Abstract: A method and apparatus for calculating distance in an assembly operation. The method includes the steps of providing an assembly comprising a first part, a second part and a driver coupled to the first part. The driver arranged to selectively move the first part relative to the second part. The method also includes actuating the driver to selectively move the first part between a first known position and a second position and registering speed and/or acceleration data of the driver between the first known position and the second position. The time interval for the first part to move between the first known position and the second position is measured. The distance moved by the first part between the first known position and the second position using the measured time interval and the data registered from the driver can then be calculated.

Abstract: In order to acquire positioning results (position and azimuth) of a moving body and reducing cumulative errors in integration processing of the positioning results, a moving body positioning apparatus includes: movement detecting means for detecting whether or not a moving body is moving; position acquiring means for acquiring a position of the moving body; integrating means for integrally processing a plurality of positions acquired by the position acquiring means as positioning results; and preprocessing means for preprocessing the positioning results to be inputted into the integrating means. In accordance with output from the movement detecting means, the preprocessing means inputs the positioning results obtained from the position acquiring means into the integrating means, which integrally processes the positioning results.

Abstract: A sensor (200, 300, 400) for the measurement of distances or of distance changes in accordance with the signal transit time principle having a transmitter (12) for the transmission of an electromagnetic signal as well as having a transmission controller (18, 20) by means of which the signals can be transmitted by the transmitter (12) at presettable transmission times and having a receiver (16) for the reception of the signal remitted in a monitored zone, wherein an evaluation unit (18, 22) of the sensor (200, 300, 400) is made to trigger the transmission of the signal at a transmission time in a respective measurement period (100) and to sample the received signal as well as to accumulate a histogram (110, 114) of such received signals over a plurality of measurement periods (100) to determine the reception time from the histogram (100, 114) and the transit time from said reception time.

Abstract: An electronic measuring device for measuring and displaying a linear displacement of a horizontal screw mechanism, the device comprising: a gravity acceleration sensor adapted for measuring an angle of rotation value of a horizontal rotational shaft of a screw mechanism; a data processing unit for converting the angle of rotation value into a linear displacement value according to characteristics of the linear screw mechanism; and a digital display unit for displaying the linear displacement value; in which the gravity acceleration sensor, the data processing unit, and the digital display unit are electronically or electrically connected.

Abstract: Embodiments described herein generally relate to a method of measuring the vibration of an aircraft engine. One embodiment herein provides an engine monitoring system either connected to and/or positioned in close proximity to an aircraft engine. Also provided is a clearance measuring device within the engine monitoring system. The clearanceometer collects clearance data that is later converted into vibration data.

Abstract: Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging.

Abstract: A system for measuring a true vertical depth of a downhole tool is provided. The system includes: a first optical clock located at a first depth and having a first frequency; a second optical clock disposable at a downhole location and having a second frequency at the downhole location; and a processor for receiving the first frequency and the second frequency, and calculating a true vertical depth of the second optical clock based on a difference between the first frequency and the second frequency. A system and computer program product for measuring a true vertical depth of a downhole tool are also provided.

Abstract: A device for measuring a length of a recoding material, includes: a rotating body that rotates in contact with a recording material which is transported; a length measuring unit that measures a length of the recording material based on a rotation of the rotating unit; a detecting unit that detects at least one of a rotation and an oblique advance of the recording material; and a correcting unit that corrects a value measured by the length measuring unit based on an output of the detecting unit.

Abstract: A system determines the revolutions of an object using multiple accelerometers. A difference vector between at least 2 multi-axis accelerometers spaced some distance apart is used to calculate the two-dimensional or three-dimensional centripetal acceleration vector. The centripetal acceleration vector is then used as a rough estimate for the sampling rate for a digital tracking bandpass filter. This bandpass filter extracts angular orientation data leading to a sampling rate and to a revolution totalizer. The number of revolutions of the object, along with a known diameter of an attached object, such as a vehicle wheel, may be used to calculate distance traveled by the object.

