SEARCH · Engineering Papers

Results for “camera response”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3

All sources NASA NTRS DOE OSTI

NASA NTRS1999

The Chandra X-Ray Observatory-Overview and Status

The Chandra X-Ray Observatory was launched early in the morning of 1999, July 23 by the Space Shuttle Columbia. The Shuttle launch was only the first step in placing NASA's latest great observatory into orbit. After release from the cargo bay, the Inertial Upper Stage performed two firings and separated from the observatory as planned. Finally, after five firings of Chandra's own Integral Propulsion System - the last of which took place 15 days after the initial launch - the observatory was placed in its highly elliptical orbit of 140,000 km apogee and 10,000 km perigee. After Observatory activation, the first x-rays focussed by the telescope were observed on 1999, August 12. Beginning with this initial observation one could conclude that the telescope had survived the launch environment and was operating as expected. The month following the opening of the sunshade door was spent adjusting the focus for each set of instrument configurations, determining the optical axis, calibrating the star camera, establishing the relative response functions, determining the energy scale(s), and performing a series of "publicity" images. Each observation proved to be far more revealing than was expected. Preliminary results will be presented and the status of the instrumentation on the observatory will be discussed.

Weisskopf, Martin C.↗

NASA NTRS2000

The Chandra X-Ray Observatory Overview

The Chandra X-Ray Observatory was launched early in the morning of July 23, 1999 by the Space Shuttle Columbia. The Shuttle launch was only the first step in placing NASA's latest great observatory into orbit. After release from the cargo bay, the Inertial Upper Stage performed two firings and separated from the observatory as planned. Finally, after five firings of Chandra's own Integral Propulsion System - the last of which took place 15 days after the initial launch - the observatory was placed in its highly elliptical orbit of 140,000 km apogee and 10,000 km perigee. After Observatory activation, the first x-rays focussed by the telescope were observed on August 12, 1999. Beginning with this initial observation one could conclude that the telescope had survived the launch environment and was operating as expected. The month following the opening of the sunshade door was spent adjusting the focus for each set of instrument configurations, determining the optical axis, calibrating the star camera, establishing the relative response functions, determining the energy scale(s), and performing a series of "publicity" images. Each observation proved to be far more revealing than was expected. Preliminary results will be presented and the status of the instrumentation on the observatory will be discussed.

Weisskopf, Martin C.↗

NASA NTRS2000

The Chandra X-Ray Observatory: An Overview

The Chandra X-Ray Observatory was launched early in the morning of July 23, 1999, by the Space Shuttle Columbia. The Shuttle launch was only the first step in placing NASA's latest great observatory into orbit. After release from the cargo bay, the Inertial Upper Stage performed two firings and separated from the observatory as planned. Finally, after five firings of Chandra's own Integral Propulsion System - the last of which took place 15 days after the initial launch - the observatory was placed in its highly elliptical orbit of 140,000 km apogee and 10,000 km perigee. After Observatory activation, the first x-rays focussed by the telescope were observed on 1999, August 12. Beginning with this initial observation one could conclude that the telescope had survived the launch environment and was operating as expected. The month following the opening of the sunshade door was spent adjusting the focus for each set of instrument configurations, determining the optical axis, calibrating the star camera, establishing the relative response functions, determining the energy scale(s), and performing a series of "publicity" images. Each observation proved to be far more revealing than was expected. Preliminary results will be presented and the status of the instrumentation on the observatory will be discussed.

Weisskopf, Martin C.↗

NASA NTRS2000

The Chandra X-Ray Observatory Overview

The Chandra X-Ray Observatory was launched early in the morning of July 23, 1999 by the Space Shuttle Columbia. The Shuttle launch was only the first step in placing NASA's latest great observatory into orbit. After release from the cargo bay, the Inertial Upper Stage performed two firings and separated from the observatory as planned. Finally, after five firings of Chandra's own Integral Propulsion System - the last of which took place 15 days after the initial launch - the observatory was placed in its highly elliptical orbit of 140,000 km apogee and 10,000 km perigee. After Observatory activation, the first x-rays focused by the telescope were observed on August 12, 1999. Beginning with this initial observation one could conclude that the telescope had survived the launch environment and was operating as expected. The month following the opening of the sunshade door was spent adjusting the focus for each set of instrument configurations, determining the optical axis, calibrating the star camera, establishing the relative response functions, determining the energy scale(s), and performing a series of "publicity" images. Each observation proved to be far more revealing than was expected. Preliminary results will be presented and the status of the instrumentation on the observatory will be discussed.

Weisskopf, Martin C.↗

NASA NTRS2000

In-flight calibration of the EOS/Multi-angle Imaging SpectroRadiometer (MISR)

The Multi-angle Imaging SpectroRadiometer (MISR) is one of five instruments on the EOS/Terra spacecraft. This paper reports on the validation studies, and the post-launch radiometric response of the MISR cameras as determined during the first six months of on-orbit MISR calibration.

