Laser Range Research Articles

Validation of long arc orbit determination method based on orbital residuals analysis and determination of coordinates of Chinese SLR stations using the LAGEOS satellites

Satellite Laser Ranging (SLR) technology is one of the main technologies in the field of space geodesy, it has played an extremely important role in laser ranging data application and research. As a commonly used geodynamic satellites, the main contribution of LAGEOS and LAGEOS-2 is the solution of orbit determination and station coordinates. At present, there are 8 analysis centers of the International Laser Ranging Service (ILRS) to release the precise orbit products for the two LAGEOS satellites. However, there is currently no relevant research on the analysis of the consistency of these orbits. So, the authors would evaluate the accuracies of them, and the results show that the orbital accuracies of the two LAGEOS satellites are 3 ∼ 5 cm. SLR is regarded as one of the important input data of the International Terrestrial Reference Frame (ITRF), the analysis center of ILRS provides weekly solutions of station coordinates for ITRF. But, due to the limitation of SLR observation conditions, for example most observations of Chinese SLR stations can be made at night, and laser ranging test cannot be conducted in rainy days, the orbit solution of the seven-day arc may have the problem of less data. Therefore, this paper proposed a method for computing the station coordinates based on long arc orbit determination, and we developed the LAODGEO software (Long Arc Orbit Determination Software for Geodynamic Satellite), which is used to solve the orbits of two LAGEOS satellites and station coordinates of five SLR stations in China. The results show that the obtained orbital precision is basically superior to 3.70 cm, and the 3DRMS values between station coordinates solved by us and the coordinates published by SLRF2014 are mostly smaller than 0.013 m, which is consistent with research results domestic and overseas.

Search for environment-dependent dilatons

The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. In this article, we present the very first experimental constraints on the parameters of this model. For this, we employ data obtained from the qBounce collaboration and the Lunar Laser Ranging (LLR) experiment. Furthermore, we forecast expected constraints for the Casimir And Non Newtonian force EXperiment (Cannex) soon to be realized in an improved setup. Finally, we provide a detailed analysis of the screening mechanism and additional symmetries of the dilaton field theory.

Laser Phase Rangefinders: Ways to Improve Accuracy

Scientific and technological progress in the field of geodetic and industrial measurements in terms of the use of laser rangefinders operating in ranges up to 5000 meters has led to a reduction in the error of such measuring instruments over the past ten years by two or more times. Such rapid development of high-precision rangefinder technologies has led to a significant revision of the requirements for their metrological support, as well as to the need to develop a new generation of length standards, the stock of metrological accuracy of which would provide an assessment of the metrological characteristics of all types of existing and promising length measuring instruments with a laser rangefinder. To solve this problem, the Institute’s staff conducted research within the framework of a number of thematic research and development works in terms of developing the appearance of a new generation of length standards operating in the range up to 5000 meters in an open atmosphere. Within the framework of this article, one of the developed models of a high-precision complex of measuring instruments for length and coordinate increments is considered, which is a serial high-precision laser phase light meter, modified by the institute’s staff in terms of the system for receiving and processing measuring signals. At the same time, in order to increase the accuracy of length measurements using the developed range finder layout, it is proposed to investigate ways to reduce the errors of the model components of the boundaries of its error. To ensure the smallest error in determining the hardware correction of the rangefinder layout, it is proposed to use funds from the state primary special standard of the unit of length. As promising ways to reduce the error in determining the phase difference of signals, it is proposed to use digital recording and signal processing devices that implement a method for calculating the phase difference of signals by mathematically processing the recorded data using a specially developed computational algorithm based on Fourier analysis. For the most accurate determination of the values of the pulse repetition frequency of signals and the values of the speed of light on the measured track, it is proposed to improve the means of determining these indicators. The use of the proposed methods to improve the accuracy of measuring the length of laser phase rangefinders allows you to provide the necessary margin of metrological accuracy.

Algorithm for restoring the urban environment profile by using information from laser rangefinders

An algorithm for the formation (reconstruction) of obstacle planes corresponding to elements of the urban environment during the flight of an unmanned aerial vehicle (UAV) of the quadcopter type is considered. Measurements from an array of laser rangefinders (sensors) installed on board the UAV are taken as initial information. The algorithm is a handling of processing measured distances to obstacle planes in real time. A mathematical model of a measuring system based on an array of laser rangefinders and an algorithm for reconstructing obstacle planes are described. The simulation results show the fundamental applicability of the algorithm for reconstructing obstacle planes. Keywords UAV, quadcopter, laser rangefinders, obstacle detection system, urban environment

