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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.

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NASA NTRS1977

To perform a gyro test of general relativity in a satellite and develop associated control technology

A satellite configuration having two gyroscopes with axes parallel to the boresight of a telescope and two at right angles to the telescope and approximately parallel and perpendicular to the earth's axis is proposed for measuring geodetic precessions due to the earth's motion about the sun, higher order geodetic terms calculated from the earth's quadrapole mass moment (0.010 arc-sec/year in a 400 nautical mile polar orbit), and deflection by the sun of the starlight signal for the reference telescope. Data from the experiment also contain large periodic signals due to the annual and orbital aberrations of starlight which are useful in providing a built in reference signal of known amplitude for scaling the relativity signals, and should yield a singularly precise measurement of the parallax of the reference star. The development of the gyroscope and its readout system are discussed, as well as signal integration, drag-free control, and attitude control.

Fairbank, W. M.↗

NASA NTRSDate not supplied

Spectrally Dependent Radiometric Measurement Errors Due to Ccd Serial Pixel-to-Pixel Readout Interference in the Ocean Color Instrument of the NASA PACE Mission

The Ocean Color Instrument on NASA’s PACE mission is a 322 887 nm hyperspectral imager with 1 km x 1 km nadir spatial resolution and 5 nm spectral resolution utilizing charge-coupled devices (CCDs) operating in Time Delay Integration (TDI) mode where each TDI column represents a different wavelength in 0.625 nm increments. After TDI, the charge is moved into serial output pixels and read out. The spatial resolution requires an 8.5 MHz readout rate. This only allows 59 ns for the CCD reset and video to be asserted and settled before sampling. The response exhibits serial pixel-to-pixel readout interference due to the lack of full settling. Each serial pixel value has a dependence on the value of the preceding pixel value. This leads to a spectrally dependent radiometric measurement error of up to 0.3 %. We explain the operation of the detection system, the behavior of the interference, and show the resulting measurement error based on data from both ground testing and on-orbit characterization.

Remote Sensing↗

NASA NTRS2024

Spectrally Dependent Radiometric Measurement Errors Due to CCD Serial Pixel-to-Pixel Readout Interference in the Ocean Color Instrument of the NASA PACE Mission

Remote Sensing↗

NASA NTRS1975

Planetary investigation utilizing an imaging spectrometer system based upon charge injection technology

An intrinsic silicon charge injection device (CID) television sensor array has been used in conjunction with a CaMoO4 colinear tunable acousto optic filter, a 61 inch reflector, a sophisticated computer system, and a digital color TV scan converter/computer to produce near IR images of Saturn and Jupiter with 10A spectral resolution and approximately 3 inch spatial resolution. The CID camera has successfully obtained digitized 100 x 100 array images with 5 minutes of exposure time, and slow-scanned readout to a computer. Details of the equipment setup, innovations, problems, experience, data and final equipment performance limits are given.

Wattson, R. B.↗

NASA NTRS1988

Characterization of direct readout Si:Sb and Si:Ga infrared detector arrays for space-based astronomy

Preliminary test results from the evaluation of Si:Sb and Si:Ga 58 x 62-element infrared detector arrays are presented. These devices are being characterized under background conditions and readout rates representative of operation in orbiting, crogenically-cooled infrared observatories. The arrays are hybridized to silicon direct-readout multiplexers which allow random-access and nondestructive readout. Array performance optimization is being conducted with a flexible microcomputer-based drive and readoaut electronics system. Preliminary Si:Sb measurements indicate a sense node capacitance of 0.06 pF, peak (28-micron) responsivity above 3 A/W at 2V bias, read noise of 130 rms e(-), dark current approximately 10 e(-)/s, and a well capacity greater than 10 to the 5th e(-). The limited test data available on the performance of the Si:Ga array are also discussed.

Mckelvey, Mark E.↗

NASA NTRS2020

First Operation of TES Microcalorimeters in Space with the Micro-X Sounding Rocket

Micro-X is a sounding rocket-borne instrument that uses a microcalorimeter array to perform high-resolution X-ray spectroscopy. This instrument flew for the first time on July 22nd, 2018, from the White Sands Missile Range, USA. This flight marks the first successful operation of a transition-edge sensor array and its time-division multiplexing readout system in space. This launch was dedicated to the observation of the supernova remnant Cassiopeia A. A failure in the attitude control system prevented the rocket from pointing and led to no time on target. The onboard calibration source provided X-rays in flight, and it is used to compare detector performance during preflight integration, flight, and after the successful post-flight recovery. This calibration data demonstrate the capabilities of the detector in a space environment as well as its potential for future flight.

