- health Close
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-19T09:16:09.000Z
Notice to Data Users: The documentation for this data set was provided solely by the Principal Investigator(s) and was not further developed, thoroughly reviewed, or edited by NSIDC. Thus, support for this data set may be limited. This data set contains Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Level-3 daily measurements of surface soil moisture and vegetation/roughness water content interpretive information, as well as brightness temperatures and quality control variables. Ancillary data include time, geolocation, and quality assessment. Input brightness temperature data, corresponding to a 56 km mean spatial resolution, are resampled to a global cylindrical 25 km Equal-Area Scalable Earth Grid (EASE-Grid) cell spacing. Data have been spatially subsetted to the SMEX03 study areas in Alabama, Georgia, and Oklahoma, USA and Brazil. The study period covers 1 April to 31 August 2003 for study areas in the USA and 6 November to 31 December 2003 for the Brazil study area. Total volume for this data set is approximately 70 MB. Data are stored in HDF-EOS format and are available via FTP. These data were collected as part of a validation study for the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 04 May 2002. AMSR-E validation studies linked to SMEX are designed to evaluate the accuracy of AMSR-E soil moisture data. Specific validation objectives include assessing and refining soil moisture algorithm performance; verifying soil moisture estimation accuracy; investigating the effects of vegetation, surface temperature, topography, and soil texture on soil moisture accuracy; and determining the regions that are useful for AMSR-E soil moisture measurements.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:44:06.000Z
Software is an integral part of many complex embedded systems, such as avionics, scientific exploration, and on-board systems. However, poor software reliability is a major impediment to the success of these mission-critical systems. Testing, formal verification, and code synthesis techniques have been proposed to achieve more reliable software, with automated code synthesis being the most promising method. But synthesizing a complex system from scratch is costly. A more practical approach is to synthesize systems from existing components, i.e., component-based system synthesis (CBSS). Existing research in CBSS focuses on synthesizing systems bottom-up, which has severe limitations. We propose to achieve CBSS by combining the top-down and bottom-up approaches. Specifically, we develop techniques to achieve automated system decomposition and semi-automated system architecture synthesis. The IDEAL decomposition technique decomposes a system into ``IDEAL'' units that are mathematically composable and can be developed and evolved independently. Consequently, the technique assures system reliability and enables on-the-fly feature/technology upgrades. The QoS-based architecture synthesis technique seeks to assure system QoS properties by synthesizing an architecture that optimizes QoS objectives. It also facilitates on-board system adaptation due to resource and power constraints. Combined with bottom-up techniques, such as Amphion and pattern-based code synthesis, a dramatic leap in automated CBSS capability can be achieved. The proposed research will lead to sophisticated automation for synthesizing highly reliable, multi-mission capable avionics and exploration systems.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:26:30.000Z
Available digital dosimeters are bulky and unable to provide real-time monitoring of dose for space radiation. The complexity of space-flight design requires reliable, fault-tolerant equipment capable of providing real-time dose readings during a mission, which is not feasible with the existing thermo-luminescent dosimeter (TLD) technology, especially during extravehicular activities (EVA). Real-time monitoring is important for low-Earth orbiting spacecraft and interplanetary space flight to alert the crew when Solar Particle Events (SPE) increase the particle flux of the spacecraft environment. The Phase-II project will design and fabricate a prototype Dosimeter-on-a-Chip (DoseChip) for personal dosimetry comprised of a tissue-equivalent scintillation crystal coupled to a solid-state photomultiplier (SSPM). The ubiquitous nature of CMOS technology provides a standardized development platform, and the ability to integrate the supporting electronics into a miniature, lightweight design. The DoseChip provides a tissue-equivalent response to the relevant energies and types of radiation for low-Earth orbit and interplanetary space flight to the moon or Mars and will be sensitive to the dose rates and particle fluxes of ambient Galactic Cosmic Rays (GCR) to the higher rates of major SPE. The DoseChip will complement the existing Crew Passive Dosimeters by providing real-time dosimetry and as an alarming monitor for SPE.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T04:34:02.000Z
