Abstract: An optical device provided by the present invention can comprise: a light transmitting unit for generating a first beam for photographing a certain area; a light receiving unit for sensing a second beam returning from the certain area; a light separating unit for distinguishing and transmitting the first beam from the second beam; and a detection unit including a micro electro-mechanical system mirror (MEMS mirror) for transmitting the first beam by changing an optical axis up to a first steering angle, and for receiving the second beam.

Abstract: Various technologies described herein pertain to context aware real-time power adjusting for steerable lidar. A lidar system can include a laser source (e.g., FMCW) configured to emit an optical signal. The lidar system can further include a scanner configured to direct the optical signal emitted by the laser source from the lidar system into an environment. The optical signal can be directed over a field of view in the environment during time periods of frames. The lidar system can further include a controller configured to modulate a power of the optical signal emitted by the laser source between the frames and/or within one or more of the frames. The controller can modulate the power of the optical signal emitted by the laser source based on a position of the lidar system in the environment and a direction in which the optical signal is to be transmitted into the environment.

Abstract: Implementations of the present invention disclose an unmanned aerial vehicle ranging method, apparatus and an unmanned aerial vehicle.

Abstract: A method, for determining the real distance separating an object and an optical detection system, includes, from several so-called reported distances respectively less than or equal to individual reference distances dependent respectively on modulation frequencies: in a first step, determining an initial deviation coefficient between the reported distances and incrementing the smallest of the reported distances with the corresponding individual reference distance; then in a second step, determining a current deviation coefficient between the current distances obtained in the preceding step and incrementing the smallest of the current distances with the corresponding individual reference distance; and in a third step, repeating the second step until all the current distances exceed a common reference distance greater than the individual reference distances.

Abstract: Systems and methods for decoding code-multiplexed Coulter signals are described herein. An example method can include receiving a code-multiplexed signal detected by a network of Coulter sensors, where the code-multiplexed signal includes a plurality of distinct Coulter signals, and inputting the code-multiplexed signal into a deep-learning network. The method can also include determining information indicative of at least one of a size, a speed, or a location of a particle detected by the network of Coulter sensors by using the deep-learning network to process the code-multiplexed signal. The method can further include storing the information indicative of at least one of the size, the speed, or the location of the particle detected by the network of Coulter sensors.

Abstract: A distance-measuring optoelectronic sensor (10) uses two sampling memories for detection of objects in a monitoring zone (20). The sensor (10) has a light transmitter (12) for transmitting a transmission light pulse (16) into the monitoring area (20), a light receiver (26) for generating a reception signal from the light pulse (22) remitted by objects in the monitoring area (20), a control and evaluation unit (32) configured to determine a reception point in time from the reception signal and the distance of the object by means of a light time of flight method, and a first and second sampling memory (34a, 34b) having a plurality of memory cells each for storing a section of the reception signal. Partially overlapping recording regions are used, with each alternately recording a reception signal for a longer duration than a time interval between two successive transmission light pulses (16).

Abstract: This disclosure describes various system and methods for monitoring photons emitted by a heat source of an additive manufacturing device. Sensor data recorded while monitoring the photons can be used to predict metallurgical, mechanical and geometrical properties of a part produced during an additive manufacturing operation. In some embodiments, a test pattern can be used to calibrate an additive manufacturing device.

Abstract: A laser distance meter includes a laser light source configured to emit temporally modulated laser light toward target objects. The laser distance meter further includes a light detector configured to detect laser light reflected by target objects. The laser distance meter further includes a light detector configured to detect laser light reflects by target objects. The laser distance meter also includes an electronic control and analyzing unit configured to control the laser light source and configured to analyze signals of the light detector. The electronic control and analyzing unit is designed to drive the laser light source, detect laser light reflected by target object by directly synchronously sampling a reception signal over a measurement time duration, generating a detection signal for each modulation frequencies, carry out an inverse Fourier transformation of the detection signal, and evaluate the propagation time spectrum.

Abstract: A system and method for projecting target tracks produced by a remote tracker onto a surface of the Earth to obtain projected tracks is provided. Projection bias in a projected track from the remote tracker projected onto a planar map is removed by computing a discrete Frechet distance from a polygonal curve associated with a track derived from the remote tracker to a corresponding polygonal curve on the planar map. A correspondence between the projected track and a track on the planar map is automatically established. A projection bias is removed based on the correspondence.

