Currently, the precise point positioning (PPP) technique is a well-established GNSS processing method for postprocessing applications, while real-time PPP is still a field of ongoing research. Meanwhile a new RTCM (Radio Technical Commission for Maritime Services) standard for exchanging PPP corrections has been released. This so-called state space representation (SSR) contains orbit and clock ...

Precise point positioning with ambiguity resolution (PPP-AR) is a powerful tool for geodetic and time-constrained applications that require high precision. The performance of PPP-AR highly depends on the reliability correct integer carrier-phase estimation. In this study, narrow-lane PPP using Least-squares AMBiguity Decorrelation (LAMBDA) bootstrapping methods extensively investigated real dat...

This paper investigates the role of the central nucleus of the barn owl's inferior colliculus in determination of the soundsource azimuth. The central nucleus contains many neurons that are sensitive to interaural time difference (ITD), the cue for azimuth in the barn owl. The response of these neurons varies in a cyclic manner with the ITD of a tone or noise burst. Response maxima recur at int...

In wave-type weakly electric fish, two distinct types of primary afferent fibers are specialized for separately encoding modulations in the amplitude and phase (timing) of electrosensory stimuli. Time-coding afferents phase lock to periodic stimuli and respond to changes in stimulus phase with shifts in spike timing. Amplitude-coding afferents fire sporadically to periodic stimuli. Their probab...

In this contribution, optimal ionosphere-free combinations for a modernized triple-frequency global positioning system ~GPS! are derived. It is shown that these ionosphere-free combinations are directly related to the model based on carrier phase observations only, in which the ionospheric delays are estimated. For this model and thus for the ionosphere-free combinations, integer ambiguity esti...

The purpose of carrier phase ambiguity resolution is to improve upon the precision of the estimated GNSS baseline by means of the integer ambiguity constraints. There exists a whole class of integer ambiguity estimators from which one can choose. Members from this class are, for instance, integer rounding, integer bootstrapping and integer leastsquares. In this review paper we will present the ...

We describe a method that combines phase-shifting and coherence-peak-sensing techniques to permit measurements with the height resolution of phase-shifting interferometry without the interval-slope limitation of lambda/4 per data sample of phase-shifting interferometry. A five-frame algorithm is used to determine both the best-focus frame position and the fractional phase from the best-focus fr...

A new two-dimensional blind channel estimation scheme for coherent detection of OFDM signals in a mobile environment is presented. The channel estimation is based on the A Posteriori Probability (APP) calculation algorithm. The time-variant channel transfer function is completely recovered without phase ambiguity with no need for any pilot or reference symbols. The two-dimensional channel estim...