Results 31 to 40 of about 6,949 (194)
Measurement of Antenna Surfaces from In- and Out-Of-Focus Beam Maps using Astronomical Sources [PDF]
, 2006 We present a technique for the accurate estimation of large-scale errors in an antenna surface using astronomical sources and detectors. The technique requires several out-of-focus images of a compact source and the signal-to-noise ratio needs to be good
Anderson +8 more
core +2 more sources
Wavefront feature extraction for SAR target recognition
The Journal of Engineering, 2019 Synthetic aperture radar (SAR) target feature extraction is a key technology for SAR target recognition. The existing SAR feature extraction methods mainly focus on amplitude information of the SAR image in spite of phase information. This study proposes
Jiping Wang +3 more
doaj +1 more source
Validation of Mahajan's formula for scaling ocular higher-order aberrations by pupil size
Indian Journal of Ophthalmology, 2020 Purpose: Zernike polynomials for describing ocular higher order aberrations are affected by pupil aperture. The current study aimed to validate Mahajan's formula for scaling Zernike polynomials by pupil size.
Henry B Wallace +2 more
doaj +1 more source
Laser Tomography Adaptive Optics (LTAO): A performance study [PDF]
, 2013 We present an analytical derivation of the on-axis performance of Adaptive Optics systems using a given number of guide stars of arbitrary altitude, distributed at arbitrary angular positions in the sky.
Ramaprakash, A. N., Tatulli, E.
core +1 more source
Advanced analytic treatment and efficient computation of the diffraction integrals in the extended Nijboer-Zernike theory [PDF]
Journal of the European Optical Society-Rapid Publications, 2013 The computational methods for the diffraction integrals that occur in the Extended Nijboer-Zernike (ENZ-) approach to circular, aberrated, defocused optical systems are reviewed and updated.
van Haver S., Janssen A. J. E. M.
doaj +1 more source
Groups, Special Functions and Rigged Hilbert Spaces [PDF]
, 2019 Ver ...
Celeghini, Enrico +2 more
core +1 more source
Applied Sciences, 2019 In this study, Zernike polynomials and optical fiber field theory are applied to build a mathematical model of coupling efficiency (CE) and spatial mode of aberrations.
Yongkai Liu +6 more
doaj +1 more source
Mathematics, 2020 In light of fine learning ability in the existing uncertainties, a sage revised reiterative even Zernike polynomials neural network (SRREZPNN) control with modified fish school search (MFSS) method is proposed to control the six-phase squirrel cage ...
Chih-Hong Lin
doaj +1 more source
Some remarks on harmonic projection operators on spheres [PDF]
, 2016 We give a survey of recent works concerning the mapping properties of joint harmonic projection operators, mapping the space of square integrable functions on complex and quaternionic spheres onto the eigenspaces of the Laplace-Beltrami operator and of a
Casarino, Valentina
core +3 more sources
FALCON: a concept to extend adaptive optics corrections to cosmological fields [PDF]
, 2004 FALCON is an original concept for a next generation spectrograph at ESO VLT or at future ELTs. It is a spectrograph including multiple small integral field units (IFUs) which can be deployed within a large field of view such as that of VLT/GIRAFFE.
+10 more
core +4 more sources