Abstract: A system for guiding a drone to an intended destination using a remote guidance system, independent of a global positioning system installed on the drone and independent of radio guidance. The system uses a two-way optical communication channel between the guidance system and the drone. The drone and the guidance system each have a light source emitting a beam of encoded light, such as a modulated laser beam, and having an extended field of illumination, and a detector receiving the impinging light beam. The guidance system can detect the angular location of the drone emission, and can transmit instructions optically to the drone, while the drone can receive flight path instructions from the guidance system. The drone can be launched from a position that is not in the line of sight of its intended destination and guided optically from the launch position to its intended target destination.

Abstract: An airborne device for surveillance of an enclosed area, comprising a platform having illuminating imaging devices, and an attached lighter than air balloon. A vertically aligned rotor provides additional lift, a rotor directed along the length of the platform provides forward and backward motion, and additional rotors aligned sideways steer and rotate the device. The rotors are driven by electric motors powered by an on-board battery. A vertically directed distance sensor measures and controls the hovering distance of the device from the roof. A reel of optical fiber is installed at the rear end of the platform, and the optical fiber unwinds from the reel and deploys behind the device as it moves forward. This optical fiber carries image data back to a monitor. The length of fiber deployed, combined with directional and accelerometer readings can be used to determine the absolute position of the device.

Abstract: A method and system for optical communication between a transmitter and receiver, using a video camera to image the location of the remote transmitter. The comparatively slow frame rate of conventional detector arrays, which would limit communication rate, is overcome by reading only pixels in a region of interest around the transmission source image, and these pixels can then be read out and the communication information on them retrieved, at a frame rate much faster than that of the conventional full frame read-out. Custom wiring of the array can be used to enable implementation of this increased frame rate. Other methods of increasing communication speed using a video camera array detector include spreading the optical signal spatially along a row of pixels, and reading those pixels simultaneously in one frame, or wavelength multiplexing the optical information, and dispersing the different wavelengths onto successive pixels of the array.

Abstract: A laser designator system using modulated CW laser diodes and a conventional high pixel count image sensor array, such as CCD or CMOS array. These two technologies, diode lasers and imaging sensor arrays are reliable, widely used and inexpensive technologies, as compared with prior art pulsed laser systems. These systems are distinguished from the prior art systems in that they filter the laser signal spatially, by collecting light over a comparatively long period of time from a very few pixels out of the entire field of view of the image sensor array. This is in contrast to the prior art systems where the laser signal is filtered temporarily, over a very short time span, but over a large fraction of the field of view. By spatially filtering the signal outputs of the individual pixels, it becomes possible to subtract the background illumination from the illuminated laser spot.

Abstract: A system for the surveillance of terrain and the detection of intrusions over a plane extending into that terrain. A curtain array of light beams is projected along the plane and reflections from the terrain are detected by a sensor array essentially spatially coincident with the array of light sources. The times of flight of the beams are determined, and these characterize the form of the terrain being surveilled. The initial background reflection pattern is acquired and stored by the system. A sudden change in this detected background pattern can be defined as arising from an unexpected reflection, indicative of an intrusion. Signal processing systems are described utilizing modulated laser beams and detection at a frequency at least twice that of the modulation, such that reflected signals arising from the ON and the OFF periods of the laser modulation can be subtracted to eliminate the background signals.

Abstract: An aerial balloon system comprising a payload platform suspended from an inflated balloon by means of a balloon cable, and an anchoring cable attaching the platform to an anchor point beneath it. The balloon cable and anchoring cable are attached to the payload platform by means of a connecting element pivotally attached to the platform. The platform may include a servo controlled pitch stabilizing system using the input from a pitch sensor mounted on the platform to control an angular actuator to change the angle which the platform makes with the pivoted connection element. Additionally, the platform may include a servo controlled orientation stabilizing system using the input from an orientation sensor mounted thereon to control the departure of the orientation of the platform from a predetermined orientation. This may be readily accomplished using a variable pitch rotor, the pitch being controlled by the orientation sensor signal.

