Method for satellite-supported position determining of a locator device

Abstract

The invention relates to a method for the satellite-supported position determining of a locator device (1) in a coverage area (2) with an insufficient-quality satellite signal (5a, 5b, 5c, 5d) of a satellite (6a, 6b, 6c, 6d), wherein the satellite signal (5a, 5b, 5c, 5d) is received outside the coverage area (2) by an omnidirectional reference antenna (3), and a repeating signal pattern and the satellite position data are extracted from the satellite signal (5a, 5b, 5c, 5d), after which a respective replica signal (10a, 10b, 10c, 10d) is generated for multiple transmitter antennas (7a, 7b, 7c, 7d) in the coverage area (2), wherein the difference between the delay time between a predefined target position in the transmission region (8a, 8b, 8c, 8d) of the respective transmitter antenna (7a, 7b, 7c, 7d) and the satellite (6a, 6b, 6c, 6d) and the delay time between the reference antenna (3) and the satellite (6a, 6b, 6c, 6d) is determined as a shift parameter Δt, and the replica signal (10a, 10b, 10c, 10d) is generated from the satellite position data and the signal pattern that has been temporally shifted by the shift parameter Δt, wherein the satellite signal (5a, 5b, 5c, 5d) and the replica signal (10a, 10b, 10c, 10d) correspond in the periphery of the coverage area (2) to the extent that they are not distinguished by the locator device (1), and wherein the difference of the shift parameters Δt for replica signals (10a, 10b, 10c, 10d) of adjacent transmission regions (8a, 8b, 8c, 8d) is smaller than half the duration of the signal pattern.

Description

[0001] Method for satellite-based positioning of a tracking device

[0002] Technical area

[0003] The invention relates to a method for satellite-based positioning of a locating device in a coverage area with insufficient quality of a satellite signal from a satellite.

[0004] State of the art

[0005] To determine the position of a tracking device, it is known from the prior art that the tracking device receives satellite signals (GNSS signals) with repeating signal patterns and satellite position data and uses the propagation time of the satellite signals to determine the distance from the tracking device to the respective satellite. In principle, the position of the tracking device can be determined in this way using three different satellite signals from different satellites. However, since the tracking device usually does not have a sufficiently accurate clock to correctly determine the propagation time of the satellite signals, the satellite signal from a fourth satellite is used to enable a sufficiently accurate position determination.This position determination method, which is known from the state of the art, is also called the pseudorange method and has the disadvantage that in order to determine the position sufficiently accurately, the tracking device must receive the satellite signal from at least four satellites.

[0006] In order to provide satellite signal coverage even in weak reception areas such as tunnels, it is known from CN207301335U to install transmitting antennas in the tunnel that transmit supply signals generated by a generator, which can be received by a train's tracking device. However, the disadvantage of the method known from CN207301335U is that the supply signals generated by the generator differ from the actual satellite signals from the satellites outside the weak reception area. As a result, the supply signals generated by the generator are perceived by the tracking device as interference and are only used for positioning if their signal is several times stronger (40-50 dB) than the satellite signals, which requires a relatively resource-intensive signal generation process for the transmitting antennas.Furthermore, various prior art positioning devices incorporate algorithms to detect such artificially amplified signals and prevent them from being used for positioning. Even if these generated coverage signals are used for positioning, the positioning results in inaccurate positioning at the transition from a strong reception area to a weak reception area due to the positioning device's sudden switch from the actual satellite signals to the generator's generated coverage signal.

[0007] US10620319B2 discloses a method for satellite-based positioning of a tracking device in a coverage area with insufficient satellite signal quality. For this purpose, the satellite signals are received, subsequently processed, and transmitted to transmitting antennas arranged in a coverage area, with each transmitting antenna specifying a specific target position. At least four directional antennas are used for reception, with each directional antenna being continuously aligned to its own satellite by a control unit using beamforming. This alignment and tracking of the individual directional antennas requires a costly and complex control system.Furthermore, interference-free reception of the satellite signal from the specific satellite to which the directional antenna is aimed is virtually impossible. Surrounding satellite signals or electromagnetic transmitters inevitably interfere with the signal of the targeted satellite, for example, through multipath propagation. As a result, directional antennas tuned to a single satellite signal receive noisy, low-quality signals. Due to these noisy, low-quality output signals, which are subsequently processed and transmitted to the transmitting antennas, the replica signals emitted by the transmitting antennas also exhibit poor quality and differ from the original satellite signals, which frequently leads to problems synchronizing the tracking device.For this reason, the method is primarily suitable for use in enclosed spaces, so that the already distorted replica signals emitted by the transmitting antennas are not further overlaid by other satellite signals. However, the distribution of the transmitting antennas in enclosed spaces results in the disadvantage that the tracking device's tracking is interrupted when crossing from one room to another. This not only leads to a sudden change in the target position but also to a delay in determining the position, since the tracking device has to acquire and track the new replica signal again.

