Certain geolocation parameters derived in the early analyses of SCIAMACHY's limb measurements deviated from the expected values. After a corrective action in the ENVISAT flight operation segment concerning state vector parameters the situation improved significantly. However small inconsistencies persisted. These include a still existing bias and a leftright asymmetry in the limb tangent height...

The Virgo and A1795 clusters of galaxies were re-observed by EUVE with in situ background measurements by pointing at small offsets. Earlier, a similar reobservational strategy applied to the cluster A2199 revealed that the background radial profile was consistent with a flat distribution, and therefore the original method of extracting cluster EUV signals by the subtraction of an aymptotically...

This paper presents field trials carried out with a Low Data Rate Location Tracking Ultra Wide Band Impulse radio testbed developed within the project PULSERS. Ranging measurements have been conducted in environments with different propagation conditions: multipath-free (anechoic chamber), Line-of-Sight (LOS) and Non Line-of-Sight (NLOS). Results show very accurate ranging performance (better t...

Routing in ad hoc wireless networks does not simply consist in finding a route with shortest length (as in wired networks with virtually error-free communication links), but it requires the creation of a stable and good quality communication route to avoid any unnecessary packet loss. In this paper,we discuss physical layer-oriented routing in ad hoc wireless networks, and we analyse the potent...

The use of the intensity change and line-of-sight (LOS) change concepts have previously been documented in the openliterature as techniques used by non-imaging infrared (IR) seekers to reject expendable IR countermeasures (IRCM). The purpose of this project was to implement IR counter-countermeasure (IRCCM) algorithms based on target intensity and kinematic behavior for a generic imaging IR (II...

Aiming at intercepting a hypersonic weapon in a hypersonic pursuit-evasion game, this paper presents a fractional calculus guidance algorithm based on a nonlinear proportional and differential guidance law. First, under the premise of without increasing the complexity degree of the guidance system against a hypersonic manoeuvering target, the principle that the differential signal of the line-o...

An effective location algorithm, which considers nonline-of-sight (NLOS) propagation, is presented. By using a new variable to replace the square term, the problem becomes a mathematical programming problem, and then the NLOS propagation’s effect can be evaluated. Compared with other methods, the proposed algorithm has high accuracy.

We investigated the radio propagation characteristics for line-of-sight (LOS) inter-vehicle communication (IVC) at 60 GHz on an actual road with an undulating surface. Radio propagation tests between two moving vehicles were carried out on a test course. From this, it was found that the measured received power on the actual road and the results calculated for a flat road approximately follow lo...

Many wireless sensor networks (WSN) use time of arrival (TOA) based ranging to localize and track the nodes in the network. In non-multipath environments the channel impulse response (CIR) will exhibit a single peak, which corresponds to the direct line-of-sight (LoS) path. In multipath environments, however, the CIR will often contain multiple peaks, and it is not known which peak, if any, is ...