A ranging system, method and satellite for ranging a target object

Abstract

The present disclosure relates to a ranging system, method and satellite for ranging a target object. The ranging system comprises a laser transmitter, an optic device for directing a plurality of laser pulses from the laser transmitter toward the target object, a first imager adapted for taking a target region image where the target object is located, a second imager adapted for receiving a plurality of received laser return pulses from the target object, a first lensing device adapted to provide a laser divergence angle to the laser pulses from the laser transmitter, a second lensing device adapted to provide a field of view to the second imager, and a controller.

Description

A RANGING SYSTEM, METHOD AND SATELLITE FOR RANGING A TARGET OBJECTField of the Invention

[0001] The present invention relates to a ranging system, method and satellite for ranging an object and in particular to a light detection and ranging system for satellites, automobiles, or autonomous devices for ranging and mapping a target object.

[0002] The invention has been developed primarily for use in object detection and ranging from a satellite, and will be described hereinafter with reference to this application. It will, however, be appreciated that the invention is not limited to this particular field of use.Background of the Invention

[0003] Light detecting and ranging (LiDAR) systems are remote sensing systems which work by emitting light pulses and receiving through a sensor the light reflected from the surface. Typical applications include aerial detection, vehicle automation, ocean surveying, and terrestrial mapping.

[0004] LiDAR systems are effective in mapping a target region or a target object that cannot typically be reached by other sensors or surveyors. For example, LiDAR systems are used to detect and / or map objects in outer space. These objects may, for example, be near-earth objects (NEOs) that are being monitored. The size and distance of NEOs is important as these factors affect how the NEOs will behave once close to Earth.

[0005] However, satellite LiDAR systems require high power consumption to operate. These LiDAR systems require high-powered lasers which are continuously activated during operation to fully range and / or map the target object.

[0006] Any discussion of the background art throughout the specification should in no way be considered as an admission that such background art is prior art, nor that such background art is widely known or forms part of the common general knowledge in the field in Australia or any other country.Summary of the Invention

[0007] According to a first aspect of the present invention, a ranging system for ranging a target object is provided, the ranging system comprising:a. a laser transmitter; b. an optic device for directing a plurality of laser pulses from the laser transmitter toward the target object; c. a first imager adapted for taking a target region image where the target object is located; d. a second imager adapter for receiving a plurality of received laser return pulses from the target object; e. a first lensing device adapted to provide a laser divergence angle to the laser pulses from the laser transmitter; f. a second lensing device adapted to provide a field of view to the second imager; and g. a controller adapted to: i. determine a target object image from the target region image; ii. determine the angular size and brightness of the target object image relative to the target region image; iii. adjust a laser power setting of the laser transmitter responsive to the brightness of the target object image; iv. cause the orientation of the first imager and the second imager to be adjusted such that the target object is substantially centered in the target region image if it is not already substantially centered in the target region image; v. control the first lensing device to configure the laser divergence angle responsive to the angular size of the target object image; vi. activate the laser transmitter to transmit a plurality of laser pulses through the first lensing device; and vii. analyse the laser return pulses received through the second lensing device to determine the range of the target object image.

[0008] Advantageously, the angular size and brightness of the target object detected by the controller will determine the laser power setting that will be outputted. Based on the determined properties, the controller may set the laser power setting at a minimumnecessary level that is needed to range the target object. This can reduce the power consumption of the system.

[0009] Advantageously, the adjustment of the laser divergence angle of the first plurality of laser pulses may aid in enabling the system to map the target object with less or no changes in orientation of the ranging system. This may save on power or propellant depending on the particular implementation.

[0010] In one embodiment, the controller is further adapted to control the second lensing device to configure a field of view of the second imager responsive to the angular size of the target object image.

[0011] In one embodiment, the controller is further adapted to: a. analyse the range of the target object against a range threshold; b. analyse the size of the target object image against an object image size threshold; c. if the target object range is above the range threshold or the object image size is below the object image size threshold, continue transmitting laser pulses in order to determine the range of the target object; and d. if the target object range is below the range threshold or the object image size is above the object image size threshold, cause the laser transmitter, the first lensing device, the second lensing device and the second imager to map the target object image in three dimensions.

[0012] Advantageously, the controller only operates the LiDAR functionality (the laser transmitter, the first lensing device, the second lensing device and the second imager) when the target object is large enough or close enough, otherwise the object is simply ranged. This may ensure that mapping is not operated under sub-optimal circumstances or unnecessarily which would waste energy.

[0013] In one embodiment, the orientation of the first imager and second imager is caused to be adjusted as an orientation of the ranging system is adjusted.

[0014] According to a further aspect of the present invention, a method for ranging a target object is provided, the method comprising the steps of: imaging a first target region using a first imager to receive a first target image; locating a target object image within the first target image; determining a first angular size and a first brightness of the target object image relative to the first target image;adjusting a first laser divergence angle setting of a first lensing device that is responsive to the first angular size of the target object image; causing the orientation of the first imager and a second imager to be adjusted, if necessary, such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image; operating the laser transmitter at a first laser power setting that is responsive to the first brightness of the target object image to transmit a first plurality of laser pulses through the first lensing device; and receiving a first plurality of laser return pulses from the target object at the second imager via a second lensing device to determine a first range of the target object.

[0015] Advantageously, the angular size and brightness of the target object detected will determine the laser power setting that will be outputted. Based on the determined properties, the laser power setting may be set at a minimum necessary level that is needed to range the target object. This can reduce the power consumption of the system.

[0016] Advantageously, the adjustment of the laser divergence angle of the first plurality of laser pulses may aid in enabling the system to map the target object with less or no changes in orientation of the first imager and second imager.

