Apparatus and method for selecting satellite based on high elevation satellite and altitude information

Abstract

The present invention relates to a satellite selection device and a method thereof. A satellite selection device according to one embodiment comprises: a high-angle satellite selection unit that selects at least one high-angle satellite among a plurality of satellites; an integrated positioning unit that calculates an integrated positioning result based on at least one correction information among satellite navigation measurement correction information, GNSS time difference correction information and altitude information correction information, and altitude information derived through high-angle satellite information and a barometer; and an effective satellite verification unit that selects at least one effective satellite based on the integrated positioning result and selects at least one final effective satellite through a residual sum verification process and a positioning solution verification process based on the effective satellite.

Description

Technology Field

[0001] The present invention relates to a satellite selection device and a method thereof, and more specifically, to a technical concept of selecting a satellite with good positioning through the combination of elevation angle GNSS information and altitude information. Background Technology

[0002] GNSS (Global Navigation Satellite System) signals are easily blocked or reflected by obstacles that interfere with signal reception, such as high-rise buildings, in environments like urban areas.

[0003] Reception of signals reflected by building walls and the ground causes a measurement distance error known as multipath error, and multipath error acts as the biggest error factor in GNSS positioning in urban areas.

[0004] Accordingly, for more accurate and reliable urban GNSS positioning, satellite measurements containing multipath errors must be excluded from positioning, and existing technology has used a method of combining GNSS measurements and elevation information in an ideal radio reception environment using GNSS measurements and elevation information that do not contain such multipath errors.

[0005] However, areas where GNSS measurement collection is poor due to reasons such as reduced visibility are areas where large multipath errors generally occur, such as urban areas, so it is difficult to expect an improvement in positioning accuracy even if GNSS measurements and elevation information are combined.

[0006] Therefore, in order to improve GNSS positioning performance by combining elevation information in environments where satellite visibility is limited and measurement errors are large due to surrounding obstacles such as buildings or mountains, it is essential to select only GNSS measurements with small multipath errors.

[0007] However, multipath error is a user-specific error that varies depending on the user's reception environment, and it is known to be very difficult to detect only the measurements containing multipath error among the multiple received satellite measurements. Prior art literature

[0008] Japanese Registered Patent No. 7,074,599, "Navigation satellite system receiving device, method and program for processing navigation satellite signals thereof" Korean Published Patent No. 10-2010-0055266, "Position measuring device and position measuring method" Japanese Registered Patent No. 6298176, "Positioning device" The problem to be solved

[0009] The present invention aims to provide a satellite selection device and a method for selecting a satellite with good positioning regardless of multipath error by utilizing integrated positioning results based on information from high-angle satellites and altitude information calculated through a barometer.

[0010] In addition, the present invention aims to provide a satellite selection device and a method for accurately selecting good positioning satellites with higher reliability through a residual sum verification process and a positioning solution verification process based on integrated positioning results. means of solving the problem

[0011] A satellite selection device according to one embodiment of the present invention may include a high-angle satellite selection unit that selects at least one high-angle satellite among a plurality of satellites, an integrated positioning unit that calculates an integrated positioning result based on at least one correction information among satellite navigation measurement correction information, GNSS time difference correction information and altitude information correction information, and altitude information derived through the high-angle satellite information and a barometer, and an effective satellite verification unit that selects at least one effective satellite based on the integrated positioning result and selects at least one final effective satellite through a residual sum verification process and a positioning solution verification process based on the effective satellite.

[0012] According to one side, the high-angle-of-elevation satellite selection unit calculates an initial satellite selection weight based on the elevation angle information and signal strength information (Signal Noise Ratio; SNR) of each of the plurality of satellites, and can select a high-angle-of-elevation satellite based on the calculated initial satellite selection weight.

[0013] According to one side, the integrated positioning unit can receive at least one correction information from a reference station device.

[0014] According to one side, the integrated positioning unit converts position information based on elevation-longitude-height (LLH) coordinate system into elevation information and can calculate an integrated positioning result based on the elevation information converted into the LLH coordinate system.

[0015] According to one side, the valid satellite verification unit derives the predicted value of the satellite measurement and the actual value of the satellite measurement based on the integrated positioning results, calculates the residual value by differentiating the predicted value of the satellite measurement and the actual value of the satellite measurement, and can select valid satellites based on the calculated residual value.

