WO2004025319A9 - Method and system for determining absolute positions of mobile communications devices using remotely generated positioning information - Google Patents
Method and system for determining absolute positions of mobile communications devices using remotely generated positioning informationInfo
- Publication number
- WO2004025319A9 WO2004025319A9 PCT/US2003/025077 US0325077W WO2004025319A9 WO 2004025319 A9 WO2004025319 A9 WO 2004025319A9 US 0325077 W US0325077 W US 0325077W WO 2004025319 A9 WO2004025319 A9 WO 2004025319A9
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- mobile
- gps
- mobiles
- positioning information
- processing module
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/0009—Transmission of position information to remote stations
- G01S5/0072—Transmission between mobile stations, e.g. anti-collision systems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
- G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/42—Determining position
- G01S19/51—Relative positioning
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
- G01S5/0284—Relative positioning
Definitions
- the present invention relates generally to determining positions of objects and, more particularly, determining absolute positions of a plurality of wirelessly networked mobile communications devices at the mobiles themselves using positioning information signals transmitted from a remote location and the wireless communications capabilities of the mobiles.
- Groups of individuals such as police officers, firefighters, rescue workers or soldiers, often need to conduct operations in built up urban areas. While operating in such areas, the individuals often find it difficult or impossible to maintain accurate and updated knowledge of one another's locations because the structures in an urban area block visual contact between the individuals. As a result of the inability to establish visual contact, soldiers in urban environments often become casualties of friendly fire. Similarly, police officers, firefighters and soldiers are not able to assist fallen comrades who may be nearby, yet cannot be visually observed.
- GPS global positioning system
- GPS fix absolute position
- an individual carrying a GPS enabled device In urban areas, an individual carrying a GPS enabled device often moves to locations that do not permit the GPS enabled device to receive GPS information signals transmitted from at least four GPS satellites. For example, natural terrain or man-made structures in an urban environment often attenuate or block signals transmitted from GPS satellites. Therefore, a group of individuals, each carrying a GPS enabled device, cannot always rely upon the computation of a GPS fix at each individual of the group, and the communication of the GPS fix from one individual to other individuals of the group, such as by wireless means, to ensure that each individual of the group continuously is aware of the absolute positions of other individuals in the group.
- each of first and second mobile communications devices cannot receive positioning information signals transmitted from a sufficient number of positioning information signal transmission sources, which are located remotely from the first and second mobiles, to determine its absolute position in the absence of any other positioning information
- the first mobile determines its absolute position and the absolute position of the second mobile based on (i) information obtained from wireless communications between the first and second mobiles, and (ii) the first and second mobiles, in combination, receiving positioning information signals transmitted over a predetermined number of line of sight (“LOS") communications signal reception paths that are established with remote positioning information signal sources which are visible to the first mobile or the second mobile.
- the first mobile wirelessly communicates the computed absolute positions of the first and second mobiles to the second mobile, such that individuals carrying the first and second mobiles, respectively, are aware of their respective absolute positions.
- LOS line of sight
- a first mobile communications device computes its absolute position and the absolute position of a second mobile communications device where (i) each of the first and second mobiles has global positioning system ("GPS") and wireless communications signal receiving capabilities, a time of day clock and data and signal processing capabilities; (ii) the first and second mobiles, in combination, can receive GPS information signals transmitted from as few as three GPS satellites; (iii) the first and second mobiles can establish at least five LOS paths to the as few as three GPS satellites; and (iii) the first and second mobiles, using their wireless communications capabilities, can determine, or obtain information representative of, their relative positions.
- GPS global positioning system
- wireless communications signal receiving capabilities a time of day clock and data and signal processing capabilities
- the first and second mobiles in combination, can receive GPS information signals transmitted from as few as three GPS satellites; (iii) the first and second mobiles can establish at least five LOS paths to the as few as three GPS satellites; and (iii) the first and second mobiles, using their wireless communications capabilities, can determine,
- a first mobile communications device computes its absolute position and the absolute position of a second mobile communications device, where (i) each of the first and second mobiles has GPS and wireless communications signal receiving capabilities, a time day of clock and data and signal processing capabilities; (ii) the first and second mobiles, in combination, can establish, using their wireless communications capabilities, LOS communications paths to at least six GPS satellites; (ii) each of the first and second mobile, using their wireless communications capabilities, can determine the distance ("range") separating each other; and (iii) the first or second mobile can determine their relative clock bias.
- a GPS enabled mobile includes a position processing module coupled to a wireless data transceiver module and a GPS and wireless communications signal ranging transceiver module.
- the ranging transceiver module communicates wirelessly with the ranging transceiver module of a second GPS enabled mobile, which is preferably a part of the same wirelessly networked group, to obtain information for computing the range between the mobiles.
- the ranging transceiver module establishes LOS paths with each visible GPS satellite and receives GPS positioning information signals transmitted from the GPS satellites on these LOS paths.
- the wireless data transceiver module receives relative position information or, optionally, range information obtained from wireless communications with the second mobile, from the data transceiver of the second mobile.
- the position processing module includes a time of day clock and GPS satellite orbital position data.
- the position processing module computes its absolute position ("GPS fix") and also the GPS fix of the second mobile, based on the stored GPS satellite orbital information, positioning information obtained from the received GPS signals and at least one of the range and the relative position information for the second mobile.
- GPS fix absolute position
- the mobile wirelessly transmits the computed GPS fixes to other mobiles of the group or to a remote communications device.
- FIG. 1 is an illustration of a geometric shape defined by ranges measured between a GPS enabled mobile communications device and three GPS satellites.
- FIG. 2 is an illustration of the geometric shape of FIG. 1 including a fourth GPS satellite and indicating the effect of the assumed GPS clock bias on the assumed position of the GPS mobile.
- FIG. 3 is a functional block diagram of a GPS enabled mobile communications device in accordance with a preferred embodiment of the present invention.
- FIG. 4 is an illustration of two GPS enabled mobile communications devices, in accordance with the present invention, positioned so that LOS paths can be established to only five GPS satellites.
- FIG. 5 is a flow diagram for computing GPS fixes for two respective GPS enabled mobile communications devices, in accordance with the present invention, where the relative positions of the two GPS mobiles are known.