MISR↗

NASA NTRS1975

Reconnaissance of marine resources

A test area along the NW Coast of Africa was used during the Skylab mission to study the distribution of temperature and plankton. The S190B Earth Terrain Camera with a spectral film response of 0.4-0.7 micrometers allowed qualitative estimates of the distribution patterns of suspended material. Differentiation between inorganic particles and phytoplankton could be made by comparing the green band and the red band of the S190A Camera System. The pictorial display of data obtained from the S191 scanning radiometer in the 10-11 micrometer atmospheric window allowed a detailed interpretation of the temperature distribution in the area where cold upwelled water reaches the euphotic zone. The comparison between infrared data and the imageries taken simultaneously indicated the origin of the cold water as well as the pathway within the Canary current. A fish survey carried out almost simultaneously in the area, by echosounding, showed high correlation between the position of good fishing grounds and the distribution of plankton as detected by remote sensing detectors on Skylab.

Szekielda, K.-H.↗

NASA NTRS1985

Television camera video level control system

A video level control system is provided which generates a normalized video signal for a camera processing circuit. The video level control system includes a lens iris which provides a controlled light signal to a camera tube. The camera tube converts the light signal provided by the lens iris into electrical signals. A feedback circuit in response to the electrical signals generated by the camera tube, provides feedback signals to the lens iris and the camera tube. This assures that a normalized video signal is provided in a first illumination range. An automatic gain control loop, which is also responsive to the electrical signals generated by the camera tube 4, operates in tandem with the feedback circuit. This assures that the normalized video signal is maintained in a second illumination range.

Kravitz, M.↗

NASA NTRS2009

Commercial Sensor Survey Fiscal Year 2009 master compendium radiation test report

The NASA Electronic Parts and Packaging (NEPP) Program Sensor Technology Commercial Sensor Survey task is geared toward benefiting future NASA space missions with low-cost, short-duty-cycle, visible-wavelength imaging needs. Such applications could include imaging for educational outreach purposes or short surveys of spacecraft, planetary, or lunar surfaces. Under the task, inexpensive, low-power, commercial grade CMOS sensors were surveyed in fiscal year 2007 (FY07), and three sensors were selected and tested for total ionizing dose (TID) and displacement damage dose (DDD) tolerance in fiscal year 2008 (FY08). The selected sensors had to meet selection criteria chosen to support small, low-mass cameras that produce good resolution color images. The commercial CMOS sensors tested under the task in FY08 showed very promising response to typical outreach and survey camera TID and DDD levels. In fiscal year 2009 (FY09), the survey was broadened to include two additional, similar sensor products. This compendium provides results for all radiation testing performed on the Micron and OmniVision sensors that were selected for radiation tolerance testing in FY08 and FY09.

Thorbourn, Dennis O.↗

NASA NTRS2003

Conjugate Auroral Imagery

Conjugate studies of high-latitude geomagnetic activity are central to understanding the (truly) global magnetospheric response to external perturbations, i.e. the solar wind, and the role of the ionosphere in modulating and coupling with the magnetosphere. Interhemispheric asymmetries as manifested in auroral emissions have been observed for over 40 years. Unfortunately, the nature of the problem has limited the type and extent of studies that can be performed to either conjugate ground based observations or comparison of space based images with all-sky cameras. Recently Frank and Sigwarth (2002) published results using unique simultaneous images from Polar of the northern and southern aurora, but these are necessarily limited to the nighttime and at oblique angles. However, conjunctive images made with the cameras from the Polar and IMAGE missions contain simultaneous conjugate images of the large-scale aurora under many and varying conditions. This rich data set provides an opportunity to study interhemispheric auroral asymmetries and investigate their occurrence as a function of solar wind conditions and ionospheric parameters such as conductivity. In order to use images of different scenes from each of these cameras, knowledge of their relative response is required. To that end, this paper will present preliminary results of comparing the images with emphasis on data from the Polar UVI LBH filters and the IMAGE FUV WIC.

Spann, Jim↗

NASA NTRS1999

STS-99 Crew Interviews: Mamoru Mohri

Live footage of a preflight interview with Mission Specialists Mamoru Mohri is seen. The interview addresses many different questions including why Mohri became an astronaut, the events that led to his interest, his career path, and then finally, his selection by NASDA as an astronaut. Other interesting information that this one-on-one interview discusses is the purpose for the Shuttle Radar Topography Mission (SRTM). Specific interest is on the importance of this SRTM flight, the knowledge that we will gain from the 3D topographic map of the Earth, and the reason why this 3D data is being recorded instead of down-linked. The two antennas that will be taking the pictures, the involvement of the National Imagery and Mapping Agency (NIMA), and EARTHCAM, a student-controlled camera on the Endeavour Orbiter, Mohri's responsibility during this 24 hour mission, and his secondary experiments with high definition TV cameras are also discussed.

