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Relevant bibliographies by topics / Planar near-field measurement

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Academic literature on the topic 'Planar near-field measurement'

Author: Grafiati

Published: 25 May 2024

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Journal articles on the topic "Planar near-field measurement"

1

Li, Yong, Jie Ou, and Ping Xu. "Errors analysis of planar near-field antenna measurement." JOURNAL OF ELECTRONIC MEASUREMENT AND INSTRUMENT 24, no. 11 (December 15, 2010): 987–92. http://dx.doi.org/10.3724/sp.j.1187.2010.00987.

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WANG, NAN, ZHENG-HUI XUE, SHING-MING YANG, BEN-QING GAO, and XIAO-WEN XU. "ANTENNA TIME DOMAIN PLANAR NEAR FIELD MEASUREMENT SYSTEM." International Journal on Wireless & Optical Communications 03, no. 02 (August 2006): 127–33. http://dx.doi.org/10.1142/s0219799506000429.

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3

Newell, A. C., and C. F. Stubenrauch. "Effect of random errors in planar near-field measurement." IEEE Transactions on Antennas and Propagation 36, no. 6 (June 1988): 769–73. http://dx.doi.org/10.1109/8.1178.

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Wittmann, R. C., B. K. Alpert, and M. H. Francis. "Nonideal measurement locations in planar near-field antenna metrology." Computer Standards & Interfaces 21, no. 2 (June 1999): 199. http://dx.doi.org/10.1016/s0920-5489(99)92302-4.

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Huang, Shan, Junhao Zheng, Peiyuan Qin, Qiwei Zhan, and Xiaoming Chen. "Improved planar near-field measurement based on data assimilation." Measurement 227 (March 2024): 114265. http://dx.doi.org/10.1016/j.measurement.2024.114265.

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6

Yang, Seunggyu, and Kangwook Kim. "One-Port Planar Near-Field Antenna Measurement and Corresponding Scatterer Compensation Method." Journal of Electromagnetic Engineering and Science 22, no. 3 (May 31, 2022): 344–51. http://dx.doi.org/10.26866/jees.2022.3.r.96.

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A one-port near-field antenna measurement technique with a small wire scatterer is proposed. In the proposed technique, a wire scatterer is scanned with an interval of less than a quarter wavelength, and the measurement is performed at the port of the antenna under test (AUT). A two-dimensional phase unwrapping method is used to remove 180° phase uncertainty. The data obtained in the near-field are transformed to the far-field pattern, and the scattering pattern is compensated for better measurements. The proposed measurement technique was validated by measuring the near-field of an AUT over a planar scanning surface. The far-field radiation pattern obtained using the proposed technique was compared with that obtained from a conventional commercial anechoic chamber. It was observed that they agreed well, especially in the region near the center.

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Sayers, Andrew E., W. Mark Dorsey, Kenneth W. O'Haver, and John A. Valenzi. "Planar Near-Field Measurement of Digital Phased Arrays Using Near-Field Scan Plane Reconstruction." IEEE Transactions on Antennas and Propagation 60, no. 6 (June 2012): 2711–18. http://dx.doi.org/10.1109/tap.2012.2194666.

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D’Agostino, Francesco, Ilaria De Colibus, Flaminio Ferrara, Claudio Gennarelli, Rocco Guerriero, and Massimo Migliozzi. "Far-Field Pattern Reconstruction from Near-Field Data Collected via a Nonconventional Plane-Rectangular Scanning: Experimental Testing." International Journal of Antennas and Propagation 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/763687.

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This paper deals with the experimental validation of an efficient near-field-far-field (NF-FF) transformation using the planar wide-mesh scanning (PWMS). Such a nonconventional plane-rectangular scanning technique is so named, since the sample grid is characterized by meshes wider and wider when going away from the center, and makes it possible to lower the number of needed measurements, as well as the time required for the data acquisition when dealing with quasi-planar antennas. It relies on the use of the nonredundant sampling representations of electromagnetic fields which employ an oblate ellipsoid or a surface formed by two circular “bowls” with the same aperture diameter but eventually different bending radii to shape a quasi-planar antenna. A two-dimensional optimal sampling interpolation formula allows the reconstruction of the NF data at any point on the measurement plane and, in particular, at those required by the classical NF-FF transformation with the conventional plane-rectangular scanning. The measurements, performed at the planar NF facility of the antenna characterization laboratories of Selex ES, have confirmed the effectiveness of this innovative scanning also from the experimental viewpoint.

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Ponomarev, M. Yu, O. Yu Platonov, and V. V. Shubnikov. "Features measurement gain on planar and spherical near-field stands." Journal of «Almaz – Antey» Air and Space Defence Corporation, no. 3 (September 30, 2015): 43–47. http://dx.doi.org/10.38013/2542-0542-2015-3-43-47.

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Three main method and highlights some features of the measurement of the gain on the near-field stands with flat and spherical surfaces scanning, described their main advantages and disadvantages. The dependence of the final result of the scan parameters and recommendations on their choice. Analyzed the degree of influence on the final outcome of the main factors affecting the accuracy of the gain.