- FIG. 6 is a flow diagram for computing GPS fixes for two respective GPS enabled mobile communications devices, in accordance with the present invention, where the two GPS mobiles can determine the range between each other and their relative GPS clock bias.
- FIG. 7 is an illustration of a configuration including first and second GPS enabled mobile communications devices, in accordance with the present invention, where the first mobile can establish LOS paths to four GPS satellites and the second mobile cannot establish LOS paths to four GPS satellites.
- FIG. 8 is an illustration of the configuration of FIG. 7 highlighting ranges used to compute GPS fixes for the first and second mobiles, in accordance with the present invention.
- FIG. 1 illustrates an exemplary GPS configuration 10 including a GPS enabled receiver A positioned so that it can establish LOS paths to three GPS satellites 11, 12 and 13.
- GPS fix absolute position
- each of the GPS satellites 11 , 12, 13 includes a time of day clock and transmits known pseudorandom ("PN") patterns at respective predetermined times of day.
- PN pseudorandom
- the GPS receiver A includes orbital ephemeris data in its memory from which it can compute, with great accuracy, the orbital positions of the GPS satellites 11, 12 and 13 at predetermined times.
- the GPS receiver also includes a time of day clock, and expects to receive a predetermined PN pattern at a predetermined time from a particular GPS satellite.
- the GPS receiver A correlates the expected PN pattern and the received PN pattern to determine precisely when the PN pattern was received from the GPS satellite. If the respective time of day clocks in each of the GPS satellites and in the GPS receiver are exactly synchronized, the propagation delay for the GPS signal transmitted from each of the GPS satellites 11, 12 and 13 to the GPS receiver A can be readily computed. As radio frequency signals travel at a constant velocity, the range from each of the GPS satellites 11, 12 and 13 to the GPS receiver A can be computed from the propagation delays using well known techniques. The three measured ranges, A- 11, A-12, and A-13, always define a unique point A.
- the GPS receiver A can compute the known orbital positions of the GPS satellites at predetermined times based on orbital data stored in its memory, the ranges between the three GPS satellites 1, 2 and 3, respectively, and the GPS receiver A can be represented as the tetrahedral configuration 10 shown in FIG. 1.
- FIG. 2 illustrates a configuration 20, which includes the GPS receiver A and the GPS satellites 11, 12 and 13 and indicates the effect that clock bias has on the configuration 10 of FIG. 1.
- the position of the GPS receiver A which constitutes the vertex of the tetrahedron 10, is displaced by some unknown amount from the true GPS receiver A location at A', based on the clock bias.
- this measured range in general, will not be an exact match for the distance that can be computed between the known position of the GPS satellite 14 and the unique location of A defined by the ranges to the GPS satellites 11, 12, and 13.
- least squares techniques can be used to compute the estimated GPS receiver A position (x, y, z) and the clock offset s that produces the best fit, in a least squared error sense, with the set of the four range measurements. In general, as ranges to more GPS satellites are added to the calculation, the best fit continues to improve. It is noted that a set of only four range measurements is needed to compute a useful estimate of the position the GPS receiver A.
- the absolute position of an object having GPS receiving and data processing capabilities can be computed using GPS positioning information signals, which permit measurement of the range (distance) between a GPS satellite, which orbits the earth, and a GPS receiver, which is positioned on or near the surface of the earth, based on determination of the time that it takes for a radio signal to propagate from the GPS satellite to the GPS receiver.
- the GPS receiver computes the measured distance for each satellite -, or the measured pseudorange, as
- the GPS receiver solves the linearized system of equations for the four unknown values (x, y, z, s) using an iterative approach, such as described below.
- the GPS receiver assumes a nominal starting position (x, y, z) and clock offset error s and initially sets all four of these values to zero.
- the GPS receiver computes an estimated range, range from each GPS satellite visible, i.e., for which a LOS path can be established, to the GPS receiver using correlation of PN patterns and estimation of carrier phase.
- the GPS receiver then computes a pseudorange from each GPS satellite to the assumed GPS receiver position as
- a group of GPS receivers collectively can receive GPS information signals from a predetermined number of GPS satellites, although not one GPS receiver of the group can receive GPS information signals transmitted from a sufficient number of GPS satellites such that the GPS receiver, solely based on the received GPS information signals, can compute a GPS fix
- GPS fixes can be computed at two of the GPS receivers if relative position or range information with respect to the two GPS receivers is available.
- each GPS enabled mobile communications device (“GPS mobile”) of a wirelessly networked group including a plurality of the GPS mobiles can compute its GPS fix and the GPS fix of another GPS mobile of the group, where none of the mobiles of the group can establish LOS paths with more than three GPS satellites, based on (i) receipt of GPS positioning information signals transmitted from a predetermined number of GPS satellites visible to either of the two GPS mobiles, and (ii) determining or exchanging range or relative positioning data with another mobile of the group using the wireless communications capabilities of the mobiles.
- a GPS enabled mobile communications device of a group of networked mobiles in accordance with a preferred embodiment of the present invention, is referred to generally as a mobile 101 and individual mobiles of the group are referred to as mobiles 101 A, 101B, etc., and modules within the respective mobiles also are referred to using the suffixes A, B, etc.
- FIG. 3 illustrates a preferred embodiment of the mobile 101 in accordance with the present invention.
- the mobile 101 includes a GPS and wireless ranging transceiver module 102, a data transceiver module 104, a position processing module 105 and a position display module 106.
- the data transceiver module 104 is coupled to the ranging transceiver module 102 and the position processing module 105.
- the position processing module 105 is coupled to the position display module 106 and the ranging transceiver module 102.
- the ranging transceiver module 102 is coupled to an antenna 120 and the data transceiver module 104 is coupled to an antenna 122.
- each of the modules of the inventive mobile 101 which are described below as performing data processing operations, constitutes a software module or, alternatively, a hardware module or a combined hardware/software module.
- each of the modules suitably contains a memory storage area, such as RAM, for storage of data and instructions for performing processing operations in accordance with the present invention.
- instructions for performing processing operations can be stored in hardware in one or more of the modules.
- the modules of the mobile 101 can be combined, as suitable, into composite modules.
- the antennae 120 and 122 which are conventional devices well known in the prior art, can be combined into a single integral antenna, as is also well known in the art.
