Discrimination techniques employing both reflective and thermal multispectral signals

Recent improvements in remote sensor technology carry implications for data processing. Multispectral line scanners now exist that can collect data simultaneously and in registration in multiple channels at both reflective and thermal (emissive) wavelengths. Progress in dealing with two resultant recognition processing problems is discussed: (1) More channels mean higher processing costs; to combat these costs, a new and faster procedure for selecting subsets of channels has been developed. (2) Differences between thermal and reflective characteristics influence recognition processing; to illustrate the magnitude of these differences, some explanatory calculations are presented. Also introduced, is a different way to process multispectral scanner data, namely, radiation balance mapping and related procedures. Techniques and potentials are discussed and examples presented

Initial results from the NASA Lewis Bumpy Torus experiment

Initial results were obtained from low power operation of the NASA Lewis Bumpy Torus experiment, in which a steady-state ion heating method based on the modified Penning discharge is applied in a bumpy torus confinement geometry. The magnet facility consists of 12 superconducting coils, each 19 cm i.d. and capable of 3.0 T, equally spaced in a toroidal array 1.52 m in major diameter. A 18 cm i.d. anode ring is located at each of the 12 midplanes and is maintained at high positive potentials by a dc power supply. Initial observations indicate electron temperatures from 10 to 150 eV, and ion kinetic temperatures from 200 eV to 1200 eV. Two modes of operation were observed, which depend on background pressure, and have different radial density profiles. Steady state neutron production was observed. The ion heating process in the bumpy torus appears to parallel closely the mechanism observed when the modified Penning discharge was operated in a simple magnetic mirror field

Characteristics of the NASA Lewis bumpy-torus plasma generated with positive applied potentials

Experimental observations were made during steady-state operation of a bumpy-torus plasma at input powers up to 150 kW in deuterium and helium gas and with positive potentials applied to the midplane electrodes. In this steady-state ion heating method a modified Penning discharge is operated such that the plasma is acted upon by a combination of strong electric and magnetic fields. Experimental investigation of a deuterium plasma revealed electron temperatures from 14 to 140 eV and ion kinetic temperatures from 160 to 1785 eV. At least two distinct modes of operation exist. Experimental data shows that the average ion residence time in the plasma is virtually independent of the magnetic field strength. Data was taken when all 12 anode rings were at high voltage, and in other symmetric configurations in which the toroidal plasma was generated by applying positive potentials to six anode rings, three anode rings, and a single anode ring

Mercator's Southern Continent

The age-old concept that a vast southern landmass must of necessity exist to counterbalance that in the northern hemisphere was given graphic expression by many cartographers, including Ptolemy, Johannes Schoener and Oronce Fine, but undoubtedly the most famous one is that depicted by Gerard Mercator

Review of Rainer Daehnhardt, George Collingridge & Richard H. Major, 'Segredos da descoberta da Australia pelos portugueses'. Sintra (Portugal): Zefiro, 2009

This is the latest book claiming that the Portuguese discovered Australia. Belief in the validity of the claim appears to be contagious, despite the lack of any reliable evidence to support it

Evaluation of algorithms for estimating wheat acreage from multispectral scanner data

The author has identified the following significant results. Fourteen different classification algorithms were tested for their ability to estimate the proportion of wheat in an area. For some algorithms, accuracy of classification in field centers was observed. The data base consisted of ground truth and LANDSAT data from 55 sections (1 x 1 mile) from five LACIE intensive test sites in Kansas and Texas. Signatures obtained from training fields selected at random from the ground truth were generally representative of the data distribution patterns. LIMMIX, an algorithm that chooses a pure signature when the data point is close enough to a signature mean and otherwise chooses the best mixture of a pair of signatures, reduced the average absolute error to 6.1% and the bias to 1.0%. QRULE run with a null test achieved a similar reduction

'Imaginography': Sensational Pseudo-Discoveries

The latter half of the 20th century has witnessed a veritable spate of reports in the press about the finding of historical artifacts concerning whose significance sensational claims have been made

Toponymy and the History of Cartography

Within the last few years historians of cartography have become increasingly aware of the potential value of toponymy for the elucidation of early cartographical enigmas. One of the most notorious of these is the real identity of the apparent continent of Jave-la-Grande which figures exclusively on a number of French manuscript maps made in Dieppe in the mid-sixteenth century. Its position south of Java gave rise to the understandable supposition that it was an inaccurate, primitive map of Australia, since Australia is the only landmass that really does exist very approximately in that position. The east coast of Jave-la-Grande, though vaguely similar to Australia's east coast, has one feature which conspicuously fails to correspond to any on Australia's east coast, namely the huge triangular projection of cap de fremose. Only the most vivid imagination can find any resemblance whatsoever between the two west coasts

Enigmatic Indian Ocean Coastlines on Early Maps and Charts

Maps by early non-Iberian cartographers tended to rely heavily on Ptolemy's hopelessly inaccurate maps, and on a literal acceptance of Marco Polo's unreliable, second-hand writings. The identification of dubious, frequently imaginary coastlines on such maps is thus usually based on guesswork, or wishful thinking. Only critical examination of the inscriptions can provide reliable identifications. Maps of the Indian Ocean improved as Portuguese charts slowly supplanted Ptolemaic and Poloesque information

An Elizabethan Pilot's Charts (1594): Spanish Intelligence Regarding the Coasts of England and Wales at the End of the Sixteenth Century

Four manuscript charts of British ports, and notes on them, were made in the 1590s by an English Catholic pilot, N. Lambert. They were sent to Don Juan de Idiaquez, Philip II's secretary, through the mediation of an English Jesuit exile, Robert Persons (or Parsons). Lambert also offered to pilot Spanish ships and guide Spanish troops in raids on the coasts of England and Wales, and prepared a list of appropriate targets. Being some of the earliest charts of the ports concerned, and hitherto unpublished, they are here presented with relevant background material