• 专利附录
  • 专利说明
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    • 专利摘要:
    The positioning signals broadcast by the GNSS constellations are affected by significant errors, in particular due to the crossing of the ionospheric layer or the tropospheric layer. Several heavy means have been deployed to provide professional users with corrections of said errors. These means, however, all require the knowledge of at least one precise reference point at a given distance. According to the invention, inaccurate positioning receivers, such as smartphones, present in a geographical area, with a precise position that is not known, can contribute to the production of precise atmospheric error corrections if they are sufficiently numerous.
    公开号:FR3025610A1
    申请号:FR1458336
    申请日:2014-09-05
    公开日:2016-03-11
    发明作者:Denis Laurichesse；Gael Scot
    申请人:Centre National dEtudes Spatiales CNES；
    IPC主号:
    专利说明:

    [0001] FIELD OF THE INVENTION [0001] The present invention applies to satellite navigation aids. More specifically, the object of the invention is to produce information for determining positioning errors resulting from the use of a satellite navigation signal.
    [0002] BACKGROUND [0002] The first constellation of satellites emitting positioning signals has been put in place for military applications by the American State (Gobai Positioning System or GPS) from the beginning of the 1980s.
    [0003] Since then, GPS signals have been used by professional civil applications (management of truck fleets, air navigation aids, geodetic surveys, etc ...), and now for general public applications (car navigation with embedded terminals and pedestrian navigation with smart phone type terminals). Other constellations were set up by the Russian state (GLONASS) and the Chinese state (Baïdou). A constellation of European satellites (Galileo) is being deployed. In general, these navigation systems are designated by the acronym GNSS (Global Navigation Satellite Systems). The basic principle of the positioning aid and satellite navigation is the calculation by a receiver with electronic data processing circuits of position, velocity and time (PVT) from electromagnetic signals of length. centimeter wave emitted by satellites in orbit. The calculation of the PVT data by a receiver from the satellite signals is affected by numerous errors of different types: impact of the crossing by the electromagnetic signals of the different layers of the atmosphere (troposphere, ionosphere), errors due to the reflections of the signals on objects in the vicinity of the receiver (multi-paths), clock errors, errors of the electronic processing circuits, etc. For military applications, these errors are corrected notably by the use of the properties of the signals transmitted on reserved carriers. (P (Y) code of the GPS). Specific means of multi-sensor processing and fusion are also generally provided to guarantee the accuracy and integrity of measurements intended for critical uses. But these solutions are small and expensive. 302 5 6 10 2 [0004] To meet the increasing need for precision of civil applications, various means have been developed to correct the main errors: acquisition of signals from several constellations, improvement of the antennas to increase the robustness of the reception, correlation loops in receivers, 5 differential GPS that uses fixed base stations that broadcast a reference signal to correct errors, terrestrial networks for broadcasting correction information, merge satellite data with sensor data embedded motion on the receiver, or giving receiver trajectory information (mapping, terrain models), etc. [0005] In particular, the errors due to the crossing of the ionosphere by the signals emitted by the radionavigation satellites weigh heavily in the global balance of positioning errors (4 standard deviations, according to the publi Angrisano et al., "lonospheric models comparison for single-frequency GNSS positionning", ENC 2011, 12/2011, http: //pano.uniparthenopejt/nodP/6/1). Several types of correction techniques for these ionospheric errors can be employed in the state of the art. A two-frequency receiver can thus use a linear combination of the pseudo-distances calculated from the signals of each of the frequencies. Since the ionospheric error is highly correlated with frequencies, it can be eliminated by said combination. However, dual-frequency receivers are not yet widely available to the general public. In addition, the convergence time to a stabilized measurement is relatively long (up to half an hour). [0007] It is also possible to use, particularly with receivers using a single frequency, corrections calculated by error models based on an estimate of the total electronic content of the corresponding atmospheric layers ionized by the ultraviolet portion of solar radiation. . One of the state-of-the-art models is Klobuchar ("lonospheric time-delay algorithm for single-frequency GPS users", IEEE Transactions on Aerospace and Electronic Systems, Volume AES-23, N.3, 325-331). ). However, the seasonal, daily and spatial fluctuations of the models are such that the calculations are complex and that it is difficult to reach an accuracy that can be guaranteed for a computation time and for making the corrections limited to a few seconds. . [0008] One method of ensuring both fast convergence, accuracy and integrity is the acquisition of specialized signals containing corrections calculated from the differences between the known positions of stationary stations belonging to a network and the positions calculated from navigation signals of a GNSS constellation. These so-called "Satellite Based Augmentation Systems" (SBAS) have regional coverage for the calculation of 3025610 3 corrections and for their broadcast or local for GBAS (Ground Based Augmentation Systems). Operational systems include EGNOS in Europe (European Geostationary Navigation Overlay Service), WAAS in the United States (Wide Area Augmentation System). These different SBAS 5 systems require a heavy and costly infrastructure in investment and operation, including reference ground stations operating under guaranteed conditions of safety and precision, an intensive computing center, communication links between the ground segment and a network. geostationary satellite telecommunications network, specific receivers. These costs today limit the use of these services, and therefore the positioning accuracy they provide, to critical (air navigation) or professional services. [0009] Less expensive approaches consist in simultaneously using the GNSS positioning signal code and the phase of its carrier (possibly on two frequencies), the receiver being positioned relative to a known fixed station of position to remove the ambiguity of cycle on the pseudo-distance calculation from the carrier phase. These approaches, which may have several variants, are known as Real Time Kinematics (RTK). An RTK system can only operate with at least one fixed station and the differential positioning with respect to this station will be accurate only within a radius of the order of 10 to 20 km around this station. It is therefore only used for professional applications whose integrity constraints and coverage radius are lower than those addressed by SBAS systems, coastal navigation and geodetic surveys. A limitation common to differential approaches of the SBAS and RTK type is to require the use of reference stations whose position is known in a very precise manner and of calculation algorithms which treat with an equivalent precision the totality or the most of the errors. This limitation restricts the access of consumer terminal users with standard GNSS signal acquisition capabilities to greater positioning accuracy.