[0017] In one embodiment, the method comprises the steps of selecting a field of view setting of the second lensing device responsive to the first angular size of the target object image.

[0018] In one embodiment, the method further comprises the steps of: imaging the first target region using a first imager to receive a second target image; locating the target object image within the second target image; determining a second angular size and a second brightness of the target object image relative to the second target image; adjusting a second laser divergence angle setting of the first lensing device that is responsive to the second angular size of the target object image; causing the orientation of the first imager and the second imager to be adjusted, if necessary, such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image;operating the laser transmitter at a second laser power setting that is responsive to the second brightness of the target object image to transmit a second plurality of laser pulses through the first lensing device; and receiving a second plurality of laser return pulses from the target object at the second imager via the second lensing device to determine a second range of the target object.

[0019] The advantages associated with this embodiment are analogous to the advantages associated above where the laser transmitter is operated to generate the first plurality of laser pulses.

[0020] In one embodiment, the method further comprises the step of selecting the field of view setting of a second lensing device responsive to the second angular size of the target object image.

[0021] In one embodiment, wherein in use, if the second angular size is greater than the first angular size, then a third laser divergence angle setting is selected that is greater than the second laser divergence angle setting, and if the second angular size is less than the first angular size, then the third laser divergence angle setting selected is less than the second laser divergence angle setting.

[0022] In one embodiment, wherein if the second brightness is greater than the first brightness, then a third laser power setting is selected that is lesser than the second laser power setting, and if the second brightness is lesser than the first brightness, then the third laser power setting selected is greater than the second laser power setting.

[0023] In one embodiment, wherein if the second range is lesser than the first range, then a third laser divergence angle setting is selected that is greater than the second laser divergence angle setting, and a third laser power setting is selected that is lesser than the second laser power setting.

[0024] In one embodiment, wherein if the second range is greater than the first range, then a third laser divergence angle setting is selected that is lesser than the second laser divergence angle setting, and a third laser power setting is selected that is greater than the second laser power setting.

[0025] In one embodiment, wherein a larger laser divergence angle setting is selected as the angular size of the target object image increases.

[0026] In one embodiment, wherein a lower laser power setting is selected as the brightness of the target object image increases.

[0027] Advantageously, the foregoing steps of the method allow the ranging system to autonomously select a third or subsequent laser divergence angle setting or laser power setting based on previous readings made by the ranging system.

[0028] In one embodiment, wherein the first laser divergence angle setting is selected from a lookup table that provides a correspondence between target object angular size and divergence angle settings.

[0029] In one embodiment, wherein the first laser power setting is selected from a lookup table that provides a correspondence between target object brightness and power settings.

[0030] According to a further aspect of the present invention, a computer implemented method for ranging a target object, the computer implemented method comprising the steps of: instructing a first imager to image a first target region to receive a first target image; storing the target image in memory; analysing the target image to detect a target object image from the target image; storing the target object image in memory; analysing the target object image to identify an angular size and brightness of the target object image relative to the target image; adjusting a laser divergence angle setting of a first lensing device that is responsive to the angular size of the target object image; causing the orientation of the first imager and a second imager to be adjusted such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image; operating the laser transmitter at a laser power setting that is responsive to the brightness of the target object image to transmit a first plurality of laser pulses through the first lensing device; recording data associated with a plurality of laser return pulses from the target object received by the second imager via the second lensing device; andanalysing the recorded data associated with the plurality of laser return pulses to determine a range of the target object.

[0031] The advantages associated with this embodiment are analogous to the advantages associated above where the laser transmitter is operated to generate the first plurality of laser pulses.

[0032] In one embodiment, the computer implemented method further comprises the step of selecting a field of view setting of a second lensing device responsive to the first angular size of the target object image.

[0033] In one embodiment, the computer implemented method further comprises the step of analysing the recorded data associated with the plurality of laser return pulses to map the target object.

[0034] In a further aspect of the present invention, a satellite is provided, the satellite comprises the ranging system of the foregoing and a communications module, the communications module being adapted to transmit the range data and mapping data to a remote system.

[0035] In one embodiment, the satellite comprises the ranging system of the foregoing and a satellite control system, the satellite control system being adapted to receive instructions from the controller of the ranging system such that in use, the controller sends an instruction to the satellite control system to cause the satellite control system to reorient the satellite to cause the adjustment of the orientation of the first imager and second imager.

[0036] Advantageously, the ranging system can autonomously control the positioning of the satellite to ensure that the target object is fully centered when captured by the first imager. This may lead to a better determination of the size of the target object image, which may lead to a better selection of the laser divergence angle of the first plurality of laser pulses to fully map the target object.

[0037] It should be noted that the web server, client computing device and the computer readable storage medium provide the same or similar advantages as the advantages provided by the corresponding computer implemented method, some of which are described herein. Additionally, the web server and / or client computing device provides the advantage of deployment across a computer network, such as the Internet, providing distribution, access and economy of scale advantages. Furthermore, the computerreadable storage medium provides further advantages, such allowing the deployment of computer instructions for installation and execution by one or more computing devices.

