Error analysis of 2-D diffraction grating interferometer for high-resolution displacement measurement

2008 ◽  
Author(s):  
Haojie Xia ◽  
Yetai Fei ◽  
Mei Zhang
Keyword(s):  
High Resolution ◽  
Error Analysis ◽  
Diffraction Grating ◽  
Displacement Measurement ◽  
Grating Interferometer

The Heights of Solar Radio Sources at 1424 MHz and 696 MHz

1969 ◽  
Vol 1 (5) ◽  
pp. 192-194 ◽  
Author(s):  
D. G. Cole ◽  
R. F. Mullaly
Keyword(s):  
Solar Activity ◽  
High Resolution ◽  
Solar Disk ◽  
Previous Investigation ◽  
Solar Radio ◽  
Radio Sources ◽  
Grating Interferometer ◽  
Maximum Solar Activity

The heights of solar radio sources at 1424 MHz and 696 MHz have been measured during the years 1965 and 1966. Solar activity at this time was near minimum. The number of radio sources appearing on the solar disk rarely exceeded three at any time and it thus was possible to resolve the majority of these with a high resolution grating interferometer. Many of the previous height measurements at these frequencies have been made near times of maximum solar activity and the confusion of sources within the beam has limited their accuracy. The number of sources studied here is quite considerably higher than in any previous investigation at these frequencies, and the period of observation has been continuous.

scholarly journals High Sensitivity and Full-circle Optical Rotary Sensor for Non-cooperatively Tracing Wrist Tremor with Nanoradian Resolution

2021 ◽  
Author(s):  
Xin Xu ◽  
Zongren Dai ◽  
Yifang Wang ◽  
Mingfang Li ◽  
Yidong Tan
Keyword(s):  
High Resolution ◽  
Error Analysis ◽  
High Sensitivity ◽  
Promising Alternative ◽  
Rotation Measurement ◽  
Full Circle ◽  
Repeatability Error ◽  
Process Error ◽  
Circle Rotation ◽  
Electromagnetic Immunity

<div> <p>An optical rotary sensor based on laser self-mixing interferometry is proposed, which enables noncontact and full-circle rotation measurement of non-cooperative targets with high resolution and sensitivity. The prototype demonstrates that the resolution is 0.1μrad and the linearity is 2.33×10<sup>-4</sup>. Stability of the prototype is 2μrad over 3600s and the repeatability error is below 0.84°under 9-gruop full-circle tests. The theoretical resolution reaches up to 16nrad. Random rotation has been successfully traced with a bionic hand to simulate the tremor process. Error analysis and limitation discussion have been also carried out in the paper. Although the accuracy needs further improvement compared with the best rotary sensor, this method has its unique advantages of non-cooperative target sensing, high sensitivity and electromagnetic immunity. Hence, the optical rotary sensor provides a promising alternative in precise rotation measurement, tremor tracing and nano-motion monitoring.</p> </div> <b><br></b>

scholarly journals The Radio Brightness Distribution on the Sun at 21 cm from Combined Eclipse and Pencil?Beam Observations

1961 ◽  
Vol 14 (3) ◽  
pp. 403 ◽  
Author(s):  
T Krishnan ◽  
NR Labrum
Keyword(s):  
High Resolution ◽  
High Sensitivity ◽  
Brightness Distribution ◽  
Pencil Beam ◽  
The Sun ◽  
Radio Brightness ◽  
Radio Brightness Distribution ◽  
Grating Interferometer

A study of the brightness distribution on the Sun at 21-cm wavelength on April 8, 1959, is described. High resolution observations were made of the partial eclipse on that day with a simple radiometer of high sensitivity. The brightness distribution of the uneclipsed Sun at the same wavelength was obtained using a cross-grating interferometer, which enabled the bright regions to be located accurately.

Sign in / Sign up

Export Citation Format

Share Document