A survey of solar absorptance and thermal emittance instrumentation at Goddard Space Flight Center
Optical and thermal method of measuring solar absorptance and thermal emittance
THERMAL EMISSION↗
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Results for “space instrumentation”
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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Study of ground-based and space vehicle infrared instrumentation for thermal photography of the moon and planets, including experimental programs at selected observatories Final report, 1 Jan. 1960 - 30 Jun. 1968
Data reduction of lunar photography and infrared measurements
Ingrao, H. C.↗
Institute of Electrical and Electronics Engineers, Nuclear Science Symposium, 18th, and Nuclear Power Systems Symposium, 3rd, San Francisco, Calif., November 3-5, 1971, Proceedings.
Potential advantages of fusion power reactors are discussed together with the protection of the public from radioactivity produced in nuclear power reactors, and the significance of tritium releases to the environment. Other subjects considered are biomedical instrumentation, radiation damage problems, low level environmental radionuclide analysis systems, nuclear techniques in environmental research, nuclear instrumentation, and space and plasma instrumentation. Individual items are abstracted in this issue.
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Magnetic bearings for instruments in the space environment
A magnetic bearing development is documented, which has been successfully applied to support a 0.9 kg - 19 cm diameter rotor in 5 degrees of freedom, with fully controlled drive capability to plus or minus 200 rad/s in the other axis. The construction details are described and illustrated. Performance data on five design variations are presented which extend the load capacity to 8 kilograms at which point the bearing element on the rotor is less than one-half of 1 percent of the total load capacity.
Studer, P. A.↗
Nuclear Science Symposium, 25th, and Symposium on Nuclear Power Systems, 10th, Washington, D.C., October 18-20, 1978, Proceedings
Detectors of various types are discussed, taking into account drift chambers, calorimetry, multiwire proportional chambers, signal processing, the use of semiconductors, and photo/optical applications. Circuits are considered along with instrumentation for space, nuclear medicine instrumentation, data acquisition and systems, environmental instrumentation, reactor instrumentation, and nuclear power systems. Attention is given to a new approach to high accuracy gaseous detectors, the current status of electron mobility and free-ion yield in high mobility liquids, a digital drift chamber digitizer system, the stability of oxides in high purity germanium, the quadrant photomultiplier, and the theory of imaging with a very limited number of projections.
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A flexible CAMAC based data system for Space Shuttle scientific instruments
An effort has been made within NASA to produce a low-cost modular system for implementation of Shuttle payloads based on the CAMAC standards for packaging and data transfer. A key element of such a modular system is a means for controlling the data system, collecting and processing the data for transmission to the ground, and issuing commands to the instrument either from the ground or based on the data collected. A description is presented of such a means based on a network of digital processors and CAMAC crate controllers, which allows for the implementation of instruments ranging from those requiring only a single CAMAC crate of functional modules and no data processing to ones requiring multiple crates and multiple data processors.
Ehrmann, C. H.↗
Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 6
Research concerning the utilization of silicon piezoresistive strain sensing technology for space shuttle main engine applications is reported. The following specific topics were addressed: (1) transducer design and materials, (2) silicon piezoresistor characterization at cryogenic temperatures, (3) chip mounting characterization, and (4) frequency response optimization.
Anderson, P. J.↗
Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5
The advantages of silicon piezoresistive strain sensing technology are being used to achieve the objectives of state of the art pressure sensors for SSME applications. The integration of multiple functions on a single chip is the key attribute being exploited. Progress is reported in transducer packaging and materials; silicon resistor characterization at cryogenic temperatures; chip mounting; and frequency response optimization.
Anderson, P. J.↗
Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5
The objective of the research project described is to define and demonstrate methods to advance the state of the art of pressure sensors for the space shuttle main engine (SSME). Silicon piezoresistive technology was utilized in completing tasks: generation and testing of three transducer design concepts for solid state applications; silicon resistor characterization at cryogenic temperatures; experimental chip mounting characterization; frequency response optimization and prototype design and fabrication. Excellent silicon sensor performance was demonstrated at liquid nitrogen temperature. A silicon resistor ion implant dose was customized for SSME temperature requirements. A basic acoustic modeling software program was developed as a design tool to evaluate frequency response characteristics.
Anderson, P. J.↗
Research pressure instrumentation for NASA Space Shuttle main engine
The development of prototype pressure transducers which are targeted to meet the Space Shuttle Main Engine SSME performance design goals is discussed. The fabrication, testing and delivery of 10 prototype units is examined. Silicon piezoresistive strain sensing technology is used to achieve the objectives of advanced state-of-the-art pressure sensors in terms of reliability, accuracy and ease of manufacture. Integration of multiple functions on a single chip is the key attribute of this technology.
Anderson, P. J.↗
A prototype combinatorial scheduler for space-borne observational instruments
A prototype scheduler has been developed for observations to be carried out by the NASA Gamma Ray Observatory. The purpose of the scheduling system is to provide an automated method to determine optimized schedules conforming to all scheduling guidelines. Strategies used in creating COMPTEL/EGRET schedules and in scheduling OSSE targets are examined. It is concluded that the hybrid scheduler creates optimal schedules, or very nearly optimal schedules, and reduces the estimated scheduling time by 18 or 19 orders of magnitude, from about 10 to the 14th years to as few as 561 seconds.