[0038] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0039] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0040] Figure 1 shows a ranging system for ranging a target object in accordance with an embodiment of the present invention;

[0041] Figure 2 shows a second embodiment of the ranging system of Fig. 1 ;

[0042] Figure 3 shows a flowchart method of ranging a target object in accordance with an embodiment of the present invention;

[0043] Figure 4 shows an embodiment of the method of ranging a target object of Fig. 3; and

[0044] Figures 5a-5c show conditional flowcharts that are further embodiments of the method of ranging a target object of Fig. 4.Description of Embodiments

[0045] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[0046] Figure 1 shows a ranging system 1000. The ranging system 1000 comprises a laser transmitter 1001 adapted to emit outgoing light pulses. An optic device 1002 is coupled to or integrated with the laser transmitter 1001 , the optic device 1002 being adapted to direct the laser pulses emitted by the laser transmitter 1001 towards a target object 1003. The ranging system further comprises a first imager 1004 and a second imager 1005. The first imager 1004 is configured to take a target region image of an area where the target object 1004 is located. The second imager 1005 is adapted to receive a plurality of laser return pulses from the target object 1003. In an embodiment, the first imager 1004 and second imager 1005 may be cameras that are configured to capture images or videos. In other embodiments, the imagers 1004, 1005 are thermal detectors, multispectral imagers, or any other suitable imagers.

[0047] The ranging system 1000 further comprises a first lensing device 1007 and a second lensing device 1008. The first lensing device 1007 is coupled to or integrated with the optic device 1002, the first lensing device being adapted to adjust a laser divergence angle of the light directed by the optic device 1002. In another embodiment (not shown), the first lensing device 1007 is coupled to or integrated with the laser transmitter 1001 so that the first lensing device 1007 can adjust the laser divergence angle of the laser pulse prior to it being directed by the optic device 1002. The second lensing device 1008 is coupled to or integrated with the second imager 1005, the second lensing device 1008 being configured to adjust a laser divergence angle of the laser return pulses from the target object 1003.

[0048] In another embodiment, the ranging system 1000 comprises a telescope coupled to the first imager 1004, first lensing device 1007, second lensing device 1008. The telescope is adapted to magnify the view of the first imager 1004 such that the first imager 1004 can image a distant target region between 1 km and 1000km away from the ranging system 1000. Once the ranging system recognizes that the distance between the target object and the ranging system 1000 is between 1 km and 1 m, the first lensing device 1007 changes the laser divergence angle of the outgoing laser pulse towards the target object. In a preferred embodiment, the telescope is a Cassegrain telescope. In other embodiments, other suitable types of telescopes can be used.

[0049] The ranging system 1000 is provided with a controller 1006 that is operatively connected to the laser transmitter 1001 , the first imager 1004, the second imager 1005, the first lensing device 1007, and the second lensing device 1008. The controller 1006 comprises a memory 1009 and a processor 1010, the memory being configured to store computer-executable instructions and data related to pre-determined object properties 1011. The pre-determined object properties 1011 comprises data related to an object range threshold and an object image size threshold. In other embodiments, the predetermined object properties may comprise an object brightness threshold. The processor 1010 is adapted to process data received from the first imager 1004 and second imager 1005.

[0050] In use, the controller 1006 is adapted to determine a target object image from the target region image captured by the first imager 1004. This can be achieved by having the processor 1010 run an object recognition algorithm over the target region image. The controller 1006 is likewise adapted to determine an angular size and brightness of the target object image using known techniques. The controller 1006 is adapted to activatethe laser transmitter 1001 . Responsive to the angular size of the target object image, the controller 1006 can adjust the first lensing device to change the laser divergence angle of the laser pulse emitted by the laser transmitter 1001 such that the frontal area of the object is mapped. Responsive to the brightness of the target object image, the controller can adjust the laser power setting of the laser transmitter 1001 .

[0051] The angular size and brightness of the target object detected by the controller will determine the laser power setting that will be outputted. Based on the determined properties, the controller may set the laser power setting at a minimum necessary level that is needed to range the target object. This can further reduce the power consumption of the ranging system 1000.

[0052] The controller 1006 can adjust the second lensing device 1008 to change the field of view of the second imager 1005 responsive to the angular size of the target object image to ensure that the plurality of laser return pulses are received at the correct area of the second imager 1005.

[0053] The processor 1010 is configured to analyse the laser return pulses that passed through the second lensing device and received by second imager 1005 to determine a range of the target object image. The processor 1010 is likewise adapted to analyse a size and range of the target object against the object size threshold and range threshold data stored in the memory 1009, respectively. Responsive to the analysis of the range of the target object, the controller 1006 can either continue activating the laser transmitter to emit laser pulses or deactivate the laser transmitter. The laser transmitter 1002, the first lensing device 1007, the second lensing device 1008, and the second imager 1005 are adapted to digitally map the target object in three dimensions. The controller only operates the LiDAR functionality (the laser transmitter, the first lensing device, the second lensing device and the second imager) when the target object is large enough or close enough, otherwise the object is simply ranged. This may ensure that mapping is not operated under sub-optimal circumstances or unnecessarily which would waste energy.

[0054] In another embodiment as shown in Fig. 2, the controller 1006 is operatively connected to a satellite control system 110 of a satellite 100. The satellite control system 110 is adapted, responsive to instructions received from the controller 1006, to re-orient the positioning of the satellite 100. In a preferred embodiment, the satellite control system 110 is an attitude determination and control system. In other embodiments, the satellite control system 110 is a propulsion system.

[0055] The ranging system 1000 further comprises a data communication device 1012 adapted to remotely send the data gathered by the controller 1006 to a remote server 1013. In other embodiments, the data communication device 1012 can remotely send the data gathered by the controller 1006 to a different satellite within a certain vicinity in real time.

[0056] The data communication device 1012 could be any known and suitable form of communication device used in space such as RF transmission, Tracking and Data Relay Satellite System (TDRS), NASA’s deep space network (DSN) or laser communication devices.

[0057] In an embodiment, the ranging system 1000 and its parts are mounted on a chassis of the satellite 100. In another embodiment, the parts of the ranging system are mounted on a gimbal that is connected to the chassis of satellite 100. The gimbal provides a separation of adjusting orientation between the ranging system and the satellite. The gimbal allows the ranging system to have its own orientation independent of the orientation of the satellite.