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Long, Rui, and Jun Ou Yang. "PLANAR PHASED ARRAY CALIBRATION BASED ON NEAR-FIELD MEASUREMENT SYSTEM." Progress In Electromagnetics Research C 71 (2017): 23–31. http://dx.doi.org/10.2528/pierc16112004.

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Dissertations / Theses on the topic "Planar near-field measurement"

1

Yan, Bing. "A low cost planar near-field / far-field antenna measurement system /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ34242.pdf.

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2

Varughese, Suma. "A Study On Effects Of Phase - Amplitude Errors In Planar Near Field Measurement Facility." Thesis, Indian Institute of Science, 2000. https://etd.iisc.ac.in/handle/2005/231.

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Antenna is an indispensable part of a radar or free space communication system. Antenna requires different stringent specifications for different applications. Designed and fabricated for an intended application, antenna or antenna array has to be evaluated for its far-field characteristics in real free space environment which requires setting up of far-field test site. Maintenance of the site to keep the stray reflections levels low, the cost of the real estate are some of the disadvantages. Nearfield measurements are compact and can be used to test the antennas by exploiting the relationship between near-field and far-field. It is shown that the far-field patterns of an antenna can be sufficiently accurately predicted provided the near-field measurements are accurate. Due to limitation in the near-field measurement systems, errors creep in corrupting the nearfield-measured data thus making error in prediction of the far field. All these errors ultimately corrupt the phase and amplitude data. In this thesis, one such near-field measurement facility, the Planar Near Field Measurement facility is discussed. The limitations of the facility and the errors that occur due to their limitations are discussed. Various errors that occur in measurements ultimately corrupt the near-field phase and amplitude. Investigations carried out aim at a detailed study of these phase and amplitude errors and their effect on the far-field patterns of the antenna. Depending on the source of error, the errors are classified as spike, pulse and random errors. The location of occurrence of these types of errors in the measurement plane, their effects on the far-field of the antenna is studied both for phase and amplitude errors. The studies conducted for various phase and amplitude errors show that the near-field phase and amplitude data are more tolerant to random errors as the far-field patterns do not get affected even for low sidelobe cases. The spike errors, though occur as a wedge at a single point in the measurement plane, have more pronounced effect on the far-field patterns. Lower the taper value of the antenna, more pronounced is the error. It is also noticed that the far-field pattern gets affected only in the plane where the error has occurred and has no effect in the orthogonal plane. Pulse type of errors which occur even for a short length in the measurement affect both the principle plane far-field patterns. This study can be used extensively as a tool to determine to the level to which various error such as mechanical, RF etc need to be controlled to make useful and correct pattern predictions on a particular facility. Thereby, the study can be used as a tool to economise the budget of the facility wherein the parameters required for building the facility need not be over specified beyond the requirement. In general, though this is a limited study, it is certainly a trendsetter in this direction.

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3

Varughese, Suma. "A Study On Effects Of Phase - Amplitude Errors In Planar Near Field Measurement Facility." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/231.

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Antenna is an indispensable part of a radar or free space communication system. Antenna requires different stringent specifications for different applications. Designed and fabricated for an intended application, antenna or antenna array has to be evaluated for its far-field characteristics in real free space environment which requires setting up of far-field test site. Maintenance of the site to keep the stray reflections levels low, the cost of the real estate are some of the disadvantages. Nearfield measurements are compact and can be used to test the antennas by exploiting the relationship between near-field and far-field. It is shown that the far-field patterns of an antenna can be sufficiently accurately predicted provided the near-field measurements are accurate. Due to limitation in the near-field measurement systems, errors creep in corrupting the nearfield-measured data thus making error in prediction of the far field. All these errors ultimately corrupt the phase and amplitude data. In this thesis, one such near-field measurement facility, the Planar Near Field Measurement facility is discussed. The limitations of the facility and the errors that occur due to their limitations are discussed. Various errors that occur in measurements ultimately corrupt the near-field phase and amplitude. Investigations carried out aim at a detailed study of these phase and amplitude errors and their effect on the far-field patterns of the antenna. Depending on the source of error, the errors are classified as spike, pulse and random errors. The location of occurrence of these types of errors in the measurement plane, their effects on the far-field of the antenna is studied both for phase and amplitude errors. The studies conducted for various phase and amplitude errors show that the near-field phase and amplitude data are more tolerant to random errors as the far-field patterns do not get affected even for low sidelobe cases. The spike errors, though occur as a wedge at a single point in the measurement plane, have more pronounced effect on the far-field patterns. Lower the taper value of the antenna, more pronounced is the error. It is also noticed that the far-field pattern gets affected only in the plane where the error has occurred and has no effect in the orthogonal plane. Pulse type of errors which occur even for a short length in the measurement affect both the principle plane far-field patterns. This study can be used extensively as a tool to determine to the level to which various error such as mechanical, RF etc need to be controlled to make useful and correct pattern predictions on a particular facility. Thereby, the study can be used as a tool to economise the budget of the facility wherein the parameters required for building the facility need not be over specified beyond the requirement. In general, though this is a limited study, it is certainly a trendsetter in this direction.

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4

Tuhela-Reuning, Stephen R. "A planar near-field scanning system for the measurement of bistatic radar cross-section in a compact range environment." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1413282146.

