23 citations · 91 across the 17 of their papers we have counts for
14 papers · 1 filter
Data Pipeline Architecture and Development for VELC onboard Space Solar Mission AdityaL1
Jagdev Singh, B. Raghavendra Prasad, Chavali Sumana +4
ADITYA L-1 is India's first dedicated mission to study Sun and its atmosphere with Visible Emission Line Coronagraph (VELC), a major payload on ADITYA-L1. VELC has provision to mak…
Spectropolarimeter on-board the Aditya-L1: Polarization Modulation and Demodulation
K. Nagaraju, B. Raghavendra Prasad, Bhavana S. Hegde +5
One of the major science goals of the Visible Emission Line Coronagraph (VELC) payload aboard the Aditya-L1 mission is to map the coronal magnetic field topology and the quantitati…
Prospect for UV observations from the Moon. III. Assembly and ground calibration of Lunar Ultraviolet Cosmic Imager (LUCI)
Joice Mathew, B. G. Nair, Margarita Safonova +14
The Lunar Ultraviolet Cosmic Imager (LUCI) is a near-ultraviolet (NUV) telescope with all-spherical mirrors, designed and built to fly as a scientific payload on a lunar mission wi…
Extrapolating Zernike Moments to Predict Future Optical Wave-fronts in Adaptive Optics Using Real Time Data Mining
Akondi Vyas, M. B. Roopashree, B. Raghavendra Prasad
We present the details of predicting atmospheric turbulence by mining Zernike moment data obtained from simulations as well as experiments. Temporally correlated optical wave-front…
Performance of centroiding algorithms at low light level conditions in adaptive optics
Akondi Vyas, M. B. Roopashree, B. Raghavendra Prasad
The performance metrics of different centroiding algorithms at low light level conditions were optimized in the case of a Shack Hartmann Sensor (SHS) for efficient performance of t…
Prediction of wavefronts in adaptive optics to reduce servo lag errors using data mining
Akondi Vyas, M B Roopashree, B Raghavendra Prasad
Servo lag errors in adaptive optics lead to inaccurate compensation of wavefront distortions. An attempt has been made to predict future wavefronts using data mining on wavefronts…
Digital long focal length lenslet array using spatial light modulator
Akondi Vyas, M B Roopashree, B Raghavendra Prasad
Under a thin lens and paraxial approximation, the phase transformation function of a lens was simulated on a Liquid Crystal (LC) based Spatial Light Modulator (SLM). The properties…
Effective coherence length estimation of optical wavefronts
Akondi Vyas, M. B. Roopashree, B. Raghavendra Prasad
In adaptive optics, the measurement of spatial coherence length helps in deciding the optimum design parameters of a Shack Hartmann Sensor (SHS). Two methods of estimating the spat…
Performance analysis of Fourier and Vector Matrix Multiply methods for phase reconstruction from slope measurements
M B Roopashree, Akondi Vyas, B Raghavendra Prasad
The accuracy of wavefront reconstruction from discrete slope measurements depends on the sampling geometry, coherence length of the incoming wavefronts, wavefront sensor specificat…
Centroid Detection by Gaussian Pattern Matching in Adaptive Optics
Akondi Vyas, M B Roopashree, B Raghavendra Prasad
Shack Hartmann wavefront sensor is a two dimensional array of lenslets which is used to detect the incoming phase distorted wavefront through local tilt measurements made by record…
Spatial Light Modulator for wavefront correction
Akondi Vyas, M. B. Roopashree, Ravinder Kumar Banyal +1
We present a liquid crystal method of correcting the phase of an aberrated wavefront using a spatial light modulator. A simple and efficient lab model has been demonstrated for wav…
Progressive Prediction of Turbulence Using Wave-Front Sensor Data in Adaptive Optics Using Data Mining
Akondi Vyas, M B Roopashree, B Raghavendra Prasad
Nullifying the servo bandwidth errors improves the strehl ratio by a substantial quantity in adaptive optics systems. An effective method for predicting atmospheric turbulence to r…
Denoising Shack Hartmann Sensor spot pattern using Zernike Reconstructor
Akondi Vyas, M B Roopashree, B Raghavendra Prasad
Shack Hartmann Sensor (SHS) is inflicted with significant background noise that deteriorates the wave-front reconstruction accuracy. In this paper, a simple method to remove the ba…
Optimization of Existing Centroiding Algorithms for Shack Hartmann Sensor
Akondi Vyas, M B Roopashree, B R Prasad
Three centroiding techniques to estimate the position of the spots in a Shack Hartmann sensor: Normalized Centre of Gravity (CoG), Iteratively Weighted Centre of Gravity (IWCoG) an…