[0058] Fig. 3 shows a method 2000 of ranging a target object 1003. The method 2000 comprises a step 2001 of imaging a first target region using the first imager 1004 to receive a first target image. A target object image is then located 2002 within the first target image. A first angular size and a first brightness of the target object image is determined 2003. Afterwards, the first laser divergence angle setting of the first lensing device 1005 is adjusted 2004 responsive to the first angular size of the target object image. The adjustment of the laser divergence angle of the first plurality of laser pulses may aid in enabling the system to map the target object with less or no changes in orientation of the ranging system. This may save on power or propellant depending on the particular implementation. The orientation of the first imager 1004 and the second imager 1005 is then adjusted 2005 such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image.

[0059] In another embodiment, the adjustment of the orientation of the first imager 1004 and second imager 1005 are caused by the reorientation of the satellite 100 when the controller 1006 sends an instruction to the satellite control system 110. The laser transmitter is then operated 2006 at a first laser power setting responsive to the first brightness of the target object image to transmit a first plurality of laser pulses through the first lensing device. This ensures that the laser transmitter can emit laser pulses at aminimum necessary level so that the power consumption of the ranging system 1000 can be reduced. A first plurality of laser return pulses from the target object are received 2007 by the second imager 1005 via the second lensing device 1008 to determine a first range of the target object. In a preferred embodiment, the field of view setting of the second lensing device 1008 is adjusted responsive to the first angular size of the target object image.

[0060] In an embodiment, the ranging system 1000 and its parts are mounted on a chassis of the satellite 100. In another embodiment, the parts of the ranging system are mounted on a gimbal that is connected to the chassis of satellite 100. The gimbal provides a separation of adjusting orientation between the ranging system and the satellite. The gimbal allows the ranging system to have its own orientation independent of the orientation of the satellite.

[0061] As shown in Fig. 4, the method 2000 may continue to further receive data from the target object. The method 2000 further comprises the step of imaging 2008 the first target region using the first imager 1004 to receive a second target image. The target object image is then located 2009 with the second target image. A second angular size and a second brightness of the target object image is then determined 2010 relative to the second target image. The orientation of the first imager 1004 and second imager 1005 is then adjusted 2011 to substantially center the target object in the target region image. In another embodiment, the orientation of the first imager 1004 and second imager 1005 is adjusted when the controller 1006 causes the satellite 100 to re-orient through the satellite control system 110. The laser transmitter is then operated 2012 at a second laser power setting responsive to the second brightness of the target object image to transmit a second plurality of laser pulses through the first lensing device. Lastly, a second plurality of laser return pulses from the target object are received 2013 by the second imager 1005 via the second lensing device 1008 to determine a second range of the target object.

[0062] The data gathered by the controller 1006 can be remotely sent through the data communication device 1012 to the remote server 1013. In other embodiments, the data communication device 1012 can remotely send the data gathered by the controller 1006 to a different satellite within a certain vicinity in real time. The data can be communicated as described using the various systems as previously described.

[0063] In an embodiment as shown in Figs. 5a-5c, the method 2000 comprises a step of controlling a third or subsequent laser power setting and a third or subsequent divergence angle setting based on delta with previous reading. As shown in Fig. 5a, if the secondangular size is greater than the first angular size, then a third laser divergence angle setting is selected that is greater than the second laser divergence angle setting. The increase of angular size between the two instances of monitoring may mean that that the ranging 1000 system is coming closer to the target object. Increasing the laser divergence angle setting ensures that the plurality of light pulses emitted hit the frontal area of the target object. In an example, if the second angular size is 10° and the first angular size is 1 °, the third or subsequent laser divergence angle setting is increased to at least 10.5°, and if the second angular size is 1 ° and the first angular size is 10°, the third or subsequent laser divergence angle setting is decreased to 1.5°. If the second angular size is less than the first angular size, then the third laser divergence angle setting selected is less than the second laser divergence angle setting. In this instance, it may mean that the ranging system 1000 is getting farther from the target object. The laser divergence angle would be decreased as necessary to allow the emitted light pulses to cover the frontal portion of the target object. The adjustment of the laser divergence angle of the first plurality of laser pulses may aid in enabling the system to map the target object with less or no changes in orientation of the ranging system. This may save on power or propellant depending on the particular implementation.

[0064] In Fig. 5b, if the second brightness is greater than the first brightness, then a third laser power setting is selected that is lesser than the second laser power setting, and if the second brightness is lesser than the first brightness, then the third laser power setting selected is greater than the second laser power setting. The first instance may mean that the satellite 100 is getting nearer to the target object. This would mean that only a lesser power setting is needed for the plurality of outgoing light pulses to reach the target object. Thus, the laser power setting is decreased to reduce power consumption. The second instance may mean that the satellite 100 is getting farther from the target object. This would mean that a greater power setting is needed for the plurality of outgoing light pulses to reach the target object. Thus, the laser power setting is increased. In an example, if the second brightness is at 2500 lumens and the first brightness is at 400 lumens, the laser power setting is reduced to its minimum level, and if the second brightness is at 400 lumens and the first brightness is at 2500 lumens, the laser power setting is increased to its maximum level. In Fig. 5c, if the second range is lesser than the first range, then a third laser divergence angle setting is selected that is greater than the second laser divergence angle setting, and a third laser power setting is selected that is lesser than the second laser power setting. If the second range is greater than the first range, then a third laser divergence angle setting is selected that is lesser than the second laserdivergence angle setting, and a third laser power setting is selected that is greater than the second laser power setting. In an example, if the range between the ranging system 1000 and the target object is between 1 m and 1 km, the laser power setting is set to its minimum level and the laser divergence angle setting is set to its maximum level. If the range between the ranging system is between 1 km and 1000km, the laser power setting is set to a higher power level or a maximum level, and the laser divergence angle is set to a lower power level or a minimum level. In another embodiment, a larger laser divergence angle setting is selected as the angular size of the target object image increases. In another embodiment, a lower laser power setting is selected as the brightness of the target object image increases.