    [0004] SUMMARY OF THE INVENTION [0011] The invention provides a solution to this problem by generating a map of ionospheric errors of sufficient precision from GNSS signal receiving terminals whose position may not be precisely known, and 35 possibly whose onboard processing capacity may be limited. For this purpose, the invention discloses a method for determining, by a computer server, calculation errors of a position calculated by users receiving positioning signals received from at least one constellation of satellites in a given geographical area, said method being characterized in that it comprises at least: a step of determining a list of contributing receivers Ri of positioning signals located in said geographical zone (Zj, the position of said receivers n not being known a priori, a step of extracting, for each of the contributing receivers Ri, code data Ci and phase t from at least one channel of the receiver, a step of calculating an atmospheric error li 10 applicable in the area to the contributing receivers Ri from said code data Ci and phase (13; a step of calculating an atmospheric error 1 (Zj) applicable in the zone Zj, from the e Lrrs li of the contributors Ri. [0013] Advantageously, the step of calculating the atmospheric error li only calculates the ionospheric error for at least one contributor receiver Ri. Advantageously, the step of calculating the atmospheric error li calculates at least the tropospheric error for at least one contributor receiver Ri. [0015] Advantageously, the troposhedral error for the at least one contributing receiver Ri is calculated as the sum of a first delay called wet delay (SWD) and a second delay called hydrostatic delay SHD. Advantageously, the step of calculating the atmospheric error 1 (Zj) receives at input the ionospheric errors of the contributing receptors Ri and a tropospheric error applicable in the geographical zone Zj coming from an external source of supply. information. Advantageously, the step of determining at least a part of the list of contributing receivers Ri (2221, 2222) located in said geographical area uses location data of said receivers relative to at least one base station of the receiver. a cellular radio network. [0018] Advantageously, the method of the invention further comprises a step of classifying the pairs of code data Ci and phase t of the channels of a receiver Ri, said classification step using a weighted combination of criteria selected from a group of criteria representative of the signal to noise ratio of the channel and the elevation of the satellite axis of the channel. Advantageously, the step of calculating an ionospheric error li applicable in the region to the receiver Ri comprises an operation for subtracting said code data Ci and phase (Di, [0020] Advantageously, the ambiguity [0021] Advantageously, the method of the invention further comprises a step (3140, 3150) for calculating a quality index (1i) of the applicable ionospheric error 10 li to receivers Ri. Advantageously, the quality index 10 (1i) is calculated by weighted combination of criteria selected from a group of criteria representative of at least one signal-to-noise ratio of a receiver channel Ri, d at least one elevation of a satellite axis acquired by the receiver Ri from the number of acquired satellite axes. Advantageously, the quality index 10 (1i) also depends on parameters characterizing the hardware configuration and / or receiver software Ri. 20 [0024 Advantageously, the errors li of the receivers Ri whose quality index (1i) is less than a threshold value Seuil1 have zero weighting in the step of calculating an ionospheric error 1 (Zj) applicable in the zone. Zi. Advantageously, the ionospheric error 1 (Zj) applicable in the zone Zj is a linear combination of the errors li weighted by the quality indices 10 (1i). Advantageously, the method of the invention further comprises a step of filtering the values 1 (Zj) by an ionospheric error model. [0027] Advantageously, the method of the invention further comprises a step of determining a confidence indicator of the ionospheric error 1 (Zj). [0028] Advantageously, the confidence indicator of the ionospheric error 1 (Zj) is a function of the number Nj of contributing receivers Ri whose quality index (1i) is greater than Seui11. Advantageously, the ionospheric error 1 (Zj) is replaced, when its confidence indicator is less than a predetermined threshold value Threshold2 by 3 0 2 5 6 1 0 6 a value 1 (Z) calculated by spatial interpolation or within a set of ionospheric error values calculated for geographical areas or neighboring periods. Advantageously, the method of the invention further comprises a step (330) for placing ionospheric error values 1 (Zj) at the disposal of the user receivers. Advantageously, the method of the invention further comprises a step (430) of acquisition by the user receivers of a position determined by the server (230). Advantageously, the method of the invention further comprises a step (450) for calculating a position corrected by merging the PVT data of the user receiver and ionospheric error values 1 (Zj). The invention also discloses a method for correcting a position calculation performed by a user receiver of positioning signals received from at least one satellite constellation in a given geographical area, said method being characterized in that it comprises at least: a step of acquisition from a server of an atmospheric error 1 (Z) calculated by a procedure of fusion by said server of atmospheric errors determined from a plurality of contributing receivers located in the geographical area; a step of melting the acquired atmospheric error with the PVT point calculated by the user receiver. The invention also discloses a collaborative system for assisting the positioning of users receiving positioning signals received from at least one constellation of satellites in at least one geographical zone, said system being characterized in that it comprises a plurality of hardware and computer code elements configured to: determine a list of contributing receivers Ri, positioning signals located in said geographical area Zj, the position of said contributing receivers not being known a priori; extracting, for each of the contributing receivers Ri, code data C1 and phase 4:13 from at least one channel of the receiver; calculating an atmospheric error li applicable in the region to the contributing receivers Ri from said code data Ci and phase (13; calculating an atmospheric error 1 (Zj) applicable in the zone Zj, from the errors li of the contributing receivers Ri; providing at least one result of the atmospheric error calculation to the user receivers in said at least one geographical area. Advantageously, a processor of at least one contributor receiver Ri is configured to perform the calculation of atmospheric error li