Abstract: A laser designator system using modulated CW laser diodes and a conventional high pixel count image sensor array, such as CCD or CMOS array. These two technologies, diode lasers and imaging sensor arrays are reliable, widely used and inexpensive technologies, as compared with prior art pulsed laser systems. These systems are distinguished from the prior art systems in that they filter the laser signal spatially, by collecting light over a comparatively long period of time from a very few pixels out of the entire field of view of the image sensor array. This is in contrast to the prior art systems where the laser signal is filtered temporarily, over a very short time span, but over a large fraction of the field of view. By spatially filtering the signal outputs of the individual pixels, it becomes possible to subtract the background illumination from the illuminated laser spot.

Abstract: A system for making distance measurements of remote points using a phenomenon related to the time of flight of an illuminating beam. A modulated beam of light is directed at the target area. The modulated beam has temporally varying information impressed upon it, such that the time of flight of the beam to the target and back can be related to the temporal signature of the received beam. An acousto-optic modulator is used to perform frequency conversion of the modulated light reflected from points in the field, before that light impinges on the pixels of a detector array. The AO modulation frequency is close to the illuminating light modulation frequency, so that the converted mixed frequency falls within the limited parallel reading rate range of the detector array, and contains the temporal signature information of the modulated light received from the target within signals of manageable frequencies.

Abstract: An aerial platform comprising a kite providing a level of directional stability when elevated by the wind, and an inflated balloon attached above the kite with a cord. The payload is attached to the kite. The physical separation of the balloon from the kite isolates the payload from shocks generated by the balloon. Additional isolation is provided by use of an elastic attachment cord. Electric power is supplied to the aerial platform by means of an optical fiber receiving optical power from a ground-based source, and conversion of the optical power to electrical power on board the platform. In order to provide a strong tether line, the optical fiber is plaited with a jacket braided from high tensile strength fibers. An aerial laser transmitter is described using a ground based laser source transmitting laser power through an optical fiber to an aerial platform for transmission from the platform.

Abstract: A system for detecting intrusion across a surface, comprising a plurality of light sources projecting an array of illuminating beams along different optical paths in the surface and a detector array system directed such that it detects along a plurality of fields of view in the surface, illumination reflected from the illuminating beams. A signal processing system detects changes along the array of fields of view, in the reflected illumination level detected by the detector system. An increase greater than a predefined level in the reflected illumination level from any field of view provides an indication of an intrusion across the surveilled surface along that field of view, at the crossing point of the direction of that field of view with the optical path whose illuminating beam generated the increase in reflected illumination from that field of view.

Abstract: A system for the surveillance of terrain and the detection of intrusions over a plane extending into that terrain. A curtain array of light beams is projected along the plane and reflections from the terrain are detected by a sensor array essentially spatially coincident with the array of light sources. The times of flight of the beams are determined, and these characterize the form of the terrain being surveilled. The initial background reflection pattern is acquired and stored by the system. A sudden change in this detected background pattern can be defined as arising from an unexpected reflection, indicative of an intrusion. Signal processing systems are described utilizing modulated laser beams and detection at a frequency at least twice that of the modulation, such that reflected signals arising from the ON and the OFF periods of the laser modulation can be subtracted to eliminate the background signals.

Abstract: An aerial balloon system comprising a payload platform suspended from an inflated balloon by means of a balloon cable, and an anchoring cable attaching the platform to an anchor point beneath it. The balloon cable and anchoring cable are attached to the payload platform by means of a connecting element pivotally attached to the platform. The platform may include a servo controlled pitch stabilizing system using the input from a pitch sensor mounted on the platform to control an angular actuator to change the angle which the platform makes with the pivoted connection element. Additionally, the platform may include a servo controlled orientation stabilizing system using the input from an orientation sensor mounted thereon to control the departure of the orientation of the platform from a predetermined orientation. This may be readily accomplished using a variable pitch rotor, the pitch being controlled by the orientation sensor signal.

