Trimble Navigation Limited

Trimble Inc.

Nicholas C Talbot

Mark Edward Nichols

Michael Timo Allison

James M Janky

Ulrich Vollath

Peter Griffioen

Xiaoming Chen

Some embodiments of the invention relate to methods carried out by an NSS receiver and/or a processing entity capable of receiving data therefrom, for estimating parameters derived from NSS signals useful to determine a position, and for generating protection level(s) for an application relying on NSS observations to produce an estimate of said parameters. A float solution is computed using NSS signals observed by the NSS receiver. A best integer ambiguity combination that minimizes an error norm is identified based on the float solution. Additional integer ambiguity combinations are identified, which have the smallest error norms that, together with the error norm of the best integer ambiguity combination, jointly satisfy the integrity risk. A measure of spread of the best and additional integer ambiguity combinations is computed. The protection level(s) is then generated from the measure of spread. Systems and computer programs are also disclosed. Some embodiments may for example be used for safety-critical applications such as highly-automated driving and autonomous driving.

Protection level generation methods and systems for applications using navigation satellite system (NSS) observations

A method and system for delivery of location-dependent time-specific corrections. In one embodiment, a first extended-lifetime correction for a first region is generated. A distribution timetable is used to determine a first time interval for transmitting the first extended-lifetime correction to the first region. The first extended-lifetime correction is then transmitted via a wireless communication network to said first region in accordance with said distribution timetable.

Method and system for location-dependent time-specific correction data

Apparatus for measuring surveying parameters, such as distances and angular displacements between an instrument survey station and a mobile survey station, with improved accuracy. The invention combines a differential satellite positioning system (DSATPS), available with positioning systems such as GPS and GLONASS, with electromagnetic measurements of distances and optically encoded angles by a conventional electro-optical survey instrument to provide survey measurements that can be accurate to within a few millimeters in favorable situations. The DSATPS relies upon pseudorange measurements or upon carrier phase measurements, after removal of certain phase integer ambiguities associated with carrier phase SATPS signals. The SATPS may be retrofitted within the housing of the conventional electro-optical instrument. In a first approach, a remote station provides DSATPS corrections for the mobile station and/or for the instrument station. In a second approach, the mobile station provides DSATPS corrections for itself and for the instrument station. In a third approach, the instrument station provides DSATPS corrections for itself and for the mobile station.

Integrated SATPS total survey station

A system embodiment of the present invention comprises a fixed and a roving pair of four-observable GPS receivers and a communication link between them for double differencing code and carrier measurements. Carrier phase integer ambiguities are resolved efficiently by searching the simultaneous narrow-lane intersections of both the L1 and L2 wave fronts propagated by the GPS satellites being tracked. External constraint information, such as elevation, is additionally used to speed up integer ambiguity resolution. Data between the reference station and the rover is communicated in compressed form at a regular interval, e.g., once a second at each epoch, and demi-measurements of carrier phase are obtained more frequently, e.g., ten times a second, and used to propagate solutions between epochs.

Centimeter accurate global positioning system receiver for on-the-fly

A guidance system for movable machinery comprising a GPS processor unit in a 'gorilla box' connected to a shock mounted and protected GPS antenna and an operator display with a lightbar that indicates to an operator of the machinery to steer up/down or left/right.

Guidance control system for movable machinery

A real-time kinematic system includes base and rover GPS units connected by a data link. The rover unit is typically moved to points of interest during a survey while the base remains over a fixed, and known location. An initialization testing program of the present invention is mounted on a personal computer platform that forces in the rover a loss of signal tracking, thus simulating losses in signal reception caused by obstructions of the satellite signals. A complete initialization is forced to occur. The test program uninitializes the RTK solution by causing a loss of integer ambiguities resolution by forcing a loss of lock on one or more satellites. The test program then monitors the subsequent initialization process, e.g., the time needed to search for phase ambiguity candidates, discovering the prevalent satellite geometry, determination of whether the correct ambiguity candidate was found, finding the ratio of the second best to best solution variances of the ambiguity candidates in the list throughout the candidate propagation process or similar statistical test, computing the RMS error of the solution at the time that initialization was declared and after initialization, and calculating the baseline vector between the rover and base at the time of initialization and after initialization. All such statistical parameters are logged and used in post and real-time analyses of the initialization algorithm.

Real-time kinematic initialization test system

A surveyor range pole, for example, equipped with a GPS receiver and antenna mounted at the top end, a battery mounted at the bottom end to better balance the pole, a tilt sensor and a direction sensor. The tilt sensor and direction sensor provide information about the vector that lies between the top and the bottom points of the range pole. The GPS receiver computes the position of the top end of the range pole from GPS satellite signals received by the GPS at the top end, and then computes the position of the bottom end of the range pole with the vector information. A variable length, telescoping range pole includes a linear transducer for automatically measuring the overall length of the range pole and contributing that length information to the vector calculation.

Pole-tilt sensor for surveyor range pole

Apparatus for measuring surveying parameters, such as distances and angular displacements between survey stations, with improved accuracy. The invention combines a differential satellite positioning system (SATPS), available with positioning systems such as GPS and GLONASS, with electromagnetic measurements of distances and optically encoded angles by a conventional electro-optical survey instrument to provide survey measurements that can be accurate to within a few millimeters in favorable situations. The differential satellite positioning system relies upon carrier phase measurements, after removal of certain phase integer ambiguities associated with carrier phase SATPS signals. The SATPS may be retrofitted within the housing of the conventional electro-optical instrument.

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Cupertino, CA, United States of America

Nicholas C Talbot