High-accuracy distance measurements with multiple-wavelength interferometry

1995 ◽  
Vol 34 (8) ◽  
pp. 2407 ◽  
Author(s):  
Rene Daendliker
Keyword(s):  
High Accuracy ◽  
Distance Measurements ◽  
Multiple Wavelength

scholarly journals High-accuracy long-distance measurements in air with a frequency comb laser

2009 ◽  
Vol 34 (13) ◽  
pp. 1982 ◽  
Author(s):  
M. Cui ◽  
M. G. Zeitouny ◽  
N. Bhattacharya ◽  
S. A. van den Berg ◽  
H. P. Urbach ◽  
...  
Keyword(s):  
Frequency Comb ◽  
High Accuracy ◽  
Long Distance ◽  
Distance Measurements

scholarly journals Enabling High Accuracy Distance Measurements With FMCW Radar Sensors

2019 ◽  
Vol 67 (12) ◽  
pp. 5360-5371 ◽  
Author(s):  
Lukas Piotrowsky ◽  
Timo Jaeschke ◽  
Simon Kueppers ◽  
Jan Siska ◽  
Nils Pohl
Keyword(s):  
High Accuracy ◽  
Distance Measurements ◽  
Fmcw Radar ◽  
Radar Sensors

scholarly journals High Accuracy Ultrasound Micro-Distance Measurements with PMUTs under Liquid Operation

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4524
Author(s):  
Iván Zamora ◽  
Eyglis Ledesma ◽  
Arantxa Uranga ◽  
Núria Barniol
Keyword(s):  
Ultrasonic Transducer ◽  
Distance Estimation ◽  
Tone Burst ◽  
High Accuracy ◽  
Distance Measurements ◽  
Continuous Waves ◽  
Medium Range ◽  
New Strategy ◽  
Propagation Medium ◽  
Range Error

Ultrasonic systems driven by multi-frequency continuous waves (MFCW) have been used for range distance measurement, offering high accuracy in long and medium range distance estimation. However, the use of continuous waves in very short-distance measurements causes large errors due to multipath reflections. This paper presents a new strategy to estimate very short relative distances with high accuracy based on the use of multi-frequency pulsed waves (MFPW). The proposed strategy allows to avoid the multipath reflections that appear when continuous waves are used, and it improves the achieved accuracy compared to the original MFCW method. To validate it, an 80 µm square AlScN piezoelectric micromachined ultrasonic transducer (PMUT) was chosen as a transmitter while a hydrophone was utilized as a target and receiver, immersed in fluorinert (FC-70) as a propagation medium. Three independent and consecutive tone-burst signals were transmitted successively. The selected frequencies are f1 = 2.3962 MHz, f2 = 2.327 MHz and f3 = 2.1195 MHz, giving first and second-order resolutions of 6.88 and 0.79 µm/°, respectively. Experimental results show a ±6.2 μm measured range error in a range of 3.5 mm, and therefore it represents a good candidate for ultrasound micro-profilometer applications under liquid operation.

scholarly journals High accuracy measurements of nanometer-scale distances between fluorophores at the single-molecule level

2017 ◽  
Author(s):  
Stefan Niekamp ◽  
Jongmin Sung ◽  
Walter Huynh ◽  
Gira Bhabha ◽  
Ronald D. Vale ◽  
...  
Keyword(s):  
Single Molecule ◽  
Single Molecules ◽  
Coiled Coil ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Molecular Shape ◽  
High Accuracy ◽  
Distance Measurements ◽  
Distance Information ◽  
Wide Range

To uncover the mechanisms of molecular machines it is useful to probe their structural conformations. Single-molecule Förster resonance energy transfer (smFRET) is a powerful tool for measuring intra-molecular shape changes of single-molecules, but is confined to distances of 2-8 nm. Current super-resolution measurements are error prone at <25 nm. Thus, reliable high-throughput distance information between 8-25 nm is currently difficult to achieve. Here, we describe methods that utilize information about localization and imaging errors to measure distances between two different color fluorophores with ∼1 nm accuracy at any distance >2 nm, using a standard TIRF microscope and open-source software. We applied our two-color localization method to uncover a ∼4 nm conformational change in the “stalk” of the motor protein dynein, revealing unexpected flexibility in this antiparallel coiled-coil domain. These new methods enable high-accuracy distance measurements of single-molecules that can be used over a wide range of length scales.

scholarly journals A Lightweight Localization Solution for Small, Low Resources WSNs

