Abstract: A system for measuring angular misalignment between marine propulsion devices. The system includes first and second members with mounting ends and distal ends. Attachment features are positioned at the mounting ends to attach the members to first and second propulsion shafts of the marine propulsion devices. Emitters configured to emit light are coupled to the first and second members. When the first and second member are attached to the propulsion shafts, a first emitter emits the light towards a target on the second member and a second emitter emits the light towards a target on the first member. The angular misalignment between the propulsion shafts is measurable based on a first offset between the target and where the light from the first emitter shines on the second member, and based on a second offset between the target and where the light from the second emitter shines on the first member.

Abstract: A surveying system comprising a rover having an illuminating lamp for emitting an illumination light, a second azimuth indicator for detecting an azimuth angle of an optical axis of the illumination light, a surveying instrument comprises a surveying instrument main body and a rotary driving unit capable of rotating the surveying instrument main body in at least a left-and-right direction, wherein the surveying instrument main body comprises a first azimuth indicator for detecting an azimuth angle of a reference optical axis, and as arithmetic control module, and wherein the arithmetic control module is configured to calculate the azimuth angle of the reference optical axis which is in parallel or approximately parallel with the optical axis of the illumination light based on the azimuth angle of the optical axis of the illumination light received from the rover and the azimuth angle of the reference optical axis.

Abstract: Described is a free space optical (FSO) node capable of communicating with a remote FSO node. The FSO node includes a Tx/Rx subassembly that is capable of simultaneously receiving and transmitting light carrying data, detecting the position/orientation of the received light signals, and aligning the Tx/Rx subassembly to account for misalignments with remote node. The Tx/Rx subassembly includes a central fiber for transmitting and receiving the optical signals so that the signal data can be processed. The Tx/Rx subassembly also includes a bundle of fibers that circumscribe the central fiber and receive a portion of received light signals to detect the position/orientation of the received light signals and align the FSO node with a remote FSO node.

Abstract: The present invention provides an optical angle sensor capable of detecting a wide range of angles with high resolution, having no scale, and specifying a reference angle. The optical angle sensor includes a light source for irradiating light, a reflection means for rotating around a predetermined axis as a measurement axis and reflecting the light irradiated from the light source, a light receiving means for receiving the light irradiated from the light source, and a calculation means for calculating the light received by the light receiving means as a signal. The light receiving means receives the light irradiated from the light source through the reflection means. The calculation means includes a specifying means for specifying the reference angle based on the light received by the light receiving means, and an angle calculating unit for calculating an absolute angle based on the light received by the light receiving means and the reference angle specified by the specifying means.

Abstract: A laser communication architecture provides precise optical alignment between terminals without requiring dedicated beacon lasers or dedicated beacon wavelength optics. Instead, the same lasers and optics are used for both alignment and communication. A beacon modulation is applied to alignment beacons transmitted at or near communication wavelengths so as to differentiate them from communication beams. The beacon modulation can include phase and/or amplitude variation of a high frequency modulation, and/or “ping-pong” toggling of the beacon wavelength. In some full duplex red/blue embodiments, ping-pong modulation is implemented by alternated red/blue tuning of the transmit laser or by switching between separate red and blue transmit lasers, for example using a 2×1 laser switch, while maintaining constant beacon amplitude, thereby avoiding optical amplifier dynamic response issues.

Abstract: A method for remotely guiding a refueling boom of a tanker to engage with a fueling receptacle of an aircraft while the tanker and the aircraft are in flight. The method comprising: transmitting a polarized RF scanning pattern from one of the refueling boom and refueling receptacle; detecting the polarized RF scanning pattern at one or more cavity sensors disposed on the other of the refueling boom and the refueling receptacle; and controlling a position of the refueling boom relative to a position of the refueling receptacle based on the detected polarized RF scanning pattern at the one or more cavity sensors.

