FR3118193A1 - TIMELESS POSITION DETERMINATION OF A ROVING RECEIVER USING A REFERENCE RECEIVER - Google Patents

Abstract

A timeless position determination of a traveling receiver includes acquiring, from a snapshot receiver in a cloud runtime process, a snapshot position of the snapshot receiver received by the receiver snapshot for a single epoch from a constellation of global positioning satellites, the snapshot position comprising a plurality of timeless observables. The method further includes retrieving in the cloud runtime process, base position data for a fixed receiver received from the constellation and including time-referenced observables. Finally, the method includes compositing in the cloud runtime process the timeless observables of the snapshot position with the time-referenced observables of the basic position data to produce time and position data for the snapshot receiver. Figure for abstract: Figure 1

Description

TIMELESS POSITION DETERMINATION OF A ROVING RECEIVER USING A REFERENCE RECEIVER

The present invention relates to the field of real-time kinematic (RTK) position determination in global positioning satellite systems.

RTK positioning is a satellite navigation technique used to improve the accuracy of position data derived from satellite positioning systems known as Global Navigation Satellite Systems (GNSS) and exemplified by Global Positioning System (GPS), the system Global Navigation Satellite (GLONASS), Galileo, NavIC and BeiDou. RTK uses measurements of the carrier wave phase of each satellite signal received in the RTK receiver, in addition to the informational content of the signal, and then relies on a single reference station or interpolated virtual station to provide real-time corrections. The result is usually in the centimeter range.

A traditional RTK receiver receives signals from satellites and also processes them to produce position data. This last exercise dramatically increases the processing resource requirements of the RTK receiver's underlying host compute platform. Of course, increased processing requirements can result in a larger physical footprint, and therefore greater RTK receiver geometry and weight, which limits the usefulness of the RTK receiver in many Internet of Things applications. (IoT) that require a light and small footprint. In addition, a host compute platform capable of providing the necessary processing resources for RTK necessarily consumes more power, which requires a larger power source, for example a battery of large size and weight, which which only compounds the RTK problem for smaller and lighter applications.

RTK receivers typically require near-continuous acquisition of positioning data from a constellation of satellites in order to support real-time positioning of a device. As the RTK receiver in this case receives positioning data over several epochs, there is a lot of data, especially time-based data, to adjust the raw positioning information received from the satellite constellation to precise positioning information. . But the continuous acquisition of positioning data over several epochs is not without consequences either. Specifically, the continuous acquisition of positioning data consumes power, which again prevents miniaturization of the RTK receiver. However, without the acquisition of positioning data over a certain number of epochs, the time-based data will be insufficient to allow a correct adjustment of the raw positioning data collected by the satellite.

Embodiments of the present invention overcome the drawbacks of the technique with respect to RTK positioning and provide a new and unobvious method, system, and computer program product for timeless position determination of a roving receiver at the using a reference receiver. In one embodiment of the invention, a method of timeless position determination of a traveling receiver first includes the step of acquiring from a snapshot receiver in a cloud runtime process , a snapshot position of the snapshot receiver, the snapshot position having been received by the snapshot receiver during a single epoch and the snapshot position having been received from a constellation of global positioning satellites. In this regard, the snapshot position includes a multiplicity of observable elements without time as opposed to observable elements in time.

Thereafter, the method further includes the step of retrieving in the cloud runtime process, base position data for a fixed receiver received from the constellation and including time-referenced observables. Finally, the method includes the step of compositing, in the cloud runtime process, the timeless observable elements of the snapshot position with the time-referenced observable elements of the base position data to produce time and position data for the snapshot receiver. In this way, the signal snapshot received from the satellite constellation in the single-epoch snapshot receiver can be tuned to produce centimeter-level accuracy despite the absence of time-referenced observables in the position. snapshot.

In one aspect of the embodiment, the timeless observables are a set of code range measurements and corresponding carrier phase measurements. In another aspect of the embodiment, the composition includes calculating an integer ambiguity resolution (IAR) for the snapshot position, based on both the code range measurements and the carrier phase measurements of the timeless observables, as well as code range measurements and carrier phase measurements of time-referenced observables. In this regard, timeless observables are pre-processed before IAR by first extrapolating a set of complete pseudo-ranges for the snapshot position using previously acquired time and position data for the snapshot receiver and then pre-aligning each of the carrier phase measurements with integers which correspond to a magnitude of associated code range measurements.