[0016] According to one side, the valid satellite verification unit selects at least one first valid satellite based on the result of comparing the calculated residual value with a preset residual threshold, calculates a covariance matrix based on the residual value of the first valid satellite, calculates a Weighted Square Sum of Error (WSSE) using the covariance matrix, and selects at least one second valid satellite based on the Chi-Square distribution based on the calculated WSSE.

[0017] According to one side, the valid satellite verification unit derives a WSSE threshold based on a false alarm rate according to a chi-square distribution, and can select a second valid satellite based on the result of comparing the calculated WSSE and the WSSE threshold.

[0018] According to one side, if the calculated WSSE is greater than or equal to the WSSE threshold, the valid satellite verification unit derives at least one recombined first valid satellite through a satellite recombination process for the first valid satellite, and can select a second valid satellite based on the result of recalculating the WSSE of the recombined first valid satellite.

[0019] According to one side, the valid satellite verification unit calculates the difference value between the calculated integrated positioning result and the positioning result of the selected valid satellite, and can select the final valid satellite based on the comparison result between the calculated difference value and a preset position threshold.

[0020] According to one side, if the calculated difference value is greater than the position threshold value, the high-angle satellite selection unit can re-select at least one high-angle satellite among a plurality of satellites.

[0021] A satellite selection method according to one embodiment of the present invention may include: a step of selecting at least one high-angle satellite among a plurality of satellites in a high-angle satellite selection unit; a step of calculating an integrated positioning result based on at least one correction information among satellite navigation measurement correction information, GNSS time difference correction information and altitude information correction information, information of the high-angle satellite and altitude information derived through a barometer in an integrated positioning unit; and a step of selecting at least one valid satellite based on the integrated positioning result in a valid satellite verification unit, and selecting at least one final valid satellite through a residual sum verification process and a positioning solution verification process based on the valid satellite. Effects of the invention

[0022] According to one embodiment, the present invention can select a satellite with good positioning regardless of multipath error by using an integrated positioning result based on information from a high-angle satellite and altitude information calculated through a barometer.

[0023] According to one embodiment, the present invention can accurately select good positioning satellites with higher reliability through a residual sum verification process and a positioning solution verification process based on integrated positioning results. Brief explanation of the drawing

[0024] FIG. 1 is a drawing illustrating a satellite selection device according to one embodiment. FIG. 2 is a diagram illustrating a satellite selection method according to one embodiment. FIG. 3 is a diagram for explaining a satellite selection method according to one embodiment in more detail. Specific details for implementing the invention

[0025] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed herein are provided merely for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described herein.

[0026] Embodiments according to the concept of the present invention may be subject to various modifications and may take various forms; therefore, embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes modifications, equivalents, or substitutions that fall within the spirit and scope of the present invention.

[0027] Terms such as "first" or "second" may be used to describe various components, but said components should not be limited by said terms. For the sole purpose of distinguishing one component from another, for example, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0028] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Expressions describing the relationships between components, such as "between," "exactly between," or "directly adjacent to," should be interpreted in the same way.

[0029] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0030] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0032] Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, the scope of the patent application is not limited or restricted by these embodiments. Identical reference numerals in each drawing indicate identical components.

[0034] FIG. 1 is a drawing illustrating a satellite selection device according to one embodiment.

[0035] Referring to FIG. 1, a satellite selection device (100) according to one embodiment can select a satellite with good positioning regardless of multipath error by using integrated positioning results based on information from a high-angle satellite and altitude information calculated through a barometer.

[0036] In addition, the satellite selection device (100) can accurately select a satellite with good positioning with higher reliability through a residual sum verification process and a positioning solution verification process based on the integrated positioning result.

[0037] To this end, the satellite selection device (100) may include a high-angle satellite selection unit (110), an integrated positioning unit (120), and an effective satellite verification unit (130).

[0038] Additionally, the satellite selection device (100) may be provided in a user terminal, and the user terminal may be an antibody (i.e., a flying vehicle) flying in a preset area, but is not limited thereto.

[0039] The high-angle satellite selection unit (110) according to one embodiment can select at least one high-angle satellite among a plurality of satellites.

[0040] According to one side, the high-angle satellite selection unit (110) calculates an initial satellite selection weight based on the elevation angle information and signal strength information (Signal Noise Ratio; SNR) of each of the plurality of satellites, and can select a high-angle satellite based on the calculated initial satellite selection weight.

[0041] The high-angle satellite selection unit (110) selects initial satellites for the selection of the final effective satellite (i.e., a satellite with good positioning), and the satellites selected through the high-angle satellite selection unit (110) may consist of high-angle and high-quality satellites.

