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Radiation measurements from a ground based polarimeter were used to infer the optical properties of atmospheric particles. The inherent nonunigueness in model calculations is discussed. The inverse problem in atmospheric optics is described, along with incident and emergent beams. Emergent radiation was calculated for all possible particulate distributions, and results were catalogued.
Air radiation measurement from flow fields of high speed bodies
A new airborne radiometric system with a time resolution as high as 60 msec has been designed for measuring radiative fluxes in the atmosphere. To verify the instrument performance, the solar constant at the top of the atmosphere has been calculated using the radiative flux densities measured in the troposphere, and the result obtained has been found to agree with the standard value to within 4%. Total heating rates of 0.175 and 0.377 K/h have been determined for hazy and foggy atmospheres, respectively, and aerosol heating rates of 0.065 and 0.235 K/h have been deduced from the total heating rates.
Thermal radiative property measurements using cyclic radiation
Radiation Portal Monitors (RPMs) have been installed worldwide to scan vehicles and cargo for the presence of radiological and nuclear materials. In field operations, the sensitivity of these systems is typically limited by the relatively high rates of nuisance alarms that usually must be followed up with secondary inspections. We have developed a machine-learning based alarm analysis system that has been deployed at numerous locations in the U.S. and internationally. Our Enhanced Radiological Nuclear Inspection and Evaluation (ERNIE) analysis software and its derivatives have demonstrated increased sensitivity to radiological and nuclear material of concern while reducing nuisance alarms by as much as an order of magnitude.
Multiple wavelength radiation measuring instrument for determining hot body or gas temperature
A series of measured radiated field patterns correlated with defined in-duct conditions is presented, along with a second series of radiation measurements for multiple mode propagation, with individual mode amplitudes and phases at duct termination as well as with angular positions of higher-order stationary duct modes relative to the plane of the radiated field measurement. Though incomplete, these experimental data should prove useful for comparisons with theoretical predictions in testing analytical procedures and prediction techniques.
The real-time measurement of radiation environment was made with an improved real-time radiation monitoring device (RRMD)-II onboard Space Shuttle STS-79 (S/MM#4: 4th Shuttle MIR Mission, at an inclination angle of 51.6 degrees and an altitude of 250-400km) for 199 h during 17-25 September, 1996. The observation of the detector covered the linear energy transfer (LET) range of 3.5-6000 keV/micrometer. The Shuttle orbital profile in this mission was equivalent to that of the currently planned Space Station, and provided an opportunity to investigate variations in count rate and dose equivalent rate depending on altitude, longitude, and latitude in detail. Particle count rate and dose equivalent rate were mapped geographically during the mission. Based on the map of count rate, an analysis was made by dividing whole region into three regions: South Atlantic Anomaly (SAA) region, high latitude region and other regions. The averaged absorbed dose rate during the mission was 39.3 microGy/day for a LET range of 3.5-6000 keV/micrometer. The corresponding average dose equivalent rates during the mission are estimated to be 293 microSv/day with quality factors from International Commission on Radiological Protection (ICRP)-Pub. 60 and 270 microSv/day with quality factors from ICRP-Pub. 26. The effective quality factors for ICRP-Pub. 60 and 26 are 7.45 and 6.88, respectively. From the present data for particles of LET > 3.5keV/micrometer, we conclude that the average dose equivalent rate is dominated by the contribution of galactic cosmic ray (GCR) particles. The dose-detector depth dependence was also investigated.
Gamma radiation measurements of lunar surface by Luna 10
Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed; attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist.
Vacuum UV radiation measurement from high temperature nitrogen, detecting radiation from shock layer of ballistic model
Microwave frequency measurements of radiation temperature of nitrogen afterglow plasma with Maxwellian electron velocity distributions
Vacuum UV radiation measurement from high temperature nitrogen, detecting radiation from shock layer of ballistic model
Earth radiation measurements by meteorological satellites
Solar and sky radiation measurements and analysis for submillimeter-wavelengths under different pathlength and weather conditions
Measurements of the vibrational temperature in a shock layer produced by a cylindrical blunt body in an arc jet nitrogen flow are made for both the neutral molecule and the molecular ion. Spectra were obtained at two locations in the shock layer produced by a 20-cm long cylindrical blunt body inserted in the arc jet conical flow. The technique used for determining the temperatures from the spectral radiation involves obtaining ratios of integrated intensities for certain spectral regions of the measured spectrum and making a comparison with computed ratios as a function of temperature for the same spectral regions. The technique is difficult to apply due to radiation overlapping bands from other species. However, using a trial and error procedure, the vibrational and rotational temperatures at the two locations are inferred. The results indicate that the shock layer is significantly out of thermal equilibrium.
The CMOS Radiation Effects Measurement (CREM) experiment is presently being flown on the Explorer-55, to evaluate device performance in the actual space radiation environment and to correlate the respective measurements to on-the-ground laboratory irradiation results. The experiment contains an assembly of CMOS and P-MOS devices shielded in front over 2 pi steradian by flat slabs of aluminum of 40, 80, 150, and 300 mils (1.02, 2.04, 3.81, and 7.62 mm) thicknesses, and by a practically infinite shield in the back. Initial results from the CREM experiment are reported. Predictions of radiation damage to CMOS devices are based on standard environment models and computational techniques. Measured space damage is smaller than predicted by about a factor of 2-3 for thin shields but agrees well with predictions for thicker shields. It is not clear at this time how the trapped particle environment models or the computational methods should be modified in order to achieve better agreement between experimental results and predicted damage curves.
The CMOS Radiation Effects Measurement (CREM) experiment is presently being flown on the Explorer-55. The purpose of the experiment is to evaluate device performance in the actual space radiation environment and to correlate the respective measurements to on-the-ground laboratory irradiation results. The experiment contains an assembly of C-MOS and P-MOS devices shielded in front by flat slabs of aluminum and by a practically infinite shield in the back. Predictions of radiation damage to C-MOS devices are based on standard environment models and computational techniques. A comparison of the shifts in CMOS threshold potentials, that is, those measured in space to those obtained from the on-the-ground simulation experiment with Co-60, indicates that the measured space damage is smaller than predicted by about a factor of 2-3 for thin shields, but agrees well with predictions for thicker shields.