In another aspect of realization, IAR is a three-step process. The three-step process consists of first calculating a floating point solution for the code range measurements and the carrier phase measurements of the non-time observable elements, as well as for the code range measurements and the carrier phase measurements of the timeless elements. time-referenced observables, the float solution being subjected to a double-difference process to produce a double-difference vector. Next, an integer estimate on the double-difference vector to produce an integer vector is performed. Finally, a re-calculation of the floating point solution with the integer vector in order to produce the IAR is performed.

In another embodiment of the invention, a data processing system is adapted for timeless position determination of a traveling receiver using a reference receiver. The system includes a host computing platform that includes one or more computers, each with memory and at least one processor. The host computing platform has a communication coupling in a computer communication network to a snapshot receiver. The snapshot receiver is adapted to receive timeless observables disposed in a snapshot position of the snapshot receiver, the snapshot position having been received by the snapshot receiver for only one epoch and the snapshot position that has been received from a constellation of global positioning satellites. The host computing platform further has a communication coupling on the computer communication network with a fixed receiver adapted to receive base position data for the constellation fixed receiver, the base position data comprising elements time-referenced observables.

Finally, the system includes a timeless position determination module. The module includes computer program instructions activated when running in the host computing platform to acquire the snapshot position of the snapshot receiver. Program instructions are also enabled to retrieve base position data from the fixed receiver. Finally, the program instructions compose the timeless observables of the snapshot position with the time-referenced observables of the basic position data to produce time and position data for the snapshot receiver. .

Other aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and achieved by means of the elements and combinations particularly indicated in the appended claims. It is understood that the foregoing general description and the following detailed description are both exemplary and explanatory and not limiting of the invention as claimed.

The accompanying drawings, which are incorporated into and form part of this description, illustrate representations of the invention and serve, together with the description, to explain the principles of the invention. The embodiments illustrated herein are currently preferred, it being understood, however, that the invention is not limited to the specific arrangements and instruments indicated, in which:

There is an illustration of a timeless position determination process of a traveling receiver using a reference receiver;

There is a schematic diagram showing a calculation architecture for a data processing system suitable for timeless position determination of a traveling receiver using a reference receiver; And,

There is a flowchart illustrating a timeless position determination process of a traveling receiver using a reference receiver.

Embodiments of the invention allow timeless position determination of a roving receiver using a reference receiver. According to one embodiment of the inventive arrangements, on a single epoch, timeless positioning data is received in an RTK snapshot receiver from four or more positioning satellites in a constellation of global positioning satellites. Timeless positioning data includes, by way of example, code range measurements and corresponding carrier phase measurements. Likewise, basic positioning data from a fixed receiver that differs from the RTK snapshot receiver may be received from the same constellation, the basic positioning data including time-referenced observables. Finally, the timeless positioning data of the snapshot position is combined with the time-referenced observables of the base position data to produce time and position data for the snapshot receiver, calculating a resolution integer ambiguity ratio (IAR) for timeless positioning data based on both code range measurements and carrier phase measurements, as well as code range measurements and carrier phase measurements of the referenced observables in time.

Furthermore, the pictorially shows a timeless position determination process of a traveling receiver using a reference receiver. As shown in , a roving station 120A with an RTK snapshot receiver receives a snapshot 140 of a set of timeless observables 160A of carrier phase measurements 170 and code range measurements 180 over a single epoch 150 from four satellites or plus 110 in a GNSS constellation. At the same time, a base station 120B receives observables 160B from satellites 110 of the GNSS constellation, including not only carrier phase measurements 170 and code range measurements 180, but also timing information 190 regarding the transmission carrier phase measurements 170 and code range measurements 180.

Roaming station 120A and base station 120B both provide the respective observables 160A, 160B over the computer communication network 130 to the timeless position determination module 300. The timeless position determination module 300 grants the observables without time 160A carrier phase measurements 170 and code span measurements 180 from snapshot 140 using the time-based observables 160B of carrier phase measurements 170 and code span measurements 180 as well as timing information 190 to produce a 100 centimeter position of roving station 120A. In this way, roving station 120A can be made smaller in size and consume less power to collect snapshot 140 over a single epoch 150 without sacrificing the ability to produce position 100 to the centimeter near roving station 120A.

