pattern recognition software. When the image of the target matches one of the plurality of target images, then the programmable processor determines the target type based on a target type linked to the matched target image. In one implementation of this embodiment, pattern matching software executed by the programmable processor90generates the target-type information.

At block804, the programmable processor receives a user input including information indicative of a target type. In one implementation of this embodiment, the information indicative of the target type is input via an operator input interface. For example with reference toFIG. 1, the programmable processor90outputs the image signals to the display75for viewing of the target image by a user of the passive-optical locator132. In this case, an operator of the passive-optical locator132views the image of the target50displayed on the display75and inputs target-type information via the operator input interface111based on the viewed image. In one implementation of this embodiment, a passive-optical locator is capable of implementing both block802and block804. In another implementation of this embodiment, a passive-optical locator is capable of implementing block802or block804.

The systems, devices, methods, and techniques described here may be implemented in digital electronic circuitry, or with a special-purpose processor or a general-purpose processor such as a computer, firmware, software, or in combinations of them. For example, an electronically processed image can focused by numerically evaluating the pixel distribution or by algorithmically processing the pixel data, i.e. intensity, spectral range, etc. to find a “best-fit” distribution that the processing system offers as range in focus. When the system “recognizes” this image, the optics are in focus and it can therefore offer a range to target.

Apparatus embodying these techniques may include appropriate input and output devices, a programmable processor, and a storage medium tangibly embodying program instructions for execution by the programmable processor. A process embodying these techniques may be performed by a programmable processor executing a program of instructions to perform desired functions by operating on input data and generating appropriate output. The techniques may advantageously be implemented in one or more programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and DVD disks. Any of the foregoing may be supplemented by, or incorporated in, specially-designed application-specific integrated circuits (ASICs). As used here, the devices, such as computers, controller processors, ASICS and memories that are implementing programs, software, algorithms or variants and associated items thereof may be used to denote functions such as neural net(s), artificial intelligence, analog and/or (super)state machines.