- the ranging transceiver module 102 which includes a conventional wireless, such as a radio frequency (“RF") signal, receiver and transmitter, collects data for determining the distance between the mobile in which it is contained and another of the other mobiles in the networked group.
- the ranging transceiver module 102 includes a time of day clock and GPS satellite data from which the orbital positions of GPS satellites, at any time of day, can be accurately computed.
- the ranging transceiver module 102 receives and processes the GPS information signals transmitted from the GPS satellites visible to the mobile 101 in accordance with well known GPS techniques, which involve using the current time of day indicated at the clock of the ranging transceiver module 102. The transceiver module 102 then routes the time-indexed, processed GPS information to the position processing module 105.
- the transceiver module 102 establishes, via the antenna 120, a wireless radio ranging link 107 between itself and the transceiver module 102 of another mobile of the group. Based on the radio raging links, the transceiver 102 measures the signal transit time between itself and the ranging transceiver module of the other mobile. From the signal time transit data, the ranging transceiver module 102 at either of the mobiles can readily compute the range between the two mobiles using well known techniques.
- the ranging transceiver module 102 uses an RF carrier modulated by a high rate pseudorandom ("PN") pattern for ranging to another mobile.
- the signal used for ranging is an ultrawideband (“UWB”) signal.
- UWB is advantageous because: (1) it provides virtually infinite frequency diversity, thus ensuring that the ranging signal can penetrate a wide variety of common building materials; (2) UWB signals have a low probability of detection and intercept; (3) the narrow pulse widths (500 psec) used in UWB allows for ranging accuracies to less than one foot; (4) and UWB signals can be used anywhere in the world without having to fit into or coordinate with local civilian and military frequency allocation plans.
- the data transceiver module 104 which includes a conventional wireless, such as an RF signal, receiver and transmitter, wirelessly exchanges, via the antenna 122, information between itself and the data transceiver module of another mobile of the group.
- the data module 104 transmits its relative position with respect to the other mobile to the other mobile via a wireless data link 108 established between itself and the data transceiver module of the other mobile.
- the relative position may have been determined as discussed in "METHOD AND SYSTEM FOR DETERMINING RELATIVE POSITIONS OF NETWORKED MOBILE COMMUNICATION DEVICES", U.S. Serial No. , filed August 11 , 2003, assigned to the assignee of this application and incorporated by reference herein.
- the data transceiver 104 transmits computed GPS fix information to the other mobile, or any other mobile of the group, as suitable, over a wireless data link 108 established between its data transceiver module and the data transceiver module of the other mobiles.
- the position processing module 105 retrieves the GPS information data and any ranging data from the ranging transceiver module 102, and any range and or relative position data received at the data transceiver module 104, and uses the retrieved data to compute, as discussed in detail below, a GPS fix for itself and also for the other mobile to which the ranging or relative position data pertains.
- the position display module 106 displays the absolute position of the mobile in which it is contained, and which was computed at the position processing module 105 of the mobile, and also the absolute position of another mobile that the position processing module 105 computed or which was received on a data link 108 established with the data transceiver module 104.
- the module 106 includes a display unit resembling an oversized ruggedized PDA.
- the module 106 is not included in selected mobiles of a group.
- the mobile 101 includes a first component structure, which does not include the antennae 120 and 122, is approximately the size of a cordless telephone handset and is configured to be worn on or attached to an article of clothing.
- the antennae 120 and 122 are embodied as a second component structure, preferably readily attachable to a shirt collar.
- the first and second component structures of the mobile 101 are electronically coupled to one another.
- the component structures of the mobile 101 are configured to be carried in a holster to provide for easy removal for use.
- each of GPS enabled mobiles 101 A and 101 B by cooperatively using its wireless communications signal capabilities, computes a GPS fix for itself and a GPS fix for the other mobile when (i) the mobiles 101 A and 101B, in combination, can receive GPS information signals transmitted from as few as three GPS satellites; (ii) at least five distinct LOS communications paths can be established between the mobiles 101 A and 101 B and the as few as three GPS satellites; and (iii) the mobiles 101 A and 101 B can determine or obtain information representative of their relative positions.
- the relative position information is stored in the memory of the position processing module 105A and expressed in the form of values XA O B ⁇ AOB and Z AOB , such that
- the mobile 101 A can receive GPS information signals from several GPS satellites and the mobile 101B can receive GPS information signals from several GPS satellites, for either of the two mobiles 101 A and 101 B, a total of five unknowns exist.
- the unknowns are the three unknown position coordinates, (x ⁇ , y ⁇ , Z A ) for the mobile 101 A, or (x B , y ⁇ , z B ) for the mobile 101 B, and, as the clock biases of the two mobiles 101 A and 101B are independent, the two additional unknown clock biases, s A and s B .
- One pseudorange equation can be generated from each LOS path established between either of the mobiles 101A and 101 B and one of the visible GPS satellites.
- the minimum five equations can be generated based on three GPS satellites being visible to one GPS mobile and two GPS satellites being visible to the other mobile.
- the two groups do not have to be distinct.
- the first mobile can establish LOS paths to three satellites and the second mobile can establish LOS paths to two of the same GPS satellites to which the first mobile can establish LOS paths.
- the first aspect of the invention permits computation of the GPS fixes for a configuration where the first mobile can establish LOS paths to four GPS satellites and the second mobile can establish an LOS path to only one GPS satellite, this configuration permits the first mobile to compute a GPS fix using prior art techniques as discussed above. Accordingly, for each GPS satellite from which the mobile 101 A can receive
- the mobile 101A can receive GPS information signals from NGPS satellites and the mobile 101 B can receive GPS information signals from GPS satellites, then the mobile 101A can use Equations (9) and (11) to form a system of N+M equations having the five unknowns x A ,y A , z A , s A and s B . For all cases in which N+M ⁇ 5 , this system can be solved using an iterative approach.
- an estimate of the bias between the clocks that the mobiles 101 A and mobile 101 B use for GPS ranging can be computed in accordance with well known prior art techniques for determining the relative positions of the mobiles 101 A and 101 B. Based on this bias estimate, the positioning processing module 105A can expressly relate the GPS clock biases of the mobiles 101 A and 101 B to reduce the total number of unknowns from five to four. Consequently, GPS fixes can be computed for two GPS mobiles, where relative position information is available, when the two GPS mobiles, together, can receive GPS information from as few as three satellites and at least four LOS paths can be established between the two GPS receivers and the three GPS satellites.