Abstract: A system is provided including a first elongated object proximate a first surface on a first side of a structure and a second elongated object proximate a second surface on a second side of the structure, the second surface and the second side opposite the structure relative to the first surface and the first side, the first object aligned with the second object at a first point on the first surface. The system also includes a first plurality of corner cubes affixed to the first object at first known distances from each other and from the first point, wherein the first object abuts the first surface at the first point. The system also includes a second plurality of corner cubes affixed to the second object at second known distances from each other and from the first point, wherein the second object abuts second surface at second point opposite first point.

Abstract: Systems and methods for determining ranges to a target disposed behind a transparent surface are described. A target acquisition system receives a plurality of lidar returns, at least some of which are from a target and at least some of which are from a transparent surface. The lidar returns correspond to a portion of a lidar signal generated by a lidar, directed toward the target, and reflected back to the lidar from either the target or the transparent surface. A range measurement for each of the plurality of lidar returns is determined. The target acquisition system generates a histogram of the range measurements. The histogram includes an array including a plurality of range bins. Each range bin defines a unique portion of a predetermined distance out from the lidar. The histogram further includes a count associated with each respective range bin.

Abstract: Systems and methods for measuring a distance to an object. An exemplary method includes directing light beams from three or more continuous-wave lasers onto a target, and also frequency shifting the light beams split off from the lasers to generate local oscillator beams. When the reflected sensor beam (reflected off the target) and the local oscillator beams are combined, the method further includes determining optical phases of heterodynes produced by combining the light beams within the reflected sensor beam and the local oscillator beams, and determining synthetic phases by taking the difference between the optical phases of the heterodynes. The method further includes determining synthetic wavelengths based on the differences between the frequencies of the lasers. The method further includes determining a distance to the target based on the synthetic phases and the synthetic wavelengths.

Abstract: Systems and methods for determining the position of an object in a coordinate system. An exemplary system includes three or more laser ranging sensors each configured to direct a sensor beam of continuous-wave light toward a target. Light reflecting off the target interferes with the sensor beam creating an interference beam. The interference beam is combined with local oscillator beams in each laser ranging sensor to create a synthetic wave beam. Each of the laser ranging sensors also includes an array of photodetectors that sense the synthetic wave beam, and is able to measure a distance to the target based on output from the array of photodetectors. The system further includes a controller that receives a distance measurement from each of the laser ranging sensors, and calculates a position of the target in the coordinate system based on the distance measurements.

Abstract: Systems and methods for determining the position of an object in a coordinate system. An exemplary system includes three or more laser ranging sensors each configured to direct a sensor beam of continuous-wave light toward a target. Light reflecting off the target interferes with the sensor beam creating an interference beam. The interference beam is combined with local oscillator beams in each laser ranging sensor to create a synthetic wave beam. Each of the laser ranging sensors also includes an array of photodetectors that sense the synthetic wave beam, and is able to measure a distance to the target based on output from the array of photodetectors. The system further includes a controller that receives a distance measurement from each of the laser ranging sensors, and calculates a position of the target in the coordinate system based on the distance measurements.

Abstract: An electro-optical distance measuring device having a photodetection unit comprising a plurality of pixels arranged in a predetermined arrangement is disclosed. A signal processing unit has a storage unit for storing the detection result in correspondence with each of the pixels, wherein the signal processing control unit sequentially changes a position of the division for every cycle wave at which the photodetection amount is detected and continues detections until a detected range becomes at least one cycle or more. The arithmetic processing unit calculates a waveform for at least one cycle stored in the storage unit for each pixel, obtains a phase difference of the waveform with respect to the irradiated distance measuring light, and calculates the distance based on the phase difference.

Abstract: Disclosed is a distance measuring device using an optical comb. In order for the absolute distance to an object to be measured which has a surface with low reflection ratio or a scattering surface and is approximately 10 m apart, to be easily measured with accuracy of 0.1 mm or more using an optical and contactless method, the distance measuring device which measures the distance to the object to be measured is configured such that the distance to the object to be measured is measured by comparing the phase of the beat signal between a light source and a plurality of CW lasers which are reflected or scattered by the object with the phase of the beat signal between the light source and a plurality of CW lasers prior to being irradiated onto the object.