applicable in the area to said contributor receiver Ri from said code data Ci and phase (Di, the result of said calculation being transmitted to a server (230) via a communication link. [0036] Advantageously, data of code Ci and phase t of at least one channel of at least one receiver Ri receiver are transmitted to a server (230) by a communication link, a said server being configured to perform the atmospheric error calculation li applicable in the area to said contributor receiver Ri from said code data Ci and phase t. The invention also discloses a positioning data server, said server comprising: means for determining a list of contributing receivers Ri located in a geographical area; acquisition means with a given frequency of time sequences of data transmitted by the contributing receivers Ri of said list, said time sequences comprising: i) the code and the phase of at least one channel of each of the contributing receivers Ri, or / and, ii) a datum calculated from said code and said phase; means for calculating a temporal sequence of atmospheric errors applicable in said geographical zone; means for providing user receivers with said temporal sequence of atmospheric errors. The invention also discloses a positioning signal receiver, characterized in that it comprises: a memory for storing data time sequences comprising: i) the code and the phase of at least one channel of the receiver , or / and, ii) a datum calculated from the code and the phase, and; iii) at least one quality index of said data, said index being chosen from a group comprising a signal-to-noise ratio of the channel, an elevation of a satellite axis corresponding to said channel, a number of acquired satellite axes; means configured to teletransmit said time sequences stored in the memory to a pre-identified remote server with a predetermined frequency. The invention also discloses a positioning signal receiver, characterized in that it comprises: means configured for remote reception with a predetermined frequency of time sequences of data of a positioning data server according to the invention; means for calculating a corrected position from the PVT calculated by the receiver and said data time sequences. Another advantage of the invention is that it allows a faster convergence of the precise position calculation (a quasi-instantaneous convergence can be envisaged) thanks to the information on the ionosphere and possibly the troposphere that would be shared. According to the invention, in certain embodiments, ionospheric errors and tropospheric errors can be determined both separately and in combination (each of these errors constitutes atmospheric errors). Another advantage of the invention is to provide a corrected position calculation of the ionospheric errors, making it possible, under most conditions of use, to obtain an overall positioning accuracy of the same order of magnitude as that provided. by SBAS systems, when the number of terminals in a given geographical area is sufficient (but without the same guarantees of integrity). Another advantage of the invention is to allow the recombination of the ionospheric error corrections obtained according to the invention with variable precision positioning data obtained elsewhere in order to obtain a global level of precision which may depend on, on the one hand, the configuration of the receiver enabling it or not to acquire and process the data of such and such a specific positioning service, on the other hand reception conditions where said receiver is located. The position data used to initialize the position calculation in a GNSS receiver may for example be data calculated by another means provided either by a radio network, cellular or WiFi terminals, or by a cartographic means. Another advantage of the invention, coupled with these initialization means, is then to allow a faster acquisition of GNSS signals by a receiver entering a given geographical area or leaving a masking area. In addition, the invention is sufficiently versatile for its implementation to accommodate several types of architectures making it possible to obtain a contribution of correction data according to different modes of receivers having on-board computing capabilities. variables.
    [0005] BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and its various features and advantages will emerge from the description of its various embodiments and from the following figures appended to the present application: FIG. principle of a RTK type system according to the prior art; FIG. 2 represents an architecture diagram for implementing the invention, in several of its embodiments; FIG. 3 represents a general flowchart of the processes for determining ionospheric errors, according to several embodiments of the invention; FIG. 4 represents a general flowchart of the processes for using the data of a positioning data server, according to several embodiments of the invention.
    [0006] DETAILED DESCRIPTION OF THE INVENTION [0047] FIG. 1 represents a basic view of an RTK system according to the prior art. In a differential type positioning system, a user 100 receives positioning signals from at least one satellite constellation 114, 119, 121, 123. The positioning signals of said satellites are also received by a station. 130. The user 100 may be mobile. The reference station 130 must be fixed, of precisely known position and located within a radius of about 10 to 20 km from the user (see http://www.navipedia.net/index.php/RTK Fundamentals). An RTK-type algorithm can be implemented using the code, the phase or a combination of both, where appropriate with variable weightings. The accuracy is better when using the phase, because its measurement is less noisy than that of the code, at the cost of greater complexity, in particular to remove the ambiguity of the cycle. The basic equation of an RTK type algorithm uses the following expression for calculating the phase (1) of a carrier (one per satellite axis): (13 = p - I + I; (bm, - bsat) + N + e ci, (1) Equation in which: 35 p is the geometric expression of the pseudo-distance calculated as a function of the Cartesian coordinates of the satellite l.XSat, YSat, zsat) and the receiver (x ',, y tt ,, zk,); , I is the delay of the signal due to the crossing of the ionosphere; T ,. is the delay of the signal from crossing the troposphere; C is the speed of light in vacuum; bR is the receiver clock bias with respect to the GNSS reference time; bsa, is the satellite clock bias with respect to the GNSS reference time; N is the ambiguity of the phase of the carrier; 5 is the nominal wavelength of the carrier; Here, synthesizes the measurement noise, especially the multipaths. P is given by the following equation: p =. '(X -%) 2 (Y sa, - 1J2 (zsa, -z) 2 (2) [0052] The ionospheric and tropospheric errors have already been commented on .
