Abstract: A computer program product for detecting anomalies from multidimensional data comprises: a) receiving multidimensional data; b) estimating background parameters of a normal compositional model from the multidimensional data; c) estimating abundance values of the normal compositional model from the background parameters and the multidimensional data; d) determining an anomaly detection statistic from the multidimensional data, the background parameters, and abundance values; and e) classifying an observation from the multidimensional data as either a background reference or an anomaly from the anomaly detection statistic.

Abstract: A dual orthogonal inverted L near vertical incidence skywave antenna incls two orthogonal RF loop elements coupled to a ground plane. The first RF loop element is mounted in a first plane and has first feed and ground nodes. The second RF loop element is mounted in a second plane substantially orthogonal to said first plane, and has second feed and ground nodes. The first and second elements are feed from a center feed node and are coupled to the ground plane at different locations. An important performance characteristic of the antenna is that it has no nulls in its azimuth pattern.