87 research outputs found
IUE Data Analysis Software for Personal Computers
This report summarizes the work performed for the program titled, "IUE Data Analysis Software for Personal Computers" awarded under Astrophysics Data Program NRA 92-OSSA-15. The work performed was completed over a 2-year period starting in April 1994. As a result of the project, 450 IDL routines and eight database tables are now available for distribution for Power Macintosh computers and Personal Computers running Windows 3.1
The Mars 2020 Perseverance Rover Mast Camera Zoom (Mastcam-Z) Multispectral, Stereoscopic Imaging Investigation
Mastcam-Z is a multispectral, stereoscopic imaging investigation on the Mars 2020 mission's Perseverance rover. Mastcam-Z consists of a pair of focusable, 4:1 zoomable cameras that provide broadband red/green/blue and narrowband 400-1000 nm color imaging with fields of view from 25.6 degrees x19.2 degrees (26 mm focal length at 283 mu rad/pixel) to 6.2 degrees x4.6 degrees (110 mm focal length at 67.4 mu rad/pixel). The cameras can resolve (>= 5 pixels) similar to 0.7 mm features at 2 m and similar to 3.3 cm features at 100 m distance. Mastcam-Z shares significant heritage with the Mastcam instruments on the Mars Science Laboratory Curiosity rover. Each Mastcam-Z camera consists of zoom, focus, and filter wheel mechanisms and a 1648x1214 pixel charge-coupled device detector and electronics. The two Mastcam-Z cameras are mounted with a 24.4 cm stereo baseline and 2.3 degrees total toe-in on a camera plate similar to 2 m above the surface on the rover's Remote Sensing Mast, which provides azimuth and elevation actuation. A separate digital electronics assembly inside the rover provides power, data processing and storage, and the interface to the rover computer. Primary and secondary Mastcam-Z calibration targets mounted on the rover top deck enable tactical reflectance calibration. Mastcam-Z multispectral, stereo, and panoramic images will be used to provide detailed morphology, topography, and geologic context along the rover's traverse; constrain mineralogic, photometric, and physical properties of surface materials; monitor and characterize atmospheric and astronomical phenomena; and document the rover's sample extraction and caching locations. Mastcam-Z images will also provide key engineering information to support sample selection and other rover driving and tool/instrument operations decisions
Ultraviolet and Multiwavelength Variability of the Blazar 3C 279: Evidence for Thermal Emission
The gamma-ray blazar 3C 279 was monitored on a nearly daily basis with IUE,
ROSAT and EGRET for three weeks between December 1992 and January 1993. During
this period, the blazar was at a historical minimum at all wavelengths. Here we
present the UV data obtained during the above multiwavelength campaign. A
maximum UV variation of ~50% is detected, while during the same period the
X-ray flux varied by no more than 13%. At the lowest UV flux level the average
spectrum in the 1230-2700 A interval is unusually flat for this object
(~1). The flattening could represent the lowest energy tail of the
inverse Compton component responsible for the X-ray emission, or could be due
to the presence of a thermal component at ~20000 K possibly associated with an
accretion disk. The presence of an accretion disk in this blazar object, likely
observable only in very low states and otherwise hidden by the beamed, variable
synchrotron component, would be consistent with the scenario in which the seed
photons for the inverse Compton mechanism producing the gamma-rays are external
to the relativistic jet. We further discuss the long term correlation of the UV
flux with the X-ray and gamma-ray fluxes obtained at various epochs. All UV
archival data are included in the analysis. Both the X- and gamma-ray fluxes
are generally well correlated with the UV flux, approximately with square root
and quadratic dependences, respectively.Comment: 22 pages, Latex, 7 PostScript figures, to appear in The Astrophysical
Journa
Certain subclasses of multivalent functions defined by new multiplier transformations
In the present paper the new multiplier transformations
\mathrm{{\mathcal{J}% }}_{p}^{\delta }(\lambda ,\mu ,l) (\delta ,l\geq
0,\;\lambda \geq \mu \geq 0;\;p\in \mathrm{% }%\mathbb{N} )} of multivalent
functions is defined. Making use of the operator two new subclasses and \textbf{\ }of multivalent analytic
functions are introduced and investigated in the open unit disk. Some
interesting relations and characteristics such as inclusion relationships,
neighborhoods, partial sums, some applications of fractional calculus and
quasi-convolution properties of functions belonging to each of these subclasses
and
are
investigated. Relevant connections of the definitions and results presented in
this paper with those obtained in several earlier works on the subject are also
pointed out
The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in-flight calibration, validation, and data archiving
Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager
The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The cameras contain identical optical assemblies that can range in focal length from 26 mm (25.5∘×19.1∘ FOV) to 110 mm (6.2∘×4.2∘ FOV) and will acquire data at pixel scales of 148-540 μm at a range of 2 m and 7.4-27 cm at 1 km. The cameras are mounted on the rover’s mast with a stereo baseline of 24.3±0.1 cm and a toe-in angle of 1.17±0.03∘ (per camera). Each camera uses a Kodak KAI-2020 CCD with 1600×1200 active pixels and an 8 position filter wheel that contains an IR-cutoff filter for color imaging through the detectors’ Bayer-pattern filters, a neutral density (ND) solar filter for imaging the sun, and 6 narrow-band geology filters (16 total filters). An associated Digital Electronics Assembly provides command data interfaces to the rover, 11-to-8 bit companding, and JPEG compression capabilities. Herein, we describe pre-flight calibration of the Mastcam-Z instrument and characterize its radiometric and geometric behavior. Between April 26thth and May 9thth, 2019, ∼45,000 images were acquired during stand-alone calibration at Malin Space Science Systems (MSSS) in San Diego, CA. Additional data were acquired during Assembly Test and Launch Operations (ATLO) at the Jet Propulsion Laboratory and Kennedy Space Center. Results of the radiometric calibration validate a 5% absolute radiometric accuracy when using camera state parameters investigated during testing. When observing using camera state parameters not interrogated during calibration (e.g., non-canonical zoom positions), we conservatively estimate the absolute uncertainty to be 0.2 design requirement. We discuss lessons learned from calibration and suggest tactical strategies that will optimize the quality of science data acquired during operation at Mars. While most results matched expectations, some surprises were discovered, such as a strong wavelength and temperature dependence on the radiometric coefficients and a scene-dependent dynamic component to the zero-exposure bias frames. Calibration results and derived accuracies were validated using a Geoboard target consisting of well-characterized geologic samples
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