    [0007] Clock biases do not call for any particular comment. The cycle ambiguity on the phase measurement is N cycles close, N being an integer. For the frequency of a carrier L1 of a GPS system (1575.42 MHz), an ambiguity of a cycle represents a gap of 20 cm. To obtain a centimetric precision, it is therefore necessary to solve the ambiguity of cycle or entire ambiguity. If the difference between the phase measurements of the receivers 100 and 130 is made for, for example, the satellites 121 and 123, the following equation is obtained: d) 112001,123 01301123 = p110201,123 p130123 / 110201 , 123 + / 11; 1), 123 Tr110201,123 Tr113201,123 + (N110201,123 N11; (1), 123,121,123 e100123 e 130,121,123 c '(3) [0054] That the code alone is used , the phase alone or a combination of both, the accuracy of the position measurement of the receiver of the user 100 will be of the same order of magnitude as the precision of the different terms of equation (3), or equivalent equations for the code and phase combinations, with a precision equivalent to the accuracy of the positioning to be provided, to obtain a metric accuracy, it is thus necessary to know the position of the reference station with identical precision, which excludes in practice it is mobile, it is also necessary to calculate r the different error terms with the same precision, which is very difficult for the ionospheric error, given the many factors that affect it. The inventors' idea has therefore been to be able to use, for the ionosphere specifically, measurements of less precision but potentially very numerous because resulting from the contribution of a large number of potentially mobile stations. FIG. 2 shows an architecture diagram for implementing the invention in several of its embodiments. The invention may be implemented with the satellites of the constellation of the prior art, 114, 119, 121, 123. Geographical zones 210, 220 are defined within which the measurements of In particular, receivers 2111, 2112, 2113, 2211, 2212, 2213, active in said geographical zones, contribute to a global calculation of ionospheric errors. Advantageously, the geographical areas 210, 220 have a mesh which may be of the order of a few kilometers (for example between 1 and 10 km). A server 230 managed by a positioning data provider 240 may receive data from and receive from the receivers. The receivers may be of any type, single-frequency or multi-frequency, capable of picking up the signals of a single GNSS constellation or of several, provided with antennas adapted to attenuate the effects of the multipaths or not, assisted by inertial hybridization or mapping or not. They are also coupled to a module allowing them to transmit and receive data over the air. Especially simple smart phones, including a standard GPS chip can be integrated into the measurements. The receivers 2111, 2112, 2211, 2212) can only be contributors, that is to say provide the server 230, and / or other receivers with raw or synthesized data enabling the card to be calculated. of the ionospheric error in the zones 210, 220, without being users thereof. This may in particular be the case of vehicles of commercial or administrative fleets (public transport, taxis, ambulances, postal vehicles, trucks, etc.) equipped with precise positioning means and receiving precision data. The receivers 2113, 2213 can only be users, that is to say receive positioning data without contributing their own position data. The receivers may also be simultaneously or successively contributors and users. To implement the invention, the receivers must be able to provide at least the code and the phase of the raw navigation signals. If the position of the receiver is to be determined from the GNSS signal, the minimum number of satellite axes should be four. If the position of the receiver is determined by other means, as indicated below, this is not necessary. A selection of the best signals will nevertheless be made. It is also possible to generate a synthesis signal, according to the modalities described below in comments in FIG. 3. The raw signals or the synthesis signal are then transmitted by radio to the server 230. [0064] The zones 210 and 220 are distinguished in that the second comprises base stations 2221, 2222, 2223 of a cellular radio network equipped with transmit relay antennas. These antennas may belong to different operators, or possibly be rented by operators who do not have their own network of base stations. The operator of a radio network is able to know at any time the base station to which an active terminal of one of its subscribers is attached. The accuracy of the position of the subscriber therefore varies according to the density of the cells, so from a hundred meters to a few kilometers. Provided that he can have access to these data, the positioning data provider 240 is therefore able to know the active receivers in the geographical area 220, which allows to initialize the method of the invention, without the precise position of the receiver is known, as indicated below. In this case, the transmission or calculation of a GNSS position is therefore not necessary. On the other hand, it must be possible to identify receivers that are located in geographical area 210, not covered by cells of a radio network of an operator with whom the positioning operator has negotiated a sharing agreement. On the other hand, it is necessary either to calculate a position from the raw code and phase data otherwise used to calculate the ionospheric error, either the data, or to acquire the PVT data (Point Time Velocity). at the output of the receiver. FIG. 3 represents a general flowchart of the processes for determining the ionospheric errors according to several embodiments of the invention. The contributors to the cooperative production of the positioning data according to the invention by the supplier 240 are provided with positioning positioning receivers, 2111, etc., designated in FIG. 3 by Ri, having the characteristics indicated in FIG. -above. The contributors are registered by the provider 240, which also records the identifiers of their GNSS receiver and their radio receiver, as well as, optionally, the configuration characteristics of said receivers. Contributors must give, at the time of registration, their consent to the permanent collection of their location data for the purposes of the service. In return for this consent, the data provider 240 will take the necessary legal and contractual obligations to respect the provisions of the countries in which it operates on the protection of personal data.