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5

Gregson, Stuart Fraser. "Probe-corrected poly-planar near field antenna measurements." Thesis, Queen Mary, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399516.

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Al-Mahdawi, Tareef Ibrahim. "Electromagnetic radiator characterization and modeling through planar near-field measurements." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70327.

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This thesis deals with the use of planar near-field measurements for characterizing and modeling general electromagnetic radiators, particularly non-directive ones.
Relationships between the measured field on a plane and the equivalent currents on the radiator plane were established. These were used to determine the resolution with which these currents can be mapped. The equivalent currents then serve as a model from which the radiator external field can be calculated. It was shown that significant filtering of measurement errors results from the utilization of such a model. The consequent reduction in errors was estimated.
The behavior of the measurement probe was studied in depth. The two general probe types, wire and aperture, were analyzed, and field extraction formulation and procedure were established.
The techniques developed were applied to the experimental study of three different radiators leading to new information about their behavior. Results show close agreement between the calculated field values from the model and those measured directly.

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7

Puskely, Jan. "Rekonstrukce blízkého pole antén." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-233540.

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Cílem disertační práce je navrhnout efektivně pracující algoritmus, který na základě bezfázového měření v blízkém poli antény bude schopen zrekonstruovat komplexní blízké pole antény resp. vyzařovací diagram antény ve vzdáleném poli. Na základě těchto úvah byly zkoumány vlastnosti minimalizačního algoritmu. Zejména byl analyzován a vhodně zvolen minimalizační přistup, optimalizační metoda a v neposlední řadě i optimalizační funkce tzv. funkcionál. Dále pro urychlení celého minimalizačního procesu byly uvažovány prvotní odhady. A na závěr byla do minimalizačního algoritmu zahrnuta myšlenka nahrazující hledané elektrické pole několika koeficienty. Na základě předchozích analýz byla navržená bezfázová metoda pro charakterizaci vyzařovacích vlastností antén. Tato metoda kombinuje globální optimalizaci s obrazovou kompresní metodou a s lokální metodou ve spojení s konvečním amplitudovým měřením na dvou površích. V našem případě je globální optimalizace použita k nalezení globálního minima minimalizovaného funkcionálu, kompresní metoda k redukci neznámých proměnných na apertuře antény a lokální metoda zajišťuje přesnější nalezení minima. Navržená metoda je velmi robustní a mnohem rychlejší než jiné dostupné minimalizační algoritmy. Další výzkum byl zaměřen na možnosti využití měřených amplitud pouze z jednoho měřícího povrchu pro rekonstrukci vyzařovacích charakteristik antén a využití nového algoritmu pro rekonstrukci fáze na válcové geometrii.

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8

Parsons, Garrett. "An investigation of adaptive acquisition techniques for planar near-field antenna measurements." Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28317.

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This thesis presents an adaptive technique that uses feedback to provide practical information during a planar near-field measurement scan. The feedback is used to decide with certainty when to terminate the planar near-field measurement process. The developed adaptive planar near-field method utilizes a rectangular spiral-type acquisition pattern to acquire the near-field measurements. At the end of each scan iteration, a set of decision functions are rapidly calculated which provide a quality measurement of the resulting far-zone transformation. The decision functions are based on the far-zone radiated patterns, directivity, and the fractional plane wave spectrum error. The decision functions were evaluated using actual planar near-field data set of five different antennas. These experiments have identified those decision functions that are directly related to antenna performance measures and would allow for the termination of the planar near-field test based on a set of relevant stopping conditions.

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9

Krueger, David William. "Array-Based Characterization of Military Jet Aircraft Noise." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3676.

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Since the 1950s the jet aeroacoustics community has been involved in predicting and measuring the noise distribution in jets. In this work, cylindrical and planar Fourier near-field acoustical holography are used to investigate radiation from a full-scale, installed jet engine. Practical problems involving measurement aperture and the highly directional nature of the source are addressed. Insights from numerical simulations reveal usable reconstruction regions. A comparison of cylindrical and planar NAH for the respective measurement apertures shows cylindrical NAH outperforms planar NAH on reconstructions both towards and away from the source.

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10

Chen, Roger, and 陳俊儀. "The Research and Implementation of a Planar Near-Field Measurement System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/72294543814578407014.

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碩士
國立中央大學
電機工程研究所
91
In the thesis, a planar near-field measurement system is implemented to measure the radiation pattern of the antenna. In the system, the operating sequences are controlled by computer programs, and the receiving probe can move on a two-dimension plane. For the calculation of the radiation pattern, the near-field data collected by the receiving probe is transformed into equivalent surface magnetic currents over a fictitious planar surface, and the currents are then used to compute the radiation pattern of the antenna under test. In addition to build the planar near-field measurement system, the distance and the truncated range of the measurement plane are also discussed.

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Books on the topic "Planar near-field measurement"

1

K, Walton E., and United States. National Aeronautics and Space Administration., eds. Planar near-field scanning for compact range bistatic radar cross-section measurement. Columbus, Ohio: Ohio State University, ElectroScience Laboratary, 1991.

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2

K, Walton E., and Lewis Research Center, eds. A planar near-field scanning technique for bistatic radar cross-section measurements. Columbus, Ohio: Ohio State University, ElectroScience Laboratary, 1990.