Abstract: Embodiments of the present invention provide methods to produce a high performance, feature rich TOF system, phase-based or otherwise using small TOF pixels, single-ended or preferably differential, as well as TOF systems so designed. IC chip area required for pixels is reduced by intelligently off-loading or removing from within the pixel certain components and/or functionality. In some embodiments during a single TOF system capture period, analog values from each pixel are repeatedly sampled and converted to digital values, which are combined and manipulated on the sensor chip. Combining this plurality of values enables appropriately compact data from the sensor chip. Embodiments of the present invention implement a TOF system with high ambient light resilience, high dynamic range, low motion blur and dealiasing support, while advantageously reducing pixel area size relative to prior art TOF pixels.

Abstract: A three-dimensional surround scanning device and a method thereof are described, which are adopted to perform surround scanning on a scene area, so as to construct a three-dimensional model. The device includes an image acquisition element, a first moving mechanism, a range acquisition element, and a controller. The controller controls the image acquisition element, the range acquisition element, and the first moving mechanism to perform three-dimensional image acquisition, so as to obtain a two-dimensional image covering the scene area, depth information with three-dimensional coordinates, and corresponding position signals. The controller rearranges and combines the two-dimensional image, position signals, and depth information, so as to construct the three-dimensional model.

Abstract: A method for measuring time delay and distance may include providing an electromagnetic radiation carrier frequency and modulating one or more of amplitude, phase, frequency, polarization, and pointing angle of the carrier frequency with a return to zero (RZ) pseudo random noise (PN) code. The RZ PN code may have a constant bit period and a pulse duration that is less than the bit period. A receiver may detect the electromagnetic radiation and calculate the scattering profile versus time (or range) by computing a cross correlation function between the recorded received signal and a three-state RZ PN code kernel in the receiver. The method also may be used for pulse delay time (i.e., PPM) communications.

Abstract: According to the invention, a light signal is emitted to one or several targets in order to derive geodetic distance data therefrom. Apparatus components such as transmitters (1?) and receivers (4?) are modeled along with the targets (3a and 3b) as a linear, time-invariant system which is excited by means of a signal s(t) and the system response y(t) of which is recorded. Unlike in delay meters or phase meters, the distance data is derived from both the delay and the signal form of the system response.

Abstract: A radar array antenna comprising: a plurality of analog to digital (A/D) converters for converting analog signals from the array to digital signals, the signals supplying input to one or more optical modulators having controllable wavelengths, each optical modulator connected to a corresponding multiplexer, the multiplexer providing outputs to a demultiplexer that distributes the signals to a beamformer.

Abstract: A distance measuring device using a multiple wave enables measurement of long distances with a high resolution and with a high precision by significantly reducing the circuit scale required for demultiplexing circuitry. A distance measuring device (1) includes an illumination unit (1) that illuminates using multiple modulated light having a plurality of frequencies satisfying a relationship in which one frequency is an even multiple of another frequency, a light receiving unit (20) that accumulates the charge of reflected light of the multiple modulated light into a plurality of accumulation units while switching an accumulation unit into which the charge is accumulated at a predetermined timing, and a distance calculation unit (30) that calculates a distance based on the charge.

Abstract: A first ranging apparatus includes a synchronizing signal generator for generating a synchronizing signal at a constant interval, a light-emitting unit for emitting an intensity-modulated light in response to the synchronizing signal input thereto, a light-detecting unit for detecting a reflected light from an object irradiated with the modulated light, in response to the synchronizing signal input thereto, a calculating unit for calculating the distance up to the object based on the phase difference between the modulated light and the reflected light, and a synchronizing signal control unit for changing an arrival time of the synchronizing signal from the synchronizing signal generator at the light-detecting unit, depending on the number of times that the synchronizing signal is generated. The light-detecting unit samples the amount of the reflected light in exposure periods established at a constant cycle length with reference to a time at which the synchronizing signal is input thereto.

Abstract: Range-finding apparatus comprises a source of pulsed radiation of variable repetition rate and a beam-splitter for dividing the pulsed radiation into two portions which are directed respectively to a local retro-reflector and to a retro-reflector co-located with a remote target the range of which is to be determined. The source, beam-splitter and retro-reflectors are arranged in the form of Michelson interferometer together with a detector. The repetition rate of the source is tuned to frequencies f such that round-trip distance to the remote target is mc/f where m is an integer, this condition being detected by observing a heterodyne signal at the detector. Two such frequencies enable range to be determined. The precision with which range is determined may be increased by carrying out interferometry using the two portions. The accuracy of the method does not depend on absolute range (as with triangulation) and is not limited by the speed of timing electronics, as is the case for time-of-flight techniques.