Abstract: An ultra-precision machine tool capable of accurately detecting a machining start position, in which movable axes are supported by fluid bearings. A workpiece is mounted on a rotary table of a B axis, and the rotary table is mounted on an X axis that is a linear motion axis. A tool is mounted on a Y axis. The Y axis is mounted on a Z axis. The X axis is moved reciprocally each time the Z axis is moved a predetermined amount, a machining surface of the workpiece is scanned, and it is determined whether or not position deviation of the X, Y and B axes reaches or exceeds a reference value. The Y axis is driven and the tool is moved toward the workpiece a predetermined amount, and the above-described scan is performed.

Abstract: A method of generating a library from a reference substrate for use in processing product wafers is described. The method includes measuring substrate characteristics at a plurality of well-defined points of a reference substrate, measuring spectra at plurality of measurement points of the reference substrate, there being more measurement points than well-defined points, and associating measured spectra with measured substrate characteristics.

Abstract: Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging.

Abstract: Methods are disclosed wherein the structural health of a civil structure, such as, but not limited to, a bridge or the like is measured by electronic distance measurement from a plurality of stable locations to a plurality of cardinal points on the structure in a methodical manner. By measuring the coordinates of the cardinal points, the dynamic and long-term static behavior of the structure provide an indication of the health of the structure. Analysis includes; comparison to a Finite Element Model (FEM), comparison to historical data, linearity, hysteresis, symmetry, creep, damping coefficient, and harmonic terms.

Abstract: The present invention relates to a method to locate a target in regard of a sensor, comprising the steps of collecting the outputs of a capacitive sensor comprising a plurality of electrodes and combining said outputs so as to obtain a signal representative of the distance separating said target from the sensor.

Abstract: Methods, systems, and products monitor athletic performance. Location information is acquired that indicates a device is in movement. A level of difficulty associated with the location information is retrieved and associated to a distance traversed during the movement. The distance traversed and the level of difficulty are stored in a database.

Abstract: A computer implemented method for identifying location information of an unknown point on an aircraft. The unknown point on the aircraft is identified. A plurality of reference points is identified for the aircraft located in a three-dimensional model of the aircraft, wherein the plurality of reference points have known locations described using a three-dimensional coordinate system to form a plurality of identified reference points. The plurality of identified reference points is displayed on a set of images of the aircraft. A measurement of distance to each of the plurality of identified reference points is obtained to form a plurality of measurements in response to displaying the plurality of identified reference points on the set of images. The location information of the unknown point is identified using the plurality of measurements.

Abstract: A chromatic point sensor (CPS) calibration object and characterizing data are provided. The calibration object comprises a flat base plane with steps extending from it. Step measurement points provided by the steps and base plane measurement points provided by portions of the base plane are intermingled along a measurement track. The characterizing data characterizes known heights of the measurement points. A calibration method acquires measurement data such that some base plane measurement points should be at nearly the same measurement distance and therefore have the same common mode errors relative to known base plane measurement point heights. If such base plane measurement points exhibit minimal error variations, then measurements for those and proximate measurement points may provide reliable calibration data. In contrast, error variations outside an expected range indicate unreliable measurements that should be screened or replaced by new calibration measurements.

Abstract: A method and system for a long range Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth ranging signal(s), including VHF of lower frequency bands, which minimizes propagation loss and loss of accuracy of the RF locating signals. The method and system includes narrow bandwidth ranging signal multi-path mitigations processor, which further improves the track-locate accuracy. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF narrow bandwidth ranging signal penetration and an increased accuracy by using VHF bands in conjunction with the narrow bandwidth ranging signal multi-path mitigations processor. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software.

Abstract: Within a prioritized mode selection dialog, either a measurement accuracy prioritized mode or a measurement speed prioritized mode is selected. If the measurement accuracy prioritized mode is selected, then processing for entering a tolerable amount of movement is executed. Then, a relative movement speed of a CCD camera to a measurement stage is calculated from the entered amount of movement. Finally, image information is captured at a lower speed than the calculated relative movement speed to execute image measurement. If the measurement speed prioritized mode is selected, then processing for entering a relative movement speed is executed, and image information is captured at the entered relative movement speed to execute image measurement.