- FIG. 4 illustrates an exemplary configuration 120 of the mobiles 101A and 101 B separated by a blocking structure 115 and GPS satellites 121 , 122 ,123, 124 and 125, positioned in relation to the mobiles 101 A and 101B and the blocking structure 115, such that the mobile 101 A can establish LOS paths only to the GPS satellites 121, 122 and 123 and the mobile 101B can establish LOS paths only to the GPS satellites 123, 124 and 125.
- each of the mobiles 101 A and 101B cannot, based solely on received GPS information signals, compute a GPS fix using prior art GPS techniques, because neither of the mobiles 101 A and 101 B can establish LOS paths to at least four GPS satellites.
- FIG. 5 illustrates a preferred process 150 for computing a GPS fix for the mobile 101 A and a GPS fix for the mobile 101 B in accordance with the first aspect of the invention, where the mobiles 101A and 101 B are positioned with respect to each other and the GPS satellites 121-125 in the configuration 120 as shown in FIG. 4, based on the relative positions of the mobiles 101 A and 101B and the GPS information signals that the mobiles 101 A and 101B can receive from the GPS satellites 121, 122, 123, 124 and 125.
- the mobiles 101A and 101 B wirelessly communicate with each other, using their respective data transceiver modules 104, to establish direct communication links 108, which can include an indirect communication link via a relay site, through which information representative of the positions of the mobiles 101 A and 101 B relative to each other can be obtained.
- the mobile 101 A preferably determines its position relative to the mobile 101B, or the mobile 101B wirelessly transmits the relative position information to the mobile 101 A. Referring to FIG. 5, in step 152 the position processing module 105A assumes a nominal starting position (x A ,y A ,z A ) for the mobile 101A and clock offset errors s A and s B for the clocks included in the respective ranging transceiver modules 102A and
- the position processing module 105A computes an assumed position ( ⁇ B ,y B ,z B ) for the mobile 101B using Equation (8).
- the position processing module 105A using results of correlation of PN patterns received at the ranging transceiver module 102A with expected PN patterns and the estimated carrier phase at the mobile 101 A estimates the range, r Ai , between the mobile 101 A and each of the GPS the GPS satellites 121 ,
- the position processing module 105B uses results of correlation of PN patterns received at the ranging transceiver module 102B with expected PN patterns and the estimated carrier phase at the mobile 101B, estimates the range, r Bj , between the mobile 101B and each of the GPS satellites 123, 124 and 125, which are visible to the mobile 101 B.
- the mobile 101 B communicates the estimated ranges r Bj to the mobile 101 A by establishing a link 108 between the respective data transceiver modules 104A and 104B.
- step 160 the position processing module 105A, for each GPS satellite to which a LOS path can be established with the mobile 101 A, namely, the GPS satellites 121, 122 and 123, computes a pseudorange between the visible satellite and the assumed position of the mobile 101 A as
- step 160 the position processing module 105A, for each GPS satellite to which a LOS path can be established to the mobile 101B, namely, the GPS satellites 123, 124 and 125, computes a pseudorange between the visible satellite and the assumed position of the mobile 101 B as
- step 162 the position processing module 105A forms the range delta vector
- ⁇ [ ⁇ ⁇ • ⁇ • ⁇ ⁇ B1 ... ⁇ 5M ] T
- a Bj P B J - r Bj
- the position processing module 105A in accordance with Equations (10) and (12), forms the ⁇ matrix ⁇ a Aiy 1 0
- step 166 the position processing module 105A determines if the RMS error is less than a predetermined threshold, such as one foot. If yes, then in step 168, the position processing module 105A accepts the current position values ( ⁇ A ,y A ,z A ) as the final estimated absolute position of the GPS mobile 101 A and proceeds to step 172. If no, then in step 170 the position processing module 105A updates the assumed values (x A ,y A ,z A ,s A ) for the mobile 101A by adding the corrections ( ⁇ x, ⁇ y, ⁇ z, ⁇ s) and proceeds to step 160.
- a predetermined threshold such as one foot.
- step 172 the position processing module 105A computes ( ⁇ B ,y B , z B ) by substituting the final absolute position values ⁇ A ,y A ,z A ) for the mobile 101 A into
- the first aspect of the invention also is applicable to a circumstance where there are more than two GPS mobiles so long as the relative positions of all of the GPS mobiles are known and can be provided to all of the GPS mobiles, which ensures that only three unknown position coordinates exist regardless of the number of GPS mobiles involved.
- Each additional GPS mobile adds an additional unknown clock bias, such that the minimum number of LOS paths ("N / / coronarfa") between the GPS receivers and GPS satellites must be three more than the number of GPS receivers ("N cv/ .”) or
- the first aspect of the invention can be applied to any number of GPS enabled mobiles, no additional value is obtained when there are more than three GPS mobiles in a configuration.
- the number of LOS paths can be split 3-2 or 4-1 between the two GPS mobiles.
- the 4-1 split permits computation of the GPS fix using the prior art technique, such that the first aspect of the invention adds value only in the case of the 3-2 split.
- the number of required LOS paths is six and can be split 2-2-2 or 3-2-1.
- the split 3-2-1 corresponds to the 3-2 split for the two GPS mobile configuration with an extra GPS mobile added that can establish an LOS path to only one GPS satellite.
- the GPS fix can be computed using only the two GPS mobiles that account for five of the LOS paths.
- the 2-2-2 split adds value in configurations where each GPS mobile can establish LOS paths to two GPS satellites and none can establish LOS paths to three or more GPS satellites. In the configuration of four GPS mobiles, the required number of LOS paths is seven and can be split 3-2-1-1 or 2-2-2- 1. There is no added value in this four GPS mobile configuration, as the 3-2-1-1 split can be solved as in the two GPS mobile configuration with a 3-2 split, and the 2-2-2-1 split can be solved as in the three GPS mobile configuration with a 2-2-2 split.