Abstract: System and method for monitoring of performance of a mirror array of a digital scanner with a use of a lateral shearing interferometer (operated in either static or a phase-shifting condition) to either simply identify problematic pixels for further troubleshooting or measure the exact magnitude of the mirror's deformation.

Abstract: Methods and devices for, among other applications, locating an emitter, comprises an array of receivers configured in different angular positions about the array relative to a corresponding array location axis, to receive a signal from the emitter having at least one burst containing a train of pulses, and at least one processor configured to profile pulse count values at each receiver, from one receiver to another in the array in relation to their respective angular positions, to designate a maximum peak angular position associated with a maximum pulse count value, and to attribute the peak angular position to an angular emitter location.

Abstract: Methods and systems for improving the uniformity of a tire are provided. More particularly, a magnitude of a uniformity parameter can be obtained for each tire in a set of a plurality of tires. The magnitudes associated with the set of tires can be transformed according to a probability distribution function (e.g. a Weibull distribution function) to obtain a set of transformed magnitudes. Parameters associated with a probability distribution function can be estimated based at least in part on the transformed magnitudes. Parameters associated with the probability distribution function can be used to determine data indicative of a measurement error in the uniformity measurements attributable to a measurement process harmonic. The data indicative of the measurement error can be used to correct uniformity measurements obtained for tires and to modify tire manufacture based at least in part on the corrected measurements.

Abstract: A leveling system for identifying high and low areas of a surface relative to a reference plane to within a desired tolerance. A light source emits light in a level plane at a height above the reference plane. Several depth-indicator targets rest on the surface to be measured in an upright manner and are struck by the light in the level plane. Each of the depth-indicator targets indicates, based on color, whether the surface at that surface location is high, low, or level based on the location at which the light strikes the depth-indicator target. The color emitted by the target can be from a fluorescing layer of the target or light signals on the target controlled by a light-detecting receiver. A user can then quickly identify problem areas of the surface that need to be adjusted (e.g., raised or lowered).

Abstract: A laser processing robot system and a laser processing method, by which the motion accuracy of a robot in the system can be improved and laser processing with high accuracy can be carried out. The robot system is configured to: execute a first robot motion for moving an laser irradiation device to a predetermined command position; measure an actual three-dimensional position of the irradiation device in the first robot motion; calculate a deviation between the command position and the measured actual three-dimensional position of the irradiation device in the first robot motion; store the calculated deviation as a time series of deviation data; and execute a second robot motion in which a robot motion similar to the first robot motion is executed while correcting the laser irradiation position so that the laser irradiation position coincides with a desired position, based on the stored deviation data.

Abstract: An energy sensing espionage detector is disclosed. The detector is designed to alert on compromised LED lighting sources used by spies on unsuspecting corporations and individuals. The detector counters one threat vector that is emerging from newly mandated energy policies to replace conventional lighting with energy efficient LED lighting. The detector senses that information is being transmitted by the light source using pulsed or modulated energy that is not detectable by the human eye.

Abstract: The invention relates to a receiving unit for light-based measurements/surveying using an analog-to-digital converter for the clocked analog-to-digital conversion of light detection signals and a clocking means for clocking the analog-to-digital converter. According to the invention, the clocking means has, for receiving modulated light signals, a phase-locked loop having an input for light detection signals modulated according to the light signal modulation and an output for outputting a frequency multiple of the detected modulation frequency for the analog-to-digital converter clocking.

Abstract: A rotation angle measuring device includes a light source for generating a first light beam with a first polarization direction and a second light beam with a second polarization direction; a first beam splitter for splitting the first light beam and the second light beam to generate a third light beam and a fourth light beam; an image sensor for sensing a first interference pattern generated by the first and second light beams passing through a first displacement measurement module, and sensing a second interference pattern generated by the third and fourth light beams passing through a second displacement measurement module; and a processing unit for calculating two displacement values at two different positions on a measured object according to the first and second interference patterns, in order to further calculate a rotation angle of the rotation angle measuring device relative to the measured object along a first axis.