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K, Walton E., and Lewis Research Center, eds. A planar near-field scanning technique for bistatic radar cross-section measurements. Columbus, Ohio: Ohio State University, ElectroScience Laboratary, 1990.

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K, Walton E., and Lewis Research Center, eds. A planar near-field scanning technique for bistatic radar cross-section measurements. Columbus, Ohio: Ohio State University, ElectroScience Laboratary, 1990.

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5

John, McCormick, Parini Clive, and Institution of Engineering and Technology, eds. Principles of planar near-field antenna measurements. London: Institution of Engineering and Technology, 2007.

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6

Planar near-field scanning for compact range bistatic radar cross-section measurement. Columbus, Ohio: Ohio State University, ElectroScience Laboratary, 1991.

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7

Gregson, Stuart, John McCormick, and Clive Parini. Principles of Planar Near-Field Antenna Measurements. Institution of Engineering and Technology, 2023. http://dx.doi.org/10.1049/sbew566e.

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8

National Aeronautics and Space Administration (NASA) Staff. Planar near-Field Scanning Technique for Bistatic Radar Cross Section Measurements. Independently Published, 2018.

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Book chapters on the topic "Planar near-field measurement"

1

Kalashnikov, Vadim Serafimovich, Maxim Yurievich Ponomarev, Oleg Yurievich Platonov, Victor Vasilievich Shubnikov, Mark Ilyich Rivkin, Artem Yurievich Shatrakov, Yury Grigorievich Shatrakov, and Oleg Ivanovich Zavalishin. "Planar Near-Field Antenna Measurements: Calculation Expressions." In Near-Field Antenna Measurements, 29–77. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6436-3_3.

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Kalashnikov, Vadim Serafimovich, Maxim Yurievich Ponomarev, Oleg Yurievich Platonov, Victor Vasilievich Shubnikov, Mark Ilyich Rivkin, Artem Yurievich Shatrakov, Yury Grigorievich Shatrakov, and Oleg Ivanovich Zavalishin. "Planar Near-Field Facility: Electrical and Mechanical Parts, Software." In Near-Field Antenna Measurements, 79–118. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6436-3_4.

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Fang, D. G. "Planar Near-Field Measurement and Array Diagnostics." In Antenna Theory and Microstrip Antennas, 279–96. CRC Press, 2017. http://dx.doi.org/10.1201/b10302-8.

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"Planar Near-Field Measurement and Array Diagnostics." In Antenna Theory and Microstrip Antennas, 279–96. CRC Press, 2009. http://dx.doi.org/10.1201/b10302-9.

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"Antenna measurement analysis and assessment." In Principles of Planar Near-Field Antenna Measurements, 359–411. Institution of Engineering and Technology, 2023. http://dx.doi.org/10.1049/sbew566e_ch8.

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"Computational electromagnetic model of a planar near-field measurement process." In Principles of Planar Near-Field Antenna Measurements, 293–358. Institution of Engineering and Technology, 2023. http://dx.doi.org/10.1049/sbew566e_ch7.

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Wu, Haijun, and Weikang Jiang. "A Mapping Relationship-Based near-Field Acoustic Holography." In Holography - Recent Advances and Applications [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.108318.

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A mapping relationship-based near-field acoustic holography (MRS-based NAH) is a kind of innovative NAH by exploring the mapping relationship between modes on surfaces of the boundary and hologram. Thus, reconstruction is converted to obtain the coefficients of participant modes on holograms. The MRS-based NAH supplies an analytical method to determine the number of adopted fundamental solution (FS) as well as a technique to approximate a specific degree of mode on patches by a set of locally orthogonal patterns explored for three widely used holograms, such as planar, cylindrical, and spherical holograms. The NAH framework provides a new insight to the reconstruction procedure based on the FS in spherical coordinates. Reconstruction accuracy based on two types of errors, the truncation errors due to the limited number of participant modes and the inevitable measurement errors caused by uncertainties in the experiment, are available in the NAH. An approach is developed to estimate the lower and upper bounds of the relative error. It supplies a tool to predict the error for a reconstruction under the condition that the truncation error ratio and the signal-to-noise ratio are given. The condition number of the inverse operator is investigated to measure the sensitivity of the reconstruction to the input errors.

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"Planar near-field antenna measurements." In Theory and Practice of Modern Antenna Range Measurements, 2nd Expanded Edition, Volume 1, 297–366. Institution of Engineering and Technology, 2020. http://dx.doi.org/10.1049/sbra538f_ch6.

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"Advanced planar near-field antenna measurements." In Principles of Planar Near-Field Antenna Measurements, 413–550. Institution of Engineering and Technology, 2023. http://dx.doi.org/10.1049/sbew566e_ch9.

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"Measurements - practicalities of planar near-field antenna measurements." In Principles of Planar Near-Field Antenna Measurements, 125–244. Institution of Engineering and Technology, 2023. http://dx.doi.org/10.1049/sbew566e_ch5.

