Rapid Alignment of High-Accuracy Reflector Panels Used in Compact Antenna Test Ranges Based on Laser Tracker and Dial Indicator

Author(s):  
Wang Mingming ◽  
Ye Mengxue ◽  
Li Dongsheng ◽  
Cheng xin
Author(s):  
J. Hartmann ◽  
P. Trusheim ◽  
H. Alkhatib ◽  
J.-A. Paffenholz ◽  
D. Diener ◽  
...  

<p><strong>Abstract.</strong> In recent years, the requirements in the industrial production, e.g., ships or planes, have been increased. In addition to high accuracy requirements with a standard deviation of 1<span class="thinspace"></span>mm, an efficient 3D object capturing is required. In terms of efficiency, kinematic laser scanning (k-TLS) has been proven its worth in recent years. It can be seen as an alternative to the well established static terrestrial laser scanning (s-TLS). However, current k-TLS based multi-sensor-systems (MSS) are not able to fulfil the high accuracy requirements. Thus, a new k-TLS based MSS and suitable processing algorithms have to be developed. In this contribution a new k-TLS based MSS will be presented. The main focus will lie on the (geo-)referencing process. Due to the high accuracy requirements, a novel procedure of external (geo-)referencing is used here. Hereby, a mobile platform, which is equipped with a profile laser scanner, will be tracked by a laser tracker. Due to the fact that the measurement frequency of the laser scanner is significantly higher than the measurement frequency of the laser tracker a direct point wise (geo-)referencing is not possible. To enable this a Kalman filter model is set up and implemented. In the prediction step each point is shifted according to the determined velocity of the platform. Because of the nonlinear motion of the platform an iterative extended Kalman filter (iEKF) is used here. Furthermore, test measurements of a panel with the k-TLS based MSS and with s-TLS were carried out. To compare the results, the 3D distances with the M3C2-algorithm between the s-TLS 3D point cloud and the k-TLS 3D point cloud are estimated. It can be noted, that the usage of a system model for the (geo-)referencing is essential. The results show that the mentioned high accuracy requirements have been achieved.</p>


2013 ◽  
Vol 823 ◽  
pp. 3-8
Author(s):  
Hong Yu Luo ◽  
Long Qing Tan ◽  
Dong Sheng Li

To solve problems of the traditional feed brace in single reflector compact antenna test rang, such as difficulty in position adjustment and the feed polarization manual switching, mechanical structure and position adjustment mechanism of feed brace system are designed, based on principle of feed positioning. The new feed brace system weight is lightened with same intensity. Function of precision rotation around axis of feed horn is realized. Control system software is developed. Two control modes, onsite and remote, are provided. Laser tracker is used to locate feed phase center in high-precision when feed brace system is installed on site. The new feed brace system has been applied in some single reflector compact antenna test range and its precision meets the requirements.


2018 ◽  
Vol 58 (1) ◽  
pp. 9
Author(s):  
Filip Dvořáček

The main aim of the research was to evaluate numeric procedures of the indirect determination of the group refractive index of air and to choose the suitable ones for requirements of ordinary and high accuracy distance measurement in geodesy and length metrology. For this purpose, 10 existing computation methods were derived from various authors’ original publications and all were analysed for wide intervals of wavelengths and atmospheric parameters. The determination of the phase and the group refractive indices are essential parts in the evaluation of the first velocity corrections of laser interferometers and electronic distance meters. The validity of modern procedures was tested with respect to updated CIPM-2007 equations of the density of air. The refraction model of Leica AT401 laser tracker was analysed.


1971 ◽  
Vol 14 (8) ◽  
pp. 1175-1178
Author(s):  
V. S. Karp ◽  
D. L. Braz ◽  
A. L. Markin

2014 ◽  
Vol 597 ◽  
pp. 365-371 ◽  
Author(s):  
Xiao Lin Zhang ◽  
Lie Shan Zhang ◽  
Wen Yan Tang ◽  
Chao Wang ◽  
Wan Cun Liu

A new flexible centroid measurement method is provided in order to meet actual demands for centroid measurement of large-thrust carrier rocket segments. The method has the benefit of utilizing a laser tracker to accurately measure positions of support points of a weighing sensor and geometrical parameters associated with an attitude status of each segment to be measured, thereby solving the problem of a traditional three-point method that measuring accuracy in centroid measurement depends on both mechanical equipment machining accuracy and positioning accuracy. The analysis result shows that the method provided herein has an engineering application value and can realize measurement to high accuracy, automation and universality for large-thrust carrier rocket segments.


2010 ◽  
Vol 44-47 ◽  
pp. 3589-3592
Author(s):  
Hong Min Wang

A new type of automatic verification apparatus based on image recognition is put forward in this paper. Data are acquired by CCD camera through digital image processing. The length reference is provided by the precision grating. Verification and data processing are completed by computer. The apparatus has features of high accuracy and precision, good reliability, efficiency and convenience in operation. The errors caused by artificial factors are lowered.


Author(s):  
M. Nishigaki ◽  
S. Katagiri ◽  
H. Kimura ◽  
B. Tadano

The high voltage electron microscope has many advantageous features in comparison with the ordinary electron microscope. They are a higher penetrating efficiency of the electron, low chromatic aberration, high accuracy of the selected area diffraction and so on. Thus, the high voltage electron microscope becomes an indispensable instrument for the metallurgical, polymer and biological specimen studies. The application of the instrument involves today not only basic research but routine survey in the various fields. Particularly for the latter purpose, the performance, maintenance and reliability of the microscope should be same as those of commercial ones. The authors completed a 500 kV electron microscope in 1964 and a 1,000 kV one in 1966 taking these points into consideration. The construction of our 1,000 kV electron microscope is described below.


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