[0042] Specifically, the high-angle-of-elevation satellite selection unit (110) is the elevation angle of the satellite (as shown in Formula 1 below) Using ) and signal strength (SNR), the weights of the satellites ( After calculating ), the calculated weight( Satellites are added one by one to the initial satellite set in ascending order of ), and this process is the minimum number of satellites (N) required for multi-satellite constellation positioning. cons A combination of high-angle satellites, i.e., a combination of initial satellites, can be constructed by repeating the process until the minimum HDOP (Horizontal Dilution of Precision) condition is satisfied.

[0043] [Formula 1]

[0044]

[0045] Here, a0 and a1 represent weight constants for the elevation angle model.

[0046] For example, the high-angle satellite selection unit (110) is the number of initial satellites (N sat ) is the minimum number of satellites (N cons ) greater than or equal to (i.e., N sat ≥ N cons ), the calculated result of HDOP based on the combination of initial satellites (HDOP0) is the preset minimum HDOP value (Tr HDOP Less than ) (i.e., HDOP0 < Tr HDOP A combination of initial satellites can be configured until the condition of ) is satisfied.

[0047] However, the high-angle satellite selection unit (110) is not limited to the configuration method of the initial satellite (i.e., high-angle satellite) described above, and can configure the combination of the initial satellite through various previously known methods.

[0048] An integrated positioning unit (120) according to one embodiment can produce an integrated positioning result based on at least one of the correction information among satellite navigation measurement correction information, GNSS time difference correction information and altitude information correction information, and altitude information derived through the information of an elevation angle satellite and a barometer (i.e., user altitude information).

[0049] According to one aspect, the integrated positioning unit (120) may receive at least one correction information from a reference station device, wherein the reference station may be an antibody (i.e., a reference station aircraft) flying in a pre-set area, but is not limited thereto.

[0050] For example, the reference station device may be equipped with a GNSS correction information generation unit, an altitude correction information generation unit, and a time difference correction information generation unit, and through this, generate satellite navigation measurement correction information, altitude information correction information and GNSS time difference correction information and provide them to the integrated positioning unit (120).

[0051] The GNSS correction information generation unit receives satellite signals from multiple satellites and can generate GNSS correction information based on the satellite signals.

[0052] For example, the GNSS correction information generation unit may generate GNSS correction information including at least one of distance information from each of a plurality of satellites to a reference station device, GNSS measurement information for each of a plurality of satellites, clock estimate information for a reference station device, and clock error information for each of a plurality of satellites, and preferably, the GNSS correction information may include pseudo-range correction information (PRC).

[0053] The altitude information correction information generation unit can generate altitude information correction information based on altitude information (i.e., user altitude information) derived through a barometer equipped in the satellite selection device (100) and GNSS correction information.

[0054] For example, the altitude information correction information generation unit can generate altitude information correction information that reflects the difference between the absolute altitude obtained through GNSS measurement information for each of the plurality of satellites and the altitude information received from the satellite selection device (100).

[0055] The time difference correction information generation unit provides GNSS time difference correction information between multiple GNSS satellites that transmit signals based on different time standards ( Can generate ).

[0056] According to one side, the integrated positioning unit (120) can convert position information based on an elevation-angle satellite into altitude information in the LLH (latitude-longitude-height) coordinate system and calculate an integrated positioning result based on the altitude information converted into the LLH coordinate system.

[0057] Specifically, GNSS multipath error generally has a larger value for low-elevation satellites located near the ground due to the influence of signal reception obstacles such as buildings, and a smaller value for high-elevation satellites located near the zenith. Therefore, assuming that high-elevation satellites located near the zenith are not affected by multipath error, a position solution (i.e., a positioning result) free from multipath error can be calculated using the following Equation 2.

[0058] [Formula 2]

[0059]

[0060] Here, X is the location of the user (i.e., user terminal), H is the navigation observation matrix, Z is the satellite measurement with pseudorange correction information applied, and the subscript 0 represents the combination of the initial elevation angle satellites.

[0061] However, when constructing navigation equations by combining only high-angle satellites, the satellites are distributed only around the zenith, resulting in an uneven geometric arrangement of satellites for calculating navigation solutions. In particular, as positioning satellites become densely concentrated at high-angles, the Vertical Dilution of Precision (VDOP) increases, leading to an increase in the level of error in the vertical position.