Global Annual PM2.5 Grids from MODIS and MISR Aerosol Optical Depth (AOD) data sets represent a series of annual average grids (2001-2010) of fine particulate matter (solid particles and liquid droplets) that were derived from MODIS and MISR AOD satellite data. Together the grids provide a continuous surface of concentrations in micrograms per cubic meter of particulate matter of 2.5 micrometers or smaller (PM2.5) for health and environmental research. The satellite AOD retrievals were converted to ground-level concentrations based on a conversion factor developed by researchers at Dalhousie University that accounts for spatial and temporal variations in aerosol properties and vertical structure as derived from a global 3-D chemical transport model (GEOS-Chem). The raster grids have a grid cell resolution of 30 arc-minutes (0.5 degree or approximately 50 sq. km at the equator) and cover the world from 70°N to 60°S latitude. The grids were produced by researchers at Battelle Memorial Institute in collaboration with the Center for International Earth Science Information Network/Columbia University under a NASA-ROSES project entitled "Using Satellite Data to Develop Environmental Indicators: An Application of NASA Data Products to Support High Level Decisions for National and International Environmental Protection". Exposure to fine particles is associated with premature death as well as increased morbidity from respiratory and cardiovascular disease, especially in the elderly, young children, and those already suffering from these illnesses. The World Health Organization guideline for PM2.5 average annual exposure is less than or equal to 10.0 micrograms per cubic meter, whereas the US Environmental Protection Agency (EPA) primary standard is less than or equal to 12.0 micrograms per cubic meter. The EPA primary standards are designed to protect public health with an adequate margin of safety.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:38:01.000Z
CU Aerospace proposes the ground test validation of a nanosat primary propulsion subsystem using non-toxic propellant with 3-axis ACS for orbit change and/or de-orbit capability, precision maneuvering, and drag makeup. Our approach, called the CubeSat High Impulse Propulsion System (CHIPS), leverages the existing Micro Propulsion System (MiPS) thruster technology development by our team partner VACCO Industries and enhances it with the CU Aerospace very high efficiency warm gas variant of an innovative resistojet that significantly boosts the performance of standard cold-gas systems. The MiPS system has been tested to 200,000 cycles without any technical issues, demonstrating excellent reliability. The 1.5U CHIPS subsystem, using non-toxic proprietary EP-76 propellant, is a compact thruster system having a total impulse of 602 N-s and a fully throttleable thrust of 50 mN. The subsystem also includes an EP-76 3-axis cold-gas attitude control system. Approximately 25 W of primary power is required from a battery included in the 1.5U package. The value of this technology is that this low cost subsystem demonstration will pioneer a family of nanosat propulsion systems, based upon an innovative warm gas system and propellant, which will become available to the CubeSat and nanosatellite community for a broad range of propulsion needs.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:08:18.000Z
The integrated NASA/DoD electric propulsion objectives are for a specific mass less than 3 kg/kW while demonstrating a throttlable thrust-to-power ratio of 100:1 at a specific impulse of 1,000 sec down to 40:1 at 4,000 sec with an operational lifetime exceeding 20,000 hours. Modern Hall-effect thrusters (HETs) are a proven technology with flight heritage, established manufacturing readiness and testing channels that nearly meet the desired specifications (as shown in Figure 1). However, the major limitation is that HETs fail to achieve all four of objectives simultaneously. This Phase I feasibility study is focused on a proof-of-concept experiment to alleviate the HET dual-mode operational envelope limitation for both high thrust-to-power and high specific impulse. Starfire Industries believes that a &quot;low hanging fruit&quot; modification to HETs exists, and such an improvement would be evolutionary to enable multi-mission EP systems for NASA's Science Mission Directorate and DoD platforms. Towards this end, Starfire has partnered with Aerojet Corporation to rapidly demonstrate feasibility in Phase I through experimental modification to an existing HET system. If results are confirmed, a Phase II design can be driven to yield immediate upgrades for flight-qualified HET systems for near-term payback.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:23:07.000Z
