Trimble Inc.

Trimble Navigation Limited

Xiaoming Chen

Ulrich Vollath

Rodrigo Leandro

Ralf Drescher

Kendall Ferguson

Nicholas Charles Talbot

Markus Glocker

Nicholas C Talbot

Stephan Seeger

Nico Reussner

Andrea Nardo

Gang Lu

Kenneth Donald Doucet

Leandro Leandro

Some embodiments of the invention pertain to generating (s) and providing (s) ionospheric disturbance information from navigation satellite system (NSS) reference stations or reference station system to NSS receivers or NSS receiver systems. Station-specific and/or satellite-specific ionospheric disturbance information may be obtained (s) on the receiver side for mitigation purposes (s, s, s) in the context of estimating parameters useful to determine a position. The ionospheric disturbance information may for example comprise ionospheric amplitude scintillation information, ionospheric phase scintillation information, and/or ionospheric delay gradient information. Systems, vehicles, and computer programs are also disclosed.

Ionospheric disturbance information generation methods and systems

Methods and apparatus for processing of GNSS signals are presented. These include GNSS processing with obtaining GNSS data derived from signals received at a rover antenna, obtaining correction data, maintaining a time sequence of at least one rover position and at least one rover position difference with associated time tags, using the time sequence to determine at least one derived rover position by, starting from a position determined using corrections synchronous with rover data as an anchor position at a time tag, deriving a new anchor position for the time tag of the anchor position and at least one other estimated rover position at the time tag of the anchor position, and/or reporting the new anchor position and/or a new derived rover position.

GNSS processing with selecting and/or blending anchor positions

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

The invention relates to a method carried out by a navigation satellite system (NSS) receiver or a processing entity receiving data therefrom, for estimating parameters useful to determine a position. The NSS receiver observes NSS signals from NSS satellites over multiple epochs. A filter, called 'precise estimator', is operated, which uses state variables, makes use of NSS signals observed by the NSS receiver, and computes its state variable values based on observations that are not derived from NSS signals observed by the NSS receiver. Seeding information is obtained, and a constrained solution, called 'seeding- and ambiguity-constrained solution', is computed by constraining the ambiguities of the precise estimator by the seeding information, by resolving the resulting ambiguities, and by constraining at least one of the other state variables of the precise estimator by the resolved ambiguities. A corresponding system is also disclosed.

Advanced navigation satellite system positioning method and system using seeding information

Methods and apparatus for processing of GNSS signals are presented. These include GNSS processing with predicted precise clocks, GNSS processing with mixed-quality data, GNSS processing with time-sequence maintenance, GNSS processing with reduction of position jumps in low-latency solutions, GNSS processing with position blending to bridge reference station changes, and GNSS processing with delta-phase correction for incorrect starting position.

GNSS processing with jump reduction

A correction message for regional GNSS data includes at least one network message and at least one cluster message. The at least one network message relates to stations of a network of stations within a region. The at least one cluster message relates to a subset of stations within the region. Network elements are extracted from the network message and cluster elements are extracted from the cluster message. Network elements and cluster elements are used to determine a position of a rover within the region.

GNSS regional correction data decoding

Some embodiments of the present invention derive an ionospheric phase bias and an ionospheric differential code bias (DCB) using an absolute ionosphere model, which can be estimated from data obtained from a network of reference stations or obtained from an external source such as WAAS, GAIM, IONEX or other. Fully synthetic reference station data is generated using the ionospheric phase bias and/or the differential code bias together with the phase leveled clock and ionospheric-free code bias and/or MW bias.