[0062] Accordingly, the integrated positioning unit (120) can effectively reduce the vertical position error level by using GNSS-altitude information integrated positioning, which utilizes altitude information from a barometer capable of providing an independent altitude solution during GNSS positioning by combining high-angle satellites. In this case, when calculating the position solution by combining the barometer and GNSS, the barometer's measurement is expressed in the LLH coordinate system rather than the ECEF (Earth-Centered Earth-Fixed) coordinate system used during GNSS positioning, so the user's position solution can be calculated using a navigation equation that includes a conversion equation such as Equation 3 below.

[0063] [Formula 3]

[0064]

[0065] Here, x, y, and z are the ECEF 3D coordinate axes, subscripts, respectively is a barometer, and is the latitude and longitude in the LLH coordinate system, h B is an altitude measurement in the LLH coordinate system measured by a barometer, etc., the superscript is the satellite number, Is is the view vector, Is The ECEF elements of, c means cos and s means sin.

[0066] For example, the integrated positioning unit (120) can calculate the user's location solution (i.e., integrated positioning result) by applying Equation 3 to Equation 2.

[0067] To explain the process of calculating the integrated positioning results described above in more detail, the results of user positioning based on GNSS code measurements can generally be calculated based on the least squares method as shown in Equation 4 below.

[0068] [Equation 4]

[0069]

[0070] At this time, since the altimeter provides altitude information in the LLH coordinate system, for GNSS and altimeter integrated positioning, the user's location information provided by the GNSS must be converted into altitude information in the LLH coordinate system as shown in Equation 5 below.

[0071] [Formula 5]

[0072]

[0073] That is, the integrated positioning unit (120) can construct an observation matrix as shown in Equation 6 below using Equation 5, and can perform integrated positioning of GNSS and altimeter using the constructed observation matrix.

[0074] [Equation 6]

[0075]

[0076] A valid satellite verification unit (130) according to one embodiment can select at least one valid satellite (hereinafter, the first valid satellite) based on the integrated positioning result, and select at least one final valid satellite through a residual sum verification process and a positioning solution verification process based on the valid satellite.

[0077] According to one side, the valid satellite verification unit (130) derives the predicted value of the satellite measurement and the actual value of the satellite measurement based on the integrated positioning result, calculates the residual value by differentiating the predicted value of the satellite measurement and the actual value of the satellite measurement, and can select the valid satellite based on the calculated residual value.

[0078] Specifically, the valid satellite verification unit (130) uses the solution (i.e., integrated positioning result) calculated through high-angle GNSS satellites and barometer integrated positioning to predict the satellite measurement value as shown in Equation 7 below ( ) can be produced.

[0079] [Equation 7]

[0080]

[0081] Here, subscript 0 represents a combination of high-angle satellites initially selected through the high-angle satellite selection unit (110), and subscript 1 represents a combination of the remaining satellites excluding the initially selected high-angle satellites.

[0082] In addition, the valid satellite verification unit (130) predicts the satellite measurement value as shown in Equation 8 below ( ) and actual values ​​of satellite measurements( Dividing ) to obtain the residual value( ) can be calculated, and the calculated residual value( Valid satellite measurements can be determined using ).

[0083] [Equation 8]

[0084]

[0085] Meanwhile, if the location of the user terminal is close to the true value, the distance between the satellite and the user becomes close to the actual value, so the residual value ( Only user clock error B, multipath error, and receiver noise remain in ), and since the user clock error used in the residual calculation is the estimated user clock error calculated from GNSS / barometer integrated positioning, the calculated residual contains a bias component generated from the user clock error estimation.

[0086] At this time, since the bias component generated in the user clock error estimation is equally included in the received satellite measurements, it can be removed by single-difference of the measurements of the pre-set reference satellite(*) as shown in Equation 9 below.

[0087] [Formula 9]

[0088]

[0089] Here, since each GNSS transmits signals based on different time references, it is necessary to estimate the clock error of each GNSS when performing positioning with different GNSS combinations; that is, as each GNSS used for positioning is added, the minimum number of visible satellites increases by one, and thus the number of satellites for the initial high-angle satellite combination must also increase.

[0090] Accordingly, to compensate for the aforementioned disadvantage, the valid satellite verification unit (130) receives GNSS time difference correction information (as shown in Equation 10 below) from the reference station device By applying ), the measurement residual can be calculated in the same way as the GPS single positioning technique.

[0091] [Equation 10]

[0092]

[0093] According to one side, the valid satellite verification unit (130) can select at least one first valid satellite based on the result of comparing the calculated residual value with a preset residual threshold value.

[0094] Here, the valid satellite verification unit (130) can form a first valid satellite group including the high-angle satellite selected through the high-angle satellite selection unit (110) and the first valid satellite.