    [0008] Optionally, the data provider will be able to collect the geo-location coordinates of the base stations of the cellular network in which the receiver Ri is successively hung. The treatments for carrying out the invention are, firstly, implemented for each of the Ri receivers of the contributors located in a zone Zj (treatments 310), and secondly implemented by all the zones Zj served by the positioning data provider (processing 320). The positioning data produced by the treatments 320, and possibly by external processing, are then made available to the users and contributors / users of the service (treatment 330). The processing operations relating to each receiver Ri can be carried out according to variants of the invention, either in the receiver itself or in the server 230. Similarly, certain treatments that can be applied concomitantly with all the receivers Ri d Zone Zi can also be made either on each of the receivers or on the server. A reasonable frequency of the processes for updating the data of the server 230, and thus for extracting and / or calculating the data required at the level of the receivers and / or the server, is of the order of a few minutes (between 1 and 5 minutes, for example, for information on the ionosphere, and probably 1 minute for information on the troposphere). As regards the treatments 310 relating to a receiver Ri: - during a step 3110, a position of the receiver Ri is determined; This position may be that supplied to the receiver by the GNSS constellation or a position provided by the contributor's radiocommunication operator, as indicated above; in the first case, it must be transmitted to the server 230 so that the receiver Ri is assigned to the zone Zj in the time interval considered; During a step 3120, the code and phase of one or more carriers on a certain number of satellite axes are extracted from the GNSS receiver Ri; the code and phase of one or more carriers on the satellite axis giving the best quality (for example, the best signal-to-noise ratio and the highest elevation) are kept for processing in the following steps; - The outputs of step 3120 can be processed in the receiver or transmitted raw to the server 230 for processing; the processing 3130 consists in calculating the ionospheric error at the position Pi by performing the sum of the code and the phase of the positioning signal for the satellite axis retained for the carrier (s), as well as explained further; In parallel, during a step 3140, the quality data corresponding to the best satellite axis, as well as summary data, such as, for example, the number of hung satellite axes are extracted for processing, either in the receiver or on the server during a step 3150 for calculating a synthetic quality index; if it is produced by the receiver, the synthetic quality index 10 (1i) of the receiver Ri is transmitted to the server 230; alternatively, the raw quality data are themselves transmitted to the server. The calculation of li is done from equations (1), relative to the phase, and (4) below, relative to the code, for each of the satellite axes: C = p + I + Tr + c (bm, - bsa,) + ec (4) Where ec is the measurement noise relative to the code. By comparing the equations (1) and (4), we obtain the ionospheric error affecting the GNSS positioning signal received by the receiver Ri at the position Pi: [0073] /, = (C, -41) ,) / 2 - N2 + () (5) [0074] At the metric order of magnitude (and not decimetric or less) at which the preferred field of application of the present invention lies, the entire ambiguity N2 can be neglected (it is of the order of 10 to 50 cm) in the case of a single-frequency receiver. The residual value of the ambiguity N2 will be processed by the positioning filter of the receiver. In the case of a dual-frequency receiver, the entire ambiguity is solved by standard receiver processing. Moreover, it is assumed that the measurement noises on the code and the phase have a Gaussian noise estimator of zero mean, which leads, according to the invention, to be able to eliminate them from calculations without loss of precision on the calculation of an applicable ionospheric correction in zone Zj, provided that a sufficient number of receiver measurements can be used in area Zj. With regard to the treatments 320 relating to all the receivers of a zone Zj: It starts, during a step 3210, by eliminating subsequent calculations all the receivers whose quality index 10 (1i) is below an acceptance threshold; this threshold is defined on the basis of the criteria indicated above, or others specific to zone Zj or to the period of measurement; likewise, the level of acceptability may be different depending on the characteristics of the area and the period; for example, a signal-to-noise ratio of less than 30 dB or an elevation of the satellite axis of less than 15 ° may lead to the elimination of the corresponding measurements; another example could be an indicator on the quality of the multipath environment detected on the signal; it is possible during a step 3220 to decide that no ionospheric error measurement point 35 for zone Zj will be provided because of insufficient number of acceptable measurements in said zone; in this case, it will still be possible to provide a point 1 (Z) calculated, during a step 3230, from an interpolation of the measurements of the zones or neighboring epochs, according to interpolation techniques discussed more far ; if the number of acceptable measurements is sufficient, during step 3240, the ionospheric error 1 (Zj) is calculated by averaging the li at the output of equation (5) of the receivers Ri active in the zone Zj, whose measurements satisfy the quality indicator threshold. As a variant, the measurements aggregated during step 3240 may be weighted by their quality indicator. In the second variant, a second weighting may be performed according to an indicator calculated on the server, for each receiver included in the supplier's database, from the configuration parameters of said receiver. For example, it is possible to use the characteristics of the antennas, of the chip, in particular the code noise indicated by the provider of the receiver. The data 1 (Z) are then made available to users and 15 users / contributors in ways that will be explained later in commentary to Figure 4. [0078] Depending on the size, the position on the globe of the zone Z for which the measurements are insufficient, and according to the number and the position relative to that of Z, neighboring zones Zj for which usable data exist, linear interpolation can be carried out or a spherical harmonic interpolation can be used according to formulas known to those skilled in the art. For example, we can refer to the following reference: http: // ainws [min. e.chdonosnhere /. In this context, one can compare the measurements in the zone Z (and also in zones Zj) to a state model and apply a filtering, for example of Kalman, 25 by the state model. It is also possible to use an interpolation from measurements in the same zone or in neighboring zones, either at near earlier periods or at times comparable in terms of the characteristics having an impact on the ionospheric error ( season, time of day, weather, etc ...). The atmospheric error is normally the sum of the ionospheric and tropospheric errors. It may, however, be decided to neglect one of the two, the atmospheric error taken into account then being reduced to the other. The tropospheric error is usually decomposed into two terms: wet delay or SWD, for Slant Wet Delay which represents the contribution of water vapor and corresponds to about 10% of total tropospheric delay and hydrostatic delay (SHD, for Slant Hydrostatic Delay) which represents the remaining contribution and can be calculated from the equation of hydrostatic equilibrium. The determination of tropospheric error is proposed for example by the international organization IGS. IGS