TES↗

NASA NTRS2012

Reducing the Read Noise of HAWAII-2RG Detector Systems with Improved Reference Sampling and Subtraction (IRS2)

IRS2 is a Wiener-optimal approach to using all of the reference information that Teledyne's HAWAII-2RG detector arrays provide. Using a new readout pattern, IRS2 regularly interleaves reference pixels with the normal pixels during readout. This differs from conventional clocking, in which the reference pixels are read out infrequently, and only in a few rows and columns around the outside edges of the detector array. During calibration, the data are processed in Fourier space, which is <;:lose to the noise's eigenspace. Using IRS2, we have reduced the read noise of the James Webb Space Telescope Near Infrared Spectrograph by 15% compared to conventional readout. We are attempting to achieve further gains by calibrating out recently recognized non-stationary noise that appears at the frame rate.

Rauscher, Bernard J.↗

NASA NTRS2019

Lynx x-ray microcalorimeter

Lynx is an x-ray telescope, one of four large satellite mission concepts currently being studied by NASA to be a flagship mission. One of Lynx’s three instruments is an imaging spectrometer called the Lynx x-ray microcalorimeter (LXM), an x-ray microcalorimeter behind an x-ray optic with an angular resolution of 0.5 arc sec and ∼2 sq. m of area at 1 keV. The LXM will provide unparalleled diagnostics of distant extended structures and, in particular, will allow the detailed study of the role of cosmic feedback in the evolution of the Universe. We discuss the baseline design of LXM and some parallel approaches for some of the key technologies. The baseline sensor technology uses transition-edge sensors, but we also consider an alternative approach using metallic magnetic calorimeters. We discuss the requirements for the instrument, the pixel layout, and the baseline readout design, which uses microwave superconducting quantum interference devices and high-electron mobility transistor amplifiers and the cryogenic cooling requirements and strategy for meeting these requirements. For each of these technologies, we discuss the current technology readiness level and our strategy for advancing them to be ready for flight. We also describe the current system design, including the block diagram, and our estimate for the mass, power, and data rate of the instrument.

Simon R. Bandler↗

NASA NTRS2014

Monolayer Graphene Bolometer as a Sensitive Far-IR Detector

In this paper we give a detailed analysis of the expected sensitivity and operating conditions in the power detection mode of a hot-electron bolometer (HEB) made from a few micro m(sup 2) of monolayer graphene (MLG) flake which can be embedded into either a planar antenna or waveguide circuit via NbN (or NbTiN) superconducting contacts with critical temperature approx. 14 K. Recent data on the strength of the electron-phonon coupling are used in the present analysis and the contribution of the readout noise to the Noise Equivalent Power (NEP) is explicitly computed. The readout scheme utilizes Johnson Noise Thermometry (JNT) allowing for Frequency-Domain Multiplexing (FDM) using narrowband filter coupling of the HEBs. In general, the filter bandwidth and the summing amplifier noise have a significant effect on the overall system sensitivity.

noise thermometry↗

NASA NTRSDate not supplied

Balloon Data Readout via Free-Space Optical Communications

Free-space optical communications is a mature technology, using eye-safe beams and small-terminals, that has the potential to increase balloon data readout rates by orders of magnitude. Large commercial memory buffers paired with incredibly high-rate bursted communications – 100 Gbps has already been demonstrated with higher rates possible with existing commercial technologies – could revolutionize how science missions are designed and run. We will give an overview of the technology, show some examples of how it could already be useful to missions, and propose next steps to make affordable and robust systems be available to the balloon community.

Don Boroson↗

NASA NTRS2004

Readout of DSN Monitor Data

DSN Monitor Data Reader is a computer program that, as its name suggests, reads file of monitor data from the Deep Space Network (DSN). The monitor data constitute information on the status and performance of tracking, telemetry, command, and pointing equipment at the DSN antennas. The DSN has recently introduced a new, more advanced monitor data format, denoted 0158-Mon, that is based on the standard formatted data unit (SFDU) and compressed header data objects (CHDO) of the Consultative Committee for Space Data Systems (CCSDS). The 0158-Mon data format is a very flexible generic format that provides for specific variable-length formats and for self-identifying parameters that obviate the proprietary NASA Communications (NASCOM) bit-packed formats of the past. The monitor data SFDUs are also encapsulated in Standard DSN Blocks and routed to DSN customers for processing at their local mission control centers. This program helps a DSN customer to read and parse the monitor data to assess the statuses of the DSN stations in support of spacecraft flight operations.