2019 ◽  
Vol 8 (2) ◽  
pp. 26 ◽  
Author(s):  
Hong Xiong ◽  
Mihail L. Sichitiu
Keyword(s):  
Wireless Sensor Networks ◽  
High Accuracy ◽  
Energy Resources ◽  
Wireless Sensor ◽  
Distance Measurements ◽  
Range Measurement ◽  
Sensor Platforms ◽  
Localization Errors ◽  
Increasing Demand ◽  
Distributed Scheme

The increasing demand for location-dependent services in wireless sensor networks (WSNs) calls for solutions capable of handling the diversified demands and the unique challenges presented in WSNs. In most applications, nodes need to determine their locations in a reliable manner while operating under stringent constraints in computation, communication, and energy resources. This paper offers a novel solution to bridge the gap between the high accuracy demand and low resources available for range-based localization. We propose KickLoc, a fully distributed scheme, which considers the uncertainty of the distance measurements to minimize localization errors introduced from the range measurement, and leverages information from all neighboring nodes for better position estimations. Our work is evaluated via extensive simulations, with comparisons to other well-known localization schemes, and the Cramér-Rao lower bound (CRLB). In addition, we implement and evaluate the proposed system on sensor platforms with different range measurement mechanisms. The results show that this localization solution outperforms existing methods in various scenarios, while remains lightweight and suitable for small, low resources WSNs.

scholarly journals THE IMPROVING OF THE ACCURACY OF ENGINEERING AND GEODETIC WORKS IN THE CONSTRUCTION AND CONTROL OF THE GEOMETRIC PARAMETERS OF HIGH-RISE BUILDINGS

2020 ◽  
Vol 6 (444) ◽  
pp. 162-168
Author(s):  
T. M. Malik ◽  
◽  
V. G. Burachek ◽  
Ya. P. Bryk ◽  
S. D. Kryachok ◽  
...  
Keyword(s):  
High Accuracy ◽  
Measurement Precision ◽  
Geometric Parameters ◽  
Distance Measurements ◽  
Engineering Structures ◽  
High Rise ◽  
Double Frequency ◽  
Geodetic Coordinates ◽  
The Moment ◽  
And Control

. In the article, the authors had done a brief analysis of existing modern, traditional methods and tools that allow to determine the planned coordinates of geodetic signs, located on the last tier of super-high engineering structures, paid special attention to the disadvantages and concluded that it’s necessary to develop a method and device for determining the geodetic coordinates on ultra-high engineering structures with high accuracy to provide engineering and geodetic works during the construction and operation of high-rise structures. In the article, the authors propose their method and device for determining the planar coordinates of the upper geodetic sign of the line of vertical design on ultra-high engineering structures with high accuracy, which is based on the method of the straight linear resection by the light distance meter. The result of the proposed method is the enhancing of the accuracy of engineering and geodetic works during the construction and control of geometric parameters of high-rise structures. This method of distance measurements allows getting the enhancing of the accuracy of the engineering and geodetic measurements by fixing the moment of occurrence of the double frequency with root mean square error (RMSE) above 0.5 mm, thus eliminating the need to measure the phase difference between direct and reflected pulses. A particular advantage of the proposed method is that the accuracy of the measurements depends on the comparison of the radiated f and double fg frequencies, which makes the measurement precision.

scholarly journals High-Accuracy AM-FM Radar with an Active Reflector

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Mun Gak Choi ◽  
Dong Sik Woo ◽  
Hyun Chul Choi ◽  
Kang Wook Kim
Keyword(s):  
Experimental Tests ◽  
High Accuracy ◽  
Phase Detection ◽  
Absolute Distance ◽  
Distance Measurements ◽  
Measured Range ◽  
Narrow Bandwidth ◽  
X Band ◽  
Active Reflector ◽  
Base Module

An amplitude-modulated and frequency-modulated (AM-FM) radar with an active reflector to produce high-accuracy distance measurements is proposed and demonstrated in this paper. The proposed radar consists of an AM-FM base module and an active reflector. The combination of AM and FM modulations resolves ambiguity of the absolute distance in typical AM radars, while improving range accuracy in typical FM radars with narrow bandwidth. Also, the active reflector, which translates the frequency of the received signal, resolves the problem of phase detection interference due to the direct Tx-to-Rx leakage in AM radars. In this paper, the operating principle, experimental tests, and analysis are presented. The implemented AM-FM radar operates in X-band (Tx: 10.5 GHz, Rx: 8.5 GHz) with the 620 MHz bandwidth. The measured range accuracy of less than ±10 mm at a distance of 70 m is obtained.

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