scholarly journals Auroral meridian scanning photometer calibration using Jupiter

2016 ◽  
Author(s):  
Brian J. Jackel ◽  
Craig Unick ◽  
Fokke Creutzberg ◽  
Greg Baker ◽  
Eric Davis ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Primary Source ◽  
Optical Field ◽  
Field Of View ◽  
Local Orientation ◽  
Atmospheric Variability ◽  
Relative Response ◽  
Cross Calibration ◽  
Photometer Calibration ◽  
Better Than

Abstract. Observations of astronomical sources provides information that can significantly enhance the utility of auroral data for scientific studies. Jupiter is used for field cross-calibration of 4 multi-spectral auroral meridian scanning photometers during 2011–15 northern hemisphere winters. Seasonal average optical field-of-view and local orientation estimates are obtained with uncertainties of 0.01° and 0.1° respectively. Estimates of absolute photometric sensitivity are repeatable to roughly 5 % from one month to the next, while the relative response between different wavelength channels is stable to better than 1 %. Astronomical field calibrations and darkroom calibration differences are on the order of 10 %. Atmospheric variability is the primary source of uncertainty; this may be reduced with data from co-located instruments such as all-sky imagers.

scholarly journals Auroral meridian scanning photometer calibration using Jupiter

2016 ◽  
Vol 5 (2) ◽  
pp. 493-512 ◽  
Author(s):  
Brian J. Jackel ◽  
Craig Unick ◽  
Fokke Creutzberg ◽  
Greg Baker ◽  
Eric Davis ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Primary Source ◽  
Optical Field ◽  
Field Of View ◽  
Local Orientation ◽  
Atmospheric Variability ◽  
Relative Response ◽  
Cross Calibration ◽  
Photometer Calibration ◽  
Better Than

Abstract. Observations of astronomical sources provide information that can significantly enhance the utility of auroral data for scientific studies. This report presents results obtained by using Jupiter for field cross calibration of four multispectral auroral meridian scanning photometers during the 2011–2015 Northern Hemisphere winters. Seasonal average optical field-of-view and local orientation estimates are obtained with uncertainties of 0.01 and 0.1°, respectively. Estimates of absolute sensitivity are repeatable to roughly 5 % from one month to the next, while the relative response between different wavelength channels is stable to better than 1 %. Astronomical field calibrations and darkroom calibration differences are on the order of 10 %. Atmospheric variability is the primary source of uncertainty; this may be reduced with complementary data from co-located instruments.

scholarly journals Hayashi spectra of the northern hemisphere mid-latitude atmospheric variability in the NCEP–NCAR and ECMWF reanalyses

2005 ◽  
Vol 25 (6) ◽  
pp. 639-652 ◽  
Author(s):  
Alessandro Dell’Aquila ◽  
Valerio Lucarini ◽  
Paolo M. Ruti ◽  
Sandro Calmanti
Keyword(s):  
Northern Hemisphere ◽  
Atmospheric Variability

scholarly journals Research on Generation Method of Grasp Strategy Based on DeepLab V3+ for Three-Finger Gripper

Information ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 278
Author(s):  
Sanlong Jiang ◽  
Shaobo Li ◽  
Qiang Bai ◽  
Jing Yang ◽  
Yanming Miao ◽  
...  
Keyword(s):  
Field Of View ◽  
Convolution Kernel ◽  
Parallel Connection ◽  
Multi Scale ◽  
Spatial Pyramid Pooling ◽  
The Stability ◽  
Parameter Values ◽  
Filter Layer ◽  
Complex Dataset ◽  
Better Than

