scholarly journals AMBER/VLTI Snapshot Survey on Circumstellar Environments

2014 ◽  
Vol 9 (S307) ◽  
pp. 297-300 ◽  
Author(s):  
Th. Rivinius ◽  
W.J. de Wit ◽  
Z. Demers ◽  
A. Quirrenbach ◽  
Keyword(s):  
Spatial Resolution ◽  
Spectral Resolution ◽  
Spatial Scales ◽  
Line Emission ◽  
High Spectral Resolution ◽  
Unique Combination ◽  
Hot Stars ◽  
Circumstellar Environments ◽  
Colour Terms ◽  
Neutral Colour

AbstractOHANA is an interferometric snapshot survey of the gaseous circumstellar environments of hot stars, carried out by the VLTI group at the Paranal observatory. It aims to characterize the mass-loss dynamics (winds/disks) at unexplored spatial scales for many stars. The survey employs the unique combination of AMBER's high spectral resolution with the unmatched spatial resolution provided by the VLTI. Because of the spatially unresolved central OBA-type star, with roughly neutral colour terms, their gaseous environments are among the easiest objects to be observed with AMBER, yet the extent and kinematics of the line emission regions are of high astrophysical interest.

scholarly journals Hyperspectral and Multispectral Remote Sensing Image Fusion Based on Endmember Spatial Information

2020 ◽  
Vol 12 (6) ◽  
pp. 1009
Author(s):  
Xiaoxiao Feng ◽  
Luxiao He ◽  
Qimin Cheng ◽  
Xiaoyi Long ◽  
Yuxin Yuan
Keyword(s):  
Image Fusion ◽  
Spatial Resolution ◽  
Spectral Resolution ◽  
Spatial Information ◽  
Spectral Unmixing ◽  
High Spectral Resolution ◽  
Remote Sensing Image Fusion ◽  
Fusion Methods ◽  
Invariant Regions ◽  
The Difference

Hyperspectral (HS) images usually have high spectral resolution and low spatial resolution (LSR). However, multispectral (MS) images have high spatial resolution (HSR) and low spectral resolution. HS–MS image fusion technology can combine both advantages, which is beneficial for accurate feature classification. Nevertheless, heterogeneous sensors always have temporal differences between LSR-HS and HSR-MS images in the real cases, which means that the classical fusion methods cannot get effective results. For this problem, we present a fusion method via spectral unmixing and image mask. Considering the difference between the two images, we firstly extracted the endmembers and their corresponding positions from the invariant regions of LSR-HS images. Then we can get the endmembers of HSR-MS images based on the theory that HSR-MS images and LSR-HS images are the spectral and spatial degradation from HSR-HS images, respectively. The fusion image is obtained by two result matrices. Series experimental results on simulated and real datasets substantiated the effectiveness of our method both quantitatively and visually.

scholarly journals The Structure and Kinematics of the Ionized Gas In Centaurus A

1987 ◽  
Vol 127 ◽  
pp. 417-418
Author(s):  
J. Bland ◽  
K. Taylor ◽  
P. D. Atherton
Keyword(s):  
Spatial Resolution ◽  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Line Of Sight ◽  
Rotating Disc ◽  
Ionized Gas ◽  
Dust Lane ◽  
Data Cubes ◽  
Fabry Perot ◽  
Centaurus A

The TAURUS Imaging Fabry-Perot System (Taylor & Atherton 1980) has been used with the IPCS at the AAT to observe the ionized gas within NGC 5128 (Cen A) at [NII]λ6548 and Hα. Seven independent (x, y,λ) data cubes were obtained along the dust lane at high spectral resolution (30 km/s FWHM) and at a spatial resolution limited by the seeing (~1″). From these data, maps of the kinematics and intensities of the ionized gas were derived over a 420″ by 300″ region. The maps are the most complete to date for this object comprising 17500 and 5300 fitted spectra in Ha and [NII]λ6548 respectively. The dust lane system is found to be well understood in terms of a differentially rotating disc of gas and dust which is warped both along and perpendicular to the line-of-sight.

scholarly journals Lunar Image Fusion using Wavelet Transform

2013 ◽  
pp. 211-215
Author(s):  
Dr.Vani. K ◽  
Anto. A. Micheal
Keyword(s):  
High Resolution ◽  
Image Fusion ◽  
Spatial Resolution ◽  
Spectral Resolution ◽  
Lunar Surface ◽  
High Spatial Resolution ◽  
Multispectral Image ◽  
High Spectral Resolution ◽  
Low Resolution ◽  
Mineral Mapping

