648 research outputs found
Detection and analysis of single event upsets in noisy digital imagers with small to medium pixels
Camera sensors are shrinking, resulting in more defects seen through image analysis. Due to cosmic radiation, camera experience both permanent defects known as hot pixels and temporal defective spikes which are Single Event Upsets (SEUs). SEUs manifest themselves as temporal random bright areas in sequential dark-frame images that are taken with long exposure times. In the past, it was difficult to separate SEUs from noise in dark-frame images taken with DSLRs at high sensitivity levels (ISO) and cell phone cameras at modest sensitivity levels. However, recent software improvements in this research have enabled the analysis of defect rates in noisy digital imagers – by leveraging local area and pixel address distribution techniques. In addition, multiple experiments were performed to understand the relationship of SEUs and elevation. This study reports data from imagers with pixels ranging from 7 μm (DSLR cameras) down to 1.2 μm (cell phone cameras)
The Auger Engineering Radio Array and multi-hybrid cosmic ray detection
The Auger Engineering Radio Array (AERA) aims at the detection of air showers induced by high-energy cosmic rays. As an extension of the Pierre Auger Observatory, it measures complementary information to the particle detectors, fluorescence telescopes and to the muon scintillators of the Auger Muons and Infill for the Ground Array (AMIGA). AERA is sensitive to all fundamental parameters of an extensive air shower such as the arrival direction, energy and depth of shower maximum. Since the radio emission is induced purely by the electromagnetic component of the shower, in combination with the AMIGA muon counters, AERA is perfect for separate measurements of the electrons and muons in the shower, if combined with a muon counting detector like AMIGA. In addition to the depth of the shower maximum, the ratio of the electron and muon number serves as a measure of the primary particle mass
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Physics of the Cosmos (PCOS) Program Technology Development 2018
We present a final report on our program to raise the Technology Readiness Level (TRL) of enhanced chargecoupleddevice (CCD) detectors capable of meeting the requirements of Xray grating spectrometers (XGS) and widefield Xray imaging instruments for small, medium, and large missions. Because they are made of silicon, all Xray CCDs require blocking filters to prevent corruption of the Xray signal by outofband, mainly optical and nearinfrared (nearIR) radiation. Our primary objective is to demonstrate technology that can replace the fragile, extremely thin, freestanding blocking filter that has been standard practice with a much more robust filter deposited directly on the detector surface. Highperformance, backilluminated CCDs have flown with freestanding filters (e.g., one of our detectors on Suzaku), and other relatively lowperformance CCDs with directly deposited filters have flown (e.g., on the Xray Multimirror MissionNewton, XMMNewton Reflection Grating Spectrometer, RGS). At the inception of our program, a highperformance, backilluminated CCD with a directly deposited filter has not been demonstrated. Our effort will be the first to show such a filter can be deposited on an Xray CCD that meets the requirements of a variety of contemplated future instruments. Our principal results are as follows: i) we have demonstrated a process for direct deposition of aluminum optical blocking filters on backilluminated MIT Lincoln Laboratory CCDs. Filters ranging in thickness from 70 nm to 220 nm exhibit expected bulk visibleband and Xray transmission properties except in a small number (affecting 1% of detector area) of isolated detector pixels ("pinholes"), which show higherthanexpected visibleband transmission; ii) these filters produce no measurable degradation in softXray spectral resolution, demonstrating that direct filter deposition is compatible with the MIT Lincoln Laboratory backillumination process; iii) we have shown that under sufficiently intense visible and nearIR illumination, outofband light can enter the detector through its sidewalls and mounting surfaces, compromising detector performance. This 'sidewall leakage' has been observed, for example, by a previous experiment on the International Space Station during its orbitday operations. We have developed effective countermeasures for this sidewall leakage; iv) we developed an exceptionally productive collaboration with the Regolith Xray Imaging Spectrometer (REXIS) team. REXIS is a student instrument now flying on the Origins Spectral Interpretation Resource Identification Security - Regolith Explorer (OSIRISREx) mission. REXIS students participated in our filter development program, adopted our technology for their flight instrument, and raised the TRL of this technology beyond our initial goals. This Strategic Astrophysics Technology (SAT) project, a collaboration between the MKI and MIT Lincoln Laboratory, began July 1, 2012, and ended on June 30, 2018
Advanced extravehicular activity systems requirements definition study. Phase 2: Extravehicular activity at a lunar base
The focus is on Extravehicular Activity (EVA) systems requirements definition for an advanced space mission: remote-from-main base EVA on the Moon. The lunar environment, biomedical considerations, appropriate hardware design criteria, hardware and interface requirements, and key technical issues for advanced lunar EVA were examined. Six remote EVA scenarios (three nominal operations and three contingency situations) were developed in considerable detail
SETI science working group report
This report covers the initial activities and deliberations of a continuing working group asked to assist the SETI Program Office at NASA. Seven chapters present the group's consensus on objectives, strategies, and plans for instrumental R&D and for a microwave search for extraterrestrial in intelligence (SETI) projected for the end of this decade. Thirteen appendixes reflect the views of their individual authors. Included are discussions of the 8-million-channel spectrum analyzer architecture and the proof-of-concept device under development; signal detection, recognition, and identification on-line in the presence of noise and radio interference; the 1-10 GHz sky survey and the 1-3 GHz targeted search envisaged; and the mutual interests of SETI and radio astronomy. The report ends with a selective, annotated SETI reading list of pro and contra SETI publications
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