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Creators/Authors contains: "Harmony, D.W."
  1. This report discusses an automatic target recognition (ATR) algorithm for synthetic aperture radar (SAR) imagery that is based on coherent change detection techniques. The algorithm relies on templates created from training data to identify targets. Objects are identified or rejected as targets by comparing their SAR signatures with templates using the same complex correlation scheme developed for coherent change detection. Preliminary results are presented in addition to future recommendations.
  2. The interaction of a collisionless conduction front with the transition region and chromosphere is investigated in a one-dimensional fluid approach as an explanation of elementary flare bursts in hard X-rays. It is shown that, for finite energy injection times, material boiled off of the chromosphere rises into the corona and eventually quenches the X-ray emission. This provides an acceptable explanation of elementary flare bursts with many testable predictions. Softer (10--20 keV) X-rays should come primarily from near the chromosphere, while harder (90--100 keV) X-rays should come primarily from higher in the corona. Ion heating to 10/sup 8/ K and upwardmore » mass motions to 1000 km s/sup -1/ should be observed. Limitations of the analysis resulting from its fluid character and implications for testable predictions are discussed. It is emphasized that, although the efficiency of this thermal model is only slightly larger than a nonthermal model for an initial density of 2.6 x 10/sup 10/ cm/sup -3/, it is much easier from the point of view of plasma physics to heat a plasma than to accelerate a significant fraction of its electrons.« less
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