Appropriate bandwidth and integration time for measurements of the degree of interaural cross correlation as a measure of apparent source width in concert halls

1999 ◽  
Vol 105 (2) ◽  
pp. 1046-1046
Author(s):  
Masayuki Morimoto ◽  
Kazuhiro Iida
Keyword(s):  
Cross Correlation ◽  
Integration Time ◽  
Apparent Source ◽  
Concert Halls

scholarly journals MAX-DOAS formaldehyde slant column measurements during CINDI: intercomparison and analysis improvement

2013 ◽  
Vol 6 (1) ◽  
pp. 167-185 ◽  
Author(s):  
G. Pinardi ◽  
M. Van Roozendael ◽  
N. Abuhassan ◽  
C. Adams ◽  
A. Cede ◽  
...  
Keyword(s):  
Cross Sections ◽  
Cross Correlation ◽  
Optical Absorption Spectroscopy ◽  
Integration Time ◽  
Measuring Instruments ◽  
Absorption Cross ◽  
Correlation Effects ◽  
Data Set ◽  
Random Uncertainties ◽  
Ring Effect

Abstract. We present intercomparison results for formaldehyde (HCHO) slant column measurements performed during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI) that took place in Cabauw, the Netherlands, in summer 2009. During two months, nine atmospheric research groups simultaneously operated MAX-DOAS (MultiAXis Differential Optical Absorption Spectroscopy) instruments of various designs to record UV-visible spectra of scattered sunlight at different elevation angles that were analysed using common retrieval settings. The resulting HCHO data set was found to be highly consistent, the mean difference between instruments generally not exceeding 15% or 7.5 × 1015 molec cm−2, for all viewing elevation angles. Furthermore, a sensitivity analysis was performed to investigate the uncertainties in the HCHO slant column retrieval when varying key input parameters such as the molecular absorption cross sections, correction terms for the Ring effect or the width and position of the fitting interval. This study led to the identification of potentially important sources of errors associated with cross-correlation effects involving the Ring effect, O4, HCHO and BrO cross sections and the DOAS closure polynomial. As a result, a set of updated recommendations was formulated for HCHO slant column retrieval in the 336.5–359 nm wavelength range. To conclude, an error budget is proposed which distinguishes between systematic and random uncertainties. The total systematic error is estimated to be of the order of 20% and is dominated by uncertainties in absorption cross sections and related spectral cross-correlation effects. For a typical integration time of one minute, random uncertainties range between 5 and 30%, depending on the noise level of individual instruments.

scholarly journals On the Impact of Channel Cross-Correlations in High-Sensitivity Receivers for Galileo E1 OS and GPS L1C Signals

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Davide Margaria ◽  
Beatrice Motella ◽  
Fabio Dovis
Keyword(s):  
Cross Correlation ◽  
High Sensitivity ◽  
Global Navigation Satellite Systems ◽  
Integration Time ◽  
Noise Component ◽  
Satellite Systems ◽  
Coherent Integration ◽  
Global Navigation Satellite ◽  
Correlation Properties ◽  
The Impact

One of the most promising features of the modernized global navigation satellite systems signals is the presence of pilot channels that, being data-transition free, allow for increasing the coherent integration time of the receivers. Generally speaking, the increased integration time allows to better average the thermal noise component, thus improving the postcorrelation SNR of the receiver in the acquisition phase. On the other hand, for a standalone receiver which is not aided or assisted, the acquisition architecture requires that only the pilot channel is processed, at least during the first steps of the procedure. The aim of this paper is to present a detailed investigation on the impact of the code cross-correlation properties in the reception of Galileo E1 Open Service and GPS L1C civil signals. Analytical and simulation results demonstrate that the S-curve of the code synchronization loop can be affected by a bias around the lock point. This effect depends on the code cross-correlation properties and on the receiver setup. Furthermore, in these cases, the sensitivity of the receiver to other error sources might increase, and the paper shows how in presence of an interfering signal the pseudorange bias can be magnified and lead to relevant performance degradation.

Experiment Research on Apparent Source Width (ASW)

2011 ◽  
Vol 374-377 ◽  
pp. 1155-1158 ◽  
Author(s):  
Yan Xiong ◽  
Yan Sun ◽  
Sheng Wo Sheng
Keyword(s):  
Energy Ratio ◽  
Experiment Research ◽  
Popular Belief ◽  
Energy Fraction ◽  
Sound Energy ◽  
Sound Fields ◽  
Listening Tests ◽  
Apparent Source ◽  
Concert Halls ◽  
Psychological Experiments

It is well-know that spatial impression is one of the important characteristics in concert halls. It is popular belief that early sound contribute to apparent source width (ASW) and late sound contribute to listener envelopment (LEV). The major concern of our study originated from the question of whether or not ASW was created only by early lateral sound energy alone. In this paper, a group of psychological experiments are performed with simulated sound fields. In the experiment, listening tests were carried out in order to exam the effect of early lateral sound energy fraction(LFE) and early to late sound energy ratio (C80) on perceived ASW. The results confirmed that C80 affects ASW.

scholarly journals A 1-GHz 64-Channel Cross-Correlation System for Real-Time Interferometric Aperture Synthesis Imaging

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1739 ◽  
Author(s):  
Xiangzhou Guo ◽  
Muhammad Asif ◽  
Anyong Hu ◽  
Zhiping Li ◽  
Jungang Miao
Keyword(s):  
Cross Correlation ◽  
Integration Time ◽  
Security Screening ◽  
Analog To Digital ◽  
Analog To Digital Conversion ◽  
Field Programmable ◽  
Correlation Processing ◽  
Sample Frequency ◽  
Correlation System ◽  
The Stability

We present a 64-channel 1-bit/2-level cross-correlation system for a passive millimeter wave imager used for indoor human body security screening. Sixty-four commercial comparators are used to perform 1-bit analog-to-digital conversion, and a Field Programmable Gate Array (FPGA) is used to perform the cross-correlation processing. This system can handle 2016 cross-correlations at the sample frequency of 1GHz, and its power consumption is 48.75 W. The data readout interface makes it possible to read earlier data while simultaneously performing the next correlation when imaging at video rate. The longest integration time is up to 68.7 s, which can satisfy the requirements of video rate imaging and system calibration. The measured crosstalk between neighboring channels is less than 0.068%, and the stability is longer than 10 s. A correlation efficiency greater than 96% is achieved for input signal levels greater than −25 dBm.

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