Research on the Parameter Measurement Methods of Digital Channelized Reconnaissance Receiver

2011 ◽  
Vol 346 ◽  
pp. 578-583
Author(s):  
Hai Qing Jiang ◽  
Mei Guo Gao ◽  
Guo Hong Sun ◽  
Pu Zhao Tang

The pulse description word (PDW) measurement method of digital channelized reconnaissance receiver was investigated. The parameter measurement flow of digital channelized reconnaissance receiver was introduced. The measurement methods of the instantaneous amplitude, the instantaneous frequency, the pulse width of wideband frequency modulated signal and the direction of arrival (DOA) were discussed in detail, which have been applied to reconnaissance receiver in ESM system successfully.

2019 ◽  
Vol 29 (3) ◽  
pp. 778-796 ◽  
Author(s):  
Patrick Taffé

Recently, a new estimation procedure has been developed to assess bias and precision of a new measurement method, relative to a reference standard. However, the author did not develop confidence bands around the bias and standard deviation curves. Therefore, the goal in this paper is to extend this methodology in several important directions. First, by developing simultaneous confidence bands for the various parameters estimated to allow formal comparisons between different measurement methods. Second, by proposing a new index of agreement. Third, by providing a series of new graphs to help the investigator to assess bias, precision, and agreement between the two measurement methods. The methodology requires repeated measurements on each individual for at least one of the two measurement methods. It works very well to estimate the differential and proportional biases, even with as few as two to three measurements by one of the two methods and only one by the other. The repeated measurements need not come from the reference standard but from either measurement methods. This is a great advantage as it may sometimes be more feasible to gather repeated measurements with the new measurement method.


2013 ◽  
Vol 347-350 ◽  
pp. 197-200
Author(s):  
Yu Gong ◽  
Jing Cai Zhang ◽  
Hong Qi Liu

In this paper, research on measurement methods of hole during the parts online detection has been made. Both diameter and position of the hole are going to be detected in the same measurement system. In order to obtain higher accuracy and efficiency, a comparative analysis test of using the contact probes, the inductive sensor, the laser sensor, the forward and back lighting CCD imaging have been achieved. Results show that the contact measurement using inductive sensor is more suitable for the system, for the reason that it has higher reliability and efficiency.


1997 ◽  
Vol 119 (2) ◽  
pp. 236-242 ◽  
Author(s):  
K. Peleg

The classical calibration problem is primarily concerned with comparing an approximate measurement method with a very precise one. Frequently, both measurement methods are very noisy, so we cannot regard either method as giving the true value of the quantity being measured. Sometimes, it is desired to replace a destructive or slow measurement method, by a noninvasive, faster or less expensive one. The simplest solution is to cross calibrate one measurement method in terms of the other. The common practice is to use regression models, as cross calibration formulas. However, such models do not attempt to discriminate between the clutter and the true functional relationship between the cross calibrated measurement methods. A new approach is proposed, based on minimizing the sum of squares of the differences between the absolute values of the Fast Fourier Transform (FFT) series, derived from the readings of the cross calibrated measurement methods. The line taken is illustrated by cross calibration examples of simulated linear and nonlinear measurement systems, with various levels of additive noise, wherein the new method is compared to the classical regression techniques. It is shown, that the new method can discover better the true functional relationship between two measurement systems, which is occluded by the noise.


2006 ◽  
Vol 3 (3) ◽  
pp. 987-1019 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi

Abstract. After pointing out the importance of the saturated hydraulic conductivity (ks) measurements and the difficulties and uncertainties that are present, and after recalling salient aspects of three well-known measurement methods of this parameter (i.e. constant-head tension infiltrometer (TI) method, constant-head pressure infiltrometer (PI) method and soil core (SC) estimates method), the results of an investigation on data which were obtained during a measurement campaign on an area of 800 m2, on a sandy loam hillslope, located in Southern Italy, were carried out again here. Three sets of values of ks, obtained with these measurement methods, were analyzed statistically, verifying that the log-normal distribution describes these better than the normal one; moreover, the more significant statistical parameters of each set were compared (average value , amplitude A, coefficient of variation CV and standard deviation SD), individualizing the more significant differences. The greatest value of hydraulic conductivity was found with method (PI), while the smallest with (SC) and the intermediate with (TI); these differences were translated into macroporosity and into the influence of the single measurement method. Moreover, referring to the possible factors affecting the results, the importance can be noted of the structure, the texture and the soil events, in terms of utilization, which can affect the measure of ks leading often to very different values even for similar soils, but with a different history, independently of the coincidence of the measurement points and they can be determining to explain the differences affecting the results obtained in analogous investigations by other researchers. Having confirmed that generalization is not possible, the need was emphasized to adopt the necessary devices relating to the specific measurement method, case by case, and to carefully explain the obtained results, in the light of the peculiarities and the limits of each situation. Finally, the results of similar statistical analysis carried out on a greater number of ks values, measured through the (TI) and (PI) methods are shown in this paper, with some statistical considerations on the increasing of the measurements number.


2018 ◽  
Vol 919 ◽  
pp. 386-395
Author(s):  
Michal Kašpárek ◽  
Martin Černík ◽  
Jana Urbánková ◽  
Pavel Mokrý

The sample of a piezoelectric semi-active shunt damping material is analyzed inside an acoustic tube. The measurement of reflected and transmitted acoustic wave through the sample is realized using 4-microphone measurement method. Acoustic properties of the sample with the emphasis on acoustic transmissibility are analyzed. The composite piezoelectric sample comprising of a piezoelectric material connected to a linear shunting circuit is described, also the multimicrophone measurement methods are described in detail and the results are discussed in context of semi-active sound damping.


2020 ◽  
Vol 68 (8) ◽  
pp. 3558-3564
Author(s):  
Aihua Wu ◽  
Chen Liu ◽  
Faguo Liang ◽  
Xuefeng Zou ◽  
Yibang Wang ◽  
...  

Author(s):  
Patrick Taffé ◽  
Mingkai Peng ◽  
Vicki Stagg ◽  
Tyler Williamson

Bland and Altman's (1986, Lancet 327: 307–310) limits of agreement have been used in many clinical research settings to assess agreement between two methods of measuring a quantitative characteristic. However, when the variances of the measurement errors of the two methods differ, limits of agreement can be misleading. biasplot implements a new statistical methodology that Taffé (Forthcoming, Statistical Methods in Medical Research) recently developed to circumvent this issue and assess bias and precision of the two measurement methods (one is the reference standard, and the other is the new measurement method to be evaluated). biasplot produces three new plots introduced by Taffé: the “bias plot”, “precision plot”, and “comparison plot”. These help the investigator visually evaluate the performance of the new measurement method. In this article, we introduce the user-written command biasplot and present worked examples using simulated data included with the package. Note that the Taffé method assumes there are several measurements from the reference standard and possibly as few as one measurement from the new method for each individual.


Geophysics ◽  
1996 ◽  
Vol 61 (1) ◽  
pp. 264-272 ◽  
Author(s):  
Arthur E. Barnes

The ideas of 1-D complex seismic trace analysis extend readily to two dimensions. Two‐dimensional instantaneous amplitude and phase are scalars, and 2-D instantaneous frequency and bandwidth are vectors perpendicular to local wavefronts, each defined by a magnitude and a dip angle. The two independent measures of instantaneous dip correspond to instantaneous apparent phase velocity and group velocity. Instantaneous phase dips are aliased for steep reflection dips following the same rule that governs the aliasing of 2-D sinusoids in f-k space. Two‐dimensional frequency and bandwidth are appropriate for migrated data, whereas 1-D frequency and bandwidth are appropriate for unmigrated data. The 2-D Hilbert transform and 2-D complex trace attributes can be efficiently computed with little more effort than their 1-D counterparts. In three dimensions, amplitude and phase remain scalars, but frequency and bandwidth are 3-D vectors with magnitude, dip angle, and azimuth.


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