The process described in relation to the can be implemented in a data processing system. In another illustration, the diagram of the shows a computational architecture for a data processing system suitable for timeless position determination of a traveling receiver using a reference receiver. The system includes a host computing platform which includes a processor 220 and memory 230 and which is coupled (for establishing communications) over a computer communications network 240, both to a snapshot receiver 210A and to a base station 210B, both of which receive positioning data from a constellation of satellites 200. A timeless position determination module 300 runs in memory 230 by processor 220 of the computing platform host.

Timeless position determination module 300 includes computer program instructions operative when executed by processor 220 in memory 230 to produce a centimeter-accurate position of snapshot receiver 210A by tuning snapshot data without received by snapshot receiver 210 from satellite constellation 200 over a single epoch, with the time-based observables received in base station 210B also from satellite constellation 200. In particular, the program instructions allow timeless snapshot data of code span measurements and carrier phase measurements to be preprocessed with an extrapolation of a partial set of code span measurements to a full set of code span measurements, and then align the carrier phase measurements to full wavelengths. Next, the operational program instructions to calculate the IAR for the preprocessed timeless snapshot data from snapshot receiver 210A using the time-based observables from base station 210B. Finally, the calculated IAR is applied to the preprocessed timeless snapshot data to produce the centimeter-precise position of snapshot receiver 210.

To further illustrate the operation of the timeless position determination module 300 program instructions, the is a flowchart illustrating a timeless position determination process of a traveling receiver using a reference receiver. From block 310, a timeless snapshot for a single epoch is received from snapshot receiver 210A. In block 320, code range extrapolation is performed on the fractional code phases of the snapshot. These fractional values are supplemented with full code periods to obtain the distance to the start of the secondary code starting edge. Then, the satellite transmission time can be anchored based on the fact that the GNSS secondary code edges are always aligned with the standard GNSS time. Once the transmission time has been accurately calculated, a common reception time will be established for all the satellites and the complete pseudo-ranges are obtained by multiplying the speed of light and the time difference between transmission and reception of each satellite signal.

Additionally, in block 330, a pre-alignment is performed on the carrier phase measurements of the snapshot. Subsequently, in block 340, the time-based observables are retrieved in conjunction with a base station. These observables include not only code range measurements and carrier phase measurements, but also the corresponding timing information regarding when information is transmitted by the respective satellites in the satellite constellation. The quantities concerned are defined as follows

And

Or : represents the satellite transmission time for a satellite; τ represents the coding phase and N represents the number of complete primary code periods inside the current secondary code, these two values are calculated inside the acquisition module; And represent the primary and secondary code periods of this satellite, respectively; represents the temporal solution calculated from the Coarse-Time filter which is an approximate solution of time and position which is an intermediate product of the timeless position determination module 300, and represents the geometric range of the satellite position and the receiver position solution from the Coarse-Time filter; c represents the speed of light; represents the reception time common to all the satellites and finally P represents the complete pseudo-range for the current satellite.

In a block 350, an IAR is calculated for the extrapolated code range measurements and the pre-aligned phase measurements, based on the base station time-based observables. For example, the IAR can be calculated as a three-step process starting with the calculation of a floating point solution for the code range measurements and the carrier phase measurements of timeless observables, as well as for the range measurements code and carrier phase measurements of time-referenced observables. The float solution can then be subjected to a double-difference process to produce a double-difference vector which, in turn, can be integer estimated to produce an integer vector. Finally, the floating point solution can be recalculated with the entire vector to produce the IAR. Therefore, the snapshot can be tuned with the IAR computed in block 360 to produce a snapshot receiver position with centimeter position accuracy.

The present invention may be embodied in a system, method, computer program, or any combination thereof. The computer program may include a computer-readable storage medium or a medium on which are located computer-readable program instructions to cause a processor to perform aspects of the present invention. The computer-readable storage medium may be a tangible device that can retain and store instructions for use by an instruction executing device. The computer-readable storage medium may be, for example, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. foregoing, but not limited to.

