Abstract: A vessel load measurement system includes a laser measurement system configured to measure distances and angles by directing a laser of the laser measurement system onto remote laser targets and a controller configured to use the laser measurement system to measure a height of a first laser target placed at a known location on a vessel, obtain pitch and roll measurements of the vessel, and compute at least one vessel corner height based on the measured height of the first laser target at the known location on the vessel, the pitch and roll measurements of the vessel, and known dimensions of the vessel. The first laser target may be part of a jig that can be placed at a known location on the vessel. The jig may include at least one tilt sensor. An additional laser target may be used to measure the water level.

Abstract: The invention relates to an airborne laser scanner configured to be arranged on an aircraft for surveying a target along a flight path, wherein the airborne laser scanner comprises an emitter configured for emitting a plurality of consecutive laser pulses towards the ground surface, at least one optical element configured for deflecting the laser pulses along pulse paths towards the target, a motor configured for moving the optical element to cause a periodically repeating movement of the pulse paths, a receiver configured for receiving the laser pulses backscattered from the target, and a computer configured for controlling the emitter, the motor, and the receiver, determining directions of the pulse paths, and triggering the emitter to emit the laser pulses.

Abstract: A dimension measuring system and method are provided. Two track reference target (TRT) assemblies are positioned at spaced-apart locations on a railroad track's rails. Each of the TRT assemblies has two targets at fixed positions in a plane perpendicular to the rails. For each of the TRT assemblies, at least one of the two targets is positioned at a known and fixed height over one of the rails. A laser-based distance measuring device measures vector distances to the two targets associated with each of the TRT assemblies. The vector distances are processed in combination with the fixed positions to determine an elevation of each of the rails in the plane associated with each of the TRT assemblies.

Abstract: A method and related apparatus for reproducing a periodic signal received over a communication channel, or signal window of a desired profile, wherein the resolution of the reproduced signal or window is not limited by a digital sampling interval. The profile can be selected to match and compensate for known or estimated characteristics of a communication channel. A frequency difference, due to a Doppler frequency shift or other errors between received signals and locally generated signals, is determined in a receiver and utilized to derive a fine code phase measurement that is then usable to generate a succession of magnitudes that reproduce the desired signal or window profile.

Abstract: A GLONASS receiver and a corresponding method for its calibration for more precise carrier phase measurements. The receiver includes a conventional receiver channel (36), having a bandpass filter (40) for establishing the sampling bandwidth prior to digitizing a plurality of received satellite signals, each having a different frequency. The receiver also includes a calibration channel (50) in which multiple satellite signals are bandbass filtered (in filter 58) at a single intermediate frequency, to avoid errors resulting from group delay variation introduced by passing multiple satellite signals through a common bandpass filter. The calibration channel (50) downconverts (56) to the intermediate frequency, bandpass filters (58), and then upconverts (60) again. Each satellite signal in turn is processed in this manner by selecting appropriate difference frequencies for downconversion and upconversion.

Abstract: An improved method and apparatus for effecting code synchronization in a global positioning system receiver is disclosed herein. Within the receiver, digital in-phase (I) and quadrature (Q) samples of a plurality of received pseudorandom noise (PRN) encoded signals are provided to a code synchronization circuit. The code synchronization circuit is designed for coherent-mode operation when the receiver has achieved phase-lock with one of the PRN encoded signals, and operates in a non-coherent mode otherwise.The code synchronization circuit includes an I-channel correlator for producing a coherent-mode discrimination signal by correlating in-phase (I) samples of a first of said PRN encoded signals with a discrimination pattern, wherein the first PRN encoded signal is encoded with a first PRN code.

Abstract: A technique for minimizing or eliminating the effect of multipath signals in a receiver processing pseudorandom (PRN) code signals, such as in a global positioning system (GPS) receiver. The presence of multipath signals adversely affects both code measurements and carrier phase measurements of received PRN signals. One aspect of the invention provides for improved code tracking in the presence of multipath signals, by sampling the received code with a multipath mitigation window (MMW) (FIG. 25D) that results in a code error function (FIG. 25F) that reduces or eliminates the multipath effects. The MMW, which may be any of a number of preferred waveforms (FIGS. 35B-35E), provides a code error function that varies in opposite directions from zero at a desired tracking point (402), but assumes a nearly zero value when the MMW is advanced from the tracking or synchronization point by more than a small fraction of a code chip.

Abstract: An improved method and apparatus for effecting code synchronization in a global positioning system receiver is disclosed herein. Within the receiver, digital in-phase (I) and quadrature (Q) samples of a plurality of received pseudorandom noise (PRN) encoded signals are provided to a code synchronization circuit. The code synchronization circuit is designed for coherent-mode operation when the receiver has achieved phase-lock with one of the PRN encoded signals, and operates in a non-coherent mode otherwise.The code synchronization circuit includes an I-channel correlator for producing a coherent-mode discrimination signal by correlating in-phase (I) samples of a first of said PRN encoded signals with a discrimination pattern, wherein the first PRN encoded signal is encoded with a first PRN code.

Abstract: A technique for minimizing or eliminating the effect of multipath signals in a receiver processing pseudorandom (PRN) code signals, such as in a global positioning system (GPS) receiver. The presence of multipath signals adversely affects both code measurements and carrier phase measurements of received PRN signals. One aspect of the invention provides for improved code tracking in the presence of multipath signals, by sampling the received code with a multipath mitigation window (MMW) (FIG. 25D) that results in a code error function (FIG. 25F) that reduces or eliminates the multipath effects. The MMW, which may be any of a number of preferred waveforms (FIGS. 35B-35E), provides a code error function that varies in opposite directions from zero at a desired tracking point (402), but assumes a nearly zero value when the MMW is advanced from the tracking or synchronization point by more than a small fraction of a code chip.