This paper is an attempt to combine high resolution panchromatic lunar image with low resolution multispectral lunar image to produce a composite image using wavelet approach. There are many sensors that provide us image data about the lunar surface. The spatial resolution and spectral resolution is unique for each sensor, thereby resulting in limitation in extraction of information about the lunar surface. The high resolution panchromatic lunar image has high spatial resolution but low spectral resolution; the low resolution multispectral image has low spatial resolution but high spectral resolution. Extracting features such as craters, crater morphology, rilles and regolith surfaces with a low spatial resolution in multispectral image may not yield satisfactory results. A sensor which has high spatial resolution can provide better information when fused with the high spectral resolution. These fused image results pertain to enhanced crater mapping and mineral mapping in lunar surface. Since fusion using wavelet preserve spectral content needed for mineral mapping, image fusion has been done using wavelet approach.

scholarly journals Wide Swath and High Resolution Airborne HyperSpectral Imaging System and Flight Validation

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1667 ◽  
Author(s):  
Dong Zhang ◽  
Liyin Yuan ◽  
Shengwei Wang ◽  
Hongxuan Yu ◽  
Changxing Zhang ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Spectral Resolution ◽  
High Efficiency ◽  
High Spatial Resolution ◽  
Imaging System ◽  
High Sensitivity ◽  
Field Of View ◽  
High Spectral Resolution ◽  
Wide Swath

Wide Swath and High Resolution Airborne Pushbroom Hyperspectral Imager (WiSHiRaPHI) is the new-generation airborne hyperspectral imager instrument of China, aimed at acquiring accurate spectral curve of target on the ground with both high spatial resolution and high spectral resolution. The spectral sampling interval of WiSHiRaPHI is 2.4 nm and the spectral resolution is 3.5 nm (FWHM), integrating 256 channels coving from 400 nm to 1000 nm. The instrument has a 40-degree field of view (FOV), 0.125 mrad instantaneous field of view (IFOV) and can work in high spectral resolution mode, high spatial resolution mode and high sensitivity mode for different applications, which can adapt to the Velocity to Height Ratio (VHR) lower than 0.04. The integration has been finished, and several airborne flight validation experiments have been conducted. The results showed the system’s excellent performance and high efficiency.

scholarly journals Self-Dictionary Regression for Hyperspectral Image Super-Resolution

2018 ◽  
Vol 10 (10) ◽  
pp. 1574 ◽  
Author(s):  
Dongsheng Gao ◽  
Zhentao Hu ◽  
Renzhen Ye
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Spectral Resolution ◽  
Cross Correlation ◽  
Hyperspectral Image ◽  
High Spatial Resolution ◽  
Super Resolution ◽  
High Spectral Resolution ◽  
Low Resolution ◽  
Image Super Resolution

Due to sensor limitations, hyperspectral images (HSIs) are acquired by hyperspectral sensors with high-spectral-resolution but low-spatial-resolution. It is difficult for sensors to acquire images with high-spatial-resolution and high-spectral-resolution simultaneously. Hyperspectral image super-resolution tries to enhance the spatial resolution of HSI by software techniques. In recent years, various methods have been proposed to fuse HSI and multispectral image (MSI) from an unmixing or a spectral dictionary perspective. However, these methods extract the spectral information from each image individually, and therefore ignore the cross-correlation between the observed HSI and MSI. It is difficult to achieve high-spatial-resolution while preserving the spatial-spectral consistency between low-resolution HSI and high-resolution HSI. In this paper, a self-dictionary regression based method is proposed to utilize cross-correlation between the observed HSI and MSI. Both the observed low-resolution HSI and MSI are simultaneously considered to estimate the endmember dictionary and the abundance code. To preserve the spectral consistency, the endmember dictionary is extracted by performing a common sparse basis selection on the concatenation of observed HSI and MSI. Then, a consistent constraint is exploited to ensure the spatial consistency between the abundance code of low-resolution HSI and the abundance code of high-resolution HSI. Extensive experiments on three datasets demonstrate that the proposed method outperforms the state-of-the-art methods.

scholarly journals Investigation of laser-produced chlorine plasma radiation for non-monochromatic X-ray scattering experiments