A reasonable grasping strategy is a prerequisite for the successful grasping of a target, and it is also a basic condition for the wide application of robots. Presently, mainstream grippers on the market are divided into two-finger grippers and three-finger grippers. According to human grasping experience, the stability of three-finger grippers is much better than that of two-finger grippers. Therefore, this paper’s focus is on the three-finger grasping strategy generation method based on the DeepLab V3+ algorithm. DeepLab V3+ uses the atrous convolution kernel and the atrous spatial pyramid pooling (ASPP) architecture based on atrous convolution. The atrous convolution kernel can adjust the field-of-view of the filter layer by changing the convolution rate. In addition, ASPP can effectively capture multi-scale information, based on the parallel connection of multiple convolution rates of atrous convolutional layers, so that the model performs better on multi-scale objects. The article innovatively uses the DeepLab V3+ algorithm to generate the grasp strategy of a target and optimizes the atrous convolution parameter values of ASPP. This study used the Cornell Grasp dataset to train and verify the model. At the same time, a smaller and more complex dataset of 60 was produced according to the actual situation. Upon testing, good experimental results were obtained.

scholarly journals Pulsar science with the CHIME telescope

2017 ◽  
Vol 13 (S337) ◽  
pp. 179-182 ◽  
Author(s):  
Cherry Ng
Keyword(s):  
Northern Hemisphere ◽  
Radio Telescope ◽  
Field Of View ◽  
Radio Bursts ◽  
Radio Telescopes ◽  
Acoustic Oscillations ◽  
Daily Monitoring ◽  
Intensity Mapping ◽  
Pulsar Timing ◽  
Pulsar Timing Array

AbstractThe CHIME telescope (the Canadian Hydrogen Intensity Mapping Experiment) recently built in Penticton, Canada, is currently being commissioned. Originally designed as a cosmology experiment, it was soon recognized that CHIME has the potential to simultaneously serve as an incredibly useful radio telescope for pulsar science. CHIME operates across a wide bandwidth of 400–800 MHz and will have a collecting area and sensitivity comparable to that of the 100-m class radio telescopes. CHIME has a huge field of view of ~250 square degrees. It will be capable of observing 10 pulsars simultaneously, 24-hours per day, every day, while still accomplishing its missions to study Baryon Acoustic Oscillations and Fast Radio Bursts. It will carry out daily monitoring of roughly half of all pulsars in the northern hemisphere, including all NANOGrav pulsars employed in the Pulsar Timing Array project. It will cycle through all pulsars in the northern hemisphere with a range of cadence of no more than 10 days.

scholarly journals In-Situ LED-Based Observation of Snow Surface and Depth Transects

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2292
Author(s):  
Celeste Barnes ◽  
Chris Hopkinson ◽  
Thomas Porter ◽  
Zhouxin Xi
Keyword(s):  
Snow Depth ◽  
Surface Albedo ◽  
Surface Condition ◽  
Field Of View ◽  
Snow Surface ◽  
Depth Measurement ◽  
Individual Distance ◽  
Strong Linear Relationship ◽  
Better Than

As part of a new snowpack monitoring framework, this study evaluated the feasibility of using an LED LIDAR (Leddar) time of flight sensor for snowpack depth measurement. The Leddar sensor has two additional features over simple sonic ranging sensors: (i) the return signal is divided into 16 segments across a 48° field of view, each recording individual distance-to-target (DTT) measurements; (ii) an index of reflectance or intensity signal is recorded for each segment. These two features provide information describing snowpack morphology and surface condition. The accuracy of Leddar sensor DTT measurements for snow depth monitoring was found to be < 20 mm, which was better than the 50 mm quoted by the manufacturer, and the precision was < 5 mm. Leddar and independent sonic ranger snow depth measurement showed strong linear agreement (r2 = 0.98). There was also a strong linear relationship (r2 = 0.98) between Leddar and manual field snow depth measurements. The intensity signal response was found to correlate with snow surface albedo and inversely with air temperature (r = 0.77 and −0.77, respectively).

scholarly journals The Baseline Metrology System of the USNO Astrometric Interferometer

1994 ◽  
Vol 158 ◽  
pp. 174-176 ◽  
Author(s):  
Nicholas M. Elias ◽  
Donald J. Hutter
Keyword(s):  
High Resolution ◽  
Northern Hemisphere ◽  
Three Dimensional ◽  
Optical Interferometer ◽  
Laser Metrology ◽  
Under Construction ◽  
Metrology System ◽  
Better Than

