Results 41 to 50 of about 533,452 (194)
AN EMPRICAL POINT ERROR MODEL FOR TLS DERIVED POINT CLOUDS [PDF]
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016 Abstract. The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions
Ozendi, Mustafa +2 more
openaire +5 more sources
Advances in AstronomyThe need for precise radio telescope pointing has driven great attention to investigating the effect of antenna local deformation or irregularity, such as unevenness in the azimuth track.
Ye Yuan, Zhi-Yong Liu, Na Wang
doaj +1 more source
Outage Probability Analysis of FSO Links Over Foggy Channel
IEEE Photonics Journal, 2017 Outdoor free-space optic (FSO) communication systems are sensitive to atmospheric impairments, such as turbulence and fog, in addition to being subject to pointing errors.
Maged Abdullah Esmail +2 more
doaj +1 more source
Micromachines, 2023 One of the key reasons for the deterioration of antenna pointing accuracy for radio telescopes is the deformation and tilt of antenna alidades, which primarily result from track unevenness and thermal gradients.
Qian Xu, Fei Xue, Hui Wang, Letian Yi
doaj +1 more source
Pointing Calibration for Spaceborne Doppler Scatterometers
Remote SensingDoppler scatterometers have demonstrated the ability to measure wide-swath ocean surface currents from airborne platforms. Since platform velocities for spaceborne platforms are almost two orders of magnitude larger, errors in the knowledge of the ...
Ernesto Rodríguez +4 more
doaj +1 more source
Evaluation of the ALMA Prototype Antennas [PDF]
, 2006 The ALMA North American and European prototype antennas have been evaluated by a variety of measurement systems to quantify the major performance specifications. Nearfield holography was used to set the reflector surfaces to 17 microns RMS.
Albert Greve +7 more
core +2 more sources
Use of the Sun to determine pointing of ST radar beams [PDF]
, 1986 Verification of the beam pointing direction for ST (stratosphere troposphere) radars is a technically difficult problem. Consequently it is not usually done. For measurement of horizontal wind, the lack of precise knowledge of the beam pointing direction
Riddle, A. C.
core +1 more source
Error bounds on complex floating-point multiplication [PDF]
Mathematics of Computation, 2007 Given floating-point arithmetic with $t$-digit base-$\beta$ significands in which all arithmetic operations are performed as if calculated to infinite precision and rounded to a nearest representable value, we prove that the product of complex values $z_0$ and $z_1$ can be computed with maximum absolute error $\abs{z_0} \abs{z_1} \frac{1}{2} \beta^{1 -
Brent, Richard +2 more
openaire +4 more sources
Array signal processing robust to pointing errors
, 2011 The objective of this thesis is to design computationally efficient DOA (direction-of- arrival) estimation algorithms and beamformers robust to pointing errors, by harnessing the antenna geometrical information and received signals.
Zhuang, Jie, Zhuang, Jie
core +1 more source