[0065] The controller only operates the LiDAR functionality (the laser transmitter, the first lensing device, the second lensing device and the second imager) when the target object is large enough or close enough, otherwise the object is simply ranged. This may ensure that mapping is not operated under sub-optimal circumstances or unnecessarily which would waste energy.

[0066] In another embodiment, the method 2000 comprises the steps of controlling the laser power setting and divergence angle setting based on predetermined thresholds. After the object angular size is determined, the first laser divergence angle setting is selected from a lookup table that provides correspondence between target object angular size and divergence angle settings. After the brightness of the object is determined, the first laser power setting is selected from a lookup table that provides a correspondence between target object brightness and power settings.

[0067] The foregoing system and method can be implemented on a satellite 100 deployed aerially within the Earth’s atmosphere, or in outer space. When the satellite is implemented with the ranging system 1000 using the method 2000, the first imager 1004 takes an image of a target region, wherein the target region image captured contains the target object 1003. The target region image will be processed by the processor 1010 to locate the target object image within the target region image. In an embodiment, the target region image and the target object image 1003 captured are stored in the memory 1009, are sent to a remote server 1013 or are sent to a different satellite within a vicinity of the ranging system 1000. Once the target object 1003 has been located, the processor 1010 determines a first angular size and a first brightness of the target object image.

[0068] Responsive to the first angular size, the controller 1006 causes an adjustment of the first laser divergence angle setting of the first lensing device 1007. In an example, ifthe angular size of the target object is 1 °, the laser divergence angle setting is set at 1 .5° and if the angular size of the target object is 10°, the laser divergence angle setting is set at 10.5°. The adjustment of the laser divergence angle of the plurality of laser pulses may aid in enabling the system to map the target object with less or no changes in orientation of the ranging system. This may save on power or propellant depending on the particular implementation.

[0069] Responsive to the first brightness, the controller 1006 adjusts a first laser power setting of the laser transmitter 1002. In an example, if the brightness of the target object detected is between 100 lumens and 700 lumens, the controller sets the laser power setting at maximum level and if the brightness of the target object detected is between 700 and 2500 lumens, the laser power setting is decreased. The angular size and brightness of the target object detected by the controller 1006 will determine the laser power setting that will be outputted. Based on the determined properties, the controller 1006 may set the laser power setting at a minimum necessary level that is needed to range the target object. This can reduce the power consumption of the ranging system 1000.

[0070] The controller 1006 likewise causes the orientation of the first imager 1004 and the second imager 1005 to be adjusted such that the target object that correspondents to the target object image is substantially centered in the target region image, if it is not already substantially centered in the target region image. In an embodiment, the orientation of the first imager 1004 and second imager 1005 is adjusted when the controller 1006 sends an instruction to the satellite control system 110 to reorient the satellite 100, effectively reorienting the center target of the first imager 1004 and second imager 1005.

[0071] The controller then operates the laser transmitter 1006 at the first laser power setting to transmit a first plurality of laser pulses through the optic device 1002. The optic device 1002 then directs the laser towards the target object. Prior to hitting the target object, the first plurality of laser pulses passes through the first lensing device 1007 which adjusts the laser divergence angle of the first plurality of laser pulses. In an embodiment, the first lensing device 1007 is placed in between the laser transmitter 1001 and the optic device 1002, which would mean that the laser divergence angle of the first plurality of laser pulses are adjusted prior to being directed by the optic device 1002 towards the target object.

[0072] A first plurality of laser return pulses from the target object will then be detected by the second imager 1005. The first plurality of laser return pulses will be processed by theprocessor 103 to determine a first range data. If the data gathered is considered insufficient by the processor 103, the controller proceeds to send an instruction towards the satellite control system 110 to cause the satellite 100 to move closer the target object.

[0073] The steps above are then repeated to receive a second target object image, determine a second angular size and second brightness, emit a second plurality of laser pulses, receive a second plurality of laser return pulses, and a second range data. If there is a subsequent need to further collect data, the controller 1006 can proceed to determine the third or subsequent laser power setting data and laser divergence angle setting data for succeeding iterations.

[0074] In an embodiment, the ranging system 1000 and its parts are mounted on a chassis of the satellite 100. In another embodiment, the parts of the ranging system are mounted on a gimbal that is connected to the chassis of satellite 100. The gimbal separates adjustment of orientation of the ranging system from the satellite. The gimbal allows the ranging system to have its own orientation independent of the orientation of the satellite.

[0075] In one embodiment, the third or subsequent laser divergence angle setting and laser power setting are based on the delta with the previous reading. If the second angular size is greater than the first angular size, then the controller 1006 selects a third laser divergence angle setting that is greater than the second laser divergence angle setting, and if the second angular size is less than the first angular size, then the third laser divergence angle setting selected is less than the second laser divergence angle setting. If the second brightness is greater than the first brightness, then the controller 1006 selects the third laser power setting that is lesser than the second laser power setting, and if the second brightness is lesser than the first brightness, then the third laser power setting selected is greater than the second laser power setting. If the second range is lesser than the first range, then the controller 1006 selects a third laser divergence angle setting that is greater than the second laser divergence angle setting, and a third laser power setting is selected that is lesser than the second laser power setting. If the second range is greater than the first range, then the controller 1006 selects a third laser divergence angle setting that is lesser than the second laser divergence angle setting, and a third laser power setting is selected that is greater than the second laser power setting. In another embodiment, a larger laser divergence angle setting is selected as the angular size of the target object image increases. In another embodiment, a lower laser power setting is selected as the brightness of the target object image increases.