Abstract: Positioning devices and positioning methods are provided. The positioning device includes a laser source and an optical assembly. The optical assembly is configured to direct a laser beam projected from the laser source toward a floor and a ceiling of a semiconductor fabrication facility to generate a first laser line on the floor and a second laser line on the ceiling. The first laser line and the second laser line are parallel to and aligned with each other when viewed in a direction perpendicular to the floor and the ceiling. Accordingly, the first laser line and the second laser line can be used to align a semiconductor tool and an overhead hoist transport system in the semiconductor fabrication facility.

Abstract: An energy sensing espionage detector is disclosed. The detector is designed to alert on compromised LED lighting sources used by spies on unsuspecting corporations and individuals. The detector counters one threat vector that is emerging from newly mandated energy policies to replace conventional lighting with energy efficient LED lighting. The detector senses that information is being transmitted by the light source using pulsed or modulated energy that is not detectable by the human eye.

Abstract: An aerial surveillance and reconnaissance system includes a gimbal-stabilized ISR imaging sensor with 0.8-1.2 microradian optical resolution, using pulsed ultraviolet laser (0.330-0.380 micrometer wavelength) radiation to illuminate the observed target, and a narrow-band-pass filter at the focal plane detector to remove light at frequencies other than the illuminating frequency. Preferred sensors can be operated in a snapshot mode using intermittent illuminating pulses, with timing of the pulses selected for minimum detectability based on observations made with a lower-resolution sensor, or in a video-mode with illuminating pulses selected to generate full-motion video at operator-selectable frame rates. Some sensor embodiments may further combine the UV system described above with conventional daylight optical and sensor systems, though alternative arrangements could also include an IR sensor as well (either using a common aperture with the UV system or with a separate set of light-gathering optics).

Abstract: The invention provides a surveying instrument, comprising a surveying instrument main body and a remote control operation unit being attachable to and detachable from the surveying instrument main body and capable of communicating with the surveying instrument main body. The remote control operation unit has an operation button, a directional angle sensor and a vertical sensor. The angle measurement value is transmitted to the remote control operation unit by pressing the operation button. The remote control operation unit calculates a difference between the directional angle and the vertical angle detected by the directional angle sensor and the vertical sensor before moving and the directional angle and the vertical angle after moving the remote control operation unit. An angle measurement value after moving is calculated based on the difference and the main body control unit rotates the telescope unit so as to become the angle measurement value after the moving.

Abstract: In some embodiments, an articulated arm coordinate measurement machine can include a plurality of transfer members and a plurality of articulation members connecting the plurality of transfer members to each other to measure an angle between the transfer members. The machine can additionally include at least one coordinate acquisition member positioned at an end of the articulated arm. Further, the machine can include a harness connected to at least one of the group consisting of the transfer members and the articulation members to support at least a portion of the weight of the transfer members and the articulation members. The harness can also be configured to mount to a human.

Abstract: The present invention relates to a lighting assembly having a principal light source, at least one secondary light source, and a focusing element adapted to focus light emanating from the principal light source and adapted to let light emanating from the at least one secondary light source pass through the focusing element. The invention also relates to a windage and elevation control mechanism having a longitudinal and lateral mobile unit and a receiving unit. The mobile unit is adapted to receive a device to be adjusted, and has two aligned protrusions located respectively on longitudinal opposite sides thereof. The receiving unit defines a cavity adapted to receive the mobile unit. The cavity is defined by facing surfaces having complimentary channels adapted to receive the protrusions of the mobile unit.

Abstract: A driving information display device includes a data generator for generating driving information of a vehicle and a display unit linked to the data generator for being supported at a desired location of the vehicle. The display unit provides visualizations regarding driving information to a driver during driving. These visualizations relates to driving data if the user is operating a motorized vehicle, GPS navigational information, etc. These visualizations are then provided at the driver's field of vision, which allows the driver to keep the eyes on the road while still being able to analyze the information. This allows the driver to operate the vehicle safely and in turn enjoy more fulfilled and enjoyable driving experience.