The USNO Astrometric Interferometer (USNOAI; a subarray of the Navy Prototype Optical Interferometer at Lowell Observatory) is presently under construction and expected to begin limited operations within a year. The main goal of the USNOAI observations is to provide a northern hemisphere catalog of several thousand stars with positions known to a few mas. In order to meet this requirement, a baseline laser metrology system must be employed to measure the three-dimensional motions of the baselines with an accuracy better than ~ 0.1 μm. The metrology scheme, as presently conceived, represents the largest and most complex high-resolution laser metrology system ever attempted.

scholarly journals Stellar Photometry with the Optical Monitors

1993 ◽  
Vol 136 ◽  
pp. 358-363
Author(s):  
E. Antonello ◽  
M. Cropper
Keyword(s):  
Field Of View ◽  
Scientific Applications ◽  
X Ray ◽  
Stellar Photometry ◽  
Optical Telescopes ◽  
Better Than

AbstractThe Optical Monitors are small optical telescopes which will fly on board of the X-ray satellites SPECTRUM-X-GAMMA (JET-X experiment) and XMM. Their main scientific applications are the simultaneous observations (imaging) in the optical and UV band of the optical counterparts of X-ray sources, with limiting magnitudes of about mv=22 (JET-X) and 24 (XMM). The OMs are developed in order to perform also serendipitous observations with high photometric precision of bright stars falling in the field of view, which should allow the detection of stellar microvariability at a level better than 10−5. The main characteristics of the instruments are presented and the problems to be solved in order to reach the scientific goals are briefly discussed.

scholarly journals New about the little-known and missing works of Oleksandr Murashko: the attribution of portraits of the German consul Erich Hering’s wife, artist A. Babenko, Tetiana Yashvil, Lidia Murashko, paintings "Evening"

2020 ◽  
pp. 69-81
Author(s):  
Daria Dobriian
Keyword(s):  
20Th Century ◽  
Primary Source ◽  
Art Museum ◽  
Field Of View ◽  
Primary Sources ◽  
Early 20Th Century ◽  
Black And White ◽  
Artistic Works

The author attempts to attribute the lesser-known artistic works by Oleksandr Murashko (1875–1919). Some of them were considered lost, e.g. the images of Tetiana Jashvil or Lidia Murashko. Others, including a portrait of the German consul Erich Hering’s wife, as well as a portrait of the artist A. Babenko (Murashko’s pupil) and the painting "Evening", can still appear in the field of view of researchers. The author describes primary sources that allowed her to carry out the attribution, and details that suggested the correct way for the scientific search. A number of iconic paintings by Oleksandr Murashko are known only from some black-and-white or colour reproductions. First and foremost, we are talking about such works of the artist as "Merry-go-round", "Sunday" (1909), "On terrace", "Over the old pond", which trails were lost in the early 20th century. The author already touched upon the question of these paintings’ fate (except for "Merry-go-round"). Nevertheless for a deeper understanding of the artist's work, it is necessary to explore the lesser-known, even lost pieces. The primary source for studying the heritage of the artist are listings of his works, that were compiled around 1919 by Marharyta Murashko. Despite the fact that they contain many inaccuracies and errors, the value of these listings cannot be overemphasized. Inter alia, there are works, which locations are unknown by far. But the idea of some of them can be formed from photos from the documentary and archival trust of the National Art Museum of Ukraine. Some researchers have managed to establish the names of many persons portrayed by Murashko, but there is a need to make further researches in this field. The attribution of each painting proves that even a limited amount of sources can give us an idea of the appearance of lost works, regardless the fact that not all of them were reproduced on the pages of printed publications or as photographs. At the same time, the assessment of various sources allows us to attribute the little-known portraits, because the names of many depicted persons remain unknown. But with each passing year it becomes more complex to set them.

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