The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium or onto an external computer or external storage device via a network to the respective computing/processing devices. The computer-readable instructions may be executed wholly on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer, and partly on a remote computer or entirely on the remote computer or server. Certain aspects of the present invention are described herein using flow charts and/or block diagrams of methods, apparatus (systems), and computer program products based on embodiments of the invention. It is understood that each block of the flowcharts and/or block diagrams, as well as combinations of blocks of the flowcharts and/or block diagrams, can be realized by means of computer readable program instructions.

These computer readable program instructions may be supplied to a processor of a general purpose computer, special purpose computer or other programmable data processing device to produce a machine, such that the instructions, which are executed through the computer processor or other programmable data processing device, create means to perform the functions/actions specified in the block(s) of the flowcharts and/or block diagrams. These computer-readable program instructions may also be stored in a computer-readable storage medium which may direct a computer, programmable data processing apparatus, and/or other devices to operate in a particular manner, so that the computer-readable storage medium in which instructions are stored comprises an article of manufacture comprising instructions which perform aspects of the functions/actions specified in the block(s) of the flowcharts and/or block diagrams.

The computer-readable program instructions may also be loaded into a computer, other programmable data processing device, or other device to cause a series of operational steps to be performed on the computer, other programmable device, or another device to produce a computer-executed process, such that the instructions that execute on the computer, other programmable device, or other device implement the functions/actions indicated in the block(s) of the flowcharts and/or block diagrams.

The flowchart and block diagrams presented in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products based on the various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment or part of instructions, which includes one or more executable instructions to implement the specified logical function(s). In some alternative implementations, the functions noted in the block may occur in the order shown in the figures. For example, two blocks shown in succession may, in fact, be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order, depending on the functionality involved. It should also be noted that each block of the block diagrams and/or flowcharts, and combinations of blocks of the block diagrams and/or flowcharts, may be implemented by special hardware systems that perform the specified functions or acts or execute combinations of special equipment and computer instructions.

Finally, the terminology used herein is only intended to describe particular embodiments and is not intended to limit the invention. In this document, the singular forms "un/une", and "le/la" are also understood to be plural, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising", when used in this specification, indicate the presence of indicated characteristics, integers, steps, operations, elements and/or components, but do not do not exclude the presence or addition of one or more other characteristics, integers, steps, operations, elements, components and/or groups thereof.

The corresponding structures, materials, acts and equivalents of all means or elements of the step and function in the claims below are intended to include any structure, material or act for performing the function in combination with other claimed items as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The embodiment has been selected and described in order to best explain the principles of the invention and its practical application, and to enable others skilled in the art to understand the invention for various embodiments with various suitable modifications for the particular intended use.

Having thus described the invention of the present application in detail and by reference to its embodiments, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. as following :

Claims (15)