[0076] In another embodiment, the third or subsequent laser divergence angle setting and laser power setting are based on predetermined thresholds. After the object angular size is determined, the first laser divergence angle setting is selected from a lookup table that provides correspondence between target object angular size and divergence angle settings. After the brightness of the object is determined, the first laser power setting is selected from a lookup table that provides a correspondence between target object brightness and power settings.

[0077] Once sufficient data is gathered, the laser transmitter 1002, the first lensing device 1007, the second lensing device 1008, and the second imager 1005can then proceed to digitally map the target object image in three dimensions.

[0078] In another embodiment, the satellite can also implement the system and method when surveying another planet. The system and method can be used for other applications not mentioned in this specification.

[0079] The computer program code instructions may be divided into one or more computer- program-code-instruction libraries, such as dynamic link libraries (DLL), wherein each of the libraries performs a one or more steps of the method. Additionally, a subset of the one or more of the libraries may perform graphical user interface tasks relating to the steps of the method.

[0080] The computing device preferably comprises semiconductor memory comprising volatile memory such as random access memory (RAM) or read only memory (ROM). The memory may comprise either RAM or ROM or a combination of RAM and ROM.

[0081] The computing device comprises a computer program code storage medium reader for reading the computer program code instructions from computer program code storage media.

[0082] The device comprises an arithmetic logic unit or processor for performing the computer program code instructions. The processor may be a reduced instruction set computer (RISC) or complex instruction set computer (CISC) processor or the like. The computing device further comprises a storage device, such as a magnetic disk hard drive or a solid-state disk drive for storing data and / or software instructions.

[0083] Computer program code instructions may be loaded into the storage device from the storage media using the storage medium reader or from the network using network interface. Alternatively, computer program code instructions may be loaded into the storage device from an online resource via the network and network interface.

[0084] During the bootstrap phase, an operating system and one or more software applications are loaded from the storage device into the memory. During the fetch- decode-execute cycle, the processor fetches computer program code instructions from memory, decodes the instructions into machine code, executes the instructions and stores one or more intermediate results in memory.

[0085] In this manner, the instructions stored in the memory, when retrieved and executed by the processor, configures the computing device as a special-purpose machine that may perform the functions described herein.

[0086] The device preferably includes a communication bus subsystem for interconnecting the various devices described above. The bus subsystem may offer parallel connectivity such as Industry Standard Architecture (ISA), conventional Peripheral Component Interconnect (PCI) and the like or serial connectivity such as PCI Express (PCIe), Serial Advanced Technology Attachment (Serial ATA) and the like. The computing device can also include a clock device configured for providing accurate time stamps for use by the processor.Interpretation

[0087] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. For the purposes of the present invention, additional terms are defined below. Furthermore, all definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms unless there is doubt as to the meaning of a particular term, in which case the common dictionary definition and / or common usage of the term will prevail.

[0088] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular articles “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise and thus are used herein to refer to one or to more than one (i.e. to “at least one”) of the grammatical object of the article. By way of example, the phrase “an element” refers to one element or more than one element.

[0089] The term “about” is used herein to refer to quantities that vary by as much as 30%, preferably by as much as 20%, and more preferably by as much as 10% to a reference quantity. The use of the word ’’about” to qualify a number is merely an express indication that the number is not to be construed as a precise value.

[0090] Throughout this specification, unless the context requires otherwise, the words “comprise”, “comprises”, and “comprising” will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements.

[0091] The term “real-time” for example “displaying real-time data,” refers to the display of the data without intentional delay, given the processing limitations of the system and the time required to accurately measure the data.

[0092] As used herein, the term “exemplary” is used in the sense of providing examples, as opposed to indicating quality. That is, an “exemplary embodiment” is an embodiment provided as an example, as opposed to necessarily being an embodiment of exemplary quality for example serving as a desirable model or representing the best of its kind.

[0093] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e. , elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0094] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items.

[0095] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least oneelement selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0096] In the context of this document, the term “bus” and its derivatives, while being described in a preferred embodiment as being a communication bus subsystem for interconnecting various devices including by way of parallel connectivity such as Industry Standard Architecture (ISA), conventional Peripheral Component Interconnect (PCI) and the like or serial connectivity such as PCI Express (PCIe), Serial Advanced Technology Attachment (Serial ATA) and the like, should be construed broadly herein as any system for communicating data.

[0097] As described herein, ”in accordance with” may also mean ”as a function of” and is not necessarily limited to the integers specified in relation thereto.

[0098] As described herein, ”a computer implemented method” should not necessarily be inferred as being performed by a single computing device such that the steps of the method may be performed by more than one cooperating computing devices.

[0099] Similarly objects as used herein such as ‘web server’, ‘server’, ‘client computing device’, ‘computer readable medium’ and the like should not necessarily be construed as being a single object, and may be implemented as a two or more objects in cooperation, such as, for example, a web server being construed as two or more web servers in a server farm cooperating to achieve a desired goal or a computer readable medium being distributed in a composite manner, such as program code being provided on a compact disk activatable by a license key downloadable from a computer network.

[0100] In the context of this document, the term “database” and its derivatives may be used to describe a single database, a set of databases, a system of databases or the like.The system of databases may comprise a set of databases wherein the set of databases may be stored on a single implementation or span across multiple implementations. The term “database” is also not limited to refer to a certain database format rather may refer to any database format. For example, database formats may include MySQL, MySQLi, XML or the like.