Abstract: An interferometric tracking device includes image dividers arranged to form an optical cascade, with one of the image dividers being an incident image divider for the optical cascade and one or more of the image dividers being one or more exit image dividers for the optical cascade. Each of the image dividers splits incident light into a plurality of non-parallel orthogonally polarized beams, the beams from the incident image divider cascading through the other image dividers in the cascade. One of a plurality of shearing interferometers is optically coupled between optically adjacent image dividers in the cascade. The orthogonally polarized beams from the one or more exit image dividers are imaged onto one or more focal plane arrays.

Abstract: A weapon sighting system for gathering ambient or generated light and projecting a fixed or adjustable ballistic reticule image for targeting. The system includes a partially reflective, zero parallax, optical lens assembly, an illuminating reticule projection component, and an adjustable bracket fixed to the weapon being sighted. The bracket supports the lens assembly at one end and the projection component at an opposing end. The projection component is aligned to project a light image onto the lens assembly to be reflected back into the target sightline. The projection component gathers ambient (or generated) light through polymer acrylic solid materials and/or fiber optics, and directs the light through a fixed or adjustable mask. The movement of the weapon effects a corresponding movement in the angle of reflection through the optics of the sighting system. An adjustable mask allows the projected image to change to accommodate near and distant targets.

Abstract: An alignment head system (1, 31) for taking alignment data with respect to a pair of shafts (4, 5) coupled to each other by means of a coupling (6) comprises a data acquisition device (11) configured to wirelessly receive data, and alignment heads (2, 3). Each alignment head (2, 3) is configured to take alignment data with respect to the shafts (4, 5), to wirelessly send the alignment data to the data acquisition device (11), and to forward alignment data received from the other alignment head (2, 3).

Abstract: Measuring with a system having retroreflector targets and a laser tracker includes storing a list of coordinates for three targets and at least one added point; capturing on a photosensitive array a portion of the light emitted by a light beam and reflected off the targets; obtaining spot positions on a photosensitive array of a tracker camera from the reflected light; determining a correspondence between three spot positions on the photosensitive array and the coordinates of the targets; directing a beam of light from the tracker to the targets based at least in part on the coordinates of the first target and the first spot position; measuring 3-D coordinates of the targets with the tracker; determining 3-D coordinates of the at least one added point based at least in part on the measured 3-D coordinates of the targets and the coordinates of the at least one added point.

Abstract: The invention relates to a device for determining the position of a first shaft (10) and of a second shaft (12) that is joined to the first shaft by means of a coupling (14), with respect to each other, having a first measurement unit being placed on a circumferential surface of the first shaft and a second measurement unit being placed on a circumferential surface of the second shaft, wherein at least one of the two measurement units has means (20) for producing at least one light beam bundle (22) and at least one of the two measurement units has detection means (24, 25, 26) in order to detect the impingement position of the light beam bundle on at least one detection area (24, 25, 26).

Abstract: The invention provides a laser scanner, comprising a main unit and a rotating unit rotatably mounted on the main unit, wherein the rotating unit has a deflection member for projecting the pulsed beams by deflecting the beams perpendicularly to center axis of the rotating unit. The main unit comprises a plurality of light emitting sources disposed in a two-dimensional arrangement for emitting a plurality of pulsed beams, an optical system for projecting and receiving the pulsed beams, a rotation angle detecting unit, a plurality of photodetectors for receiving a reflection light from an object via the deflection member and being disposed respectively at positions conjugate to the light emitting sources, a distance measuring unit for measuring a distance based on a photodetection signal from the photodetector, and a control arithmetic unit for calculating projecting directions of the pulsed laser beams projected from the deflection member.

