scholarly journals The state of the focus and image quality of the Spitzer Space Telescope as measured in orbit

2004 ◽  
Author(s):  
Robert D. Gehrz ◽  
Edward A. Romana ◽  
William F. Hoffmann ◽  
John P. Schwenker ◽  
John E. Mentzell ◽  
...  
Keyword(s):  
Image Quality ◽  
The State ◽  
Spitzer Space Telescope ◽  
Space Telescope

scholarly journals Pixel level decorrelation in service of the Spitzer microlens parallax survey

2020 ◽  
Vol 497 (4) ◽  
pp. 5309-5317 ◽  
Author(s):  
Lisa Dang ◽  
S Calchi Novati ◽  
S Carey ◽  
N B Cowan
Keyword(s):  
State Of The Art ◽  
The State ◽  
Spitzer Space Telescope ◽  
Space Telescope ◽  
Self Calibration ◽  
Short Period ◽  
Calibration Techniques

ABSTRACT Microlens parallax measurements combining space-based and ground-based observatories can be used to study planetary demographics. In recent years, the Spitzer Space Telescope was used as a microlens parallax satellite. Meanwhile, Spitzer IRAC has been employed to study short-period exoplanets and their atmospheres. As these investigations require exquisite photometry, they motivated the development of numerous self-calibration techniques now widely used in the exoplanet atmosphere community. Specifically, pixel level decorrelation (PLD) was developed for starring-mode observations in uncrowded fields. We adapt and extend PLD to make it suitable for observations obtained as part of the Spitzer Microlens Parallax Campaign. We apply our method to two previously published microlensing events, OGLE-2017-BLG-1140 and OGLE-2015-BLG-0448, and compare its performance to the state-of-the-art pipeline used to analyses Spitzer microlensing observation. We find that our method yields photometry 1.5–6 times as precise as previously published. In addition to being useful for Spitzer, a similar approach could improve microlensing photometry with the forthcoming Nancy Grace Roman Space Telescope.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Organ doses and subjective image quality of indirect digital panoramic radiography

2001 ◽  
Vol 30 (6) ◽  
pp. 308-313 ◽  
Author(s):  
F Gijbels ◽  
G Sanderink ◽  
C Bou Serhal ◽  
H Pauwels ◽  
R Jacobs
Keyword(s):  
Image Quality ◽  
Panoramic Radiography ◽  
Organ Doses ◽  
Subjective Image Quality ◽  
Digital Panoramic Radiography

Manajemen Ekonomi Outopilot: Kegagalan Negara Mencari Identitas?

Liquidity ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 142-152
Author(s):  
Mukhaer Pakkanna
Keyword(s):  
Economic Development ◽  
National Economy ◽  
The State ◽  
Political Democracy ◽  
Economic Democracy ◽  
Quality Of Democracy ◽  
Economic Disparities ◽  
National Economic ◽  
Production And Distribution

Political democracy should be equivalent to the economic development of the quality of democracy, economic democracy if not upright, even the owner of the ruling power and money, which is parallel to force global corporatocracy. Consequently, the economic oligarchy preservation reinforces control of production and distribution from upstream to downstream and power monopoly of the market. The implication, increasingly sharp economic disparities, exclusive owner of the money and power become fertile, and the end could jeopardize the harmony of the national economy. The loss of national economic identity that makes people feel lost the “pilot of the state”. What happens then is the autopilot state. Viewing unclear direction of the economy, the national economy should clarify the true figure.

Image Quality Enhancing by Efficient Histogram Equalization

2014 ◽  
Vol 2 (2) ◽  
pp. 47-58
Author(s):  
Ismail Sh. Baqer
Keyword(s):  
Image Quality ◽  
Contrast Enhancement ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Histogram Equalization ◽  
Gray Level ◽  
Signal To Noise ◽  
Squared Error ◽  
Noise Ratio

A two Level Image Quality enhancement is proposed in this paper. In the first level, Dualistic Sub-Image Histogram Equalization DSIHE method decomposes the original image into two sub-images based on median of original images. The second level deals with spikes shaped noise that may appear in the image after processing. We presents three methods of image enhancement GHE, LHE and proposed DSIHE that improve the visual quality of images. A comparative calculations is being carried out on above mentioned techniques to examine objective and subjective image quality parameters e.g. Peak Signal-to-Noise Ratio PSNR values, entropy H and mean squared error MSE to measure the quality of gray scale enhanced images. For handling gray-level images, convenient Histogram Equalization methods e.g. GHE and LHE tend to change the mean brightness of an image to middle level of the gray-level range limiting their appropriateness for contrast enhancement in consumer electronics such as TV monitors. The DSIHE methods seem to overcome this disadvantage as they tend to preserve both, the brightness and contrast enhancement. Experimental results show that the proposed technique gives better results in terms of Discrete Entropy, Signal to Noise ratio and Mean Squared Error values than the Global and Local histogram-based equalization methods

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