Showing papers by "Geophysical Survey published in 2003"

Preseismic ULF electromagnetic effect from observation at Kamchatka

Abstract: . Some results of ULF magnetic field observation at Karimshino site (Kamchatka, Russia) since June 2000 to September 2001 are presented here. Using case study we have found an effect of suppression of ULF intensity about 2–6 days before rather strong and nearby seismic shocks (magnitude M = 4.0 – 6.2). It is revealed for nighttime and horizontal component of ULF field (G) in the frequency range 0.01 – 0.1 Hz. Then we prove the reliability of the effect by computed correlation between G (or 1/G) and specially calculated seismic indexes Ks for the whole period of observation. Basing on the simple criteria we conclude that reliability of seismo-associated ULF suppression effect is comparable with well-known effect of connection between ULF variation and Kp index of global magnetic activity. It seems the reason of suppression is located at the atmosphere or ionosphere but not in the ground medium.

Ground-penetrating radar as a tool for probing the shallow subsurface of Mars

Abstract: [1] Design and testing of an impulse ground-penetrating radar (GPR) for possible rover deployment on Mars in 2009 is well underway. The GPR has mass, power, volume, and data-rate targets of 0.5 kg, 3 W (peak), 3400 cm3, and 0.3 Mb/d and will possess easily modified bistatic high-frequency (e.g., 500–600 MHz) and monostatic “rat-tail” (e.g., 100 MHz) antennas. The GPR should be capable of measuring in situ radar properties on Mars to depths of up to 10–20 m, thereby helping to constrain near-surface geology and structure. Initial GPR tests at the site of the 2001 FIDO rover field trials near Cronese Lake, California, confirm the value of the instrument in defining local geologic setting and in providing context for data collected using other rover science payload elements. A rover-deployed GPR may enable three-dimensional mapping of local stratigraphy, which in turn can assist in evaluating the history of aqueous activity and the accessibility of near-surface water.

Automatic data capture technology to enhance data collection

Abstract: Method, apparatus and system for determining accurately at least one coordinate of a sensor (or a transducer including a sensor) relative to a predetermined reference location, particularly where the sensor is part of a transducer for ground penetrating radar. A marker detector is positioned in a predetermined relationship with the sensor; a marker is detected with the marker detector and positional information associated with the marker is received, from which a position of the transducer or sensor is determined, based on the received positional information associated with the marker and the predetermined relationship between the marker detector and the sensor. The marker may, for example, be a bar code and the marker detector may be an optical scanner. The sensor may be a receiving antenna for a GPR signal.

Spectral identification tree (SIT) for mineral extraction using AVIRIS data

Abstract: The Spectral Identification Tree (SIT) based on diagnostic absorption spectra of minerals was designed and developed to extract minerals directly. The spectral absorption features of different ions or bonds such as CO32+, Fe2+, Fe3+, Mn2+, Al-Oh and Mg-Oh and so on, of some minerals were summarized. Some spectral identification trees (SIT) and decision rules from various ions to minerals were established using IF-THEN rules which based on some spectral absorption features. Various spectral absorption features which were combine by logistic relationship were used to extract and discriminate different levels’ minerals (e.g. mineral group and mineral) in SIT technique. Information of ions, such as CO32+, Fe2+, Fe3+, Mn2+, Al-OH and Mg-OH, and of some minerals, such as alunite, montmorillonite, muscovite, halloysite, smect-kaolinite and illite were identified and extracted effectively by SIT technique using AVIRIS data at Cuprite, Nevada of USA, which was a test area.