- each of first and second GPS mobiles 101 A and 101B can be in a configuration where each mobile cannot compute its GPS fix using prior art techniques requiring that at least four GPS satellites are visible and where each mobile does not have information as to and cannot compute its position relative to the other mobile
- each of the mobiles 101 A and 101 B working cooperatively using their respective wireless communications capabilities, can obtain a GPS fix for itself and a GPS fix for the other mobile when (i) at least six LOS paths can be established between the mobiles 101A and 101 B and visible GPS satellites, and (ii) each of the mobiles 101 A and 101B can compute the distance (range) between each other and the relative clock bias between the mobiles 101A and 101B.
- the position processing module at one of the mobiles 101 A and 101 B computes the range, r AB , between the mobiles 101 A and 101B based on measurement of propagation times of communications signals transmitted between the ranging transceiver modules of the respective mobiles 101 A and 101 B.
- the position processing module 105A preferably computes the range r AB based on the average of the apparent propagation times from the mobile 101A to the mobile 101 B and from the mobile 101 B to the mobile 101 A as follows: r ⁇ c-' ⁇ — ⁇ (16)
- the propagation times are averaged to attempt to remove the affect of any clock bias between the mobiles 101 A and 101B.
- the position processing module 105A computes the clock bias, b AB , as one half the difference between the mobile 101A-to- mobile 101 B propagation time and the mobile 101 B-to-mobile 101 A propagation time, or:
- the propagation time measurements for the mobiles 101 A and 101B provide that the clock bias of the mobile 101B can be expressed as a function of the clock bias of the mobile 101 A, such that there is only one unknown for clock bias.
- the position processing module 105A also constructs a supplemental equation of the form
- PAB ABxA ⁇ x A + a AByA 5 y A + ®ABzA ⁇ z A + ABxB ⁇ B + a A B> B ⁇ y B + AByB ⁇ z B (21 )
- X A X B Continue ⁇ y A y B u ABxA ""AB A "A-..
- Equation (21) which is a pseudorange equation that is not created based on an LOS path that is established with a GPS satellite, the two mobiles 101A and 101 B only need to establish LOS paths with at least six GPS satellites.
- Equation (21) which is a pseudorange equation that is not created based on an LOS path that is established with a GPS satellite, the two mobiles 101A and 101 B only need to establish LOS paths with at least six GPS satellites.
- N+M ⁇ 6 the system of equations can be solved for the unknowns using an iterative least squares approach.
- FIG. 6 illustrates a preferred process 200 for computing GPS fixes for each of first and second GPS mobiles, in accordance with the second aspect of the invention, based on the measured range between the two mobiles, which is determined based on wireless communications between the two mobiles, where the two mobiles can establish at least six LOS paths with GPS satellites and neither of the two mobiles can establish LOS paths with at least four GPS satellites.
- the process 200 is described below with reference to a configuration 190 as shown in FIG. 7. Referring to FIG.
- the configuration 190 includes GPS mobiles 101 A and 101 B positioned in relation to GPS satellites 121-124 such that (i) the GPS mobile 101A can establish LOS paths to each of the GPS satellites 121-124, which provides that the mobile 101A can compute its GPS fix using prior art GPS techniques; (ii) the GPS mobile 101B is located within wireless communications proximity of the GPS mobile 101 A, such that each of the GPS mobiles 101 A and 101B can compute the range between the mobiles using conventional RF signal ranging techniques; and (iii) LOS paths only can be established between the GPS mobile 101 B and each of the GPS satellites 121 and 124, such that the GPS mobile 101 B cannot determine its GPS fix using prior art techniques which require receipt of GPS information signals from at least four GPS satellites. Referring to FIG.
- step 202 the position processing module 105A assumes nominal starting positions (x A ,y A ,z A ) and ( ⁇ B ,y B ,z B ) , respectively, for the mobiles 101A and 101 B and a clock offset error s A for the clock in the ranging transceiver module 102A.
- the ranging transceiver modules 102A and 102B using any suitable prior art wireless ranging technology, respectively measure the time that it takes for a signal transmitted from the mobile 101A to reach the mobile 101B, or the propagation time ⁇ M , and the time that it takes for a signal transmitted from the mobile 01B to reach the mobile 101B, or the propagation time ⁇ BA .
- the ranging transceiver module 102A transmits a time encoded wireless signal, such as an RF signal, to the ranging transceiver module 102B. Based on this transmission, the ranging transceiver module 102B can determine the time that it took for the RF signal to propagate from the mobile 101 A to the mobile 101B.
- a time encoded wireless signal such as an RF signal
- the data transceiver module 104B retrieves the propagation time data, ⁇ M , from the ranging transceiver module 102B and routes .this data on a wireless link 108 to the data transceiver module 104A of the mobile 101 A.
- the data transceiver 104A then routes the received propagation time information to the position processing module 105A for storage therein.
- the mobile 101A includes in its memory measurements of RF signal propagation time between the mobiles 101 A and 101 B, where the measurements have been made at the mobile 101 A and the mobile 101B.
- the mobiles 101 A and 101B in steps 204 and 206, operate cooperatively to collect the propagation time data necessary for determining the range between each other.
- step 208 the position processing module 105A computes the range to the mobile 101 B as
- step 210 the position processing module 105A performs the same computations and actions as set forth in steps 156 and 158 of the process 150 for computing estimated ranges r ⁇ . and ⁇ and for transmitting the estimated ranges r ⁇ -from the mobile 101A to the mobile 101B on a wireless link 108.
- step 212 the position processing module 105A computes a pseudorange between each GPS satellite to which the mobile 101 A can establish an LOS path, namely the GPS satellites 121-124, and the assumed position of the mobile 101A as
- the position processing module 105A computes a pseudorange between each GPS satellite to which the mobile 101B can establish an LOS path, namely the GPS satellites 121 and 124, and the assumed position of the mobile 101B as
- step 214 the position processing module 105A computes a pseudorange between the assumed position for the mobile 101 A and the assumed position for mobile 101B as
- PAB J( X A ⁇ X B) 2 + ( X A ⁇ X B ⁇ + ( X A ⁇ X BY (26)
- step 216 the position processing module 105A computes a range delta vector ⁇ as
- step 216 the position processing module 105A, using the Equations (10) and (21), forms the ⁇ matrix as
- step 220 the position processing module 105A determines if the RMS error is less than a predetermined threshold. If yes, then in step 222, the position processing module 105A accepts the current values for ( ⁇ A ,y ⁇ ,z A ) as the final absolute position of the GPS mobile 101 A and proceeds to step 226. If no, then in step 224 the position processing module 105A updates the assumed values (x A ,y A ,z A ,s A ) by adding the corrections ( ⁇ x, ⁇ y, ⁇ z, ⁇ s) and proceeds to step 212.