The miniSLR: a low-budget, high-performance satellite laser ranging ground station

Satellite Laser Ranging (SLR) is an established technique providing very accurate position measurements of satellites in Earth orbit. However, despite decades of development, it remains a complex and expensive technology, which impedes its further growth to new applications and users. The miniSLR implements a complete SLR system within a small, transportable enclosure. Through this design, costs of ownership can be reduced significantly, and the process of establishing a new SLR site is greatly simplified. A number of novel technical solutions have been implemented to achieve a good laser ranging performance despite the small size and simplified design. Data from the initial six months of test operation have been used to generate a first estimation of the system performance. The data include measurements to many of the important SLR satellites, such as Lageos, Etalon and most of the geodetic and Earth observation missions in LEO. It is shown that the miniSLR achieves sub-centimetre accuracy, comparable with conventional SLR systems. The miniSLR is an engineering station in the International Laser Ranging Service and supplies data to the community. Continuous efforts are undertaken to further improve the system operation and stability.

Ellipse Fitting Method based on Pendulum Genetic Algorithm Particle Swarm Optimization for Well Diameter Measurement by Laser Distance Sensor

Ellipse Fitting Method based on Pendulum Genetic Algorithm Particle Swarm Optimization for Well Diameter Measurement by Laser Distance Sensor

Sag Measurement Method of Wind-Induced Vibration for Uniced Overhead Power Line via Laser Rangefinder and Angle Monitoring

Sag Measurement Method of Wind-Induced Vibration for Uniced Overhead Power Line via Laser Rangefinder and Angle Monitoring

Spectral broadening scheme for high stimulated Brillouin scattering thresholds on multi-harmonic linear frequency modulation

This paper proposes a spectral-broadening scheme for suppressing the stimulated Brillouin scattering (SBS) in fibers using multi-harmonic linear frequency modulation (LFM). The frequency tuning range of the LFM lasers is further expanded by incorporating sinusoidal phase modulation (PM) to achieve more effective spectrum spreading. Furthermore, the ability of multi-harmonic-LFM light sources to suppress SBS is investigated using the effective Brillouin gain spectra (BGS). Meanwhile, the experimental results reveal that at a 3 dB bandwidth of ∼480 MHz, the SBS thresholds of multi-harmonic-LFM light sources were improved by 8.36 times compared to a single-frequency laser, and by appropriately 69% compared to the LFM light sources. Because the spectra of the multi-harmonic-LFM light sources and the multifrequency-sinusoidal-PM light sources have a near-rectangular shape, the capacity of the two schemes to suppress SBS is comparable, which verifies the advantages of the multi-harmonic-LFM light sources in suppressing SBS. Our study also investigated the effects of frequency intervals between each chirp harmonic and the chirp period of multi-harmonic-LFM light sources on the suppression of SBS, which provides guidance for optimizing multi-harmonic-LFM light sources.

Integrated Technology of Laser Spread Spectrum Communication and Ranging for Deep Space (Invited)

Integrated Technology of Laser Spread Spectrum Communication and Ranging for Deep Space (Invited)

Optical phased array output beam calibration method based on Adam algorithm

<sec>Optical phased array (OPA) technology, as a pivotal component of laser detection and ranging (LiDAR) systems, plays a crucial role in augmenting the application efficiency in fields such as autonomous driving, precision measurement, and remote sensing detection. With the escalating demands for high-resolution imaging, the array size of OPAs is continuously expanding, imposing higher requirements on the calibration precision and efficiency of the output beam. Existing calibration algorithms, such as the simultaneous perturbation stochastic gradient descent (SPGD) and the Gerchberg-Saxton (GS) algorithm, often face challenges of prolonging calibration times and insufficient precision when dealing with large-scale OPA systems.</sec><sec>In order to address this problem, our study introduces the Adam optimization algorithm, renowned for its adaptive learning rate feature, into the calibration process of OPA output beams. Through simulation modeling and experimental validation, this work comprehensively examines the differences in performance between the Adam algorithm and conventional SPGD and GS algorithms in beam calibration, especially under various OPA array configurations. For a 16×16 OPA array, the application of the Adam algorithm significantly enhances the peak side lobe ratio (PSLR) to over 15.98 dB, while notably reducing the number of iterations to less than 600, thereby shortening the calibration cycle and improving calibration precision effectively.</sec><sec>Furthermore, this work provides an in-depth analysis of parameter selection, convergence speed, and stability of the Adam algorithm in OPA calibration, offering detailed guidance for achieving more efficient and high-quality beam calibration. Through comparative analysis, this work not only demonstrates the substantial advantages of the Adam algorithm in enhancing OPA calibration efficiency, reducing calibration duration, and optimizing output beam quality but also emphasizes its critical role in advancing OPA technology.</sec><sec>The main contribution of this work lies in providing an innovative algorithmic approach for achieving efficient calibration of OPA output beams, which has important theoretical and practical significance for advancing the LiDAR technology, particularly in the field of high-precision beam control. Moreover, by applying optimized algorithms, this study not only improves the performance of OPA technology within existing domains but also paves new ways for its application in emerging fields such as optical communication, optical networking, and high-resolution imaging.</sec>

