Digital Measurement of Radio Source Positions

1967 ◽  
Vol 1 (1) ◽  
pp. 32-33
Author(s):  
H. S. Murdoch ◽  
M. I. Large
Keyword(s):  
High Resolution ◽  
Radio Source ◽  
Radio Telescope ◽  
Instrumental Response ◽  
Response Pattern ◽  
Accurate Determination ◽  
Analysis Procedure ◽  
Digital Measurement ◽  
Critical Stage

The accurate determination of radio source positions is one of the principal uses of high resolution instruments such as the Molonglo Radio Telescope. A critical stage in this process familiar to all radio astronomers involves the measurement of the instrumental response pattern relative to some accurate time or position marker. Ideally, the analysis procedure should introduce no further errors either random or systematic beyond those which are already present in the data. This is virtually impossible with chart analysis.

Accurate determination of lattice mismatch in the epitaxial AlAs/GaAs system by high-resolution X-ray diffraction

1993 ◽  
Vol 132 (3-4) ◽  
pp. 427-434 ◽  
Author(s):  
C. Bocchi ◽  
C. Ferrari ◽  
P. Franzosi ◽  
A. Bosacchi ◽  
S. Franchi
Keyword(s):  
High Resolution ◽  
Lattice Mismatch ◽  
Accurate Determination ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Strategies for measuring canonical tracer relationships in the stratosphere

2003 ◽  
Vol 3 (1) ◽  
pp. 259-266 ◽  
Author(s):  
O. Morgenstern ◽  
J. A. Pyle
Keyword(s):  
High Resolution ◽  
Satellite Data ◽  
Trace Gases ◽  
Accurate Determination ◽  
Mixing Processes ◽  
Resolution Simulation

Abstract. A high-resolution simulation of stratospheric long-lived trace gases is subsampled in ways resembling various commonly used measurement platforms. The resulting measurements are analyzed with respect to whether they allow an accurate determination of stratospheric tracer relationships, as a prerequisite for a quantification of mixing processes from them. By varying the simulated locations, frequencies, and, in the case of satellite data, accuracies of the measurements we determine minimal requirements that the measurements need to satisfy in order to be suitable for a derivation of tracer relationships.

scholarly journals The application of full spectrum analysis to NaI(Tl) gamma spectrometry for the determination of burial dose rates

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Minqiang Bu ◽  
Andrew S. Murray ◽  
Myungho Kook ◽  
Jan-Pieter Buylaert ◽  
Kristina J. Thomsen
Keyword(s):  
High Resolution ◽  
Gamma Spectrometry ◽  
Spectrum Analysis ◽  
Accurate Determination ◽  
Precise Determination ◽  
Laboratory Method ◽  
Least Square ◽  
Full Spectrum ◽  
Dose Rates

Abstract In this study, we explored the potential of a NaI(Tl) scintillator-based gamma spectrometer for the accurate determination of burial dose rates in natural geological samples using a full spectrum analysis (FSA) approach. In this method, an iterative reweighted least-square regression is used to fit calibration standard spectra (40K, and 238U and 232Th series in equilibrium) to the sample spectrum, after subtraction of an appropriate background. The resulting minimum detection limits for 40K, 238U, and 232Th are 4.8, 0.4 and 0.3 Bq·kg–1, respectively (for a 0.23 kg sample); this is one order of magnitude lower than those obtained with the three-window approach previously reported by us, and well below the concentrations found in most natural sediments. These improved values are also comparable to those from high-resolution HPGe gamma spectrometry. Almost all activity concentrations of 40K, 238U, and 232Th from 20 measured natural samples differ by ≤5% from the high resolution spectrometry values; the average ratio of dose rates derived from our NaI(Tl) spectrometer to those from HPGe spectrometry is 0.993 ± 0.004 (n=20). We conclude that our scintillation spectrometry system employing FSA is a useful alternative laboratory method for accurate and precise determination of burial dose rates at a significantly lower cost than high resolution gamma spectrometry.

pParse: A method for accurate determination of monoisotopic peaks in high-resolution mass spectra

PROTEOMICS ◽  
2011 ◽  
Vol 12 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Zuo-F ei Yuan ◽  
Chao Liu ◽  
Hai-Peng Wang ◽  
Rui-Xiang Sun ◽  
Yan Fu ◽  
...  
Keyword(s):  
High Resolution ◽  
Mass Spectra ◽  
Accurate Determination ◽  
High Resolution Mass ◽  
Resolution Mass

High-resolution coherent imaging in STEM

1993 ◽  
Vol 51 ◽  
pp. 1082-1083
Author(s):  
J.M. Cowley ◽  
M.A. Gribelyuk
Keyword(s):  
High Resolution ◽  
Accurate Determination ◽  
High Resolution Electron Microscopy ◽  
Image Resolution ◽  
Coherent Imaging ◽  
Reconstruction Process ◽  
Original Proposal ◽  
Resolution Electron ◽  
Imaging Theory

The ultimate aim of high resolution electron microscopy is the accurate determination of the positions and types of the atoms in a specimen. The coherent imaging theory for STEM is reviewed with the emphasis on its potential for achieving this aim by holographic methods. The STEM modes of holography are in many respects equivalent to the corresponding TEM modes, but have the advantage that, because with a FEG electron source the focussed probes have sub-nanometer diameter, a strong signal is obtained from the illuminated region and the problem of shot-noise is much less important.The original proposal for holography by Gabor envisaged the use of a reconstruction process on the recorded hologram to correct for the lens aberrations and hence improve the image resolution. The more general and more challenging problem is to reconstruct the aberration-free wave function at the exit face of the specimen (with its real and imaginary, or amplitude and phase, components) and then to invert the dynamical diffraction process and derive the projected potential distribution of the object.

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