2006 ◽  
Vol 24 (3) ◽  
pp. 335-345 ◽  
Author(s):  
M. SCHOLLMEIER ◽  
G. RODRÍGUEZ PRIETO ◽  
F.B. ROSMEJ ◽  
G. SCHAUMANN ◽  
A. BLAZEVIC ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Pyrolytic Graphite ◽  
Line Emission ◽  
Plasma Radiation ◽  
High Spectral Resolution ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Dense Plasmas ◽  
X Ray Scattering ◽  
Ray Scattering

The chlorine Heαradiation of polyvinyl chloride (PVC) was investigated with respect to X-ray scattering experiments on dense plasmas. The X-ray source was a laser-produced plasma that was observed with a highly reflective highly oriented pyrolytic graphite (HOPG) crystal spectrometer as it is used in current x-ray scattering experiments on dense plasmas. The underlying dielectronic satellites of Heαcannot be resolved, therefore the plasma was observed at the same time with a focusing spectrometer with spatial resolution. To reconstruct the spectrum a simple model to calculate the spectral line emission based on dielectronic recombination and inner shell excitation of helium- and lithium-like ions was used. The analysis shows that chlorine dielectronic satellite emission is intense compared to Heαin laser-produced chlorine plasmas with a temperature of 300 eV in this wavelength range of Δλ = 0.07 Å (ΔE= 43 eV). The method proposed in this paper allows deducing experimentally the role of the underlying dielectronic satellites in the scatter spectrum measured with a HOPG crystal spectrometer. It is shown that the dielectronic satellites can be neglected when the scattering is measured with low spectral resolution in the non-collective regime. They are of major importance in the collective scatter regime where a high spectral resolution is necessary.

scholarly journals Recent High Spectral and Spatial Resolution Spectroscopy of Laser-Produced Plasmas and Electron-Ion Beam Plasmas

1977 ◽  
Vol 43 ◽  
pp. 18-18
Author(s):  
G.A. Doschek ◽  
U. Feldman ◽  
D.J. Johnson ◽  
D.J. Nagel
Keyword(s):  
Spatial Resolution ◽  
Spectral Resolution ◽  
Ion Beam ◽  
Normal Incidence ◽  
Grazing Incidence ◽  
Spectral Lines ◽  
Atomic Transition ◽  
Transition Time ◽  
High Spectral Resolution ◽  
Expansion Velocity

Spectra of plasmas produced by a CO2 laser have recently been obtained using a normal incidence slitless spectrograph and a high spectral resolution (0.028 mÅ) grazing incidence spectrograph. The slitless spectrograph forms images of the plasmas in spectral lines and is similar to the instrument flown by NRL on Skylab. The total wavelength coverage is from about 100 Å to about 600 Å. The shapes of the images depend markedly on the type of atomic transition. Time-averaged electron densities in the expanding plumes are calculated, and the expansion velocity is estimated from the profiles of lines recorded by the grazing incidence spectrograph. In addition, spectra of electron-ion beam plasmas between ∼200 Å and 2000 Å were obtained using a stigmatic normal incidence slit spectrograph. The distribution of plasma emisston between the anode and cathode, and the mass motions in the plasmas are discussed.

scholarly journals Radio and optical observations at high spatial and spectral resolution of compact young Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 360-360
Author(s):  
L. F. Miranda ◽  
J. M. Torrelles ◽  
C. Eiroa
Keyword(s):  
Spatial Resolution ◽  
Spectral Resolution ◽  
Spatial Scales ◽  
Planetary Nebulae ◽  
Radio Continuum ◽  
Optical Observations ◽  
Optical Data ◽  
Electron Density And Temperature ◽  
Spectrally Resolved ◽  
Mass Ejection

We present VLA-A radio continuum at 3.6 cm and H92α observations, and optical long-slit spectra at high spectral and spatial resolution of the compact Planetary Nebulae (PNs) Hu 2-1, IC 4997, IC 5117 and NGC 6884. The radio continuum maps show the subarcsecond structure of the PNs in detail. From the optical spectra, the basic kinematical properties can be deduced. The H92α emission line, spatially and spectrally resolved in IC 5117 and Hu 2-1, allows us to observe the kinematics of the PNs in spatial scales of ∼ 0.3″. By combining the radio and optical data, it is possible to identify the components present in the nebulae, to deduce their spatio-kinematical structure, and to obtain estimates for the electron density and temperature, ionized masses and kinematical ages. All this information permits to impose constraints about the mass ejection processes involved in the formation of PNs and when they have occurred.

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