is a sparse global network of stations. The disadvantage of a sparse network is that the tropospheric error will be precise only near the stations. It is therefore important to have a dense network of stations to make an accurate evaluation. Organizations such as the IGN in France which operates such a dense network realize a determination of the tropospheric error. Access to this error usually requires a commercial agreement. The description of the invention made for the ionospheric error is adapted in the following manner to determine at least one of the contributions (wet delay, hydrostatic delay) of the tropospheric error. The main requirement that differs from the determination of the ionospheric contribution is the need for precise knowledge, preferably submeteric or less, of the position of the receiver to perform the calculation. Those skilled in the art will have no difficulty in implementing the mathematical steps either from the foregoing description or the literature. In the method of determining the tropospheric error, after the step of determining the error, based on the precise position of the receiver, comes the step of transmitting this error which is done without transmitting the position. precise. Since the troposphere varies only very little on a kilometric scale, a position of an order of magnitude of one kilometer is generally sufficient. According to a first variant of the invention, only the ionospheric error is determined. According to a second variant, the tropospheric component is determined by an external means such as that of the IGN network in France. The atmospheric error is then the sum of this tropospheric error with the ionospheric error determined according to the invention. According to a third variant, the tropospheric error only is determined according to the invention. According to a fourth variant, the tropospheric and ionospheric error is determined simultaneously or successively by the same receivers. According to a fifth variant, a combination of the preceding variants is implemented in order to take advantage of the environment and the specificities and capacity of the different receivers. Thus, the presence of at least one receiver having precise positioning capabilities (PPP) in a geographical area of about 1 km in diameter may allow the system to acquire tropospheric errors applicable in said geographical area and retransmit them. to other subscribers after integration of the ionospheric error. FIG. 4 represents a general flowchart of the processes for using the data of a positioning data server, according to several embodiments of the invention. The data made available on the server 230 can be transmitted to the receivers of the users in multicast mode, or removed on the server, either by an automatic procedure or by a request procedure of said receivers addressed to said server. The data distribution of the server can be done either by message or in http or https mode. A combination of the different modes of distribution is possible, according to the invention. Step 410 is constituted by this broadcast in multicast mode or the request addressed to the server. During a step 420, the receiver acquires the satellite axis (s) at sight. During an optional step 430, the position of the receiver determined by the server according to a variant of the invention, from data of the mobile radio operator to which the user of the receiver is subscribed. This step makes it possible, combined with the ionospheric error data 1 (Z) applicable to the receiver, to shorten the acquisition time of the satellite axes and the convergence time of the next step of calculating the PVT from the satellite axes. During a step 440, the uncorrected PVT positioning data is calculated by the receiver. In a step 450, the PVT data is corrected by merging with the data 1 (Z) transmitted by the server. According to the invention, the accuracy of the position measurement provided by the GNSS system is improved by merging with the data relating to the ionospheric errors transmitted by the server 230. Likewise, in particular in the variant comprising the step use of the server position data, computation acquisition and convergence time are also improved. The examples described above are only illustrative of some of the embodiments of the invention. They do not limit in any way the scope of the invention which is defined by the claims which follow.
    权利要求:
    Claims (28)
    [0001]
    REVENDICATIONS1. A method of determining, by a computer server (230), calculation errors of a calculated position by user receivers (2113, 2223) of positioning signals received from at least one satellite constellation (114, 119, 121, 123 ) in a given geographical area (210, 220), said method being characterized in that it comprises at least: - A step (3110) for determining a list of contributing receivers (Ri, 2111, 2112, 2221, 2222 ) positioning signals located in said geographical area (Zj, 210, 220), the position of said receivers not being known a priori; A step (3120) for extracting, for each of the contributing receivers Ri, code data Ci and phase t from at least one channel of the receiver; A step (3130) for calculating an atmospheric error li applicable in the zone to the contributing receivers Ri from said data of code Ci and of phase (Di; - a step (3230, 3240) of calculating an atmospheric error 1 (Zj) applicable in the zone Zj, from the errors li of the contributing receivers Ri.
    [0002]
    2. Method according to claim 1, wherein the step of calculating the atmospheric error li calculates only the ionospheric error for all the contributing receivers Ri.
    [0003]
    3. Method according to claim 1, wherein the step of calculating the atmospheric error i i calculates at least the tropospheric error for at least one contributor receiver Ri.
    [0004]
    4. The method of claim 3, wherein the troposhérique error for the at least one contributor receiver Ri is calculated as the sum of a first delay said wet delay (SWD) and a second delay said hydrostatic delay SHD.
    [0005]
    5. Method according to one of claims 1 to 4, wherein the step of calculating the atmospheric error 1 (Zj) receives as input the ionospheric errors of the contributing receivers Ri and a tropospheric error applicable in the geographical area. Zj from an external source of information supply.
    [0006]
    The method according to one of claims 1 to 5, wherein the step of determining at least a portion of the list of contributing receivers Ri (2221, 2222) located in said geographic area uses location data of said receivers for at least one base station of a cellular radio network. 10
    [0007]
    The method according to one of claims 1 to 6, further comprising a step of classifying the pairs of code data Ci and phase t of the channels of a receiver Ri, said classification step using a weighted combination of selected criteria. in a group of criteria representative of the signal to noise ratio of the channel and the elevation of the satellite axis of the channel. 15
    [0008]
    8. Method according to one of claims 1 to 7, wherein the step of calculating an ionospheric error li applicable in the region to the receiver Ri comprises a subtraction operation of said code data Ci and phase (Di.
    [0009]
    9. The method of claim 8, wherein the entire ambiguity of the phase (Di is neglected.
    [0010]
    10. The method according to one of claims 1 to 9, further comprising a step (3140, 3150) of calculating a quality index (1i) of the ionospheric error li applicable to the Ri receptors.
    [0011]
    The method of claim 10, wherein the quality index (1i) is calculated by weighted combination of criteria selected from a group of criteria representative of at least one signal to noise ratio of a channel of the Ri receiver. of at least one elevation of a satellite axis acquired by the receiver Ri from the number of acquired satellite axes.
