Joint Soil Moisture Experiment (JSME) scatterometer systems
Specifications are given for the 400 MHz, the 1.6 GHz, and 13.3 GHz scatterometers used in the Joint Soil Moisture Experiment.
Reid, S. C.↗
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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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Soil moisture detection from radar imagery of the Phoenix, Arizona test site
The Environmental Research Institute of Michigan (ERIM) dual-polarization X and L band radar was flown to acquire radar imagery over the Phoenix (Arizona) test site. The site was covered by a north-south pass and an east-west pass. Radar response to soil moisture was investigated. Since the ERIM radar does not have accurately measured antenna patterns, analysis of the L band data was performed separately for each of several strips along the flight line, each corresponding to a narrow angle of incidence. For the NS pass, good correlation between the radar return and mositure content was observed for each of the two nearest (to nadir) angular ranges. At higher angular ranges, no correlation was observed. The above procedure was not applied to the EW pass due to flight path misalignments. The results obtained stress the importance of radar calibration, the digitization process, and the angle of incidence.
Cihlar, J.↗
Microwave remote sensing of soil moisture
The potential application of microwave remote sensing devices in estimating soil moisture content over extended areas was examined. Experimental measurements involving both active and passive microwave sensors acquired from a variety of platforms are presented.
Ulaby, F. T.↗
Remote sensing of soil moisture
The results of thermal and microwave studies of soil moisture are presented, and the relative advantage of each method is discussed.
Schmugge, T.↗
Soil moisture ground truth: Steamboat Springs, Colorado, site and Walden, Colorado, site
Ground-truth data taken at Steamboat Springs and Walden, Colorado in support of the NASA missions in these areas during the period March 8, 1976 through March 11, 1976 was presented. This includes the following information: snow course data for Steamboat Springs and Walden, snow pit and snow quality data for Steamboat Springs, and soil moisture report.
Jones, E. B.↗
Sasaki's variational optimization analysis of temperature and moisture advection in a severe storm environment
Temperature and moisture advection patterns of dry air intrusion were analyzed by a variational optimization method to relate mesoscale advection to a severe thunderstorm environment. The analysis results presented here were obtained from a case study, May 26, 1973, when a tornado squall line developed in Oklahoma in conjunction with a clearly delineated dry air intrusion. Observations from the synoptic upper air network were used for inputs of horizontal wind components, potential temperature, and mixing ratio at each 50 mb increment from 950 to 100 mb. An objective analysis was performed to assign values of the variables to grid points of a 15 x 14 horizontal grid with approximate 125 km grid spacing at each pressure level. After the analysis the data fields were smoothed using a variational formalism.
Mcfarland, M. J.↗
Moisture resistant and anti-reflection optical coatings produced by plasma polymerization of organic compounds
The need for protective coatings on critical optical surfaces, such as halide crystal windows or lenses used in spectroscopy, has long been recognized. It has been demonstrated that thin, one micron, organic coatings produced by polymerization of flourinated monomers in low temperature gas discharge (plasma) exhibit very high degrees of moisture resistence, e.g., hundreds of hours protection for cesium iodide vs. minutes before degradation sets in for untreated surfaces. The index of refraction of these coatings is intermediate between that of the halide substrate and air, a condition for anti-reflection, another desirable property of optical coatings. Thus, the organic coatings not only offer protection, but improved transmittance as well. The polymer coating is non-absorbing over the range 0.4 to 40 microns with an exception at 8.0 microns, the expected absorption for C-F bonds.
Hollahan, J. R.↗
Compensating for environmental variability in the thermal inertia approach to remote sensing of soil moisture
A procedure is developed for removing data scatter in the thermal-inertia approach to remote sensing of soil moisture which arises from environmental variability in time and space. It entails the utilization of nearby National Weather Service air temperature measurements to normalize measured diurnal surface temperature variations to what they would have been for a day of standard diurnal air temperature variation, arbitrarily assigned to be 18 C. Tests of the procedure's basic premise on a bare loam soil and a crop of alfalfa indicate it to be conceptually sound. It is possible that the technique could also be useful in other thermal-inertia applications, such as lithographic mapping.
Idso, S. B.↗
Storage Stability and Improvement of Intermediate Moisture Foods, Phase 3
Methods were determined for the improvement of shelf-life stability of intermediate moisture foods (IMF). Microbial challenge studies showed that protection against molds and Staphylococcus aureus could be achieved by a combination of antimicrobial agents, humectants and food acids. Potassium sorbate and propylene glycol gave the best results. It was also confirmed that the maximum in heat resistance shown by vegetative pathogens at intermediate water activities also occurred in a solid food. Glycols and sorbitol both achieve browning inhibition because of their action as a medium for reaction and effect on viscosity of the adsorbed phase. Chemical availability results showed rapid lysine loss before visual discoloration occurred. This is being confirmed with a biological test using Tetrahymena pyriformis W. Accelerated temperature tests show that effectiveness of food antioxidants against rancidity development can be predicted; however, the protection factor changes with temperature. BHA was found to be the best antioxidant for iron catalyzed oxidation.