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Conference papers on the topic "Planar near-field measurement"

1

Liu, Xingxun, Chengzhu Huang, and Yongjie Cheng. "Antenna Planar Near-Field Measurement System Using Robotics." In 2021 13th Global Symposium on Millimeter-Waves & Terahertz (GSMM). IEEE, 2021. http://dx.doi.org/10.1109/gsmm53250.2021.9511916.

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Arai, Hiroyuki, and Riho Suzuki. "Cross Scanning Near Field Measurement for Symmetrical Planar Array." In 2018 IEEE Conference on Antenna Measurements & Applications (CAMA). IEEE, 2018. http://dx.doi.org/10.1109/cama.2018.8530528.

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Niu, Chen, Puyan Mojabi, and Yaser Maddahi. "A pendulum-based planar near-field antenna measurement system." In 2016 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE, 2016. http://dx.doi.org/10.1109/aps.2016.7696387.

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Balma, Serge, Dominique Picard, and Pascal Meisse. "Far field pattern and gain measurement in planar near field techniques." In 2017 11th European Conference on Antennas and Propagation (EUCAP). IEEE, 2017. http://dx.doi.org/10.23919/eucap.2017.7928749.

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Wang, Nan, Zheng-Hui Xue, Shing-Ming Yang, Ruixiang Liu, and Xiaowen Xu. "Aperture field rebuilding in antenna time domain planar near field measurement." In 2008 International Conference on Microwave and Millimeter Wave Technology (ICMMT). IEEE, 2008. http://dx.doi.org/10.1109/icmmt.2008.4540401.

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Balma, Serge, Dominique Picard, and Pascal Meisse. "Far field uncertainty due to noise and receiver nonlinearity in planar-near field measurements." In 2016 Antenna Measurement Techniques Association Symposium (AMTA). IEEE, 2016. http://dx.doi.org/10.1109/amtap.2016.7806277.

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Ala-Laurinaho, Juha, Sabin Kumar Karki, Ville Viikari, Ari Alanne, Risto Lehto, Paul Moseley, and Massimiliano Simeoni. "Design of a Multiprobe Planar Near-Field Scanner for Ku-Band." In 2023 Antenna Measurement Techniques Association Symposium (AMTA). IEEE, 2023. http://dx.doi.org/10.23919/amta58553.2023.10293503.

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Yang, Jingxian, Longying Guo, and Meng Yang. "A Planar Near-field Measurement System for Microwave Power Transmission." In 2020 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP). IEEE, 2020. http://dx.doi.org/10.1109/imws-amp49156.2020.9199755.

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Kyosuke, Kusunose, and Arai Hiroyuki. "Near Field Co-Planar Phase-less Measurement for EIRP Evaluation." In 2020 International Symposium on Antennas and Propagation (ISAP). IEEE, 2021. http://dx.doi.org/10.23919/isap47053.2021.9391402.

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Hou, Xuebin, Clive Parini, and Stuart Gregson. "Planar near-field measurement on an omni-directional UWB antenna." In 2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications. IEEE, 2007. http://dx.doi.org/10.1109/iwat.2007.370154.

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Reports on the topic "Planar near-field measurement"

1

Rousseau, Paul R. Investigation of the Planar Near-Field Measurement of a Reflector Antenna and a Reflector-plus-Splash Plate Antenna System at X-band. Fort Belvoir, VA: Defense Technical Information Center, October 1996. http://dx.doi.org/10.21236/ada323471.

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Hart, Carl, Gregory Lyons, and Michael White. Spherical shock waveform reconstruction by heterodyne interferometry. Engineer Research and Development Center (U.S.), May 2024. http://dx.doi.org/10.21079/11681/48471.

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The indirect measurement of shock waveforms by acousto-optic sensing requires a method to reconstruct the field from the projected data. Under the assumption of spherical symmetry, one approach is to reconstruct the field by the Abel inversion integral transform. When the acousto-optic sensing modality measures the change in optical phase difference time derivative, as for a heterodyne Mach–Zehnder interferometer, e.g., a laser Doppler vibrometer, the reconstructed field is the fluctuating refractive index time derivative. A technique is derived that reconstructs the fluctuating index directly by assuming plane wave propagation local to a probe beam. With synthetic data, this approach is compared to the Abel inversion integral transform and then applied to experimental data of laser-induced shockwaves. Time waveforms are reconstructed with greater accuracy except for the tail of the waveform that maps spatially to positions near a virtual origin. Furthermore, direct reconstruction of the fluctuating index field eliminates the required time integration and results in more accurate shock waveform peak values, rise times, and positive phase duration.

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Butterweck, Gernot, Alberto Stabilini, Benno Bucher, David Breitenmoser, Ladislaus Rybach, Cristina Poretti, Stéphane Maillard, et al. Aeroradiometric measurements in the framework of the swiss exercise ARM23. Paul Scherrer Institute, PSI, March 2024. http://dx.doi.org/10.55402/psi:60054.