Abstract: A method and system for at least three dimensional imaging comprising a processor for processing information; at least one photon light source generating a beam of light; a modulator for modulating the light of the at least one photon light source; a plurality of first receivers operative to detect the influence of a subject on the beam; the plurality of first receivers being operatively connected to the processor and operating to transmit nonspatial information to the processor; the plurality of first receivers being spaced at known, different distances from the subject, whereby comparison of each of the outputs of the plurality of first receivers provides three dimensional information concerning the subject; the processor operating to correlate the outputs of the plurality of first receivers with spatial information derived from the modulated light at correlating intervals of time to create a three dimensional image of the subject.

Abstract: Systems and methods are provided for targetless optical measurement and optical information projection. A non-contact optical measurement device is provided for determining at least one of position and orientation of a workpiece. A projector is provided for projecting a part definition on the workpiece. Advantageously, beams from the non-contact optical measurement device and the projector pass through common optics.

Abstract: A technique for not causing a gap of the central beam axes depending on wavelengths of emitted light is provided. A laser apparatus includes a laser oscillation portion for oscillating laser light; a nonlinear crystal inputting a first output light from the laser oscillation portion, the nonlinear crystal outputting the first output light and a second output light which is a second harmonic wave of the first output light and has a central beam axis not corresponding to a central beam axis of the first output light; a central beam axis bending means for bending at least one central beam axis of the first output light and the second output light; and a optical fiber in which the edge is in a position or a neighborhood in which the central beam axes of the first output light and the second output light intersects.

Abstract: For acquiring a 3-D image of a scene, the scene is illuminated with modulated light emitted by an illumination unit and imaged onto an array of lock-in pixel sensor cells, which detect the previously emitted light after it has been scattered or reflected by an object or a living being in the scene. One determines the modulation phase of the light detected at the lock-in pixel sensor cells and provides a reference modulation phase that stands in a known relationship with the modulation phase of the light at the time of the emission. Based upon the reference modulation phase and the modulation phase of the light detected at the lock-in pixel sensor cells one then calculates depth information on the scene.

Abstract: A robot system including a beacon provided with a transmitting part to transmit a light for location determination, and a mobile robot provided with a receiving part to receive the light. The robot system further includes a rotation driving part to rotate the transmitting part about a predetermined axis; an encoder to add phase information regarding how much the transmitting part is rotated by the rotation driving part with respect to a reference direction to the light; and a location determiner to determine a location of the mobile robot based on the phase information of the light received by the receiving part. Accordingly, a robot system is provided, which can precisely determine a location of a mobile robot regardless of external environmental conditions, distance, and reduction of cost by using a few transmitters.

Abstract: Method for determining a mean radiation power P rad 0 _ of electromagnetic radiation of a radiation source, the radiation being intensity-modulated with modulation frequency ?0, in a predetermined time interval.

Abstract: The invention relates to an electronic distance measuring apparatus for surveying, e.g. for measuring the distance from the apparatus to an object. The apparatus comprises: a) an objective lens (101), defining an optical axis (OA), b) at least two sources (111, 112) of structured light for transmitting beams (?1, ?2) of separate wavelengths towards said object, said beams on reflection from said object received by the objective lens (101), (c) at least two receivers (141, 142) arranged outside a beam path (109) as defined by the objective lens (101), and adapted to receive said received beams (?1, ?2) of structured light.

Abstract: It is an object of the present invention to provide an electric optical distance wavelength meter detecting the time when the switching is completed and shortening the time required for distance measurement by immediately starting the distance measurement when measurement light and reference light are switched by a light path switching device. An electric optical distance wavelength meter includes a light emitting element for emitting measurement light toward a target placed on a measurement point; a light receiving element for receiving the measurement light coming back after reflecting on the target; a CPU for calculating the distance to the target or the object based on light receiving signals from the light receiving element; and a light path switching device for switching the measurement light so that the measurement light passes through an internal light path from the light emitting element to the light receiving element.

Abstract: A distance measuring device is provided that reduces the time required for a distance measurement without degrading accuracy of the measured value.

Abstract: A method and a device for optically measuring a distance by emitting an amplitude modulated and bundled optical signal and by receiving the signal reflected from a target object. The modulation frequency is continuously regulated by means of a regulating loop in such a manner that between the emitted and the received signal a fixed phase difference prevails that is independent of the distance. For reducing the circuitry required for a distance evaluation circuit, while maintaining a high accuracy and for increasing the attainable regulation speed, the detection of the phase difference occurs with a phase comparator.