Abstract: A method of operating a laser reference system orients a reference plane of laser light generated by a transmitter so compensation is made for rake angles between the first and second axes of the transmitter and first and second non-orthogonal alignment axes. The transmitter includes an optical system arranged to generate a laser beam, the optical system projecting said laser beam radially along a rotational arc defined about a central rotational axis, thereby substantially defining a reference plane of laser light, and a positioning arrangement, coupled to said optical system, for adjusting the angular orientation of the optical system with respect to a first transmitter axis and with respect to a second transmitter axis. Detectors are arranged to detect reception of the laser beam.

Abstract: An optical calibration and testing device for machine tools includes a light source unit, a beam splitter, and at least one photo detector. The light source emits a laser light hitting the beam splitter and is split into two beams. One is perpendicular to the foundation of the light source unit, and the other is parallel with the foundation so as to test straightness, inclination angle, verticalness, vertical column inclination, vertical column parallelism and guide bar inclination of a machine tool. If there is no tested error, the position of the testing light spot coincides with that of the initial light spot. If there is an error, the position of testing light spot varies according to the error.

Abstract: A method and system comprising a Master station, a processor and one or more targets that allows a user of said system to automatically generate a 3 dimensional graphical representation of a construction site and also overlay a drawing onto the graphical representation to guide the user within a virtual space being displayed by the processor.

Abstract: A stage for aligning a workpiece relative to analyzing apparatus. The stage has a platform and means for maintaining a workpiece on the platform. The platform is operable to tilt relative to the analyzing apparatus and thereby rotate the workpiece relative to the analyzing apparatus.

Abstract: A height recording system includes a telescopic rule formed from a head and a telescopic assembly used to vary a distance between one support end forming a base for the telescopic assembly and an upper end supporting the head. The height recording system comprises: a measurement system that measures the distance; a receiver including photosensitive cell(s) to detect an optical beam output from a laser system; a module starts or validates a height measurement by the measurement system starting the measurement or the validation in response to the module receiving a determined signal from the receiver; the determined signal being representative of the laser beam being detected by one of the photosensitive cells.

Abstract: A detection sensor to detect a receiving position of laser light according to the present invention includes a pair of light receiving element arrays (11X and 11Y), wherein adjacent light receiving elements (PDXi) are positioned as spaced equidistantly from one another and are mutually connected via a resistor (RXj), and wherein the output lines (11a and 11b) are respectively connected to the light receiving elements that are present at both ends of the respective light receiving element arrays (11X and 11Y). The light receiving element arrays (11X and 11Y) configure a composite array wherein the light receiving elements of a first light receiving element array are respectively positioned between the mutually adjacent light receiving elements of a second light receiving element array.

Abstract: A first method determines a position of a point of interest on a target object surface in a target object coordinate system using orientation and distance measurements of a pointing instrument in an instrument coordinate system. A second method determines an orientation of a pointing instrument in an instrument coordinate system for the instrument to be aligned with a point of interest on a target object surface having a target object coordinate system, wherein a position of the point of interest in the target object coordinate system is known. A third method controls orientation of a laser beam of a laser in an instrument coordinate system for the laser beam to trace an image on a target object surface having a target object coordinate system, wherein positions of points for the image on the surface of the target object in the target object coordinate system are known.

Abstract: Apparatus for monitoring the alignment of marking lasers in a room for diagnosis and/or treatment in the radiation therapy, characterized by a housing, which is provided with holding means for the installation in the room and which has the following a linearly extending photosensor and an analyzing unit, which compares the position of the light generated by the laser on the photosensor with a reference position, and generates a corresponding signal upon a deviation of the measured position from the reference position.

Abstract: A local positioning navigation system and method for controlling navigation are provided. The local positioning navigation includes a stationary unit having a pointing device configured to emit a light signal and a roving unit having a detector including a plurality of light detecting elements configured to detect the emitted light signal from the stationary unit. The local positioning system further includes a controller configured to receive navigation information from the roving unit based on the detected emitted light signal and to provide control commands to the stationary unit to move the pointing device to direct the emitted light signal based on the navigation information.