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The flights of the civil (ARM23c) and military (ARM23m) parts of the exercise were performedbetween June 19th and 23rd and between September 11th and September 15th,respectively. The measuring system RLL001 was employed for all measurements. As usual, during the civil exercise the environs of some of the Swiss nuclear power plants were screened, on behalf of the Swiss Nuclear Safety Inspectorate (ENSI). At the site of the nuclear power plant Gösgen (KKG) with its pressurized water reactor, the activation products of the primary coolant loop are kept in the well shielded reactor building, thus generating no elevated readings neither on the premises nor in the vicinity of the power plant. The nuclear power plant of Mühleberg (KKM) is now being decommissioned. During this phase, activated components are temporarily stored and processed on the plant premises. The dose rate produced by these components, easily detected and identified with the Swiss airborne gamma spectrometry system, is nevertheless very modest and closely monitored by the Swiss Nuclear Safety Inspectorate (ENSI). Search exercises for radionuclide sources were performed in both parts of ARM23. The operational software of the RLL systems was able to detect the radionuclide sources placed in military training areas. The Man-Made Gross-Count (MMGC) ratio demonstrated a good sensitivity for the identification of radionuclide sources. Nevertheless, a weak radionuclide source placed in the field of view of the helicopter (300 m x 300 m at a ground clearance of 100 m) together with a much stronger radionuclide source emitting higher energy photons was obscured due to Compton scattered photons and therefore could not be detected. Measurements of two teams using drones equipped with radiation monitors demonstrated that low flying drones (ground clearance below 10 m) can be a valuable and complementary tool to identify sources and to further reduce the target area to be searched with ground teams. An altitude profile over Lake Constance confirmed the already observed influence of airborne radon progeny on the determination of cosmic and background corrections. Background flights were performed over several Swiss regions. Besides attenuation effects of water bodies, variations of natural radionuclide content could be observed. A new flight strategy in alpine topography was tested near the Swiss mountain Chrüz. Following contour lines of the topography reduces the necessity for drastic flight altitude changes compared to the parallel line pattern normally used, but is much more challenging for the pilots.

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Hopper. L30500 Analysis of the Effects of High-Voltage Direct-Current Transmission Systems on Buried Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2008. http://dx.doi.org/10.55274/r0010196.

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The economics of high voltage direct current for long-distance transmission of electrical energy have been reported as very attractive, to the extent that several projects are in the making. Several reasons other than the savings in transmission costs, for example the exchange of peak power between time zones and seasonal zones, would permit utilities to save on plant investment for generating capacity while maintaining a high level of service. This report summarizes work on the initial phase of a study to determine the effects of high-voltage direct-current (H.V.D.C.) electric transmission lines on buried pipeline systems. Pipeline Research Council International, Inc. initiated this work in response to an anticipated threat posed by the Pacific Northwest-Southwest Intertie H.V.D.C. system now being designed (and other possible H.V.D.C. lines in the future) because of the announced plans to pass direct current through the earth. The objectives of the overall program are:(1) To determine the nature and magnitude of problems that will be created by the earth current from H.V.D.C. systems, and(2) To devise means of protecting pipelines from the effects of such currents. A computer program was written based on a mathematical model of a buried pipeline in the environment created by an H.V.D.C. system. Excellent agreement was obtained between computed soil potential gradients and measurements obtained during a field test of H.V.D.C. in Oregon. Reasonably good agreement was also obtained between measured pipe-to-soil potentials on the Pacific Lighting Gas Supply Company pipeline near Camino, California, and computed values during a field test of H.V.D.C. power transmission.

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Fridman, Eyal, Jianming Yu, and Rivka Elbaum. Combining diversity within Sorghum bicolor for genomic and fine mapping of intra-allelic interactions underlying heterosis. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597925.bard.

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Heterosis, the enigmatic phenomenon in which whole genome heterozygous hybrids demonstrate superior fitness compared to their homozygous parents, is the main cornerstone of modern crop plant breeding. One explanation for this non-additive inheritance of hybrids is interaction of alleles within the same locus. This proposal aims at screening, identifying and investigating heterosis trait loci (HTL) for different yield traits by implementing a novel integrated mapping approach in Sorghum bicolor as a model for other crop plants. Originally, the general goal of this research was to perform a genetic dissection of heterosis in a diallel built from a set of Sorghum bicolor inbred lines. This was conducted by implementing a novel computational algorithm which aims at associating between specific heterozygosity found among hybrids with heterotic variation for different agronomic traits. The initial goals of the research are: (i) Perform genotype by sequencing (GBS) of the founder lines (ii) To evaluate the heterotic variation found in the diallel by performing field trails and measurements in the field (iii) To perform QTL analysis for identifying heterotic trait loci (HTL) (iv) to validate candidate HTL by testing the quantitative mode of inheritance in F2 populations, and (v) To identify candidate HTL in NAM founder lines and fine map these loci by test-cross selected RIL derived from these founders. The genetic mapping was initially achieved with app. 100 SSR markers, and later the founder lines were genotyped by sequencing. In addition to the original proposed research we have added two additional populations that were utilized to further develop the HTL mapping approach; (1) A diallel of budding yeast (Saccharomyces cerevisiae) that was tested for heterosis of doubling time, and (2) a recombinant inbred line population of Sorghum bicolor that allowed testing in the field and in more depth the contribution of heterosis to plant height, as well as to achieve novel simulation for predicting dominant and additive effects in tightly linked loci on pseudooverdominance. There are several conclusions relevant to crop plants in general and to sorghum breeding and biology in particular: (i) heterosis for reproductive (1), vegetative (2) and metabolic phenotypes is predominantly achieved via dominance complementation. (ii) most loci that seems to be inherited as overdominant are in fact achieving superior phenotype of the heterozygous due to linkage in repulsion, namely by pseudooverdominant mechanism. Our computer simulations show that such repulsion linkage could influence QTL detection and estimation of effect in segregating populations. (iii) A new height QTL (qHT7.1) was identified near the genomic region harboring the known auxin transporter Dw3 in sorghum, and its genetic dissection in RIL population demonstrated that it affects both the upper and lower parts of the plant, whereas Dw3 affects only the part below the flag leaf. (iv) HTL mapping for grain nitrogen content in sorghum grains has identified several candidate genes that regulate this trait, including several putative nitrate transporters and a transcription factor belonging to the no-apical meristem (NAC)-like large gene family. This activity was combined with another BARD-funded project in which several de-novo mutants in this gene were identified for functional analysis.