Source record↗

NASA NTRS2024

Thermal Inspection of Low Emissivity Surfaces Using a Pulsed Light Emitting Diodes (PLED) Heat Source

Thermal inspections of a structure typically utilize a flash or quartz lamp heat source located on the same side of an infrared camera. The heat source provides light energy for heating while the infrared camera measures the surface transient temperature response. The inspection can be difficult for low emissivity surfaces for several reasons. First, the high intensity light can reflect off the surface and cause “burn-in” to the camera’s detector. The “burn-in” can take time for the sensors to recover and potentially damage the detector. Secondly, the heat source after pulsing, has a transient cool down component. The cool down component can be reflected and therefore superimposed over the structure’s thermal response which can cause an error (false defect indications) in the inspection. Lastly, the heat source is spectrally broad and therefore while heating, infrared components of the heat source can produce non-uniformity in the measured temperature field. Typically for the inspection of reflective surfaces, paint or other emissivity enhancing coatings are applied before inspection. In this paper, a pulsed light emitting diodes (PLED) heat source is used. The PLED heat source is spectrally narrow, contained within the visible band, and therefore not detectable by the infrared camera. The PLED heat source is configured to reduce any transient cool down components that could produce false defect indications. The PLED thermal inspections are compared to commercially available flash thermography inspections on unpainted aluminum samples with simulated corrosion and additively manufactured Ti-6AL-4V metal specimens.

thermal nondestructive evaluation↗

NASA NTRS2024

Thermal Inspection of Low Emissivity Surfaces Using a Pulsed Light Emitting Diodes (PLED) Heat Source

thermal nondestructive evaluation↗

NASA NTRS1976

A spectral reflectance estimation technique using multispectral data from the Viking lander camera

A technique is formulated for constructing spectral reflectance curve estimates from multispectral data obtained with the Viking lander camera. The multispectral data are limited to six spectral channels in the wavelength range from 0.4 to 1.1 micrometers and most of these channels exhibit appreciable out-of-band response. The output of each channel is expressed as a linear (integral) function of the (known) solar irradiance, atmospheric transmittance, and camera spectral responsivity and the (unknown) spectral responsivity and the (unknown) spectral reflectance. This produces six equations which are used to determine the coefficients in a representation of the spectral reflectance as a linear combination of known basis functions. Natural cubic spline reflectance estimates are produced for a variety of materials that can be reasonably expected to occur on Mars. In each case the dominant reflectance features are accurately reproduced, but small period features are lost due to the limited number of channels. This technique may be a valuable aid in selecting the number of spectral channels and their responsivity shapes when designing a multispectral imaging system.

Park, S. K.↗

NASA NTRS1984

Image dissector camera system study

Various aspects of a rendezvous and docking system using an image dissector detector as compared to a GaAs detector were discussed. Investigation into a gimbled scanning system is also covered and the measured video response curves from the image dissector camera are presented. Rendezvous will occur at ranges greater than 100 meters. The maximum range considered was 1000 meters. During docking, the range, range-rate, angle, and angle-rate to each reflector on the satellite must be measured. Docking range will be from 3 to 100 meters. The system consists of a CW laser diode transmitter and an image dissector receiver. The transmitter beam is amplitude modulated with three sine wave tones for ranging. The beam is coaxially combined with the receiver beam. Mechanical deflection of the transmitter beam, + or - 10 degrees in both X and Y, can be accomplished before or after it is combined with the receiver beam. The receiver will have a field-of-view (FOV) of 20 degrees and an instantaneous field-of-view (IFOV) of two milliradians (mrad) and will be electronically scanned in the image dissector. The increase in performance obtained from the GaAs photocathode is not needed to meet the present performance requirements.

Howell, L.↗

NASA NTRS2000

The Low Energy Effective Area of the Chandra Low Energy Transmission Grating Spectrograph

The Chandra X-ray Observatory was successfully launched on July 23, 1999, and subsequently began an intensive calibration phase. We present the preliminary results from the in-flight calibration of the low energy response of the High Resolution Camera spectroscopic readout (HRC-S) combined with the Low Energy Transmission Grating (LETG) aboard Chandra. These instruments comprise the Low Energy Transmission Grating Spectrograph (LETGS). For this calibration study, we employ a pure hydrogen non-LTE white dwarf emission model (T = 25000 K and log g = 9.0) for comparison with the Chandra observations of Sirius B. The pre-flight calibration of the LETGS effective area only covered wavelengths shortward of 44 A (E less than 277 eV). Our Sirius B analysis shows that the HRC-S quantum efficiency (QE) model assumed for longer wavelengths leads to an overestimate of the effective area by an average factor of about 1.6. We derive a correction to the low energy HRC-S QE model to match the predicted and observed Sirius B spectra over the wavelength range of 44-185 A. We make an independent test of our results by the comparison of a Chandra LETGS observation of HZ 43 with pure hydrogen model atmosphere predictions and find good agreement.

