&lt;title&gt;Digital transformations of the phase measurement information in the high resolution heterodyne laser interferometry&lt;/title&gt;

Teleshevsky, V. I.; Grishin, S. G.

doi:10.1117/12.802270

Cited by 7 publications

(11 citation statements)

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“…Until relatively recently, 10-30 years ago, the noise of the photodetector was the most important limitation determining the resolution of AO LDI [15,16]. Progress in the construction of the schemes of AO LDI led to the understanding that the reduction of the influence of these noises can be implemented in two ways: 1) selection of photodetectors with an optimal ratio between the frequency of AO modulation f aom and the level of the photodetector's own noise, taking into account their significantly nonlinear increase the noise from frequency;…”

Section: Phase Error Due To Photodetector Noisementioning

confidence: 99%

“…The current trend of their improvement is to increase the resolution to the level of subpicometric values, less than 1 ρm [7][8][9]. LDI with acousto-optic (AO) modulation of the optical flow can be considered one of the most promising [11][12][13][14][15][16][17][18][19][20]. To increase the resolution of AO LDI, it was proposed to use two measuring channels (in future -channel) with the same stages for measuring cyclic start-stop movements: "fast inaccurate" and "slow accurate".…”

Section: Introductionmentioning

confidence: 99%

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Features of an acousto-optical two-channel laser displacement interferometer with multi-frequency photodetectors with subpycometer resolution

Leun

2022

J. Phys.: Conf. Ser.

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The article discusses the issues of improving acousto-optical (AO) heterodyne laser displacement interferometers (LDI) by using two independent multi-frequency photodetectors: high- frequency (HF) and low-frequency (LF) low-noise, working with "fast inaccurate" and "slow accurate" measuring channels, respectively. The "fast inaccurate" channel allows you to measure displacements with high velocity peed movements. The scheme of the "slow accurate" channel is based on the joint operation of a phase-locked frequency system and a small-range phase meter, providing high resolution for low velocity. Such a scheme of AO LDI most fully implements its capabilities in the control of start-stop cyclic movements of objects, providing high resolution at the initial and final stages of movements with low velocity. A metrological analysis of the "slow accurate" channel is carried out, the possibilities and conditions for achieving AO LDI at low velocity of subpicometer resolution are shown.

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Section: Phase Error Due To Photodetector Noisementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Features of an acousto-optical two-channel laser displacement interferometer with multi-frequency photodetectors with subpycometer resolution

Leun

2022

J. Phys.: Conf. Ser.

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“…Heterodyne speckle pattern interferometry [1] is a relatively new speckle technique by combining electronic speckle pattern interferometry [2] and heterodyne interferometry [3][4][5] and which can provide full-field measurement of dynamic displacement down to submicron scale. However, most of the reported designs of heterodyne speckle pattern interferometer found in literature required complicated optics and control systems.…”

Section: Introductionmentioning

confidence: 99%

A Simple Heterodyne Temporal Speckle-Pattern Interferometer

Wong

Gao

2010

AIP Conference Proceedings

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“…The calibration method has the following advantages: high rate of calibration procedure; lack of any need for the use of measurement markers of special form; and the fact that it is possible to use the method in mobile coordinatemeasuring systems. The principal drawback of the method lies in the complexity of the process of estimating the actual coordinates of the centers of the markers in a three-dimensional coordinate system in the course of calibration [9,10].…”

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confidence: 99%

Calibration of the Cameras of Photogrammetric Measurement Systems by Means of the Method of Least Squares

Konov

Gololobova

2014

Meas Tech

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The use of the method of least squares in calibration of cameras in contactless spatial measurement systems is investigated.The technology of contactless spatial measurements has become increasingly more common in recent years both in machine construction and in related fields of industry [1]. By comparison to contact measurement systems, contactless measurement systems exhibit a host of advantages, chief among which are the absence of any need for mechanical contact with the subject of measurement; high rate at which measurement information is obtained (down to several tens of thousands of points per minute); and the fact that it is possible to perform spatial measurements of objects of complex form.Contactless spatial measurement systems are based on such technologies as photogrammetry, triangulation, and laser interferometry; moreover, still or film cameras (depending on the nature of the problems that have to be solved, whether static or dynamic) are most often used to implement the technologies. The cameras constitute an optical system ( Fig. 1) consisting of several lenses that determine the magnification, solid angle, and the guides of the light flux 1 to the digital array 3 through a semitransparent plate 2 that transmits a portion of the light flux through the optical system 4, 5 into the view finder 6. Thus, a digital image which, from the geometric point of view, is a central projection of the three-dimensional subject of measurement into the camera's plane of projection is usually formed at the camera output. Schematically, a model of a still camera may be depicted in accordance with Fig. 2. Upon projection to some point S, the polyhedron ABCD in three-dimensional space leaves a track abcd in the plane of projection (in the CCD array of the camera). Measurements by means of cameras are related directly or indirectly with reconstruction of the lines of the projection link connecting the center of projection S, a point in the test object, and its track in the plane of the image [2, 3]. The use of photogrammetric technologies to produce measurement information makes it possible to investigate surfaces of complex form with sufficient precision (down to 0.01 mm) [4].On the basis of mathematical models, a camera is described by nine parameters, among which may be distinguished internal and external parameters [2,3]. The internal parameters are those which determine the solid angle of the camera as well as the deviation of the principal optical axis from the nominal position. The parameters of external orientation in the projective model of the camera include the coordinates of the center of projection of the camera S(x S , y S , z S ) and the angles α, ω, and χ, which specify the direction of its principal optical axis. Basically, these parameters determine the matrices of transformation from some absolute (global) coordinate system X a , Y a , Z a into a coordinate system bound with the camera X, Y, Z in which the axes X and Y are respectively parallel to the axes X p and Y p of the planar coordinate syste...

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<title>Digital transformations of the phase measurement information in the high resolution heterodyne laser interferometry</title>

Cited by 7 publications

References 0 publications

Features of an acousto-optical two-channel laser displacement interferometer with multi-frequency photodetectors with subpycometer resolution

Features of an acousto-optical two-channel laser displacement interferometer with multi-frequency photodetectors with subpycometer resolution

A Simple Heterodyne Temporal Speckle-Pattern Interferometer

Calibration of the Cameras of Photogrammetric Measurement Systems by Means of the Method of Least Squares

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