Abstract: A method for processing road use data. A first moving vehicle has an encounter with vehicles in motion. An apparatus in the first vehicle generates and stores encounter records for the encounters. Each encounter record includes a location of the first moving vehicle and a location and identifier of a corresponding vehicle in motion, and is stored in the apparatus. A first encounter record for an encounter between the first moving vehicle and a second moving vehicle is sent by the first moving vehicle to a charging system of a road use charging authority having a data store. If the charging system determines that the data store includes a second encounter record of the encounter received from the second moving vehicle, then the second encounter record is not used in a charging process and/or is deleted from the data store; otherwise, the first encounter record is stored in the data store.

Abstract: The invention relates to an imaging method with synthetic aperture for determining an incident angle and/or a distance of a sensor from at least one object in space, wherein at each of a number of aperture points one echo profile is sensed. Advantageously, for several angles assumed as the incident angle, one phase correction value and/or one distance correction value is calculated, adapted profiles are generated based on the echo profiles by adapting the phase with the phase correction value for each assumed angle and/or by shifting the distance with the distance correction value, for the assumed angle, the adapted profiles are summed or integrated, and a probability distribution is derived, and a probability value for the incident angle and/or for the distance is determined therefrom. A determination of the incident angle is also possible independently of the distance, wherein it is possible to only consider velocities or accelerations.

Abstract: An industrial roll includes: a substantially cylindrical core having an outer surface; a polymeric cover circumferentially overlying the core outer surface; and a sensing system. The sensing system comprises: a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roll and provide signals representative of the operating parameter, wherein one of the plurality of sensors is a tracking sensor and the remaining sensors are non-tracking sensors; and a processor operatively associated with the sensors that processes signals provided by the sensors. The sensors are arranged at a substantially equal radial distance from the core outer surface, such that they define a circle when viewed from an end of the roll. Each of the non-tracking sensors is further arranged at a substantially equal first angular distance from its immediate non-tracking sensor neighbors, two endmost non-tracking sensors defining an angular gap.

Abstract: A method is disclosed whereby a laser-based spherical coordinate measurement system is dynamically calibrated. A mechanical oscillator, such as, but not limited to, a Foucault pendulum is used to generate periodic motions which can be fitted to Fourier series models. The residuals between the experimental measurements and the model can provide information which can be used to calibrate the instrument. The calibration information is used to augment the ASME B89.4.19-2006 standard to improve sensitivity to cyclic errors and include the servo systems.

Abstract: A device for determining the category of mail of a mailpiece, which device comprises: an stand designed to receive said mailpiece; at least one gauge fastened to said stand and provided with a slot of predetermined length and of predetermined height, which length and which height are suitable for defining a determined maximum width and a determined maximum thickness for the mailpiece; means for automatically estimating a length of the mailpiece depending on its position on the stand, and relative to the gauge; and means for acting, on the basis of that single estimate of the length of the mailpiece, to deliver, to a franking machine, information about the category of mail to which said mailpiece belongs.

Abstract: A method of estimating a clearance between at least one rotating object of a rotary machine and a second object is provided. The method includes measuring an operating parameter of the rotary machine. The method also includes obtaining signals corresponding to the at least one rotating object across multiple revolutions in time, wherein the number of the revolutions is determined based upon the measured operating parameter. The method further includes generating waveforms corresponding to the at least one rotating object from the obtained signals for the revolutions. The method also includes estimating the clearance between the second object and the at least one rotating object based upon the generated waveforms.

Abstract: A system for determining a distance of travel of a brake cylinder piston includes a brake cylinder having the brake cylinder piston, a pressure transducer operationally coupled to the brake cylinder and configured to determine a pressure measurement within the brake cylinder, and a control module of an electrically controlled pneumatic (ECP) brake control system. The control module is operationally coupled to the pressure transducer and configured to convert the pressure measurement within the brake cylinder determined by the pressure transducer into at least one of a displacement time of the brake cylinder piston, an equalization pressure within the brake cylinder, a pressure build-up time within the brake cylinder, a pressure leakage from the brake cylinder, or any combination thereof.

Abstract: A system and associated method for selecting or creating an area which meets meet a set of marking criteria, for example, corresponding to a minimum surface area; a maximum slope angle; and a minimum deviation from a specified height. A marking station is directed to mark the selected area that meets the marking criteria.