    [0012]
    12. The method of claim 10, wherein the quality index 10 (1i) further depends on parameters characterizing the hardware and / or software configuration of the receiver Ri. 3025610 20
    [0013]
    The method according to one of claims 10 to 12, wherein the errors li of the receivers Ri whose quality index (1i) is less than a threshold value Seuil1 have zero weighting in the calculation step d. an ionospheric error 1 (Zj) applicable in zone Zj. 5
    [0014]
    14. Method according to one of claims 10 to 13, wherein the ionospheric error 1 (Zj) applicable in the zone Zj is a linear combination of the errors li weighted by the quality indices 10 (1i). 10
    [0015]
    15. Method according to one of claims 10 to 14, further comprising a step of filtering values 1 (Zj) by an ionospheric error model.
    [0016]
    16. The method according to one of claims 1 to 15, further comprising a step of determining a confidence indicator of the ionospheric error 1 (4).
    [0017]
    17. The method of claims 13 and 16, wherein the confidence indicator of the ionospheric error 1 (Zj) is a function of the number Nj of contributors Ri whose quality index (1i) is greater than Seui11. 20
    [0018]
    18. Method according to one of claims 1 to 17, wherein the ionospheric error 1 (Zj) is replaced, when its confidence indicator is less than a predetermined threshold value Threshold2 by a value 1 (Z) calculated by interpolation. spatial or temporal within a set of ionospheric error values calculated for geographical areas or neighboring periods.
    [0019]
    19. The method according to one of claims 1 to 18, further comprising a step (330) ionospheric error setting step (1) (Zj) available to user receivers. 30
    [0020]
    20. The method of claim 19, further comprising a step (430) of acquisition by the user receivers of a position determined by the server (230). 35
    [0021]
    21. The method according to one of claims 19 to 20, further comprising a step (450) for calculating a position corrected by merging the PVT data of the user receiver and ionospheric error values 1 (Zj). 3025610 21
    [0022]
    22. A method of correcting a position calculation performed by a user receiver (2113, 2223) of positioning signals received from at least one satellite constellation (114, 119, 121, 123) in a given geographical area (210). , 220), said method being characterized in that it comprises at least: a step (410) of acquisition from a server (230) of an ionospheric error 1 (Z) calculated by a procedure of said server fusing atmospheric errors determined from a plurality of contributing receivers (2111, 2112, 2221, 2222) located in the geographical area; - A step (450) of melting the atmospheric error acquired with the PVT point calculated by the user receiver.
    [0023]
    23. Collaborative system for positioning user receivers 15 (2113, 2223) for positioning signals received from at least one satellite constellation (114, 119, 121, 123) in at least one geographic area (210, 220). ), said system being characterized in that it comprises a plurality of hardware and computer code elements configured to: - Determine a list of contributing receivers (Ri, 2111, 2112, 2221, 2222) of positioning signals located in said geographical area (Zj, 210, 220), the position of said contributing receivers not being known a priori; Extracting, for each of the contributing receivers Ri, code data Ci and phase t from at least one channel of the receiver; 25 - Calculate an atmospheric error li applicable in the area to the contributing receivers Ri from said code data Ci and phase (13; - Calculate an atmospheric error 1 (Zj) applicable in the zone Zj, from the errors li of the receivers contributors R1; 30 - Providing user receivers with at least one result of the atmospheric error calculation in said at least one geographical area.
    [0024]
    24. The system according to claim 23, wherein a processor of at least one contributor receiver Ri is configured to perform the atmospheric error calculation li applicable in the area to said contributor receiver Ri from said code data Ci and phase (Di, the result of said calculation being transmitted to a server (230) by a communication link.
    [0025]
    25. The system of claim 23, wherein code data Ci and phase t of at least one channel of at least one receiver Ri receiver are transmitted to a server (230) by a communication link, a processor said server being configured to perform the atmospheric error calculation li applicable in the area to said contributor receiver Ri from said code data Ci and phase t. 10
    [0026]
    A positioning data server (230), said server comprising: means for determining a list of contributing receivers (Ri, 2111, 2112, 2221, 2222) located in a geographic area (210, 220); Acquisition means with a given frequency of time sequences of data transmitted by the contributing receivers Ri of said list, said time sequences comprising: the code and the phase of at least one channel of each of the contributing receivers Ri, or and o a datum calculated from said code and said phase A means of calculating a temporal sequence of atmospheric errors applicable in said geographical zone; Means for providing user receivers (2113, 2223) with said temporal sequence of atmospheric errors.