[0101] The invention may be embodied using devices conforming to other network standards and for other applications, including, for example other WLAN standards and other wireless standards. Applications that can be accommodated include IEEE 802.11 wireless LANs and links, and wireless Ethernet.

[0102] In the context of this document, the term “wireless” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, although in some embodiments they might not. In the context of this document, the term “wired” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a solid medium. The term does not imply that the associated devices are coupled by electrically conductive wires.

[0103] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing”, “computing”, “calculating”, “determining”, “analysing” or the like, refer to the action and / or processes of a computer or computing system, or similar electronic computing device, that manipulate and / or transform data represented as physical, such as electronic, quantities into other data similarly represented as physical quantities.

[0104] In a similar manner, the term “processor” may refer to any device or portion of a device that processes data, e.g., from registers and / or memory to transform that data into other data that, e.g., may be stored in registers and / or memory. A “computer” or a “computing device” or a “computing machine” or a “computing platform” may include one or more processors.

[0105] The methodologies described herein are, in one embodiment, performable by one or more processors that accept computer-readable (also called machine-readable) code containing a set of instructions that when executed by one or more of the processors carry out at least one of the methods described herein. Any processor capable ofexecuting a set of instructions (sequential or otherwise) that specify actions to be taken are included. Thus, one example is a typical processing system that includes one or more processors. The processing system further may include a memory subsystem including main RAM and / or a static RAM, and / or ROM.

[0106] Furthermore, a computer-readable carrier medium may form, or be included in a computer program product. A computer program product can be stored on a computer usable carrier medium, the computer program product comprising a computer readable program means for causing a processor to perform a method as described herein.

[0107] In alternative embodiments, the one or more processors operate as a standalone device or may be connected, e.g., networked to other processor(s), in a networked deployment, the one or more processors may operate in the capacity of a server or a client machine in server-client network environment, or as a peer machine in a peer-to- peer or distributed network environment. The one or more processors may form a web appliance, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine.

[0108] Note that while some diagram(s) only show(s) a single processor and a single memory that carries the computer-readable code, those in the art will understand that many of the components described above are included, but not explicitly shown or described in order not to obscure the inventive aspect. For example, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.

[0109] Thus, one embodiment of each of the methods described herein is in the form of a computer-readable carrier medium carrying a set of instructions, e.g., a computer program that are for execution on one or more processors. Thus, as will be appreciated by those skilled in the art, embodiments of the present invention may be embodied as a method, an apparatus such as a special purpose apparatus, an apparatus such as a data processing system, or a computer-readable carrier medium. The computer-readable carrier medium carries computer readable code including a set of instructions that when executed on one or more processors cause a processor or processors to implement a method. Accordingly, aspects of the present invention may take the form of a method, an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may takethe form of carrier medium (e.g., a computer program product on a computer-readable storage medium) carrying computer-readable program code embodied in the medium.

[0110] The software may further be transmitted or received over a network via a network interface device. While the carrier medium is shown in an example embodiment to be a single medium, the term “carrier medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store the one or more sets of instructions. The term “carrier medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by one or more of the processors and that cause the one or more processors to perform any one or more of the methodologies of the present invention. A carrier medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media.

[0111] It will be understood that the steps of methods discussed are performed in one embodiment by an appropriate processor (or processors) of a processing (i.e. , computer) system executing instructions (computer-readable code) stored in storage. It will also be understood that the invention is not limited to any particular implementation or programming technique and that the invention may be implemented using any appropriate techniques for implementing the functionality described herein. The invention is not limited to any particular programming language or operating system.

[0112] Furthermore, some of the embodiments are described herein as a method or combination of elements of a method that can be implemented by a processor of a processor device, computer system, or by other means of carrying out the function. Thus, a processor with the necessary instructions for carrying out such a method or element of a method forms a means for carrying out the method or element of a method. Furthermore, an element described herein of an apparatus embodiment is an example of a means for carrying out the function performed by the element for the purpose of carrying out the invention.

[0113] Similarly, it is to be noticed that the term connected, when used in the claims, should not be interpreted as being limitative to direct connections only. Thus, the scope of the expression a device A connected to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. “Connected” may mean that two or more elementsare either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.

[0114] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0115] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Description of Embodiments are hereby expressly incorporated into this Description of Embodiments, with each claim standing on its own as a separate embodiment of this invention.

[0116] Furthermore, while some embodiments described herein include some, but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.Terminology

[0117] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwardly", "downwardly", and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.Comprising and Including

[0118] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. , to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[0119] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements / features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.Scope of Invention

[0120] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[0121] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.Industrial Applicability

[0122] It is apparent from the above, that the arrangements described are applicable to the surveying, mapping, and space industries.

Claims

ClaimsThe claims defining the invention are as follows:1 . A ranging system for ranging a target object, comprising: a. a laser transmitter; b. an optic device for directing a plurality of laser pulses from the laser transmitter toward the target object; c. a first imager adapted for taking a target region image where the target object is located; d. a second imager adapted for receiving a plurality of received laser return pulses from the target object; e. a first lensing device adapted to provide a laser divergence angle to the laser pulses from the laser transmitter; f. a second lensing device adapted to provide a field of view to the second imager; g. a controller adapted to: i. determine a target object image from the target region image; ii. determine the angular size and brightness of the target object image relative to the target region image; iii. adjust a laser power setting of the laser transmitter responsive to the brightness of the target object image; iv. cause the orientation of the first imager and the second imager to be adjusted such that the target object is substantially centered in the target region image if it is not already substantially centered in the target region image; v. control the first lensing device to configure the laser divergence angle responsive to the angular size of the target object image; vi. activate the laser transmitter to transmit a plurality of laser pulses through the first lensing device; and vii. analyse the plurality of laser return pulses received through the second lensing device to determine the range of the target object image.

