Enhancing the multi-tone continuous-wave lidar with phase detection

2021 ◽  
Author(s):  
Mert Bayer ◽  
George N. Guentchev ◽  
Xun Li ◽  
Jose E. Velazco ◽  
Ozdal Boyraz
Keyword(s):  
Continuous Wave ◽  
Phase Detection

scholarly journals Improved FMCW Radar System for Multi-Target Detection of Human Respiration Vital Sign

2019 ◽  
Vol 19 (2) ◽  
pp. 38
Author(s):  
Hana Pratiwi ◽  
Mujib R. Hidayat ◽  
A. A. Pramudita ◽  
Fiky Y. Suratman
Keyword(s):  
Target Detection ◽  
Continuous Wave ◽  
Beat Frequency ◽  
Radar System ◽  
Small Displacement ◽  
Phase Detection ◽  
Detection Capability ◽  
Fmcw Radar ◽  
Large Bandwidth ◽  
Human Respiration

Frequency Modulated Continuous Wave (FMCW) radar system has been developed and applied for various needs. Based on the conventional FMCW radar concept, a large bandwidth is needed to detect small displacements in the chest wall or abdomen related with respiratory activity. To overcome the need for large bandwidths in detecting vital respiratory signs, several improvements to the FMCW system are proposed in this paper. The phase-detection concept has been elaborated in improving the capability of FMCW to detect the small displacement. In developing multi-target detection capability, range detection capability through beat frequency output needs to be combined with the phase-detection method. Theoretical and simulation studies were performed to investigate the concept of combining range detection and phase detection for detecting respiration on multi-target. The results show that the proposed method is well-performed in detecting the multi-target respiration in high noise reflection.

scholarly journals Application Research of Frequency-Modulated Continuous-Wave Displacement Sensor Based on Zero-Crossing Phase Detecting Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Bin Sun ◽  
Junfang Song ◽  
Gang Zheng ◽  
Xiongxing Zhang
Keyword(s):  
Optical Fiber ◽  
Continuous Wave ◽  
Optical Measurement ◽  
Complex Surface ◽  
Detection Algorithm ◽  
Displacement Sensor ◽  
Phase Detection ◽  
Laser Interference ◽  
Zero Crossing ◽  
Technical Specifications

Frequency-modulated continuous-wave (FMCW) interference, as a new technology of laser interferometry, has the advantages of length traceability, large range, high accuracy, simple structure, and optical fiber transmission. Based on the formula of FMCW laser interference displacement, a zero-crossing phase detection algorithm is proposed, which can accurately calculate the initial phase of a cosine signal in a modulation period, and it is successfully applied to the contact laser interference displacement sensor. The experimental results show that the FMCW technology based on the zero-crossing phase detection algorithm can achieve the technical specifications of the contact displacement sensor with a measurement range greater than 15 mm and the standard deviation is less than 0.01 μm. The conversion of noncontact measurement to contact measurement can realize the direct measurement of workpieces with complex surface conditions on the production line, breaking through the limitation of optical measurement and expanding the application of optical fiber interferometry.

Direct phase detection in continuous-wave photomixing THz systems

2008 ◽  
Author(s):  
Thorsten Gobel ◽  
Daniel Schoenherr ◽  
Cezary Sydlo ◽  
Michael Feiginov ◽  
Peter Meissner ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Phase Detection

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

1848: Revolix 70 Watt 2 Micron Continuous Wave Laser Vaporesection of the Prostate. Preliminary Results After a One Year Follow-Up

2007 ◽  
Vol 177 (4S) ◽  
pp. 614-614
Author(s):  
Thorsten Bach ◽  
Thomas R.W. Herrmann ◽  
Roman Ganzer ◽  
Andreas J. Gross
Keyword(s):  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Preliminary Results ◽  
Wave Laser ◽  
One Year

Leitlinien zur peripheren Gefäßdiagnostik mit der direktionalen continuous-wave (CW) Doppler-Sonographie

Phlebologie ◽  
2000 ◽  
Vol 29 (05) ◽  
pp. 142-145
Author(s):  
T. Hertel ◽  
B. Kahle ◽  
H. G. Kluess ◽  
M. Marshall ◽  
E. Rabe ◽  
...  
Keyword(s):  
Continuous Wave
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