The objective of this proposed effort is to demonstrate the promise of advanced C/SiC and SiC/SiC composites having improved environmental durability and longer life at higher allowable stress levels without using problematic external barrier coatings. Both oxidation inhibited C/SiC and SiC/SiC composite material systems are proposed for this effort on the basis that: (1) C/SiC offers the highest use temperature and lowest cost of all currently available refractory composite systems, and (2) SiC/SiC offers the highest durability and longest life. Each material system offers unique performance/cost benefits and limitations, and each has been identified as a viable candidate for advanced propulsion and thermal protection system component applications. Oxidation resistant C/SiC and SiC/SiC composite plates will be fabricated incorporating a recently developed, 2nd generation oxidation inhibited matrix produced by chemical vapor infiltration (CVI). Test samples from each material system will be prepared and experimentally evaluated in high-temperature tensile stress oxidation environments. The tensile stress rupture results will be compared to "baseline" uninhibited C/SiC and SiC/SiC composites to establish the performance benefits of the proposed approach.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-19T09:17:17.000Z
This data set includes data collected over the Soil Moisture Experiment 2003 (SMEX03) area of northern Alabama, USA between 22 June and 1 July 2003. The parameters measured were plant height, plant stand density, phenology, wet biomass, dry biomass, row spacing, and row direction. Data were collected at crop, pasture, and forested sites. Those sites are part of the Alabama MesoNet (ALMNet), which is run by Alabama A&M University's Center for Hydrology, Soil Climatology and Remote Sensing (HSCaRS). Data are provided in an ASCII text file and a Microsoft Excel spreadsheet, and are available via FTP. These data were collected as part of a validation study for the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 04 May 2002. AMSR-E validation studies linked to SMEX are designed to evaluate the accuracy of AMSR-E soil moisture data. Specific validation objectives include assessing and refining soil moisture algorithm performance; verifying soil moisture estimation accuracy; investigating the effects of vegetation, surface temperature, topography, and soil texture on soil moisture accuracy; and determining the regions that are useful for AMSR-E soil moisture measurements.
Self-Biased Radiation Hardened Ka-Band Circulators for Size, Weight and Power Restricted Long Range Space Applications Projectnasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:38:09.000Z
Ferrite control components including circulators and isolators are fundamental building blocks of Transmit/Receive modules (TRM) utilized in high data rate active space transceivers and transponders for both long-range (LR) and low earth orbit (LEO) systems. These components are utilized to protect high power amplifiers (HPA) during the transmit cycle from destabilizing, and potentially harmful, power reflections from the antenna element. During receive cycle these components are utilized to direct lower power received signals with minimal attenuation to the low noise amplifiers (LNA). As such, performance specifications of these ferrite control components, such as bandwidth, insertion loss, isolation, power handling, temperature stability, radiation hardness, and linearity impose strict limitations on the overall system performance. Over the course of the proposed Ph1 SBIR program self-biased ferrite control components based on highly textured hexagonal ferrite compacts which have the potential to eliminate biasing magnets and significantly reduce the size, cost, and weight of the TRM while concurrently increasing power handling capability, and improving temperature stability and radiation hardness will be investigated. Specifically, a research and development path to realizing high performance self-biased ferrite materials and device designs for operation in space based environments at Ka-band (>27 GHz, 31.5 - 34 GHz targeted) is outlined.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-19T09:16:45.000Z
This data set comprises gravimetric soil moisture and soil bulk density data collected during the Soil Moisture Experiment 2003 (SMEX03), which was conducted during June and July of 2003 in northern Alabama and southern Tennessee, USA. Data were collected at crop, pasture, and forested sites at depths of 0-3 and 3-6 cm. Data are provided in ASCII text and are available via FTP. These data were collected as part of a validation study for the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 04 May 2002. AMSR-E validation studies linked to SMEX are designed to evaluate the accuracy of AMSR-E soil moisture data. Specific validation objectives include assessing and refining soil moisture algorithm performance; verifying soil moisture estimation accuracy; investigating the effects of vegetation, surface temperature, topography, and soil texture on soil moisture accuracy; and determining the regions that are useful for AMSR-E soil moisture measurements.