Abstract: A laser designator system using modulated CW laser diodes and a conventional high pixel count image sensor array, such as CCD or CMOS array. These two technologies, diode lasers and imaging sensor arrays are reliable, widely used and inexpensive technologies, as compared with prior art pulsed laser systems. These systems are distinguished from the prior art systems in that they filter the laser signal spatially, by collecting light over a comparatively long period of time from a very few pixels out of the entire field of view of the image sensor array. This is in contrast to the prior art systems where the laser signal is filtered temporarily, over a very short time span, but over a large fraction of the field of view. By spatially filtering the signal outputs of the individual pixels, it becomes possible to subtract the background illumination from the illuminated laser spot.

Abstract: A system for making distance measurements of remote points using a phenomenon related to the time of flight of an illuminating beam. A modulated beam of light is directed at the target area. The modulated beam has temporally varying information impressed upon it, such that the time of flight of the beam to the target and back can be related to the temporal signature of the received beam. An acousto-optic modulator is used to perform frequency conversion of the modulated light reflected from points in the field, before that light impinges on the pixels of a detector array. The AO modulation frequency is close to the illuminating light modulation frequency, so that the converted mixed frequency falls within the limited parallel reading rate range of the detector array, and contains the temporal signature information of the modulated light received from the target within signals of manageable frequencies.

Abstract: Apparatus for generating optical radiation includes a laser, which is configured to operate in multiple transverse modes simultaneously so as to generate an input beam, which is characterized by a first speckle contrast. The transverse modes of the input beam are optically mixed so as to generate an output beam have a second speckle contrast, which is substantially less than the first speckle contrast.

Abstract: An aerial platform comprising a kite providing a level of directional stability when elevated by the wind, and an inflated balloon attached above the kite with a cord. The payload is attached to the kite. The physical separation of the balloon from the kite isolates the payload from shocks generated by the balloon. Additional isolation is provided by use of an elastic attachment cord. Electric power is supplied to the aerial platform by means of an optical fiber receiving optical power from a ground-based source, and conversion of the optical power to electrical power on board the platform. In order to provide a strong tether line, the optical fiber is plaited with a jacket braided from high tensile strength fibers. An aerial laser transmitter is described using a ground based laser source transmitting laser power through an optical fiber to an aerial platform for transmission from the platform.

Abstract: Apparatus for generating optical radiation includes a laser, which is configured to operate in multiple transverse modes simultaneously so as to generate an input beam, which is characterized by a first speckle contrast. The transverse modes of the input beam are optically mixed so as to generate an output beam have a second speckle contrast, which is substantially less than the first speckle contrast.

Abstract: Apparatus for generating optical radiation includes a laser, which is configured to operate in multiple transverse modes simultaneously so as to generate an input beam, which is characterized by a first speckle contrast. The transverse modes of the input beam are optically mixed so as to generate an output beam have a second speckle contrast, which is substantially less than the first speckle contrast.

Abstract: A system for detecting intrusion across a surface, comprising a plurality of light sources projecting an array of illuminating beams along different optical paths in the surface and a detector array system directed such that it detects along a plurality of fields of view in the surface, illumination reflected from the illuminating beams. A signal processing system detects changes along the array of fields of view, in the reflected illumination level detected by the detector system. An increase greater than a predefined level in the reflected illumination level from any field of view provides an indication of an intrusion across the surveilled surface along that field of view, at the crossing point of the direction of that field of view with the optical path whose illuminating beam generated the increase in reflected illumination from that field of view.

Abstract: A method for imaging an article, the method includes: (i) providing short duration light pulses; (ii) directing the light pulses, by multiple optical heads, to illuminate multiple spaced apart areas of an article; and (iii) directing light from the multiple areas towards multiple two-dimensional light sensors; whereas (iv) imparting motion between the article and the multiple optical heads during the stages of providing and directing. An apparatus for inspecting an article that includes: (i) at least one pulsating source for providing short duration light pulses; (ii) multiple optical heads, adapted to direct the light pulses to illuminate multiple spaced apart areas of an article and to collect light from the multiple areas towards multiple two-dimensional light sensors; and (iii) a positioning device which is adapted to impart motion between the article and the multiple optical heads.