Abstract: A system and method for passively estimating range and angle of a source are disclosed. The source may be any wave source including radio-frequency (RF), optical, acoustic or seismic sources. In some RF embodiments, the system includes a single aperture antenna to simultaneously receive RF signals from the RF source through a plurality of sub-apertures, and a signal processor to perform a proximity test using samples simultaneously collected from the sub-apertures to determine whether or not to calculate angle and range estimates to the source based on either a curved wavefront assumption or a planar wavefront assumption.

Abstract: A local positioning navigation system and method for controlling navigation are provided. The local positioning navigation includes a stationary unit having a pointing device configured to emit a light signal and a roving unit having a detector including a plurality of light detecting elements configured to detect the emitted light signal from the stationary unit. The local positioning system further includes a controller configured to receive navigation information from the roving unit based on the detected emitted light signal and to provide control commands to the stationary unit to move the pointing device to direct the emitted light signal based on the navigation information.

Abstract: [Problem] In a surveying instrument that automatically tracks or collimates a target, the target that is moved to a measurement point and is placed there can be found in the shortest possible time. [Solution Means] In a survey system made up of a target (60) and a surveying instrument (50) that automatically tracks or collimates the target, the target is provided with a direction angle sensor (86) that measures a surveying-instrument direction angle (?ta, ?tb) obtained when the target is directed toward the surveying instrument, whereas the surveying instrument is provided with a horizontal angle measuring portion that measures a target direction angle (?sa, ?sb, ?sc) indicating the direction of the target. An estimated target direction angle (?sb) is calculated from an angular difference (?o) between the surveying-instrument direction angle (?ta) and the target direction angle (?sa) obtained at the last measurement and from the surveying-instrument direction angle (?tb) obtained at the present measurement.

Abstract: A survey system is made up of a target and a surveying instrument provided with an automatic collimator that automatically collimates the target. The target includes a guide light transmitter that emits guide light, an azimuth angle sensor that detects a direction angle (?A, ?B) at which the target is directed, and a central processing unit that sends a rotation command, which includes the rotational direction of the instrument body, to the surveying instrument. The central processing unit determines the rotational direction of the instrument body based on an angular difference (?B-?A) between a direction angle (?A) obtained when the target is caused to approximately face the surveying instrument at the last measurement and a direction angle (?B) obtained when the target is caused to approximately face the surveying instrument at the present measurement.

Abstract: A novel test device and method for calibrating the alignment of a laser beam emitted from a laser metrology tool with respect to a target area on a substrate. The test device includes a laser-sensitive material having a calibration pattern that includes a target point. When the tool is properly adjusted, the laser beam strikes the target point and is released to production. If the laser beam misses the target point, the tool is re-adjusted and re-tested until the laser beam strikes the target point.

Abstract: The present invention relates to a method and apparatus for alignment of two mechanical parts. An inventive measuring device has a housing comprising a light source and a detector for detection of light beams. The light source is capable of transmitting a light beam modulated according to a modulation scheme for information transmission. The output of said detector is connected to an interpreter arranged to demodulate a detected light beam and to a signal conditioner arranged to extract the position of impingement of a detected light beam on the detector surface.

Abstract: A method and system is disclosed for determining a flight characteristic of an object in a flight path, the flight characteristic to be determined can be the object's position while in flight, a linear velocity, a rotational velocity or an acceleration of the object. In one embodiment, the method comprises arranging a radiation source in a plane, the plane being located to intersect the flight path of the object. The radiation source irradiates the object at least at the intersection with the flight path. The object is provided with at least first and second surface features having a predetermined configuration such as, for example, equally spaced parallel lines painted on the surface of the object. Reflected radiation from the object is measured with a sensor from the surface features and a flight characteristic of the object is determined based on the measured reflected radiation and the predetermined configuration of the surface features.