- step 226 the position processing module 105A computes (x B ,y B , z B ) by substituting the final values (x A ,y A ,z A ) for the mobile 101 A into Equation (8), and then the data transceiver module 102A transmits the computed GPS fixes for the respective mobiles 101A and 101B to the data transceiver module 102B.
- the second aspect of the invention provides that, for first and second GPS mobiles, GPS fixes for the respective GPS mobiles 101 A and 101 B can be computed where the GPS mobile 101 A can establish LOS paths with four GPS satellites, such that there is a 4-2 split in LOS paths for the configuration 120, and only information as to the range between the mobiles 101A and 101 B, and not the relative positions of the mobiles 101 A and 101B, is available or can be computed.
- GPS fixes for the respective GPS mobiles 101 A and 101 B can be computed where the GPS mobile 101 A can establish LOS paths with four GPS satellites, such that there is a 4-2 split in LOS paths for the configuration 120, and only information as to the range between the mobiles 101A and 101 B, and not the relative positions of the mobiles 101 A and 101B, is available or can be computed.
- two GPS mobiles 101 A and 101B have a
- adding a third GPS mobile 101C results in two new GPS mobile-to-GPS mobile pseudorange equations for p AC and /.scand three new unknowns ( ⁇ c , y c and z c ), such that one additional LOS path would be needed for computing the GPS fixes of each of the three GPS mobiles.
- the absolute positions of three GPS mobiles can be computed if at least seven LOS paths can be established for the three GPS mobiles, where the LOS paths can be split 3-3-1 , 3-2-2 or 4-2-1.
- the second aspect of the invention is illustrated based on the ranges that the mobiles 101 A and 101 B can compute.
- the ranges between the GPS mobile 101 A and the GPS satellite 121 , the GPS mobile 101 B and the GPS satellite 121 , and the GPS mobile 101 A and the GPS mobile 101 B can be determined, such that a triangle having lengths 101A-121 , 101 B-121 and 101A-101 B is defined, the position of the mobile 101 B cannot be computed solely from this range information.
- the triangle 101A/101 B/121 is swung around the axis that passes through 101 A and 121 , the mobile 101 B traces out a circle CL and the actual location of the mobile 101 B is anywhere on the circle CL.
- Center, X, of the circle CL is not at point 101A, but rather, at the end of the line perpendicular to 101A-121 that passes through the point 101 B.
- a fixed distance from the GPS satellite 121 defines a sphere centered at the GPS satellite 121
- a fixed distance from point 101A defines a sphere centered at point 101A.
- the intersection of the two spheres is the circle CL.
- the points 101A, 101 B, 121 and 124 are vertices of a tetrahedron with six known edge lengths and three fixed known vertices.
- the tetrahedron defines a unique location for the GPS mobile 101 B which is the fourth vertex of the tetrahedron.
- the GPS mobile 101 continuously computes its absolute position and the absolute position of another mobile of the group and displays these absolute positions on a handheld device that resembles a large PDA.
- the mobile 101 of the present invention includes long-haul radio communication capabilities at the data transceiver module, as known in the art, and communicates the computed absolute position information to another communications device, such as a remotely located communications device or another mobile in the group.
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002495229A CA2495229C (en) | 2002-08-13 | 2003-08-11 | Method and system for determining absolute positions of mobile communications devices using remotely generated positioning information |
JP2004536020A JP2005535908A (en) | 2002-08-13 | 2003-08-11 | Method and system for determining the absolute position of a mobile communication device using remotely generated positioning information |
AU2003291620A AU2003291620A1 (en) | 2002-08-13 | 2003-08-11 | Method and system for determining absolute positions of mobile communications devices using remotely generated positioning information |
EP03768506A EP1552247A2 (en) | 2002-08-13 | 2003-08-11 | Method and system for determining absolute positions of mobile communications devices using remotely generated positioning information |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US40296302P | 2002-08-13 | 2002-08-13 | |
US60/402,963 | 2002-08-13 |
Publications (3)
Publication Number | Publication Date |
---|---|
WO2004025319A2 WO2004025319A2 (en) | 2004-03-25 |
WO2004025319A9 true WO2004025319A9 (en) | 2004-06-03 |
WO2004025319A3 WO2004025319A3 (en) | 2004-09-30 |
Family
ID=31993928
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2003/025077 WO2004025319A2 (en) | 2002-08-13 | 2003-08-11 | Method and system for determining absolute positions of mobile communications devices using remotely generated positioning information |
Country Status (7)
Country | Link |
---|---|
US (1) | US6922635B2 (en) |
EP (1) | EP1552247A2 (en) |
JP (1) | JP2005535908A (en) |
AU (1) | AU2003291620A1 (en) |
CA (1) | CA2495229C (en) |
PL (1) | PL375314A1 (en) |
WO (1) | WO2004025319A2 (en) |
Families Citing this family (47)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040143392A1 (en) * | 1999-07-12 | 2004-07-22 | Skybitz, Inc. | System and method for fast acquisition reporting using communication satellite range measurement |
US8255149B2 (en) | 1999-07-12 | 2012-08-28 | Skybitz, Inc. | System and method for dual-mode location determination |
US20030125045A1 (en) * | 2001-12-27 | 2003-07-03 | Riley Wyatt Thomas | Creating and using base station almanac information in a wireless communication system having a position location capability |
