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We have developed a precise airborne temperature-sensing technology to detect buried objects for use by law enforcement. Demonstrations have imaged the sites of buried foundations, walls and trenches; mapped underground waterways and aquifers; and been used to locate underground military objects. Our patented methodology is incorporated in a commercially available, high signal-to-noise, dual-band infrared scanner with real-time, 12-bit digital image processing software and display. Our method creates color-coded images based on surface temperature variations of 0.2°C. Unlike other less-sensitive methods, it maps true (corrected) temperatures by removing the (decoupled) surface emissivity mask equivalent to 1°C or 2°C; this mask hinders interpretation of apparent (blackbody) temperatures. Once removed, we are able to identify surface temperature patterns from small diffusivity changes at buried object sites which heat and cool differently from their surroundings. Objects made of different materials and buried at different depths are identified by their unique spectral, spatial, thermal, temporal, emissivity and diffusivity signatures. We have successfully located the sites of buried (inert) simulated land mines 0.1 to 0.2 m deep; sodcovered rock pathways alongside dry ditches, deeper than 0.2 m; pavement covered burial trenches and cemetery structures as deep as 0.8 m; and aquifers more than 6 m and less than 60 m deep. Our technology could be athpted for drug interdiction and pollution control. For the former, we would locate buried tunnels, underground structures built beneath typical surface structures, mof-tops disguised by jungle canopies and covered containers used for contraband. For the latter, we would depict buried waste containers, sludge migration pathways from faulty containers and the juxtaposition of groundwater channels, if present, nearby. Our precise airborne temperature-sensing technology has a promising potential to detect underground epicenters of smuggling and pollution. BACKGROUND AND TECHNICAL APPROACHThe first successful demonstration of the precise temperature survey technology recently adapted for buried land mine detection was for geothermal resource investigations in 1977. Predawn surface temperature patterns were spatially correlated with sub-surface heat flow anomalies, soil moisture differences and variations in solar heat retained by near-surface rock tcroJ2 A 2 square km aquifer was depicted by the corrected thermal imagery. The aquifer was covered by more than 6 m of soil and was less than 60 m deep. See Figure 1 and Figure 2.Other applications of the technology were conducted at the Mercury Nevada Test Site for treaty verification. We investigated the surface temperature signatures near "ground zero" before and after an underground nuclear explosion. Soil "fluffmg" changed the soil thermal diffusivity and consequently the heating and cooling properties of near-surface materials near "ground zero." All else being equal, the ground nearby had a different temperature variation with...

We are investigating a new airborne method for measuring surface temperatures that may be useful for identifying thermal anomalies of geologic origin. From Planck’s equation we derive the valuable approximation that, for small temperature variations, the radiant emittance is proportional to the emissivity times the absolute temperature to the power of (50/wavelength in μm). From this, expressions are obtained for the emitted infrared (ir) radiation measured simultaneously in the 5 and 10 μm bands. Ratios of these expressions are shown to have the following useful properties at 288 K: (a) they are insensitive to surface emissivity variations for vegetated terrain, (b) they vary nearly as the 5th power of the surface temperature, and (c) they distinguish emissivity‐related from temperature‐related effects. We have made preliminary tests of this methodology at a field site in Scipio Center, New York. We have characterized the observed surface temperature variations, the significant effects of soil moisture, and separated out the purely emissivity‐related features of vegetated terrain. Cluster analysis served to divide the ir data into groups that behave similarly as a function of the measured soil moisture. Two such distinct terrain groups were identified at the field site. The ir data were corrected for: (a) natural surface emissivity variations, (b) the intervening atmospheric path, and (c) the reflected sky radiation. The corrected surface temperature data were compared with calculated values computed from a model that simulates the surface temperature, using meteorological, hydrological, topographical, and soil thermal input parameters. The simulated mean surface temperatures, 291.9 K (group 1) and 291.6 K (group 2), differed only by, respectively, 0.0 K and 0.1 K from the measured mean surface temperatures. Our preliminary results suggest the potential for developing a new airborne geophysical method for isolating abnormal heat flows. Weak heat flows, about 10–20 times the terrestrial average, have the effect of raising the surface temperature about 0.1–0.2 K. These temperature anomalies would, with the methodology suggested, appear as a residual difference between the measured (corrected) surface temperature and the simulated surface temperature. Such surface temperature differences appear, from our research, to be measurable by airborne ir scanners when data over surface areas of [Formula: see text] or larger are averaged. Accordingly, our research appears to support the conclusion that surface temperature enhancements of geophysical origin between 0.1 and 0.2 K can be identified using airborne infrared methods.

Total absolute photoabsorption cross sections were measured at 1 keV to 40 keV for Fe, Ni, Sn, Ta, Pt, Au, Pb and U.Overall measurement uncertainties were 3 %, less than 2% of which were statistical.The measurements tested widely -used theoretical and experimental tables.They favored relativistic Hartree -Slater atomic calculations. Agreement with theory was typically 5% or better, except near the absorption edge energy region with EXAFS peaks.The measured peak and valley magnitudes for the solid samples ranged from 0% to 20% (with an average of 10 %) above the atomic calculations for Fe and Ni.Discrepancies with experimental tables, at energies below 6 keV, were 10% to 40 %.Authors of widely -used tables have been fraught with problems where there were few or no prior measurements, only interpolations and theory.The present measurements used samples from a few hundred to a few thousand ug /cm2, such that the mean free path thicknesses, ppx, were 1 and 3 at 1.5 keV.Samples were vapor-deposited q2n, and floated off of, optically flat glass slides. Their weights per unit area, px g /cm , were determined within 2% or 3 %. Thicker samples, of known weights per unit area, were used for the higher energy measurements. The ratio of ppx for thick and thin samples tested px for the thin samples. Back-scattered protons and alpha particles, as well as ion microanalyses, were used to test the samples' purity. Uranium deposits were sandwiched between two beryllium layers to impede surface oxidation.The transmission measurements were taken with a demountable x -ray tube, vacuum crystal monochromator and flow proportional counter, using slits that provided a narrow -beam geometry.Abstract Total absolute photoabsorption cross sections were measured at 1 keV to 40 keV for Fe, Ni, Sn, Ta, Pt, Au, Pb and U. Overall measurement uncertainties were 3%, less than 2% of which were statistical.The measurements tested widely-used theoretical and experimental tables.They favored relativistic Hartree-Slater atomic calculations. Agreement with theory was typically 5% or better, except near the absorption edge energy region with EXAFS peaks. The measured peak and valley magnitudes for the solid samples ranged from 0% to 20% (with an average of 10%) above the atomic calculations for Fe and Ni. Discrepancies with experimental tables, at energies below 6 keV, were 10% to 40%.Authors of widely-used tables have been fraught with problems where there were few or no prior measurements, only interpolations and theory.The present measurements used samples from a few hundred to a few thousand ug/cm, such that the mean free path thicknesses, ypx, were 1 and 3 at 1.5 keV.Samples were vapor-deposited on, and floated off of, optically flat glass slides. Their weights per unit area, px g/cm , were determined within 2% or 3%. Thicker samples, of known weights per unit area, were used for the higher energy measurements. The ratio of ypx for thick and thin samples tested px for the thin samples. Back-scattered protons and alpha particles, as well as ion microa...

The total photoionization cross section for uranium has been calculated in the energy range 60-540 eV using a local-density based random phase approximation (LDRPA). The result is compared t o compilations of experimental photoabsorption data and is found to clear up a number of discrepancies between experiment and other calculations in the region between onset of 5d-and 4f-absorption.