2. The ranging system for ranging a target object as claimed in claim 1 , wherein the controller is further adapted to control the second lensing device to configure a field of view of the second imager responsive to the angular size of the target object image.

3. The ranging system for ranging a target object as claimed in 2, wherein the controller is further adapted to: i. analyse the range of the target object against a range threshold; ii. analyse the size of the target object image against an object image size threshold; iii. if the target object range is above the range threshold or the object image size is below the object image size threshold, continue transmitting laser pulses in order to determine the range of the target object; and iv. if the target object range is below the range threshold or the object image size is above the object image size threshold, cause the laser transmitter, the first lensing device, the second lensing device and the second imager to map the target object image in three dimensions.

4. The ranging system for ranging a target object as claimed in claim 1 , wherein the orientation of the first imager and second imager is caused to be adjusted as an orientation of the ranging system is adjusted.

5. A method for ranging a target object, the method comprising the steps of: imaging a first target region using a first imager to receive a first target image; locating a target object image within the first target image; determining a first angular size and a first brightness of the target object image relative to the first target image; adjusting a first laser divergence angle setting of a first lensing device that is responsive to the first angular size of the target object image; causing the orientation of the first imager and a second imager to be adjusted, if necessary, such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image; operating the laser transmitter at a first laser power setting that isresponsive to the first brightness of the target object image to transmit a first plurality of laser pulses through the first lensing device; and receiving a first plurality of laser return pulses from the target object at the second imager via a second lensing device to determine a first range of the target object.

6. The method for ranging a target object as claimed in claim 5, further comprising the step of selecting a field of view setting of the second lensing device responsive to the first angular size of the target object image.

7. The method for ranging a target object as claimed in claim 5, further comprising the steps of: imaging the first target region using the first imager to receive a second target image; locating the target object image within the second target image; determining a second angular size and a second brightness of the target object image relative to the second target image; adjusting a second laser divergence angle setting of the first lensing device that is responsive to the second angular size of the target object image; causing the orientation of the first imager and the second imager to be adjusted, if necessary, such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image; operating the laser transmitter at a second laser power setting that is responsive to the second brightness of the target object image to transmit a second plurality of laser pulses through the first lensing device; and receiving a second plurality of laser return pulses from the target object at the second imager via the second lensing device to determine a second range of the target object.

8. The method for ranging a target object as claimed in claim 7, further comprising the step of selecting the field of view setting of a second lensing device responsive to the second angular size of the target object image.

9. The method for ranging a target object as claimed in claim 8, wherein in use, if the second angular size is greater than the first angular size, then a third laserdivergence angle setting is selected that is greater than the second laser divergence angle setting, and if the second angular size is less than the first angular size, then the third laser divergence angle setting selected is less than the second laser divergence angle setting.

10. The method for ranging a target object as claimed in claim 8, wherein if the second brightness is greater than the first brightness, then a third laser power setting is selected that is lesser than the second laser power setting, and if the second brightness is lesser than the first brightness, then the third laser power setting selected is greater than the second laser power setting.11 . The method for ranging a target object as claimed in claim 8, wherein if the second range is lesser than the first range, then a third laser divergence angle setting is selected that is greater than the second laser divergence angle setting, and a third laser power setting is selected that is lesser than the second laser power setting.

12. The method for ranging a target object as claimed in claim 8, wherein if the second range is greater than the first range, then a third laser divergence angle setting is selected that is lesser than the second laser divergence angle setting, and a third laser power setting is selected that is greater than the second laser power setting.

13. The method for ranging a target object as claimed in claim 8, wherein a larger laser divergence angle setting is selected as the angular size of the target object image increases.

14. The method for ranging a target object as claimed in claim 8, wherein a lower laser power setting is selected as the brightness of the target object image increases.

15. The method for ranging a target object as claimed in claim 5, wherein the first laser divergence angle setting is selected from a lookup table that provides a correspondence between target object angular size and divergence angle settings.

16. The method for ranging a target object as claimed in claim 5, wherein the first laser power setting is selected from a lookup table that provides a correspondence between target object brightness and power settings.

17. A computer implemented method for ranging a target object, comprising the steps of: instructing a first imager to image a first target region to receive a first target image; storing the target image in memory; analysing the target image to detect a target object image from the target image; storing the target object image in memory;analysing the target object image to identify an angular size and brightness of the target object image relative to the target image adjusting a laser divergence angle setting of a first lensing device that is responsive to the angular size of the target object image; causing the orientation of the first imager and a second imager to be adjusted such that the target object that corresponds to the target object image is substantially centered in the target region image if it is not already substantially centered in the target region image; operating the laser transmitter at a laser power setting that is responsive to the brightness of the target object image to transmit a first plurality of laser pulses through the first lensing device; recording data associated with a plurality of laser return pulses from the target object received by the second imager via the second lensing device; and analysing the recorded data associated with the plurality of laser return pulses to determine a range of the target object.

18. The computer implemented method for ranging a target object as claimed in claim 17 further comprising the step of selecting a field of view setting of a second lensing device responsive to the first angular size of the target object image.

19. The computer implemented method for ranging a target object as claimed in claim 17, further comprising the step of analysing the recorded data associated with the plurality of laser return pulses to map the target object.

20. A satellite comprising the ranging system of claim 1 and a communications module, the communications module being adapted to transmit the range data and mapping data to a remote system.21 . A satellite comprising the ranging system of claim 1 and a satellite control system, the satellite control system being adapted to receive instructions from the controller of the ranging system such that in use, the controller sends an instruction to the satellite control system to cause the satellite control system to reorient the satellite to cause the adjustment of the orientation of the first imager and second imager.

Images