A method of timeless position determination of a traveling receiver using a reference receiver, the method comprising the steps of:
acquiring from a snapshot receiver in a computer communication network in a cloud runtime process, a snapshot position of the snapshot receiver received by the snapshot receiver during a single epoch from a constellation global positioning satellites and comprising a multiplicity of timeless observable elements;
retrieving in the cloud runtime process from the computer communication network, base position data for a fixed receiver received from the constellation and including time-referenced observables;
compose in the cloud runtime process the timeless observables of the snapshot position with the time-referenced observables of the basic position data to produce time and position data for the snapshot receiver . A method according to claim 1, wherein the timeless observables are a set of code span measurements and corresponding carrier phase measurements. The method of claim 2, wherein the composition includes calculating an integer ambiguity resolution (IAR) for the snapshot position based on both the code range measurements and the carrier phase measurements of the elements timeless observables, as well as code range measurements and carrier phase measurements of time-referenced observables. A method as claimed in claim 3, wherein the timeless observables are preprocessed prior to the IAR by first extrapolating a full set of code range measurements for the snapshot position using previously acquired time and position data for the snapshot receiver and then pre-aligning each of the carrier phase measurements with integers that correspond to a magnitude of associated code range measurements. A method according to claim 3, wherein the IAR is a three-step process which comprises:
first, calculate a floating point solution for the code range measurements and also for the carrier phase measurements of the timeless observables, and for the code range measurements and as well as for the carrier phase measurements of the referenced observables over time, the float solution being subjected to a double-difference process to produce a double-difference vector;
second, doing an integer estimate of the double-difference vector to produce an integer vector; And,
third, recalculate the floating point solution with the integer vector to produce the IAR. A data processing system suitable for timeless position determination of a traveling receiver using a reference receiver, the system comprising:
a host computing platform comprising one or more computers, each comprising memory and at least one processor, the host computing platform having a communication coupling in a computer communication network with a snapshot receiver adapted to receive timeless observables disposed in a snapshot position of the snapshot receiver received in the snapshot receiver for a single epoch from a constellation of global positioning satellites, the host computing platform further having a communication coupling over the computer communication network with a fixed receiver adapted to receive base position data for the fixed receiver of the constellation, the base position data including time-referenced observables; And,
a timeless position determination module comprising computer program instructions activated upon execution in the host computing platform to be executed:
acquiring the snapshot position of the snapshot receiver;
retrieving base position data from the fixed receiver; And
composite the timeless observable elements of the snapshot position with the time-referenced observable elements of the base position data to produce time and position data for the snapshot receiver. A system according to claim 6, wherein the timeless observables are a set of code range measurements and corresponding carrier phase measurements. The system of claim 7, wherein the composition includes calculating an integer ambiguity resolution (IAR) for the snapshot position based on both the code range measurements and the carrier phase measurements of the elements timeless observables, as well as code range measurements and carrier phase measurements of time-referenced observables. A system according to claim 8, wherein the timeless observables are pre-processed prior to the IAR by first extrapolating a full set of code range measurements for the snapshot position using previously acquired time and position data for the snapshot receiver and then pre-aligning each of the carrier phase measurements with integers that correspond to a magnitude of the associated code range measurements. A system according to claim 9, wherein the IAR is a three-step process which includes:
first, the calculation of a floating solution for the code range measurements and as well as the carrier phase measurements of the elements observable without time, as well as for the code range measurements and as well as for the carrier phase measurements of the elements time-referenced observables, the float solution being subjected to a double-difference process to produce a double-difference vector;
second, an integer estimate of the double-difference vector to produce an integer vector; And,
third, a recalculation of the floating point solution with the integer vector to produce the IAR. A computer program product for timeless position determination of a traveling receiver using a reference receiver, the computer program product comprising a computer-readable storage medium on which are embedded program instructions, the program instructions being executable by a device to cause the device to execute a method comprising the steps of:
acquiring, from a snapshot receiver in a computer communication network in a cloud runtime process, a snapshot position of the snapshot receiver received by the snapshot receiver during a single epoch from a constellation of global positioning satellites and comprising a multiplicity of timeless observable elements;
retrieving in the cloud runtime process of the computer communication network, base position data for a fixed receiver received from the constellation and including time-referenced observables;
compose in the cloud runtime process the timeless observables of the snapshot position with the time-referenced observables of the basic position data to produce time and position data for the snapshot receiver . A computer program product according to claim 11, wherein the timeless observables are a set of code range measurements and corresponding carrier phase measurements. A computer program product according to claim 12, wherein the composition includes a calculation of an integer ambiguity resolution (IAR) for the snapshot position based on both the code range measurements and as well as the carrier phase of timeless observables, as well as code range measurements and carrier phase measurements of time-referenced observables. A computer program product according to claim 13, wherein the timeless observables are preprocessed prior to the IAR by first extrapolating a full set of code range measurements for the snapshot position using time and position previously acquired for the snapshot receiver and then pre-aligning each of the carrier phase measurements with integers which correspond to a magnitude of associated code range measurements. A computer program product according to claim 13, wherein the IAR is a three-step process of:
first, calculate a floating point solution for the code range measurements, as well as the carrier phase measurements of timeless observables, and for the code range measurements and carrier phase measurements of time-referenced observables, the float solution being subjected to a double difference process to produce a double difference vector;
second, doing an integer estimate of the double-difference vector to produce an integer vector; And,
third, recalculate the floating point solution with the integer vector to produce the IAR.