US7948769B2 (en) | 2007-09-27 | 2011-05-24 | Hemisphere Gps Llc | Tightly-coupled PCB GNSS circuit and manufacturing method |
US7027822B1 (en) * | 2002-09-25 | 2006-04-11 | Rockwell Collins, Inc. | Distributed GPS for geolocation of a network of nodes |
US7689354B2 (en) | 2003-03-20 | 2010-03-30 | Hemisphere Gps Llc | Adaptive guidance system and method |
US7885745B2 (en) | 2002-12-11 | 2011-02-08 | Hemisphere Gps Llc | GNSS control system and method |
US8634993B2 (en) | 2003-03-20 | 2014-01-21 | Agjunction Llc | GNSS based control for dispensing material from vehicle |
US9002565B2 (en) | 2003-03-20 | 2015-04-07 | Agjunction Llc | GNSS and optical guidance and machine control |
US8686900B2 (en) * | 2003-03-20 | 2014-04-01 | Hemisphere GNSS, Inc. | Multi-antenna GNSS positioning method and system |
US8138970B2 (en) | 2003-03-20 | 2012-03-20 | Hemisphere Gps Llc | GNSS-based tracking of fixed or slow-moving structures |
US8271194B2 (en) | 2004-03-19 | 2012-09-18 | Hemisphere Gps Llc | Method and system using GNSS phase measurements for relative positioning |
US8140223B2 (en) | 2003-03-20 | 2012-03-20 | Hemisphere Gps Llc | Multiple-antenna GNSS control system and method |
US8214111B2 (en) | 2005-07-19 | 2012-07-03 | Hemisphere Gps Llc | Adaptive machine control system and method |
US8265826B2 (en) * | 2003-03-20 | 2012-09-11 | Hemisphere GPS, LLC | Combined GNSS gyroscope control system and method |
US8594879B2 (en) | 2003-03-20 | 2013-11-26 | Agjunction Llc | GNSS guidance and machine control |
US8190337B2 (en) | 2003-03-20 | 2012-05-29 | Hemisphere GPS, LLC | Satellite based vehicle guidance control in straight and contour modes |
US7292186B2 (en) * | 2003-04-23 | 2007-11-06 | Csi Wireless Inc. | Method and system for synchronizing multiple tracking devices for a geo-location system |
US7123928B2 (en) | 2003-07-21 | 2006-10-17 | Qualcomm Incorporated | Method and apparatus for creating and using a base station almanac for position determination |
US7839916B1 (en) * | 2003-10-08 | 2010-11-23 | L-3 Communications Corporation | Systems and methods for communication in a global positioning system (GPS) device |
US8583315B2 (en) | 2004-03-19 | 2013-11-12 | Agjunction Llc | Multi-antenna GNSS control system and method |
US9137771B2 (en) * | 2004-04-02 | 2015-09-15 | Qualcomm Incorporated | Methods and apparatuses for beacon assisted position determination systems |
US20050227705A1 (en) * | 2004-04-08 | 2005-10-13 | Seppo Rousu | Data communication method, telecommunication system and mobile device |
EP1800146A1 (en) * | 2004-10-11 | 2007-06-27 | Telefonaktiebolaget LM Ericsson (publ) | Method and arrangements relating to satellite-based positioning |
US7522099B2 (en) * | 2005-09-08 | 2009-04-21 | Topcon Gps, Llc | Position determination using carrier phase measurements of satellite signals |
US7843862B2 (en) * | 2006-05-18 | 2010-11-30 | Encore Software Limited | Adhoc networking |
US8345658B2 (en) * | 2006-10-18 | 2013-01-01 | Nec Corporation | Mobile communication terminal with GPS function, positioning system, operation control method, and program |
US8311696B2 (en) | 2009-07-17 | 2012-11-13 | Hemisphere Gps Llc | Optical tracking vehicle control system and method |
USRE48527E1 (en) | 2007-01-05 | 2021-04-20 | Agjunction Llc | Optical tracking vehicle control system and method |
US7835832B2 (en) | 2007-01-05 | 2010-11-16 | Hemisphere Gps Llc | Vehicle control system |
US8000381B2 (en) | 2007-02-27 | 2011-08-16 | Hemisphere Gps Llc | Unbiased code phase discriminator |
US7808428B2 (en) | 2007-10-08 | 2010-10-05 | Hemisphere Gps Llc | GNSS receiver and external storage device system and GNSS data processing method |
US9002566B2 (en) | 2008-02-10 | 2015-04-07 | AgJunction, LLC | Visual, GNSS and gyro autosteering control |
US8018376B2 (en) | 2008-04-08 | 2011-09-13 | Hemisphere Gps Llc | GNSS-based mobile communication system and method |
US8478228B2 (en) * | 2008-10-20 | 2013-07-02 | Qualcomm Incorporated | Mobile receiver with location services capability |
US8217833B2 (en) | 2008-12-11 | 2012-07-10 | Hemisphere Gps Llc | GNSS superband ASIC with simultaneous multi-frequency down conversion |
US8386129B2 (en) | 2009-01-17 | 2013-02-26 | Hemipshere GPS, LLC | Raster-based contour swathing for guidance and variable-rate chemical application |
US8085196B2 (en) | 2009-03-11 | 2011-12-27 | Hemisphere Gps Llc | Removing biases in dual frequency GNSS receivers using SBAS |
US8401704B2 (en) | 2009-07-22 | 2013-03-19 | Hemisphere GPS, LLC | GNSS control system and method for irrigation and related applications |
US8600297B2 (en) * | 2009-07-28 | 2013-12-03 | Qualcomm Incorporated | Method and system for femto cell self-timing and self-locating |
US8174437B2 (en) | 2009-07-29 | 2012-05-08 | Hemisphere Gps Llc | System and method for augmenting DGNSS with internally-generated differential correction |
US8334804B2 (en) | 2009-09-04 | 2012-12-18 | Hemisphere Gps Llc | Multi-frequency GNSS receiver baseband DSP |
US8649930B2 (en) | 2009-09-17 | 2014-02-11 | Agjunction Llc | GNSS integrated multi-sensor control system and method |
US8548649B2 (en) | 2009-10-19 | 2013-10-01 | Agjunction Llc | GNSS optimized aircraft control system and method |
US8583326B2 (en) | 2010-02-09 | 2013-11-12 | Agjunction Llc | GNSS contour guidance path selection |
US8626189B2 (en) * | 2011-12-06 | 2014-01-07 | Raytheon Company | Position optimization |
US9766338B2 (en) * | 2015-03-02 | 2017-09-19 | Iposi, Inc. | GNSS cooperative receiver system |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5317321A (en) * | 1993-06-25 | 1994-05-31 | The United States Of America As Represented By The Secretary Of The Army | Situation awareness display device |
US5422816A (en) * | 1994-02-22 | 1995-06-06 | Trimble Navigation Limited | Portable personal navigation tracking system |