Abstract: A survey system for transmitting guide light for instructing the direction of a target, the guide light having a wide range with small power. The survey system includes a target having a recursion reflector for reflecting light and a survey apparatus having an automatic collimation device for automatically coinciding the collimation axis of the recursion reflector with that of a telescope. The target includes a guide light transmitter for emitting guide light and scans a fan beam that is wide in the horizontal direction and narrow in the vertical direction in the vertical direction as guide light. The survey apparatus includes a direction detector for receiving guide light and detecting the direction of the guide light transmitter and also includes a collimation preparing device for turning the telescope roughly to the recursion reflector based on an output signal from the direction detector prior to commencing the automatic collimation.

Abstract: A pair of rotary laser devices are vertically arranged while aligning their respective axes into a single axis and keeping said rotary laser devices away from each other in an axial direction thereof by a predetermined interval, and a light-receiving sensor is kept radially away from the single axis. A plurality of fan-shaped laser beams are emitted from each of the rotary laser devices, while rotating the laser beams. The laser beams include at least one fan-shaped laser beam in a plane inclined to a plane containing said single axis. The laser beams are received and detected with the light-receiving sensor. Inclinations of the rotary laser devices are determined relative to the light-receiving sensor, respectively, based on time intervals of said detection of the laser beams, and the position of the sensor are determined relative to said pair of the rotary laser devices in the axial direction.

Abstract: A photodetection device for a rotary laser system for projecting at least two fan-shaped beams tilted at a known angle with respect to a horizontal plane and having a known spreading angle, comprising at least three photodetectors arranged in a known relationship.

Abstract: A protective device for securing to a component movable along a track and for the monitoring of a protected zone moving with the component includes a light transmitter for the radiation of a divergent transmitted light beam into a spatial zone containing the protected zone, a light receiver for the reception of at least some of the light of the transmitted light beam of the light transmitter radiated into the spatial zone and for the emitting of corresponding received signals, and a restriction device which is arranged in the direction of a transmitted light path after a section of the transmitted light path which contains the protected zone and by means of which the transmitted light beam can be restricted to a less divergent received light beam defining the width of the protected zone in at least one direction.

Abstract: The invention relates to a system for monitoring the movements, if any, of construction work parts. It comprises: a plurality of measurement taking stations (S1, S2 . . . ) able to sight targets; a plurality of reference targets (c?i) linked to at least one station; a plurality of monitoring targets (ci) mounted on the said construction work parts, at least one of the said monitoring targets (ki) being associated with at least two stations; means of control (30) of each station for measuring at successive instants the coordinates of the reference targets and of the monitoring targets which are associated therewith with respect to the said station; and means of processing (34) the coordinates of the reference targets and of the monitoring targets computed by the said stations at the said successive instants so as to deduce therefrom a displacement, if any, of a monitoring target between two measurement instants.

Abstract: An accuracy analyzing apparatus 1 comprises: a light projector 2 attached to a main spindle 26 for emitting a light beam having a light axis coaxial with the axis of the main spindle 26; a semitransparent mirror 3 which transmits part of the emitted light beam and reflects other part; a first imaging device 4a for receiving the transmitted light beam; a second imaging device 4b for receiving the reflected light beam; and an analyzer 10 which calculates light receiving positions in the first and second imaging devices 4a and 4b, which estimates the light receiving position where the reflected light beam is to be received by the second imaging device 4b in the case where it is assumed that the axis of the main spindle 26 coincides with the first axis, and which compares the estimated light receiving position with the calculated light receiving position to analyze the perpendicularity of the axis of the main spindle 26.

Abstract: In an angle detecting apparatus and projector using range finder units, range finding calculations are performed in plural directions using line type passive range finders as the range finding units. An average value of inclination angles calculated based on the range finding calculations is selected as the inclination angle. Thus, if one range finding result has an abnormal value, the adverse effects thereof are reduced and the structure is miniaturized.