Gilstrap, Lewey O.↗
The SOHO space satellite - UV instrumentation
The UV and EUV instruments designed for the ESA/NASA Solar and Heliospheric Observatory (SOHO) are described, and their characteristics are presented. The SOHO instruments include the SUMER telescope for measuring line profiles and images in the wavelength range 500-1600 A, with a 1.5-arcsec resolution; the Coronal Diagnostics Spectrometer for measuring line ratios and images in the range 170-800 A, with a 2 arcsec resolution; a EUV imaging telescope for producing narrow band pass images in the spectral lines at 171 A, 195 A, 195 A, 284 A, and 304 A, with a 3-arcsec resolution; a UV coronagraph spectrometer for measuring line profiles and images of EUV lines from about 500 A to about 1200 A, with a several arcsec rosolution; and the SWAN, a lens with hydrogen absorption cell for measuring Ly-alpha profiles in the far corona and heliosphere.
Poland, Arthur I.↗
Bidirectional MeV/n ion intervals - Observations from the Goddard Space Flight Center instruments on the ISEE 3/ICE, IMP 8, Helios 1 and Helios 2 spacecraft
A search is made for intervals of bidirectional energetic ion streaming in approximately 1 MeV data from the instruments on ISEE 3/ICE, IMP 8 and Helios 1 and 2 during 1973 to 1989. The longest duration intervals are found around solar maximum, consistent with the expected association with coronal mass ejections. The ISEE 3/ICE intervals are associated with previously identified bidirectional 35-1000 keV ions and solar-wind electron heat fluxes, though additional bidirectional intervals are found.
Richardson, I. G.↗
Perspective on the National Aero-space Plane program instrumentation development
Development of advanced measurement technology for the NASP program is reviewed. The technical need and the program commitment are discussed which are required to ensure that adequate and timely measurement capabilities are provided for ground and flight testing in the NASP program. Particular attention is given to an assessment of the current development status and a perspective on the features of the NASP program that contributed to the current state of instrumentation technology readiness.
Bogue, Rodney K.↗
Perspective on the National Aero-Space Plane Program instrumentation development
A review of the requirement for, and development of, advanced measurement technology for the National Aerospace Plane program is presented. The objective is to discuss the technical need and the program commitment required to ensure that adequate and timely measurement capabilities are provided for ground and flight testing in the NASP program. The scope of the measurement problem is presented, the measurement process is described, how instrumentation technology development has been affected by NASP program evolution is examined, the national effort to define measurement requirements and assess the adequacy of current technology to support the NASP program is discussed, and the measurement requirements are summarized. The unique features of the NASP program that complicate the understanding of requirements and the development of viable solutions are illustrated.
Bogue, Rodney K.↗
Research on the Problem of High-Precision Deployment for Large-Aperture Space-Based Science Instruments
The present paper summarizes results from an ongoing research program conducted jointly by the University of Colorado and NASA Langley Research Center since 1994. This program has resulted in general guidelines for the design of high-precision deployment mechanisms, and tests of prototype deployable structures incorporating these mechanisms have shown microdynamically stable behavior (i.e., dimensional stability to parts per million). These advancements have resulted from the identification of numerous heretofore unknown microdynamic and micromechanical response phenomena, and the development of new test techniques and instrumentation systems to interrogate these phenomena. In addition, recent tests have begun to interrogate nanomechanical response of materials and joints and have been used to develop an understanding of nonlinear nanodynamic behavior in microdynamically stable structures. The ultimate goal of these efforts is to enable nano-precision active control of micro-precision deployable structures (i.e., active control to a resolution of parts per billion).