Levister, Katherine↗

NASA NTRS1993

A Spatial Analysis and Modeling System (SAMS) for environment management

This is a proposal to develop a uniform global environmental data gathering and distribution system to support the calibration and validation of remotely sensed data. SAMS is based on an enhanced version of FEMA's Integrated Emergency Management Information Systems and the Department of Defense's Air land Battlefield Environment Software Systems. This system consists of state-of-the-art graphics and visualization techniques, simulation models, database management and expert systems for conducting environmental and disaster preparedness studies. This software package will be integrated into various Landsat and UNEP-GRID stations which are planned to become direct readout stations during the EOS (Earth Observing System) timeframe. This system would be implemented as a pilot program to support the Tropical Rainfall Measuring Mission (TRMM). This will be a joint NASA-FEMA-University-Industry project.

Stetina, Fran↗

NASA NTRS1997

Precise Measurements of the Density and Critical Phenomena Near Phase Transitions in Liquid Helium

The first-year progress for the project of precise measurements of the density and critical phenomena of helium near phase transitions is summarized below: (1) completion of a cryogenic sample probe for the proposed measurements, and the rehabilitation of a designated laboratory at Caltech for this project; (2) construction and testing of a superconducting niobium cavity; (3) acquisition of one phase-locked-loop system for high-resolution frequency control and read- out; (4) setting up high-resolution thermometry (HRT) for temperature readout and control; (5) developing new approaches for calibrating the coefficient between the resonant frequency shift (delta f) and the helium density (rho), as well as for measuring the effect of gravity on T(sub lambda) to a much better precision; (6) programming of the interface control of all instruments for automatic data acquisition; and (7) improving data analyses and fitting procedures.

Yeh, Nai-Chang↗

NASA NTRS1992

A Spatial Analysis and Modeling System (SAMS) for environment management

This is a proposal to develop a uniform global environmental data gathering and distribution system to support the calibration and validation of remotely sensed data. SAMS is based on an enhanced version of FE MA's Integrated Emergency Management Information Systems and the Department of Defense's Air Land Battlefield Environment Software Systems. This system consists of state-of-the-art graphics and visualization techniques, simulation models, database management and expert systems for conducting environmental and disaster preparedness studies. This software package will be integrated into various Landsat and UNEP-GRID stations which are planned to become direct readout stations during the EOS timeframe. This system would be implemented as a pilot program to support the Tropical Rainfall Measuring Mission (TRMM). This will be a joint NASA-FEMA-University-Industry project.

Vermillion, Charles H.↗

NASA NTRS2003

Development of a 1K x 1K GaAs QWIP Far IR Imaging Array

In the on-going evolution of GaAs Quantum Well Infrared Photodetectors (QWIPs) we have developed a 1,024 x 1,024 (1K x1K), 8.4-9 microns infrared focal plane array (FPA). This 1 megapixel detector array is a hybrid using the Rockwell TCM 8050 silicon readout integrated circuit (ROIC) bump bonded to a GaAs QWIP array fabricated jointly by engineers at the Goddard Space Flight Center (GSFC) and the Army Research Laboratory (ARL). The finished hybrid is thinned at the Jet Propulsion Lab. Prior to this development the largest format array was a 512 x 640 FPA. We have integrated the 1K x 1K array into an imaging camera system and performed tests over the 40K-90K temperature range achieving BLIP performance at an operating temperature of 76K (f/2 camera system). The GaAs array is relatively easy to fabricate once the superlattice structure of the quantum wells has been defined and grown. The overall arrays costs are currently dominated by the costs associated with the silicon readout since the GaAs array fabrication is based on high yield, well-established GaAs processing capabilities. In this paper we will present the first results of our 1K x 1K QWIP array development including fabrication methodology, test data and our imaging results.