Abstract: TOF system shutter time needed to acquire image data in a time-of-flight (TOF) system that acquires consecutive images is reduced, thus decreasing the time in which relative motion can occur. In one embodiment, pixel detectors are clocked with multi-phase signals and integration of the four signals occurs simultaneously to yield four phase measurements from four pixel detectors within a single shutter time unit. In another embodiment, phase measurement time is reduced by a factor (1/k) by providing super pixels whose collection region is increased by a factor “k” relative to a normal pixel detector. Each super pixel is coupled to k storage units and four-phase sequential signals. Alternatively, each pixel detector can have k collector regions, k storage units, and share common clock circuitry that generates four-phase signals. Various embodiments can reduce the mal-effects of clock signal transients upon signals, and can be dynamically reconfigured as required.

Abstract: A spectrometer and spectrometry method comprising modulating a light source with a carrier waveform multiplied by an envelope function, directing light from the light source through a sample region and to a photodetector, and demodulating current from the photodetector at a reference frequency. Also a method for computing a modulation waveform comprising specifying a target detection efficiency in a Fourier space, computing a response of a waveform that comprises a carrier wave multiplied by an envelope function, and modifying the envelope function using nonlinear optimization means to minimize a difference between the computed response and a predetermined target detection efficiency.

Abstract: Chirped synthetic wave laser radar apparatus and methods are disclosed. In one embodiment, a system includes a laser source, a controller operatively coupled to the laser source and adapted to frequency-modulate first and second laser outputs, and an optical assembly. The optical assembly includes a plurality of reference channels adapted to receive a portion of a combined laser output and to provide a reference interference signal, and a signal channel having a focusing telescope adapted to focus and transmit at least part of the combined laser output onto the target, and to receive a scattered signal from target, and to provide a return interference signal. The system further includes a signal processing portion adapted to receive the reference interference signals and the return interference signal and to determine the distance to the target based on the reference and return interference signals.

Abstract: A reference electrical signal oscillated by the main oscillator (11) has two kinds of frequencies (f1, f2) which are different from each other and any one of which is alternatively selected, a sampling signal is synchronized with the reference electrical signal once every n times, and a frequency (fs) of the sampling signal is an average value of the two kinds of frequencies (f1, f2) of the reference electrical signal, and the A/D conversion portion carries out at least one A/D conversion per period of the reference electrical signal and the received electrical signal based on the sampling signal.

Abstract: A method and apparatus (10) is provided which employs phase or amplitude modulated electromagnetic probing waves (20) (in optical or microwave frequency ranges or both) emitted toward a vibrating object (8). The optical and/or microwave probing signals (20) remotely irradiate an object (8) of interest. The object (8) reflects and/or scatters the probing wave (20) toward a receiver (22). The reflected/scattered modulated signal (24) is received with a remote sensor (receiver) (22). Vibration causes additional phase modulation to the probing wave (20). At the receiving end, the signal is demodulated to extract and analyze the vibration waveform (26,28). The present invention can be utilized for nondestructive testing, monitoring of technological processes, structural integrity, noise and vibration control, mine detection, etc.

Abstract: The invention is based on a laser range finder that has a transmitter unit (10) with at least one laser, a receiver unit (12), and a single sideband modulation unit (14) that can use a first single sideband modulation frequency (ZF1) generated by an oscillator unit (16) and a carrier frequency (T1) to generate a modulation frequency (S1) of the transmitter unit (10). According to the invention, the oscillator unit (16) can generate at least one additional frequency (ZF2) and the single sideband modulation unit (14) can use the additional frequency (ZF2) to generate a demodulation frequency (S2) of the receiver unit (12).

Abstract: A laser distance measuring device (1) includes a laser diode (4) for emitting a high frequency intensity modulated measurement light beam (3) and connected with a signal generating unit (SGU) that generates a high frequency measurement signal (9) for high frequency signal transfer, at least one receiver photodetector (8a) for receiving a measurement light beam (3) reflected from a measurement object (5) and connected to a high frequency demodulator (13) for generating a low frequency phase delay signal (S1) containing phase information of the reflected intensity modulated measurement light beam (3), and a microcontroller (?C) for calculating a distance (D) from the phase delay signal (S1) and connected to the high frequency demodulator (13), with the microcontroller (?C) being connected to a control photodetector (8c) arranged in the measurement light beam (3) for low frequency transfer for determining an interference modulation component.