Pease, D.↗

NASA NTRS2005

Characterization of InGaAs Linear Array for Applications to Remote Sensing

An Indium Gallium Arsenide linear photodiode array in the 1.1-2.5 micron spectral range was characterized. The array has 1024x1 pixels with a 25 micron pitch and was manufactured by Sensors Unlimited, Inc. Characterization and analysis of the electrical and optical properties of a camera system were carried out at room temperature to obtain detector performance parameters. The signal and noise were measured while the array was uniformly illuminated at varying exposure levels. A photon transfer curve was generated by plotting noise as a function of average signal to obtain the camera gain constant. The spectral responsivity was also measured, and the quantum efficiency, read noise and full-well capacity were determined. This paper describes the characterization procedure, analyzes the experimental results, and discusses the applications of the InGaAs linear array to future earth and planetary remote sensing mission.

Garcia, Christopher S.↗

NASA NTRS2014

NASA Tech Briefs, February 2014

Topics include: JWST Integrated Simulation and Test (JIST) Core; Software for Non-Contact Measurement of an Individual's Heart Rate Using a Common Camera; Rapid Infrared Pixel Grating Response Testbed; Temperature Measurement and Stabilization in a Birefringent Whispering Gallery Resonator; JWST IV and V Simulation and Test (JIST) Solid State Recorder (SSR) Simulator; Development of a Precision Thermal Doubler for Deep Space; Improving Friction Stir Welds Using Laser Peening; Methodology of Evaluating Margins of Safety in Critical Brazed Joints; Interactive Inventory Monitoring; Sensor for Spatial Detection of Single-Event Effects in Semiconductor-Based Electronics; Reworked CCGA-624 Interconnect Package Reliability for Extreme Thermal Environments; Current-Controlled Output Driver for Directly Coupled Loads; Bulk Metallic Glasses and Matrix Composites as Spacecraft Shielding; Touch Temperature Coating for Electrical Equipment on Spacecraft; Li-Ion Electrolytes Containing Flame-Retardant Additives; Autonomous Robotic Manipulation (ARM); CARVE Log; Platform Perspective Toolkit; Convex Hull-Based Plume and Anomaly Detection; Pre-Filtration of GOSAT Data Using Only Level 1 Data and an Intelligent Filter to Remove Low Clouds; Affordability Comparison Tool - ACT; "Ascent - Commemorating Shuttle" for iPad; Cassini Mission App; Light-Weight Workflow Engine: A Server for Executing Generic Workflows; Model for System Engineering of the CheMin Instrument; Timeline Central Concepts; Parallel Particle Filter Toolkit; Particle Filter Simulation and Analysis Enabling Non-Traditional Navigation; Quasi-Terminator Orbits for Mapping Small Primitive Bodies; The Subgrid-Scale Scalar Variance Under Supercritical Pressure Conditions; Sliding Gait for ATHLETE Mobility; and Automated Generation of Adaptive Filter Using a Genetic Algorithm and Cyclic Rule Reduction.

Source record↗

NASA NTRS2016

A Comparison of Radiometric Calibration Techniques for Lunar Impact Flashes

Video observations of lunar impact flashes have been made by a number of researchers since the late 1990's and the problem of determination of the impact energies has been approached in different ways (Bellot Rubio, et al., 2000 [1], Bouley, et al., 2012.[2], Suggs, et al. 2014 [3], Rembold and Ryan 2015 [4], Ortiz, et al. 2015 [5]). The wide spectral response of the unfiltered video cameras in use for all published measurements necessitates color correction for the standard filter magnitudes available for the comparison stars. An estimate of the color of the impact flash is also needed to correct it to the chosen passband. Magnitudes corrected to standard filters are then used to determine the luminous energy in the filter passband according to the stellar atmosphere calibrations of Bessell et al., 1998 [6]. Figure 1 illustrates the problem. The camera pass band is the wide black curve and the blue, green, red, and magenta curves show the band passes of the Johnson-Cousins B, V, R, and I filters for which we have calibration star magnitudes. The blackbody curve of an impact flash of temperature 2800K (Nemtchinov, et al., 1998 [7]) is the dashed line. This paper compares the various photometric calibration techniques and how they address the color corrections necessary for the calculation of luminous energy (radiometry) of impact flashes. This issue has significant implications for determination of luminous efficiency, predictions of impact crater sizes for observed flashes, and the flux of meteoroids in the 10s of grams to kilogram size range.

Suggs, R.↗