[0095] In other words, the valid satellite verification unit (130) calculates the residual (calculated using the GPS single positioning technique as shown in Equation 11 below) ) is the standard value( If the value is less than ) it can be determined as a valid measurement and the satellite corresponding to the valid measurement can be selected as the first valid satellite.

[0096] [Equation 11]

[0097]

[0098] According to one side, the valid satellite verification unit (130) calculates a covariance matrix based on the residual value of the first valid satellite, calculates a Weighted Square Sum of Error (WSSE) using the covariance matrix, and can select at least one second valid satellite as a valid satellite based on a Chi-Square distribution based on the calculated WSSE, and can derive a WSSE threshold value based on the false alarm rate based on the Chi-Square distribution, and can select at least one second valid satellite based on the comparison result between the calculated WSSE and the WSSE threshold value.

[0099] Here, the effective satellite verification unit (130) can form a second effective satellite group including the high-angle satellite selected through the high-angle satellite selection unit (110) and the second effective satellite.

[0100] Specifically, the valid satellite verification unit (130) can determine the positioning validity by deriving a positioning result based on the following Equation 12 for the satellites selected as the first valid satellite, calculating the sum of squares of the residuals, and determining whether the sum of the residuals follows a chi-square distribution.

[0101] [Equation 12]

[0102]

[0103] Here, This refers to the positioning result calculated after including all selected combinations, including the initial selected high-angle satellite combinations, and the valid combinations (i.e., the first valid satellite group).

[0104] The valid satellite verification unit (130) is the residual of the first valid satellite group ( A covariance matrix (V) for ) is defined, and WSSE can be calculated as shown in Equation 13 below, where the measured residual of the calculated WSSE ( Since it is the value obtained by dividing the squares of the values ​​by the square of the standard deviation, it follows a chi-square distribution.

[0105] [Equation 13]

[0106]

[0107] In addition, the valid satellite verification unit (130) has a false alarm rate (P FA ) such that the WSSE threshold (Th ) satisfies the following Equation 14 WSSE ) can be derived, and the calculated WSSE and WSSE threshold (Th WSSE If the comparison result of ) satisfies the following Equation 15, the selected satellites (i.e., the first effective satellites) are selected as the second effective satellites, a second effective satellite group is formed, and positioning can be performed using the second effective satellite group.

[0108] [Equation 14]

[0109]

[0110] [Formula 15]

[0111]

[0112] Meanwhile, the valid satellite verification unit (130) calculates the WSSE value and the WSSE threshold value (Th WSSE If ) or more (i.e., if the condition of Equation 15 is not satisfied), at least one recombined first effective satellite is derived through a satellite recombination process for the first effective satellite, and a second effective satellite can be selected based on the WSSE recalculation result of the recombined first effective satellite.

[0113] Specifically, the valid satellite verification unit (130) calculates the WSSE to be a WSSE threshold (Th WSSE If the result is greater than ) the selection process for the second valid satellite can be performed by calculating WSSE for the remaining satellites excluding one of the first valid satellites (i.e., the recombined first valid satellite) and then re-performing residual verification.

[0114] According to one side, the valid satellite verification unit (130) can calculate the difference value between the calculated integrated positioning result and the positioning result of the selected valid satellite (i.e., the second valid satellite group), and select the final valid satellite based on the result of comparing the calculated difference value with a pre-set position threshold.

[0115] In other words, the valid satellite verification unit (130) calculates the positioning results from all selected satellites (i.e., the second valid satellite group) as in the following Equation 16 ( ) positioning result based on initial location( The difference from ) is the position threshold ( In the case where the value is less than ), the second valid satellite group can be selected as the final valid satellite, and the positioning result based on the final valid satellite can be determined as the final positioning result.

[0116] [Equation 16]

[0117]

[0118] Here, This is a positioning result calculated after including all selected combinations, including the initial selected high-angle satellite combinations, and the selected combinations, valid (i.e., the second valid satellite group), and can be calculated based on Equation 12.

[0119] Meanwhile, the high-angle satellite selection unit (110) can re-select at least one high-angle satellite among the multiple satellites if the calculated difference value is greater than or equal to the position threshold value (i.e., if the condition of Equation 16 is not satisfied).

[0121] FIG. 2 is a diagram illustrating a satellite selection method according to one embodiment.

[0122] Referring to FIG. 2, in step 210, the satellite selection method can select at least one high-angle satellite among a plurality of satellites in the high-angle satellite selection unit.