Abstract: A spectrometer and spectrometry method comprising modulating a light source with a carrier waveform multiplied by an envelope function, directing light from the light source through a sample region and to a photodetector, and demodulating current from the photodetector at a reference frequency. Also a method for computing a modulation waveform comprising specifying a target detection efficiency in a Fourier space, computing a response of a waveform that comprises a carrier wave multiplied by an envelope function, and modifying the envelope function using nonlinear optimization means to minimize a difference between the computed response and a predetermined target gain spectrum.

Abstract: A calibration system for ccalibrating orientation parameters of a digital optoelectronic sensor system includes an attitude and position determining system arranged in a mobile carrier, such as an airplane or a satellite, for determining the orientation parameters in flight. An optoelectronic component emits light in a defined direction with respect to the mobile carrier. A planar optical detector is arranged relative to the optoelectronic device for detecting the reflection of radiation emitted from the optoelectronic device and reflected off of a reference module arranged on the ground. The orientation parameters of the reference module are known, wherein the offsets of the orientation parameters of the attitude and position determining system may be determined by evaluating the radiation emitted by the light-emitting component, reflected from the reference module and received by the planar detector.

Abstract: A method and apparatus for the characterization of optical pulses and modulators includes modulating, using a modulator, a train of optical pulses, measuring a spectrum of the modulated train of optical pulses, recording the measured spectrum as an entry in a spectrogram at a position in the spectrogram corresponding to a relative delay between the modulation and the train of optical pulses, incrementing the relative delay, and repeating the above steps until the accumulated relative delay is equal to the period of the spectrogram. The train of optical pulses and the modulator are then characterized using the measured spectra recorded in the spectrogram.

Abstract: A method for determining optical properties of a target, using a plurality of transmitters for transmitting signals at the target, and a plurality of receivers for detecting reflected signals from the target, comprises the steps of: a) transmitting radiation signals with a plurality of wavelengths at the target; b) detecting trace reflected radiation signals from the target; c) modulating the plurality of transmitters with a waveform for generating transmitter modulation codes; d) mixing the transmitter modulation codes with the trace reflected radiation signals to generate total signals; e) transmitting the total signals at the target; f) detecting reflected total signals from the target; g) digitizing the reflected total signals with an analog-digital converter to generate digitized signals; h) integrating the digitized signals with decoding functions to extract individual signals from the total signals; and i) determining the optical properties of the target from the individual signals.

Abstract: A system and method of efficiently obtaining distance measurements of a target by scanning the target. An optical beam is provided by a light source and modulated by a frequency source. The modulated optical beam is transmitted to an acousto-optical deflector capable of changing the angle of the optical beam in a predetermined manner to produce an output for scanning the target. In operation, reflected or diffused light from the target may be received by a detector and transmitted to a controller configured to calculate the distance to the target as well as the measurement uncertainty in calculating the distance to the target.

Abstract: A method and system are provided for measuring water current direction and magnitude. A plurality of beams of radiation are transmitted radially outward from a location above a body of water. Each beam is incident on the water's surface at an angle with respect thereto. Each beam experiences a Doppler shift as a result of being incident on the water's surface such that a plurality of Doppler shifts are generated. Each Doppler shift is measured with the largest one thereof being indicative of water current direction and magnitude.

Abstract: A system and method of efficiently obtaining distance measurements of a target. A modulated optical beam may be used to determine the distance to the target. A first beam splitter may be used to split the optical beam and a second beam splitter may be used to recombine a reference beam with a return ranging beam. An optical mixing detector may be used in a receiver to efficiently detect distance measurement information.

Abstract: A device for distance measurement using a semiconductor laser in the visible wavelength range, which functions according to the echo time method, includes a collimation objective for bundling the transmitted measuring beam bundle, a circuit arrangement for modulating the measuring beam, a receiving objective for receiving and imaging the measuring beam bundle reflected at the distant object onto a receiving device, and an evaluation device for determining and displaying the distance measured to the object. The circuit arrangement for modulating the measuring beam and the evaluation device can be switched between two different operating modes. In the first operating mode, the modulation takes place using a first frequency and in the second operating mode using a second frequency. These frequencies stand in a whole-member ratio to each other.