This paper describes the first successful attempt to detect wake vortices axially using an on-board infrared pulsed Doppler LiDAR (Light Detection And Ranging). On-board axial detection is more complex than the classic ground-based tangential approach, because the axial air speed in vortices is low and the atmospheric particle density is reduced, yielding a poorer SNR. To provide meaningful res...

A suite of geometric sensor and platform modeling tools has been developed which have achieved consistent subpixel accuracy in orthorectification experiments. Aircraft platforms in turbulent atmospheric conditions present unique challenges and have required creative modeling approaches. The geometric relationship between an image point and a ground object has been modeled by rigorous photogramm...

The refractive index structure constant (Cn2) is a key parameter used in describing the influence of turbulence on laser transmissions atmosphere. Three different methods for estimating Cn2 were analyzed detail. A new method that uses combination these continuous profiling with both high temporal and spatial resolution proposed demonstrated. Under assumption Kolmogorov “2/3 law”, profile can be...

Spaceborne synthetic aperture radar (SAR) measurements of the Earth's surface depend on electromagnetic waves that are subject to atmospheric path delays, in turn affecting geolocation accuracy. The atmosphere influences radar signal propagation by modifying its velocity and direction, effects which can be modeled. We use TerraSAR-X (TSX) data to investigate improvements in the knowledge of the...

This paper describes a method for the determination of the four grasping points that are necessary to get a force closure grasp for a planar object considering frictionless contacts. The geometric model of the object is assumed to be unknown. The proposed approach starts from the object boundary obtained from the binary digitalization of an object image, and then uses the dual representation of...

PURPOSE To examine the applicability of the recently developed laser Doppler interferometry technique for measuring the axial length of cataract eyes in a realistic clinical situation. To determine the performance of the instrument as a function of cataract grade. To compare the results to those of ultrasound methods. METHODS A total of 196 cataract eyes of 100 patients were examined. The axi...