US6720920B2 (en) * | 1997-10-22 | 2004-04-13 | Intelligent Technologies International Inc. | Method and arrangement for communicating between vehicles |
JPH0942981A (en) * | 1995-08-02 | 1997-02-14 | Sony Corp | Position detector |
US6072433A (en) * | 1996-07-31 | 2000-06-06 | California Institute Of Technology | Autonomous formation flying sensor |
DK0963228T3 (en) | 1997-02-28 | 2002-09-09 | Cagniard De La Tour As | Process for simultaneous extraction of dispersible and dissolved hydrocarbon contaminants from water |
DE69841174D1 (en) * | 1997-03-21 | 2009-11-05 | Univ R | NAVIGATION SYSTEM WITH CENTRALIZED ACCURACY USING LOW-SATELLITE SATELLITES |
US6343254B1 (en) * | 1998-10-22 | 2002-01-29 | Trimble Navigation Limited | Seamless surveying system |
US6337657B1 (en) * | 1999-03-12 | 2002-01-08 | Topcon Positioning Systems, Inc. | Methods and apparatuses for reducing errors in the measurement of the coordinates and time offset in satellite positioning system receivers |
US6469663B1 (en) * | 2000-03-21 | 2002-10-22 | Csi Wireless Inc. | Method and system for GPS and WAAS carrier phase measurements for relative positioning |
US20030013462A1 (en) * | 2000-12-28 | 2003-01-16 | Yasuhiro Adachi | Position information notifying system and method |
US6529136B2 (en) * | 2001-02-28 | 2003-03-04 | International Business Machines Corporation | Group notification system and method for implementing and indicating the proximity of individuals or groups to other individuals or groups |
US6898526B2 (en) * | 2001-06-20 | 2005-05-24 | International Business Machines Corporation | Method and apparatus for enhanced safety in hunting environments |
-
2003
- 2003-08-11 US US10/639,022 patent/US6922635B2/en not_active Expired - Lifetime
- 2003-08-11 AU AU2003291620A patent/AU2003291620A1/en not_active Abandoned
- 2003-08-11 PL PL03375314A patent/PL375314A1/en not_active Application Discontinuation
- 2003-08-11 JP JP2004536020A patent/JP2005535908A/en not_active Ceased
- 2003-08-11 CA CA002495229A patent/CA2495229C/en not_active Expired - Fee Related
- 2003-08-11 EP EP03768506A patent/EP1552247A2/en not_active Withdrawn
- 2003-08-11 WO PCT/US2003/025077 patent/WO2004025319A2/en active Application Filing
Also Published As
Publication number | Publication date |
---|---|
CA2495229A1 (en) | 2004-03-25 |
US20040034471A1 (en) | 2004-02-19 |
CA2495229C (en) | 2008-11-04 |
US6922635B2 (en) | 2005-07-26 |
WO2004025319A2 (en) | 2004-03-25 |
WO2004025319A3 (en) | 2004-09-30 |
AU2003291620A1 (en) | 2004-04-30 |
EP1552247A2 (en) | 2005-07-13 |
PL375314A1 (en) | 2005-11-28 |
AU2003291620A8 (en) | 2004-04-30 |
JP2005535908A (en) | 2005-11-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6922635B2 (en) | Method and system for determining absolute positions of mobile communications devices using remotely generated positioning information | |
US20040033808A1 (en) | Method and system for determining relative positions of networked mobile communication devices | |
US6414629B1 (en) | Tracking device | |
EP2312331B1 (en) | Method and system of utilizing broadcast fm signal to determine geographical position | |
US7760132B1 (en) | Method and system of three-dimensional positional finding | |
US7420510B2 (en) | Location and tracking of people with combined use of RF infrastructure and dead reckoning modules | |
CA2384383C (en) | Method and apparatus for determining the position of a mobile communication device using low accuracy clocks | |
JP3576177B2 (en) | GPS pointing or attitude system using a single receiver | |
US7379015B2 (en) | First responder positioning apparatus | |
US11573335B2 (en) | Method and apparatus for position estimation | |
US20020198001A1 (en) | Method and apparatus for an independent positioning system and augmentation of GPS | |
RU112446U1 (en) | PASSIVE RADIOELECTRONIC COMPLEX FOR ONE-POINT DETERMINATION OF HORIZONTAL COORDINATES AND OBJECTS OF MOTION OF THE OBJECT BY THE LINE-FILTRATION CALMAN-BUSSI METHOD | |
KR101555995B1 (en) | Method and Apparatus for detecting Global Navigation Satellite System spoofing signal and estimating position of the signal based on multiple references stations | |
EP1497711B1 (en) | Method for improving accuracy of a velocity model | |
MXPA05000621A (en) | Apparatus and method of position determination of a first mobile device using information from a second mobile device. | |
CN107505635B (en) | Method for detecting satellite positioning spoofing attack | |
CA2375452A1 (en) | Narrowband based navigation scheme | |
JPH05180925A (en) | Vehicle tracking syste using global positioning system (gps) | |
Shen et al. | A DSRC Doppler/IMU/GNSS tightly-coupled cooperative positioning method for relative positioning in VANETs | |
EP1166142B1 (en) | Position finding | |
US20080249713A1 (en) | Gps position accuracy using feedback from a map database | |
KR101302565B1 (en) | System and method for estimating position of lost mobile terminal and mobile terminal | |
JP4544878B2 (en) | Mountain victim search system | |
KR100433467B1 (en) | Method and appratus for persuing movable thing through ad - hoc wireless network | |
CN108345013A (en) | A kind of method and satellite navigation receiver improving satellite navigation signals receiving sensitivity |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
COP | Corrected version of pamphlet |
Free format text: DUE TO A SCANNING ERROR DURING THE TECHNICAL PREPARATIONS FOR INTERNATIONAL PUBLICATION, REPLACE PAGES 3-25 BY CORRECT PAGES 3-25 |
|
ENP | Entry into the national phase |
Ref document number: 2495229 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2004536020 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 375314 Country of ref document: PL Ref document number: 2003768506 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 2003768506 Country of ref document: EP |