Abstract: Examples disclosed herein include methods and systems for automatically estimating the length of an implantable catheter by measuring the pressure decay response to pumping fluid through the catheter. The decay time for a unit fluid pressure pulse generated within the catheter is proportional to the length of the catheter, i.e. as the length of the catheter increases so does the decay time. The catheter length can therefore be estimated based on, e.g., the decay time of the pressure pulse. The estimated catheter length can also be analyzed to determine if it is representative of the actual length of the catheter, or, e.g., is affected by one or more catheter malfunctions including cuts and occlusions.

Abstract: A data acquisition device for an auto triggering thereof comprises a movement detector, a distance detector, a processor, and a data acquiring component. The movement detector detects movement data of the data acquisition device. The movement data indicates a state of movement for the data acquisition device. The state of movement is one of static and dynamic. The distance detector detects distance data between the data acquisition device and an object to which data is to be acquired. The processor receives the movement data to determine the state of movement and, when the state of movement is determined to be static, receives the distance data to determine the distance of the object from the data acquisition device. The data acquiring component acquires the data from the object when the processor initially determines that the state of movement is static and subsequently determines the distance is within a predetermined range.

Abstract: The invention relates to a turbomachine having a rotor (10) comprising rotor blades (12), having a rotor housing (16) which surrounds at least sections of the rotor (10) or the rotor blade (12) so as to form a rotor gap (d), and having a gap-measuring system (18) which is coupled to a capacitive sensor device (20) having an electrode and a counterelectrode for determining measured capacitance values (C) which characterize the rotor gap (d), wherein the rotor (10) or the rotor blades (12) is/are connected as the electrode of the sensor device (20), wherein at least part (22) of the rotor housing (16) is connected as the counterelectrode. The invention also relates to a gap-measuring system (18) and to a method for determining a rotor gap (d) between a rotor (10) comprising rotor blades (12) and a rotor housing (16) of a turbomachine, which rotor housing surrounds at least sections of the rotor (10) or the rotor blades (12).

Abstract: This application generally relates to methods and systems for detecting spectrophotometer misalignment. In particular, the application may characterize the noise of a spectral measurement relative to a reference substrate known to exhibit a generally linear (flat) spectral output over a known spectrum. From the spectral measurement, a linear regression may be performed on a portion of the spectral output to determine a best fit line and a correlation of determination (“R-squared value”) may be determined correlated the measured data to the best fit line. Finally, the R squared value may be compared to a predetermined threshold R squared value to determine if the sensor is misaligned beyond an acceptable amount. If so, an alert may be generated.

Abstract: The present disclosure relates to interactive systems and methods for dimensioning with a mobile device. The mobile device can include an accelerometer, imager, and a corresponding algorithm configured to compute dimensions based on a plurality of inputs from the accelerometer, imager, etc. Specifically, the accelerometer allows the mobile device to measure acceleration and time, and the algorithm is configured to convert these measurements into distances. Additionally, with a three-axis accelerometer, the user can move the device off an axis being measured and still receive an accurate measurement, i.e. the algorithm can compensate for off-axis movement. Further, the present invention can incorporate an imager on the mobile device to provide additional compensation supplementing the algorithm and allowing the user additional freedom to be positioned away from the starting and end-point of a measurement.

Abstract: A dynamic motion and distance measuring device for estimating and measuring speed and distance covered by a subject engaged in an athletic endeavor and more particularly to measuring and estimating the speed and distance and providing a relative indication of a measured speed and distance to an optimal speed and distance and/or time including finish time of the subject engaged in an athletic event, even where the event is occurring in changing environment or terrain conditions where remote data collection and signal reception is inconsistent and variable.

Abstract: A calibration system for a surgical instrument. The calibration system includes an actuator, such as a motor system and a flexible shaft. The calibration system also includes a surgical instrument actuatable by the actuator. The calibration system also include calibration data corresponding to the surgical instrument. A processor is configured to process the calibration data for determining a position of the surgical instrument. The calibration system may include a sensor configured to provide a signal corresponding to a movement of the actuator, the processor being further configured to process the signal for determining a position of the surgical instrument.