[0123] According to one side, in step 210, the satellite selection method calculates an initial satellite selection weight based on the elevation angle information and signal strength information (Signal Noise Ratio; SNR) of each of the plurality of satellites in the high-elevation satellite selection unit, and can select a high-elevation satellite based on the calculated initial satellite selection weight.

[0124] Next, in step 220, the satellite selection method can produce an integrated positioning result based on at least one of the correction information among satellite navigation measurement correction information, GNSS time difference correction information and altitude information correction information, and altitude information derived through the high elevation angle satellite and the barometer in the integrated positioning unit.

[0125] For example, in step 220, the satellite selection method can receive at least one correction information from a reference station device in the integrated positioning unit.

[0126] According to one side, in step 220, the satellite selection method can convert position information based on high-elevation satellites into altitude information in the LLH (latitude-longitude-height) coordinate system and calculate an integrated positioning result based on the altitude information converted into the LLH coordinate system.

[0127] Next, in step 230, the satellite selection method can select at least one valid satellite based on the integrated positioning result in the valid satellite verification unit, and select at least one final valid satellite through the residual sum verification process and the positioning solution verification process based on the valid satellite.

[0128] According to one side, in step 230, the satellite selection method can derive a predicted value of the satellite measurement and a measured value of the satellite measurement based on the integrated positioning result in the valid satellite verification unit, calculate a residual value by differentiating the predicted value of the satellite measurement and the measured value of the satellite measurement, and select a valid satellite (hereinafter, the first valid satellite) based on the calculated residual value, wherein the valid satellite verification unit can form a first valid satellite group including the high-elevation satellite selected through the high-elevation satellite selection unit and the first valid satellite.

[0129] Specifically, in step 230, the satellite selection method can select at least one first valid satellite based on the result of comparing the calculated residual value with a preset residual threshold value in the valid satellite verification unit, calculate a covariance matrix based on the residual value of the first valid satellite, calculate a Weighted Square Sum of Error (WSSE) using the covariance matrix, and select at least one second valid satellite based on the Chi-Square distribution based on the calculated WSSE, wherein the valid satellite verification unit can form a second valid satellite group including the high-elevation satellite selected through the high-elevation satellite selection unit and the second valid satellite.

[0130] According to one side, in step 230, the satellite selection method derives a WSSE threshold value based on a false alarm rate according to a chi-square distribution in the valid satellite verification unit, and can select a second valid satellite based on the result of comparing the calculated WSSE and the WSSE threshold value.

[0131] For example, in step 230, the satellite selection method can select all selected first valid satellites as second valid satellites if the calculated WSSE is smaller than the WSSE threshold in the valid satellite verification unit.

[0132] In addition, in step 230, the satellite selection method can derive at least one recombined first valid satellite through a satellite recombination process for the first valid satellite if the calculated WSSE is greater than or equal to the WSSE threshold in the valid satellite verification unit, and select a second valid satellite based on the result of recalculating the WSSE of the recombined first valid satellite.

[0133] According to one side, in step 230, the satellite selection method can calculate the difference value between the calculated integrated positioning result and the positioning result of the selected valid satellite (i.e., the second valid satellite group) in the valid satellite verification unit, and select the final valid satellite based on the result of comparing the calculated difference value with a pre-set position threshold.

[0134] Meanwhile, in step 230, if the difference between the calculated integrated positioning result and the positioning result of the selected valid satellite is greater than the position threshold value, the high-angle satellite selection unit may re-select at least one high-angle satellite among the multiple satellites.

[0136] FIG. 3 is a diagram for explaining a satellite selection method according to one embodiment in more detail.

[0137] In other words, steps 310 to 340 described below through FIG. 3 can be performed in steps 210 to 230 of FIG. 2.

[0138] Referring to FIG. 3, in step 310, the satellite selection method can select at least one high-angle satellite among a plurality of satellites in the high-angle satellite selection unit.

[0139] For example, in step 310, the satellite selection method in the high-elevation satellite selection unit, based on Equation 1, weights ( After calculating ), the calculated weight( Satellites are added one by one to the initial satellite set in ascending order of ), and this operation is the minimum number of satellites (N) required for multi-satellite constellation positioning. consA combination of high-elevation satellites {SV0} can be constructed by repeating the process until the minimum HDOP (Horizontal Dilution of Precision) condition is satisfied.

[0140] Next, in step 320, the satellite selection method can produce an integrated positioning result based on at least one of the correction information among satellite navigation measurement correction information, GNSS time difference correction information and altitude information correction information, and altitude information derived through the high elevation angle satellite and the barometer in the integrated positioning unit.