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Warrick, Arthur, Uri Shani, Dani Or, and Muluneh Yitayew. In situ Evaluation of Unsaturated Hydraulic Properties Using Subsurface Points. United States Department of Agriculture, October 1999. http://dx.doi.org/10.32747/1999.7570566.bard.

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The primary information for accurately predicting water and solute movement and their impact on water quality is the characterization of soil hydraulic properties. This project was designed to develop methods for rapid and reliable estimates of unsaturated hydraulic properties of the soil. Particularly, in situ methodology is put forth, based on subsurface point sources. Devices were designed to allow introduction of water in subsurface settings at constant negative heads. The ability to operate at a negative head allows a direct method of finding unsaturated soil properties and a mechanism for eliminating extremely rapid preferential flow from the slow matrix flow. The project included field, laboratory and modeling components. By coupling the measurements and the modeling together, a wider range of designs can be examined, while at the same time realistic performance is assured. The developed methodology greatly expands the possibilities for evaluating hydraulic properties in place, especially for measurements in undisturbed soil within plant rooting zones. The objectives of the project were (i) To develop methods for obtaining rapid and reliable estimates of unsaturated hydraulic properties in situ, based on water distribution from subsurface point sources. These can be operated with a constant flow or at a constant head; (ii) To develop methods for distinguishing between matrix and preferential flow using cavities/permeameters under tension; (iii) To evaluate auxiliary measurements such as soil water content or tensions near the operating cavities to improve reliability of results; and (iv: To develop numerical and analytical models for obtaining soil hydraulic properties based on measurements from buried-cavity sources and the auxiliary measurements. The project began in July 1995 and was terminated in November 1998. All of the objectives were pursued. Three new subsurface point sources were designed and tested and two old types were also used. Two of the three new designs used a nylon cloth membrane (30 mm) arranged in a cylindrical geometry and operating at a negative water pressure (tension). A separate bladder arrangement allowed inflation under a positive pressure to maintain contact between the membrane and the soil cavity. The third new design used porous stainless steel (0.5 and 5 mm) arranged in six segments, each with its own water inlet, assembled to form a cylindrical supply surface when inflated in a borehole. The "old" types included an "off-the-shelf" porous cup as well as measurements from a subsurface drip emitter in a small subsurface cavity. Reasonable measurements were made with all systems. Sustained use of the cloth membrane devices were difficult because of leaks and plugging problems. All of the devices require careful consideration to assure contact with the soil system. Steady flow was established which simplified the analysis (except for the drip emitter which used a transient analysis).

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McCarthy, James, Jeffrey Panek, and Tom McGrath. PR-312-12206-R02 FTIR Formaldehyde Measurement at Turbine NESHAP and Ambient Levels. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), April 2018. http://dx.doi.org/10.55274/r0011476.

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When natural gas is combusted, formaldehyde is formed as an intermediate product as methane is converted to CO2 during combustion. Formaldehyde is regulated by the U.S. EPA as a hazardous air pollutant (HAP) under National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations, and both turbines and reciprocating engines are listed source categories where EPA is required to develop regulations. NESHAPs have been adopted for natural gas-fired combustion turbines and reciprocating internal combustion engines (RICE), with initial regulations in 2004 that included a 91 parts per billion (ppb) standard for new turbines at "major source" facilities. However, the Turbine NESHAP was "stayed" by EPA as the agency considered whether natural gas-fired turbines should be regulated (i.e., whether those turbines would be "delisted" or removed from the rule). In response to a legal challenge regarding EPA's failure to meet Clean Air Act mandated schedules, EPA recently indicated that it plans to initiate a required periodic review of the Turbine NESHAP and that review will also address the delisting request. The "residual risk and technology review" (RTR) for the Turbine NESHAP will likely be conducted in 2018. Revisions to the regulation may be proposed when that review process is complete. Formaldehyde is ubiquitous (e.g., naturally formed through atmospheric chemistry even if not directly emitted), and there is also the potential that atmospheric levels and atmospheric chemistry are not adequately understood. Earlier pipeline industry testing of turbine formaldehyde emissions using refined methods indicated exhaust formaldehyde below 100 ppb and near the method detection limit. Anecdotal data from that test program showed ambient levels comparable to turbine exhaust in some cases, with naturally occurring emissions from an adjacent corn field resulting in ambient concentrations higher than formaldehyde exhaust levels. Evidence of "high" ambient formaldehyde levels (relative to turbine exhaust) may provide context and a counterargument to restrictive formaldehyde regulations. Understanding turbine formaldehyde emissions as compared to ambient levels is challenged by the ability to measure formaldehyde concentrations less than 100 parts per billion (ppb). Extractive Fourier Transform Infrared (FTIR) methods were developed for combustion exhaust formaldehyde measurement. However, measuring the ultra-low levels from turbines, commensurate with the NESHAP standard, will likely pose challenges. This project measured ambient formaldehyde levels using FTIR testing for comparison to the NESHAP standard. Significant challenges for conducting such measurements are apparent, which presents technical questions related to the feasibility of implementing emissions tests for the Turbine NESHAP standard.