GNSS signal processing with ionosphere model for synthetic reference data

The invention relates to generating correction information to be used to correct observations coming from a navigation satellite system (NSS) receiver in a region of interest. For each of a plurality of reference stations in said region, raw observations obtained by the reference station observing NSS multiple-frequency signals from a plurality of satellites over multiple epochs are received. Then, precise satellite information on the orbit position, clock offset, and biases of each satellite is obtained. For each reference station, ambiguities in the carrier phase of the received raw observations are estimated, using the precise satellite information and the position coordinates of the reference station. Geometric-free phase linear combination values are then computed based on the received raw observations together with the estimated ambiguities. The correction information is generated based on the computed geometric-free phase linear combination values. The correction information comprises, for each NSS satellite, a regional ionospheric delay function and its coefficients, those representing, per NSS satellite, the ionospheric delay in said region. The correction information is sent, for example to facilitate position determination, to the NSS receiver or to a server in charge of processing observations from the NSS receiver.

Navigation satellite system positioning involving the generation of correction information

The invention relates to generating regional tropospheric correction information for correcting observations useful for estimating phase ambiguities and/or a position of global or regional navigation satellite systems (NSS) receiver(s). For each of a plurality of reference stations, at least one troposphere correction parameter is estimated by evaluating NSS observation equations using i) precise satellite information or the information derived from the precise satellite information, and ii) received multiple-frequency-signals-based raw observations or a linear combination thereof. The regional tropospheric correction information is then generated based on the estimated troposphere correction parameter(s) per reference station, the tropospheric correction information comprising a regional tropospheric delay function(s) and coefficients representing a tropospheric delay affecting a NSS signal passing through the troposphere in a region of interest. The generated tropospheric correction information may then be sent to NSS receiver(s) and used by the receiver(s) for example to facilitate position determination.

Navigation satellite system positioning involving the generation of advanced correction information

The invention relates to methods, apparatuses and computer programs for generating receiver-specific correction information for correcting pseudorange observations. The method comprises: receiving raw observations obtained by the NSS receiver observing NSS multiple frequency signals from a plurality of NSS satellites over multiple epochs; obtaining precise satellite information on: (i) the orbit position of each of the satellites, (ii) a clock offset of each of the satellites, and (iii) a set of biases associated with each of the satellites; estimating ambiguities in the carrier phase of the received raw observations, using the precise satellite information, or information derived therefrom; computing combination values based on the received raw observations together with the estimated ambiguities, to cancel out the effects of the geometry, the effects of the clocks, troposphere and ionosphere; and generating the correction information per satellite, based on the computed combination values.

Navigation satellite system positioning involving the generation of receiver-specific or receiver-type-specific correction information

Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospheric delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections. The correction data comprises at least one code bias per satellite, a fixed-nature MW bias per satellite and/or values from which a fixed-nature MW bias per satellite is derivable, and an ionospheric delay per satellite for each of multiple regional network stations and/or non-ionospheric corrections. Methods and apparatus for encoding and decoding the correction messages containing correction data are also presented, in which network messages include network elements related to substantially all stations of the network and cluster messages include cluster elements related to subsets of the network.

GNSS signal processing with regional augmentation message

Methods and apparatus are described for determining position of a rover antenna, comprising: obtaining rover GNSS data derived from code observations and carrier phase observations of GNSS signals of multiple satellites over multiple epochs, obtaining precise satellite data for the satellites, determining a virtual base station location, generating epochs of synthesized base station data using at least the precise satellite data and the virtual base station location, and applying a differential process to at least the rover GNSS data and the synthesized base station data to determine at least rover antenna positions.

GNSS signal processing with synthesized base station data

GNSS signal processing with delta phase for incorrect starting position

Accuracy information for an ionosphere model is generated. Phase residual information of a parameter estimation procedure is obtained and coordinates of pierce points are computed on a sphere around the earth. The coordinates indicate where signals pierce the sphere. Phase residual information is mapped for each pierce point. A grid of equidistant points is put on the sphere and the pierce points are identified. For each selected grid point, vertical accuracy information is computed based on vertical residual information, and a scale factor is computed based on the vertical accuracy information. The accuracy information for the ionosphere model is generated based on the vertical accuracy information computed for the selected grid points and an overall scale factor computed based on computed scale factors.

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Hoehenkirchen, Germany

Xiaoming Chen