[0141] In addition, in step 320, the satellite selection method can select at least one valid satellite (hereinafter, the first valid satellite) based on the integrated positioning result in the valid satellite verification unit.

[0142] For example, in step 320, the satellite selection method in the valid satellite verification unit uses the integrated positioning results to predict the satellite measurement value as shown in Equation 7 ( Calculate ) and the predicted value of the satellite measurement as in Equation 8 ( ) and actual values ​​of satellite measurements( Dividing ) to obtain the residual value( Calculate ), remove the bias component generated in the user clock error estimation by single-difference the measurement of the pre-set reference satellite(*) as in Equation 9, and GNSS time difference correction information as in Equation 10 ( Residual values ​​calculated using the GPS single positioning technique by applying ) ) can be produced.

[0143] In addition, in step 320, the satellite selection method in the valid satellite verification unit is the residual calculated by the GPS single positioning technique as in Equation 11 ( ) is the standard value( If the value is less than ) it can be determined as a valid measurement and the satellite corresponding to the valid measurement can be selected as the first valid satellite, and the valid satellite verification unit can form a first valid satellite group including the high-angle satellite selected through the high-angle satellite selection unit and the first valid satellite.

[0144] Next, in step 330, the satellite selection method can select at least one second valid satellite through a residual sum verification process based on the first valid satellite (i.e., a verification process of the first valid satellite) in the valid satellite verification unit, wherein the valid satellite verification unit can form a second valid satellite group including the second valid satellite and the high-elevation satellite selected through the high-elevation satellite selection unit.

[0145] For example, in step 330, the satellite selection method calculates a covariance matrix based on the residual value of the first valid satellite in the valid satellite verification unit, performs WSSE using the covariance matrix, and can select at least one second valid satellite based on the Chi-Square distribution based on the calculated WSSE.

[0146] Specifically, in step 330, the satellite selection method in the valid satellite verification unit involves the calculated WSSE based on Equation 15 and the WSSE threshold (Th WSSE If the WSSE calculated based on the comparison process of ) is less than the WSSE threshold, all selected first valid satellites can be selected as second valid satellites.

[0147] Meanwhile, the calculated WSSE and WSSE threshold (Th WSSE If ) or more, in step 330-1 the satellite selection method can derive at least one recombined first valid satellite through a satellite recombination process for the first valid satellite in the valid satellite verification unit, and in step 330 the satellite selection method can select a second valid satellite based on the WSSE recalculation result of the recombined first valid satellite in the valid satellite verification unit.

[0148] Specifically, in steps 330-1 and 330, if the calculated WSSE is greater than or equal to the WSSE threshold (i.e., if the condition of Equation 15 is not satisfied), the selection process for the second valid satellite can be repeated by calculating the WSSE for the remaining satellites excluding one of the first valid satellites (i.e., the recombined first valid satellite) and then re-performing the residual verification.

[0149] Next, in step 340, the satellite selection method can select at least one final valid satellite through a positioning verification process based on the second valid satellite (i.e., a verification process of the second valid satellite) in the valid satellite verification unit.

[0150] For example, in step 340, the satellite selection method can calculate the difference value between the integrated positioning result and the positioning result of the selected second valid satellite in the valid satellite verification unit, and select the final valid satellite based on the comparison result between the calculated difference value and a preset position threshold.

[0151] Specifically, in step 340, the satellite selection method in the valid satellite verification unit, as shown in Equation 16, the integrated positioning result ( ) and positioning results of the second effective satellite constellation ( Derive the difference value of ), and the derived difference value and the position threshold ( A comparison process between ) can be performed, and if the difference value derived through the comparison process is less than the position threshold (i.e., if the condition of Equation 16 is satisfied), the satellites included in the selected second valid satellite group can be selected as the final valid satellites.

[0152] In addition, in step 340, if the derived difference value is greater than or equal to the position threshold (i.e., if the condition of Equation 16 is not satisfied), the high-angle satellite selection unit may re-select the high-angle satellite, and steps 320 through 340 may be repeated based on the information of the re-selected high-angle satellite.

[0154] Ultimately, by using the present invention, it is possible to select a satellite with good positioning regardless of multipath error based on an integrated positioning result based on information from a high-angle satellite and altitude information calculated through a barometer.

[0155] In addition, by using the present invention, satellites with good positioning can be selected more accurately and with higher reliability through a residual sum verification process and a positioning solution verification process based on integrated positioning results.