Разработка метода определения угла наклона опор контактной сети железнодорожного транспорта

This paper discusses a new method for measuring and calculating the angle of inclination of a railway support or a contact network support, using an unmanned aerial vehicle flying along a straight path, parallel to the railway track. A review of existing measurement methods is carried out, their advantages and disadvantages are indicated. In the method under consideration, it is proposed to measure angles and distances with six laser scanning rangefinders installed in threes on horizontal and inclined planes on an unmanned aerial vehicle. This allows you to increase the speed and accuracy of determining the angle of inclination of vertical supports. The calculations use the minimum distances from the laser scanning range finder to the top and bottom of the support surface. The formulas use geometric relationships and the cosine theorem to calculate the roll of supports taking into account their taper. Measuring distances and angles three times allows for averaging over them, which significantly increases the accuracy of calculations. A model experiment is carried out on a model of a reinforced concrete contact network support in four orientations. A comparison is made between theoretically calculated and experimentally measured distances and inclination angles. The accuracy of parameter determination complies with regulatory requirements.

Accurate 3-D Positioning of Aircraft Based on Laser Rangefinder Combining Monocular Vision Measurement

Accurate 3-D Positioning of Aircraft Based on Laser Rangefinder Combining Monocular Vision Measurement

РАЗВИТИЕ УРАЛЬСКОГО ОПТИКО-МЕХАНИЧЕСКОГО ЗАВОДА ВО ВТОРОЙ ПОЛОВИНЕ 1940-х — СЕРЕДИНЕ 1960-х гг.

The article is devoted to the development of the Ural Optical-Mechanical Plant (UOMZ) in the conditions of transition to late industrial modernization. The relevance of the problem under consideration is due to the presence of some analogies between the patterns of the period of transition to late industrial modernization in the USSR and the current trends of the formation of a post-industrial society. The characteristic features of the socio-economic development in the period under study were the science intensity of production, the creation of new materials, military-technical progress, and the development of the space industry. The authors proceeded from the principles of modernization theory. Research methods of high priority were historical-comparative, narrative, causal, problem-chronological. After the war, Plant No. 217 (since 1964 — Ural Optical and Mechanical Plant) produced optical devices for the military-industrial complex, the space industry, aviation, and construction. Some of the enterprise’s products were exported. The plant reached the level of the fourth technological order on the basis of conveyor mechanized and automated production. In the second half of the 1940s — middle 1960s, the plant, as part of the scientific and industrial cluster of the region, mastered new technologies: the manufacture of glassintensive devices and optoelectronic devices of the laser rangefinder family, new methods of glass casting. UOMZ developed cooperation with scientific and educational institutions of the industry, design bureaus, the USSR Academy of Sciences, design and technological institutions.

Handheld Laser Rangefinder Based Location Estimation via Regularity of Fractionally Integrated Signals

Handheld Laser Rangefinder Based Location Estimation via Regularity of Fractionally Integrated Signals

Passive Attitude Estimation of Spacecraft Based on Multi-Retroreflector Differential Satellite Laser Ranging

Passive Attitude Estimation of Spacecraft Based on Multi-Retroreflector Differential Satellite Laser Ranging

Review of the Development of Lunar Laser Ranging

Review of the Development of Lunar Laser Ranging

A Measurement Method for Needle Insertion Depth Utilizing a Laser Ranging Device Combined with the Puncture Needle

A Measurement Method for Needle Insertion Depth Utilizing a Laser Ranging Device Combined with the Puncture Needle

Laser Ranging Technology Based on Photonic Resonant Tunneling

Laser Ranging Technology Based on Photonic Resonant Tunneling

Satellite Laser Ranging Echo Characteristics Based on Lidar Atmospheric Correction Model

Satellite Laser Ranging Echo Characteristics Based on Lidar Atmospheric Correction Model

Laser Ranging Data Assessment and Improvement of Changchun Station Using Precise Ephemerides

Laser Ranging Data Assessment and Improvement of Changchun Station Using Precise Ephemerides