    [0027]
    27. Receiver (2111, 2112, 2221, 2222) of positioning signals, characterized in that it comprises: A memory for storing time sequences of data comprising: o the code and the phase of at least one channel of the receiver, or / and o a data computed from the code and the phase o and at least one quality index of said data, said index being selected from a group comprising a signal-to-noise ratio of the channel, an elevation of a satellite axis corresponding to said channel, a number of acquired satellite axes; A means configured to teletransmit said time sequences stored in the memory to a pre-identified remote server with a predetermined frequency. 5
    [0028]
    28. Receiver (2113, 2223) for positioning signals, characterized in that it comprises: means configured for remote reception with a predetermined frequency of time sequences of data from a positioning data server according to claim 26; Means for calculating a corrected position from the PVT calculated by the receiver and said data time sequences. 15
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    同族专利:
    公开号 | 公开日
    US20170307761A1|2017-10-26|
    CN107076856A|2017-08-18|
    WO2016034622A1|2016-03-10|
    EP3189349A1|2017-07-12|
    KR20170039718A|2017-04-11|
    FR3025610B1|2022-01-14|
    US10641902B2|2020-05-05|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20120127032A1|2010-11-19|2012-05-24|Mcclure John A|Portable base station network for local differential gnss corrections|
    DE102011051100A1|2011-06-16|2012-12-20|Universität Kassel|Method for providing correction signals for terminal of satellite supported position determining system, involves determining position of mobile reference device for unit of position determining system in form of position data|
    US5867411A|1996-12-19|1999-02-02|The Aerospace Corporation|Kalman filter ionospheric delay estimator|
    US6397147B1|2000-06-06|2002-05-28|Csi Wireless Inc.|Relative GPS positioning using a single GPS receiver with internally generated differential correction terms|
    JP2005517931A|2002-02-13|2005-06-16|サーフテクノロジーインコーポレイテッド|Prediction and correction of ionospheric errors in satellite positioning systems.|
    US6701253B2|2002-02-19|2004-03-02|Eride, Inc.|Total correction strategy|
    US7877207B2|2003-04-17|2011-01-25|The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland|Correction of troposphere induced errors in global positioning systems|
    WO2006073490A2|2004-07-23|2006-07-13|California Institute Of Technology|Generating high precision ionospheric ground-truth measurements|
    US7656352B2|2005-09-20|2010-02-02|Novariant, Inc.|Troposphere corrections for ground based positioning systems|
    FR2929015B1|2008-03-21|2010-04-23|Thales Sa|NETWORK AND METHOD FOR CALCULATING IONOSPHERIC CORRECTIONS|
    US20120119944A1|2010-05-30|2012-05-17|Trimble Navigation Limited|Gnss atmospheric estimation with ambiguity fixing|
    CN102426374A|2011-09-02|2012-04-25|东南大学|GPS mobile base station rapid positioning and resolving method|
    CN103018758A|2012-12-03|2013-04-03|东南大学|Method for moving differential base station based on global positioning system /inertial navigation system /assisted global positioning system |
    DE112013007301T8|2013-08-07|2016-07-14|Sergey Vladislavovich Averin|Attenuation of scintillations in signals from global navigation satellite systems caused by ionospheric irregularities|
    CN103592653B|2013-10-17|2016-08-17|中国科学院光电研究院|Ionosphere delay modification method for local area single-frequency Satellite navigation users|
    CN103645482A|2013-12-25|2014-03-19|上海华测导航技术有限公司|Arbitrary point based set achievement method of GPS real-time dynamic measurement of base station|
    EP3106897A1|2015-06-19|2016-12-21|Centre National d'Etudes Spatiales|Gnss receiver with an on-board capability to implement an optimal error correction mode|
    EP3226034A1|2016-04-01|2017-10-04|Centre National d'Etudes Spatiales|Improved gnss receiver using velocity integration|
    WO2018034580A1|2016-08-15|2018-02-22|Limited Liability Company "Topcon Positioning Systems"|Adaptive gnss positioning method capable of adjusting to ionospheric delay|
    US10690775B2|2017-06-29|2020-06-23|Novatel Inc.|Crowdsourcing atmospheric correction data|
    DK201870263A1|2018-05-02|2019-12-03|Intelligent Marking Aps|Method for marking a ground surface using a robot unit and a local base station, the system therefore and use thereof|US10012738B2|2016-03-24|2018-07-03|Hitachi Zosen Corporation|Positioning method and positioning apparatus using satellite positioning system|
    EP3226034A1|2016-04-01|2017-10-04|Centre National d'Etudes Spatiales|Improved gnss receiver using velocity integration|
    EP3316001A1|2016-10-25|2018-05-02|Centre National d'Etudes Spatiales|Collaborative improvement of a vehicle's positioning|
    DE102017206275A1|2017-04-12|2018-10-18|Robert Bosch Gmbh|A method of operating a correction service system and correction service system|
    FR3085082B1|2018-08-17|2020-07-17|Continental Automotive France|ESTIMATION OF THE GEOGRAPHICAL POSITION OF A ROAD VEHICLE FOR PARTICIPATORY PRODUCTION OF ROAD DATABASES|
    IL269263A|2019-09-10|2021-09-30|Veeride Geo Ltd|Cellular-based navigation method|
    CN111045042B|2019-12-20|2022-03-04|西安空间无线电技术研究所|PPP-RTK enhancement method and system based on 'cloud-end' framework|
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    2016-03-11| PLSC| Publication of the preliminary search report|Effective date: 20160311 |
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    优先权:
    申请号 | 申请日 | 专利标题
    FR1458336A|FR3025610B1|2014-09-05|2014-09-05|METHOD FOR COLLABORATIVE DETERMINATION OF POSITIONING ERRORS OF A SATELLITE NAVIGATION SYSTEM|FR1458336A| FR3025610B1|2014-09-05|2014-09-05|METHOD FOR COLLABORATIVE DETERMINATION OF POSITIONING ERRORS OF A SATELLITE NAVIGATION SYSTEM|
    EP15763847.9A| EP3189349A1|2014-09-05|2015-09-02|Method of collaborative determination of positioning errors of a satellite-based navigation system|
    KR1020177006063A| KR20170039718A|2014-09-05|2015-09-02|Method of collaborative determination of positioning errors of a satellite-based navigation system|
    PCT/EP2015/070047| WO2016034622A1|2014-09-05|2015-09-02|Method of collaborative determination of positioning errors of a satellite-based navigation system|
    CN201580047618.6A| CN107076856A|2014-09-05|2015-09-02|The method that the collaboration of the Wrong localization of satellite-based navigation system is determined|
    US15/508,296| US10641902B2|2014-09-05|2015-09-02|Method of collaborative determination of positioning errors of a satellite-based navigation system|
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