Jhabvala, M.↗

NASA NTRS2010

Algorithms for High-Speed Noninvasive Eye-Tracking System

Two image-data-processing algorithms are essential to the successful operation of a system of electronic hardware and software that noninvasively tracks the direction of a person s gaze in real time. The system was described in High-Speed Noninvasive Eye-Tracking System (NPO-30700) NASA Tech Briefs, Vol. 31, No. 8 (August 2007), page 51. To recapitulate from the cited article: Like prior commercial noninvasive eyetracking systems, this system is based on (1) illumination of an eye by a low-power infrared light-emitting diode (LED); (2) acquisition of video images of the pupil, iris, and cornea in the reflected infrared light; (3) digitization of the images; and (4) processing the digital image data to determine the direction of gaze from the centroids of the pupil and cornea in the images. Most of the prior commercial noninvasive eyetracking systems rely on standard video cameras, which operate at frame rates of about 30 Hz. Such systems are limited to slow, full-frame operation. The video camera in the present system includes a charge-coupled-device (CCD) image detector plus electronic circuitry capable of implementing an advanced control scheme that effects readout from a small region of interest (ROI), or subwindow, of the full image. Inasmuch as the image features of interest (the cornea and pupil) typically occupy a small part of the camera frame, this ROI capability can be exploited to determine the direction of gaze at a high frame rate by reading out from the ROI that contains the cornea and pupil (but not from the rest of the image) repeatedly. One of the present algorithms exploits the ROI capability. The algorithm takes horizontal row slices and takes advantage of the symmetry of the pupil and cornea circles and of the gray-scale contrasts of the pupil and cornea with respect to other parts of the eye. The algorithm determines which horizontal image slices contain the pupil and cornea, and, on each valid slice, the end coordinates of the pupil and cornea. Information from multiple slices is then combined to robustly locate the centroids of the pupil and cornea images. The other of the two present algorithms is a modified version of an older algorithm for estimating the direction of gaze from the centroids of the pupil and cornea. The modification lies in the use of the coordinates of the centroids, rather than differences between the coordinates of the centroids, in a gaze-mapping equation. The equation locates a gaze point, defined as the intersection of the gaze axis with a surface of interest, which is typically a computer display screen (see figure). The expected advantage of the modification is to make the gaze computation less dependent on some simplifying assumptions that are sometimes not accurate

Talukder, Ashit↗

NASA NTRS1993

Research relative to the heavy isotope spectrometer telescope experiment

The Heavy Isotope Spectrometer Telescope (HIST) was launched during August 1978 on ISEE-3 (ICE). HIST was designed to measure the isotopic composition of solar, galactic, and interplanetary cosmic ray nuclei for the elements from H to Ni (1 less than or equal to Z less than or equal to 28) in the energy range from approximately 5 to approximately 200 MeV/nucleon. The results of these measurements have been used in studies of the composition of solar matter and galactic cosmic ray sources, the study of nucleosynthesis processes, studies of particle acceleration and propagation, and studies of the life-history of cosmic rays in the heliosphere and in the galaxy. On December 1, 1978, after 110 days in orbit, HIST suffered an electronic failure in its readout system. After that point, only one-half of the telemetry bits associated with the pulse heights measured by HIST were transmitted to Earth. As a result, the resolution of HIST was significantly degraded, and it served as an element rather than an isotope spectrometer. Fortunately, HIST was able to measure the isotopic composition of heavy nuclei in the 9/23/78 solar event (the largest solar energetic particle event since 1972) during the brief period that it operated at full resolution. This grant funded the analysis of data from the HIST instrument over the period from 12/1/85 to 11/30/92. In section 2 of this final report, we summarize the scientific accomplishments that have resulted from HIST measurements during this time period. A bibliography of tasks and papers that resulted is attached.

Stone, Edward C.↗

NASA NTRS1995

Electronic Ambient-Temperature Recorder

Electronic temperature-recording unit stores data in internal memory for later readout. Records temperatures from minus 40 degrees to plus 60 degrees C at intervals ranging from 1.875 to 15 minutes. With all four data channels operating at 1.875-minute intervals, recorder stores at least 10 days' data. For only one channel at 15-minute intervals, capacity extends to up to 342 days' data. Developed for recording temperatures of instruments and life-science experiments on satellites, space shuttle, and high-altitude aircraft. Adaptable to such terrestrial uses as recording temperatures of perishable goods during transportation and of other systems or processes over long times. Can be placed directly in environment to monitor.

Russell, Larry↗