Lake, Mark S.↗
A Conceptual Approach to Assimilating Remote Sensing Data to Improve Soil Moisture Profile Estimates in a Surface Flux/Hydrology Model: Overview - Part 1
Knowledge of the amount of water in the soil is of great importance to many earth science disciplines. Soil moisture is a key variable in controlling the exchange of water and energy between the land surface and the atmosphere. Thus, soil moisture information is valuable in a wide range of applications including weather and climate, runoff potential and flood control, early warning of droughts, irrigation, crop yield forecasting, soil erosion, reservoir management, geotechnical engineering, and water quality. Despite the importance of soil moisture information, widespread and continuous measurements of soil moisture are not possible today. Although many earth surface conditions can be measured from satellites, we still cannot adequately measure soil moisture from space. Research in soil moisture remote sensing began in the mid 1970s shortly after the surge in satellite development. Recent advances in remote sensing have shown that soil moisture can be measured, at least qualitatively, by several methods. Quantitative measurements of moisture in the soil surface layer have been most successful using both passive and active microwave remote sensing, although complications arise from surface roughness and vegetation type and density. Early attempts to measure soil moisture from space-borne microwave instruments were hindered by what is now considered sub-optimal wavelengths (shorter than 5 cm) and the coarse spatial resolution of the measurements. L-band frequencies between 1 and 3 GHz (10-30 cm) have been deemed optimal for detection of soil moisture in the upper few centimeters of soil. The Electronically Steered Thinned Array Radiometer (ESTAR), an aircraft-based instrument operating a 1,4 GHz, has shown great promise for soil moisture determination. Initiatives are underway to develop a similar instrument for space. Existing space-borne synthetic aperture radars (SARS) operating at C- and L-band have also shown some potential to detect surface wetness. The advantage of radar is its much higher resolution than passive microwave systems, but it is currently hampered by surface roughness effects and the lack of a good algorithm based on a single frequency and single polarization. In addition, its repeat frequency is generally low (about 40 days). In the meantime, two new radiometers offer some hope for remote sensing of soil moisture from space. The Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), launched in November 1997, possesses a 10.65 GHz channel and the Advanced Microwave Scanning Radiometer (AMSR) on both the ADEOS-11 and Earth Observing System AM-1 platforms to be launched in 1999 possesses a 6.9 GHz channel. Aside from issues about interference from vegetation, the coarse resolution of these data will provide considerable challenges pertaining to their application. The resolution of TMI is about 45 km and that of AMSR is about 70 km. These resolutions are grossly inconsistent with the scale of soil moisture processes and the spatial variability of factors that control soil moisture. Scale disparities such as these are forcing us to rethink how we assimilate data of various scales in hydrologic models. Of particular interest is how to assimilate soil moisture data by reconciling the scale disparity between what we can expect from present and future remote sensing measurements of soil moisture and modeling soil moisture processes. It is because of this disparity between the resolution of space-based sensors and the scale of data needed for capturing the spatial variability of soil moisture and related properties that remote sensing of soil moisture has not met with more widespread success. Within a single footprint of current sensors at the wavelengths optimal for this application, in most cases there is enormous heterogeneity in soil moisture created by differences in landcover, soils and topography, as well as variability in antecedent precipitation. It is difficult to interpret the meaning of 'mean' soil moisture under such conditions and even more difficult to apply such a value. Because of the non-linear relationships between near-surface soil moisture and other variables of interest, such as surface energy fluxes and runoff, mean soil moisture has little applicability at such large scales. It is for these reasons that the use of remote sensing in conjunction with a hydrologic model appears to be of benefit in capturing the complete spatial and temporal structure of soil moisture. This paper is Part I of a four-part series describing a method for intermittently assimilating remotely-sensed soil moisture information to improve performance of a distributed land surface hydrology model. The method, summarized in section II, involves the following components, each of which is detailed in the indicated section of the paper or subsequent papers in this series: Forward radiative transfer model methods (section II and Part IV); Use of a Kalman filter to assimilate remotely-sensed soil moisture estimates with the model profile (section II and Part IV); Application of a soil hydrology model to capture the continuous evolution of the soil moisture profile within and below the root zone (section III); Statistical aggregation techniques (section IV and Part II); Disaggregation techniques using a neural network approach (section IV and Part III); and Maximum likelihood and Bayesian algorithms for inversely solving for the soil moisture profile in the upper few cm (Part IV).
Crosson, William L.↗
The Runaway Greenhouse Effect on Earth and other Planets
Water vapor is an efficient absorber of outgoing longwave infrared radiation on Earth and is the primary greenhouse gas. Since evaporation increases with increasing sea surface temperature, and the increase in water vapor further increases greenhouse warming, there is a positive feedback. The runaway greenhouse effect occurs if this feedback continues unchecked until all the water has left the surface and enters the atmosphere. For Mars and the Earth the runaway greenhouse was halted when water vapor became saturated with respect to ice or liquid water respectively. However, Venus is considered to be an example of a planet where the runaway greenhouse effect did occur, and it has been speculated that if the solar luminosity were to increase above a certain limit, it would also occur on the Earth. Satellite data acquired during the Earth Radiation Budget Experiment (ERBE) under clear sky conditions shows that as the sea surface temperature (SST) increases, the rate of outgoing infrared radiation at the top of the atmosphere also increases, as expected. Over the pacific warm pool where the SST exceeds 300 K the outgoing radiation emitted to space actually decreases with increasing SST, leading to a potentially unstable system. This behavior is a signature of the runaway greenhouse effect on Earth. However, the SST never exceeds 303K, thus the system has a natural cap which stops the runaway. According to Stefan-Boltzmann's law the amount of heat energy radiated by the Earth's surface is proportional to (T(sup 4)). However, if the planet has a substantial atmosphere, it can absorb all infrared radiation from the lower surface before the radiation penetrates into outer space. Thus, an instrument in space looking at the planet does not detect radiation from the surface. The radiation it sees comes from some level higher up. For the earth#s atmosphere the effective temperature (T(sub e)) has a value of 255 K corresponding to the middle troposphere, above most of the water vapor and clouds. "Additional information is contained in the original extended abstract."
Rabbette, Maura↗