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Lers, Amnon, Majid R. Foolad, and Haya Friedman. genetic basis for postharvest chilling tolerance in tomato fruit. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7600014.bard.

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ABSTRACT Postharvest losses of fresh produce are estimated globally to be around 30%. Reducing these losses is considered a major solution to ensure global food security. Storage at low temperatures is an efficient practice to prolong postharvest performance of crops with minimal negative impact on produce quality or human health and the environment. However, many fresh produce commodities are susceptible to chilling temperatures, and the application of cold storage is limited as it would cause physiological chilling injury (CI) leading to reduced produce quality. Further, the primary CI becomes a preferred site for pathogens leading to decay and massive produce losses. Thus, chilling sensitive crops should be stored at higher minimal temperatures, which curtails their marketing life and in some cases necessitates the use of other storage strategies. Development of new knowledge about the biological basis for chilling tolerance in fruits and vegetables should allow development of both new varieties more tolerant to cold, and more efficient postharvest storage treatments and storage conditions. In order to improve the agricultural performance of modern crop varieties, including tomato, there is great potential in introgression of marker-defined genomic regions from wild species onto the background of elite breeding lines. To exploit this potential for improving tomato fruit chilling tolerance during postharvest storage, we have used in this research a recombinant inbred line (RIL) population derived from a cross between the red-fruited tomato wild species SolanumpimpinellifoliumL. accession LA2093 and an advanced Solanum lycopersicumL. tomato breeding line NCEBR-1, developed in the laboratory of the US co-PI. The original specific objectives were: 1) Screening of RIL population resulting from the cross NCEBR1 X LA2093 for fruit chilling response during postharvest storage and estimation of its heritability; 2) Perform a transcriptopmic and bioinformatics analysis for the two parental lines following exposure to chilling storage. During the course of the project, we learned that we could measure greater differences in chilling responses among specific RILs compared to that observed between the two parental lines, and thus we decided not to perform transcriptomic analysis and instead invest our efforts more on characterization of the RILs. Performing the transcriptomic analysis for several RILs, which significantly differ in their chilling tolerance/sensitivity, at a later stage could result with more significant insights. The RIL population, (172 lines), was used in field experiment in which fruits were examined for chilling sensitivity by determining CI severity. Following the field experiments, including 4 harvest days and CI measurements, two extreme tails of the response distribution, each consisting of 11 RILs exhibiting either high sensitivity or tolerance to chilling stress, were identified and were further examined for chilling response in greenhouse experiments. Across the RILs, we found significant (P < 0.01) correlation between field and greenhouse grown plants in fruit CI. Two groups of 5 RILs, whose fruits exhibited reproducible chilling tolerant/sensitive phenotypes in both field and greenhouse experiments, were selected for further analyses. Numerous genetic, physiological, biochemical and molecular variations were investigated in response to postharvest chilling stress in the selected RILs. We confirmed the differential response of the parental lines of the RIL population to chilling stress, and examined the extent of variation in the RIL population in response to chilling treatment. We determined parameters which would be useful for further characterization of chilling response in the RIL population. These included chlorophyll fluorescence Fv/Fm, water loss, total non-enzymatic potential of antioxidant activity, ascorbate and proline content, and expression of LeCBF1 gene, known to be associated with cold acclimation. These parameters could be used in continuation studies for the identification and genetic mapping of loci contributing to chilling tolerance in this population, and identifying genetic markers associated with chilling tolerance in tomato. Once genetic markers associated with chilling tolerance are identified, the trait could be transferred to different genetic background via marker-assisted selection (MAS) and breeding. The collaborative research established in this program has resulted in new information and insights in this area of research and the collaboration will be continued to obtain further insights into the genetic, molecular biology and physiology of postharvest chilling tolerance in tomato fruit. The US Co-PI, developed the RIL population that was used for screening and measurement of the relevant chilling stress responses and conducted statistical analyses of the data. Because we were not able to grow the RIL population under field conditions in two successive generations, we could not estimate heritability of response to chilling temperatures. However, we plan to continue the research, grow the RIL progeny in the field again, and determine heritability of chilling tolerance in a near future. The IS and US investigators interacted regularly and plan to continue and expand on this study, since combing the expertise of the Co-PI in genetics and breeding with that of the PI in postharvest physiology and molecular biology will have great impact on this line of research, given the significant findings of this one-year feasibility project.

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