Labuza, T. P.↗
Storage Stability and Improvement of Intermediate Moisture Foods
Shelf life tests are used to estimate the rate of nonenzymatic browning; however, controlling the reducing sugar levels below 23:1 molar ratio to amines, slows the rate. In addition, liquid glycols surpress browning. The protozoan Tetrahymena pyriformis W can be used to estimate nutrition losses during browning. At high temperatures (80 to 120 C) used in processing intermediate moisture foods (IMF), vitamin C destruction shifts to a zero order mechanism. BHA and BHT are the most effective antioxidants against rancidity. In shelf life testing however, 45 C should be the maximum temperature used. Water binding agents are studied. The five isotherms of thirteen humectants were determined. The results show that neither the method of addition nor sequence of addition affects the a sub u lowering ability of these humectants. Results were used to formulate shelf stable IMF processed cheese foods with at least four months shelf life.
Labuza, T. P.↗
Soil moisture ground truth, Hand County, South Dakota, October 20, 1976
Analyses of soil samples taken at three depths are presented in tables. Data include soil types, temperature, and moisture content.
Jones, E. B.↗
Regenerable device for scrubbing breathable air of CO2 and moisture without special heat exchanger equipment
The device concerns the circulation of cabin air through canisters which absorb and adsorb carbon dioxide, together with excess moisture, and return the scrubbed air to the cabin for recirculation. A coating on an inert substrate in granular form absorbs and adsorbs the impurities at standard temperatures and pressures, but desorbs such impurities at low pressures (vacuum) and standard temperatures. This fact is exploited by making the device in a stack of cells consisting of layers or cells which are isolated from one another flow-wise and are connected to separate manifolds and valving systems into two separate subsets. A first subset may be connected for the flow breathable air therethrough until the polyethyleneimine of its cells is saturated with CO2 and H2O. During the same period the second subset of cells is manifolded to a vacuum source.
Tepper, E. H.↗
Response of graphite/epoxy composites to moisture
Report presents comparative absorption and desorption data obtained from response of graphite epoxy composites to moisture experiments with Fiberite 934, Narmco 5208, and Hexcel F-263 epoxy resin systems in cross-piled collimated laminates containing Thornel-300 graphite fibers.
Powell, H.↗
The effect of moisture on the dynamic thermomechanical properties of a graphite/epoxy composite
A study has been made of the effect of moisture absorption on the dynamic thermomechanical properties of a graphite/epoxy composite recently considered for building primary aircraft structures. Torsional braid analysis (TBA) and thermomechanical analysis (TMA) techniques were used to measure changes in the glass transition temperature (Tg) and the initial softening temperature (heat distortion temperature, HDT) of T-300/5209 graphite/epoxy composites exposed to room temperature water soak.
Sykes, G. F.↗
Measuring moisture in the atmosphere
Report describes instruments for measuring moisture in air by categorizing instruments according to their thermodynamic, hygroscopic, condensation, absorption, diffusion, and optical properties.
Johnson, D. L.↗
Moisture penetration in microcircuit packages
Results of study of hybrid microcircuit packages tested in temperature/humidity environments ranging from 25 C at 98 percent relative humidity (RH) to 85 C at 85 percent RH shows that package susceptibility to moisture is affected more by high temperature than humidity, and room temperature tests are inadequate for testing package seal integrity.
Licari, J. J.↗
High resolution soil moisture radiometer
An electrically scanned pushbroom phased antenna array is described for a microwave radiometer which can provide agriculturally meaningful measurements of soil moisture. The antenna size of 100 meters at 1400 MHz or 230 meters at 611 MHz requires several shuttle launches and orbital assembly. Problems inherent to the size of the structure and specific instrument problems are discussed as well as the preliminary design.
Wilheit, T. T.↗
Studies of vorticity imbalance and stability, moisture budget, atmospheric energetics, and gradients of meteorological parameters during AVE 3
Four diagnostic studies of AVE 3. are presented. AVE 3 represents a high wind speed wintertime situation, while most AVE's analyzed previously represented springtime conditions with rather low wind speeds. The general areas of analysis include the examination of budgets of vorticity, moisture, kinetic energy, and potential energy and a synoptic and statistical study of the horizontal gradients of meteorological parameters. Conclusions are integrated with and compared to those obtained in previously analyzed experiments (mostly springtime weather situations) so as to establish a more definitive understanding of the structure and dynamics of the atmosphere under a wide range of synoptic conditions.
Scoggins, J. R.↗