[0157] The device described above may be implemented as a hardware component, a software component, and / or a combination of a hardware component and a software component. For example, the device and components described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on the operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. Additionally, other processing configurations, such as parallel processors, are also possible.

[0158] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0159] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below. Explanation of the symbols

[0160] 100: Satellite sorting device 110: Elevation angle satellite selection unit 120: Integrated Positioning Unit 130: Valid Satellite Verification Unit

Claims

Claim 1 A high-angle satellite selection unit for selecting at least one high-angle satellite among a plurality of satellites; an integrated positioning unit for calculating an integrated positioning result based on at least one correction information among satellite navigation measurement correction information, GNSS time difference correction information, and altitude information correction information, and altitude information derived through the information of the high-angle satellite and a barometer; and a valid satellite verification unit for selecting at least one valid satellite based on the integrated positioning result, and selecting at least one final valid satellite through a residual sum verification process and a positioning solution verification process based on the valid satellite, wherein the valid satellite verification unit derives a predicted value of a satellite measurement and an actual value of a satellite measurement based on the integrated positioning result, calculates a residual value by differentiating the predicted value of the satellite measurement and the actual value of the satellite measurement, and selects the valid satellite based on the calculated residual value, wherein at least one first valid satellite is selected based on the comparison result between the calculated residual value and a preset residual threshold, and calculates a covariance matrix according to the residual value of the first valid satellite, and using the covariance matrix A satellite selection device that calculates a Weighted Square Sum of Error (WSSE) and selects at least one second valid satellite based on a Chi-Square distribution according to the calculated WSSE. Claim 2 In claim 1, the high-angle-of-elevation satellite selection unit calculates an initial satellite selection weight based on the elevation angle information and signal strength information (Signal Noise Ratio; SNR) of each of the plurality of satellites, and the satellite selection device selects the high-angle-of-elevation satellite based on the calculated initial satellite selection weight. Claim 3 In paragraph 1, the integrated positioning unit is a satellite selection device that receives at least one correction information from a reference station device. Claim 4 In claim 1, the integrated positioning unit is a satellite selection device that converts position information based on the elevation angle satellite into altitude information in an LLH (latitude-longitude-height) coordinate system and calculates the integrated positioning result based on the altitude information converted into the LLH coordinate system. Claim 5 delete Claim 6 delete Claim 7 In claim 1, the valid satellite verification unit derives a WSSE threshold value based on a false alarm rate according to the chi-square distribution, and the satellite selection device selects the second valid satellite based on the result of comparing the calculated WSSE with the WSSE threshold value. Claim 8 In claim 7, the valid satellite verification unit derives at least one recombined first valid satellite through a satellite recombination process for the first valid satellite if the calculated WSSE is greater than or equal to the WSSE threshold, and the satellite selection device selects the second valid satellite based on the result of recalculating the WSSE of the recombined first valid satellite. Claim 9 In claim 1, the valid satellite verification unit calculates the difference value between the calculated integrated positioning result and the positioning result of the selected valid satellite, and the satellite selection device selects the final valid satellite based on the comparison result between the calculated difference value and a preset position threshold. Claim 10 In claim 9, the high-angle satellite selection unit is a satellite selection device that re-selects at least one high-angle satellite among the plurality of satellites if the calculated difference value is greater than the position threshold value. Claim 11 A step of selecting at least one high-angle satellite among a plurality of satellites in a high-angle satellite selection unit; a step of calculating an integrated positioning result based on at least one correction information among satellite navigation measurement correction information, GNSS time difference correction information, and altitude information correction information, and altitude information derived through the information of the said high-angle satellite and a barometer in an integrated positioning unit; A satellite selection method comprising, in a valid satellite verification unit, a step of selecting at least one valid satellite based on the integrated positioning result, and selecting at least one final valid satellite through a residual sum verification process and a positioning solution verification process based on the valid satellite, wherein the step of selecting at least one final valid satellite comprises deriving a predicted value of a satellite measurement and an actual value of a satellite measurement based on the integrated positioning result, calculating a residual value by differentiating the predicted value of the satellite measurement and the actual value of the satellite measurement, and selecting the valid satellite based on the calculated residual value, wherein at least one first valid satellite is selected based on the comparison result between the calculated residual value and a preset residual threshold, calculating a covariance matrix according to the residual value of the first valid satellite, calculating a Weighted Square Sum of Error (WSSE) using the covariance matrix, and selecting at least one second valid satellite based on a Chi-Square distribution according to the calculated WSSE.

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