As an alternative to focusing nanosecond pulses for stand-off LIBS detection of energetic materials, we use self-channeled femtosecond pulses from a Ti:Sapphire laser to produce filaments at 12 meters and create a plasma on copper, graphite and polyisobutylene film. We show the possibilities of this Laser-Induced Breakdown Spectroscopy configuration for thin organic sample detection on a surfac...

Introduction: The elemental composition of rocks and soils is one of the most fundamental types of information needed to understand geologic contexts and to search for likely locations of biological activity. Nearly all methods for determining elemental composition involve in-situ analysis, requiring time-consuming maneuvering of a rover to acquire the desired sample. By contrast, analyses at s...

we investigated the relations among infection intensity of european mistletoe (viscum album l.) with host tree features in nour forest park, located in caspian forests in north of iran. the number of 30 circular plots with an area of 0.1 ha were sampled in all places have an aggregation of infested trees. parameters including dbh, height, distance to stand edge, distance to conspecific tree, ba...

The detection and characterization of energetic materials at distances up to 45 m using stand-off laser induced breakdown spectroscopy (LIBS) has been demonstrated. A field-portable open-path LIB spectrometer working under a coaxial configuration was used. A preliminary study allowed choosing a single-pulse laser source over a double-pulse system as the most suitable source for the stand-off an...

The effect of pressure, stand-off distance and time on the penetration of sandstones by a 0.84 mm. jet of water was investigated. Pressures ranged up to 9000 lb/in 2 (62 MN/M), stand-off distances to 2 in. (5.08 cm) and time from 0.5 to 30 sec. The effect of using a friction reducing agent was determined. The advantages of allowing the spent jet to escape and not interfere with penetration are ...

Abstract Frequency-swept interferometry (FSI) is a powerful ranging method with high precision and immunity to ambient light. However, the stand-off distance of current FSI-based system for noncooperative targets relatively short because weak echo power cannot provide needed signal-to-noise ratio (SNR). Here, we report that combines FSI laser feedback technique. Compared conventional FSI, inter...

We present a pole inspection system for outdoor environments comprising a high-speed camera on a vertical take-off and landing (VTOL) aerial platform. The pole inspection task requires a vehicle to fly close to a structure while maintaining a fixed stand-off distance from it. Typical GPS errors make GPS-based navigation unsuitable for this task however. When flying outdoors a vehicle is also af...