Abstract: To provide a step number measuring apparatus in which a reduction in electric power is intended by a simple constitution, and which can correspond to plural movements. A CPU calculates a moving motion pitch on the basis of a detection signal from sensors that a switching circuit has selected, calculates the moving motion pitch by performing a processing having been selected from among plural kinds of processings, which have been stored in a memory, on the basis of the detection signal from the sensors that the switching circuit has selected, calculates the moving motion pitch by selecting the other processing among the plural kinds of processings when both the moving motion pitches differ, and performs a step number measurement by the selected processing when both the moving motion pitches become the same.

Abstract: Some embodiments of the present invention provide a system that generates a simulated vibration pattern in a computer subsystem. During operation, a vibration pattern is monitored at a location in the computer subsystem, wherein the vibration pattern is monitored while the computer subsystem is incorporated into the computer system and the computer system is operating. Then, the vibrations of the computer subsystem are mimicked by generating the simulated vibration pattern at the same location in the computer subsystem based on the monitored vibration pattern.

Abstract: An indenter is pressed onto a test piece; a displacement of the indenter is detected; and a testing force applied to the test piece through the indenter is detected. FFT analysis is performed on a displacement detection signal detected in a non-load state to detect a frequency band of noise. Filter characteristics are calculated based on the detected frequency band, and filtering is performed on the displacement detection signal based on the filter characteristics. Physical properties of the test piece are evaluated based upon the displacement detection signal after the filtering and the testing force.

Abstract: A system and method is provided for determining changes in the angular position of a driven pulley, with respect to a driving pulley, when the driven and driving pulleys are synchronously linked by a flexible drive member such as a toothed belt or a chain. From these determined changes in the angular positions, the system and method can determine the condition of the flexible drive member and can output an appropriate signal when the condition of the flexible drive member has exceed a pre-defined value. Further, the system and method can detect a variety of other undesired conditions in the operation of an engine and/or the relative angular position information can be used to alter operation of the engine to improve the engine's operating efficiency and/or reduce the emissions created during operation of the engine.

Abstract: The present invention discloses a method for the online determination of a bulge/upset dimension xST and rivet head end position K of a rivet 3 with a length L in a punch rivet process with the help of a moveable punch 10 and a rigid die 20. The path covered by the punch 10 and the force applied by it are determined and evaluated online during the joining process. The quality characteristics of the joint connection are determined with the help of defined threshold values or a graphical evaluation of force/path data of the joining process.

Abstract: First and second devices (7, 8) are configured to transmit and receive signals wirelessly and have first and second clocks respectively for determining signal transmission and arrival times. The first device transmits first and second signals (9, 10) and the second device transmits a third signal (11). By introducing a delay into the first signal, a thief may be able to fool the devices into thinking that they are closer than they really are. To help identify if a delay has been introduced into the first signal, the first device calculates a ratio of clock rates for the first and second clocks and determines whether the calculated ratio falls within a predefined range.

Abstract: The object of the invention of developing a three-dimensional flexible registering unit which can measure mechanical operations in the region at any desired positions over a defined length is achieved by virtue of the fact that said registering unit is in the form of a cable and comprises, in the three-dimensional extent, a flexible protective sleeve and two coaxially arranged conductor tracks, wherein one conductor track surrounds the other conductor track, and one of the conductor tracks is used as a measuring electrode and the other conductor track is in the form of an electrical resistor and has a voltage gradient, and a dielectric which electrically separates the two conductor tracks from one another in the quiescent state and enables punctiform or areal contact between the two conductor tracks when a mechanical force acts from the outside is situated between the two conductor tracks, and a measured value recording and evaluation unit which is suitable for determining a change in voltage or resistance tr

Abstract: A method and a device are provided for testing the design of a seat comprising a seat area, a backrest, and a headrest. The method includes positioning a body simulating element with a reference measuring point on the seat by means of a robot kinematics; passive switching of the robot kinematics; measuring a distance between the reference measuring point and the headrest; and comparing the measured distance with a reference value.

Abstract: A method of checking turbomachine blades is presented that may be implemented using a computer and a measuring device. Turbomachine blades compatible with embodiments of the method have a profile including a centerline, suction face, pressure face, leading edge and trailing edge. The method measures geometrical coordinates of many points on a blade section profile, calculates an aerodynamic parameter of the blade section as a function of the measured coordinates, verifies whether the calculated aerodynamic parameter value departs from a valid range of parameters from a reference blade, and validates or rejects the blade depending upon whether the value of the aerodynamic parameter falls within the valid range.

Abstract: A portable apparatus including an interface configured to input first motion data of a user from a foot-worn first self-contained activity determining unit is disclosed. The portable apparatus also includes a second self-contained activity determining unit configured to determine second motion data of the user. Furthermore, the portable apparatus includes a processing unit configured to determine and store a user-specific dependency between the first motion data and the second motion data, and determine a current speed of the user or a current traveled distance of the user based on current second motion data and the user-specific dependency.

Abstract: An electronic measuring device that includes a transceiver device, a microprocessor operatively connected to the transceiver device, as well as a memory, an electronic output device, and a plurality of input mechanisms, all of which are operatively connected to the microprocessor. In some embodiments, the microprocessor may be programmed with logic that allows a user of the device to take and manipulate measurements using a menu-driven procedure by using the input mechanisms to select and activate desired operations.

Abstract: A method is for setting at least one predetermined distance between a machine tool (10) and a metallic or non-metallic electrically conductive workpiece (12) according to which a capacitive and/or inductive sensor (16) fixed to the machine tool (10) while facing the workpiece (12). The machine tool (10) is displaced with constant speed toward the workpiece (12) by means of a drive device, and a sensor signal is output at predetermined time intervals by means of a data processing unit (24). The sensor signal has a characteristic quantity that continuously changes in a non-linear manner according to the distance of the machine tool (10) from the workpiece (12). The data processing unit (24) compares each read out value of the characteristic quantity with a comparative value read out before at a predetermined number of time intervals and calculates the difference between the values that are compared with one another.

Abstract: A method of checking the height of a mail item relative to at least one dimensional threshold SH defining a change in postage. The mail items are advanced at a constant speed V along a reference surface. The presence of a mail item is detected relative to a given point of the reference surface. First and second times t1, t2 for which the same mail item is present at the first and second distances d1, d2 relative to the reference surface is detected. The ratio t2/t1 is compared with a value equal to (1??), where ? represents a correction coefficient of less than 1 that depends on the tolerances for detection of the presence of a mail item. The height of a mail item is considered greater than the dimensional threshold SH if, and only if, the relationship t2/t1>1?? is true.

Abstract: There is provided a distance measuring apparatus having system flexibility by varying a distance measuring range and a distance measuring resolution according to an environment and circumstance. The apparatus includes a reference pulse generator and a delay pulse generator capable of controlling frequencies of a reference pulse and a delay pulse and duty ratios of the reference pulse and the delay pulse. The reference pulse generator and the delay pulse generator include a programmable clock generation unit generating a clock of a frequency determined by a frequency control signal and a duty ratio control unit controlling a duty ratio of the clock generated by the programmable clock generation unit.

Abstract: Tools and techniques for estimating elevations, including without limitation tools and techniques that employ mobile stations with laser detectors for receiving a beam emitted from a laser source and estimating an elevation of the mobile station based on the received beam. In some instances, a mobile station may be configured to identify, based on some or all of a variety of factors, a situation in which the elevation of the detector is likely to change to the extent that the slope of the emitter needs to be adjusted to account for this change in elevation. The mobile station may also be configured to inform the laser source that the slope of the emitted beam should be adjusted. In response, the laser source may adjust the slope of the emitted beam accordingly.

Abstract: A laser interferometric apparatus for measuring a displacement of an object is disclosed, the apparatus comprising a laser source for producing a laser beam having a given intensity, a beam splitter for dividing the laser beam into a reference beam and an object beam to be directed to the object, thereby producing a scattered object beam being modulated according to the displacement of the object, interference means adapted to provide at least two electrical interference signals from the scattered object beam and the reference beam, the at least two electrical interference signals each comprising a wanted signal component indicative of the object displacement and an intensity noise component, and processing means for subtracting the at least two electrical interference signals, thereby generating an output signal, the output signal comprising substantially the wanted signal component alone, wherein the intensity noise is substantially rejected.