[0008] DE102012007205 also discloses a method for satellite-based positioning of a tracking device in a coverage area with insufficient satellite signal quality. The method uses a pseudolite that specifies a target position for a tracking device located within the coverage area, for example, in a tunnel. The target position can be, for example, the center of the tunnel. The method known from DE102012007205 therefore only allows for an inaccurate positioning of the tracking device.

[0009] WO2007 / 030384A2 discloses another method for satellite-based positioning of a locating device in a coverage area with insufficient satellite signal quality. One embodiment discloses a synchronization mode, for example, shown in Fig. 2A, and discloses that satellite signals are received via a reference antenna, and replica signals derived from the satellite signals are transmitted to a transmitting antenna, via which the position of the transmitting antenna is specified as the target position for a locating device. If the locating device is located in a coverage area with poor reception, the replica signals transmitted by the transmitting antenna are used to determine the position. If the locating device is located in an area with strong reception, the satellite signals are used.In synchronization mode, the replica signals emitted by the transmitting antenna are synchronized with the satellite signals that would be present at the exact location of the transmitting antenna. The disadvantage of this, however, is that the tracking device always outputs the same target position transmitted by the transmitting antenna, regardless of the exact position in the weak reception area, which leads to a significant error for tracking devices located far away from this target position.Furthermore, especially in extensive coverage areas where the transmitting antenna is located far from the transition zone between the coverage area and the area with strong reception, synchronization errors arise due to the different signal properties of the replica signal emitted by the transmitting antenna and the satellite signals, as the positioning device must make a sudden change during tracking, which in turn leads to a delay in determining the position. Another embodiment discloses, for example, shown in Fig. 6, that multiple transmitting antennas are provided, wherein the transmitting antennas generate the replica signal according to a computer network mode, whereby the replica signals are only initially synchronized with the original satellite signals and subsequently the replica signals are generated autonomously.Especially when the tracking device remains in the coverage area for a long time, synchronization-related errors in positioning can occur in the transition zone between the coverage area and the area with strong reception. This is because the accessibility of satellite signals is constantly changing and thus differs more and more from the replica signals over time. Sudden changes in positioning also occur in the transition zone between two different transmission ranges of different transmitting antennas. A further disadvantage is that a separate GNSS emitter must be provided for each transmitting antenna, which entails high costs and computational effort.

[0010] Description of the invention The invention is therefore based on the object of proposing a method for supplying a service area with a satellite signal, which allows a resource-saving operation of several transmitting antennas and, regardless of the type of service area with weak reception, enables a sufficiently accurate position determination in the service area, as well as in the transition area between the service area and the area with strong reception, without having to adapt locating devices known from the prior art.

[0011] The invention solves the stated problem by receiving the satellite signal outside the coverage area by an omnidirectional reference antenna and extracting a repeating signal pattern and the satellite position data from the satellite signal, after which a replica signal is generated for several transmitting antennas in the coverage area, wherein the difference between the propagation time between a predetermined target position in the transmission range of the respective transmitting antenna and the satellite and the propagation time between the reference antenna and the satellite is determined as a shift parameter and the replica signal is generated from the satellite position data and the signal pattern shifted in time by the shift parameter, wherein the satellite signal and the replica signal in the peripheral area of ​​the coverage area agree to the extent thatthat they are not differentiated by the locating device, and wherein the difference in the displacement parameters Δt for replica signals from adjacent transmission areas is less than half the duration of the signal pattern. As a result of the measures according to the invention, a seamless transition of the locating device's positioning can be achieved at the transition area between an area in which the locating device can receive the satellite signal and therefore uses this satellite signal to determine its position, and the transmission area in the coverage area. So that the locating device does not, or cannot, distinguish between the satellite signal and the replica signal in the peripheral area of ​​the coverage area,The replica signal transmitted via the respective transmitting antenna in the peripheral area of ​​the coverage area is generally synchronized with the satellite signal or coherent with the satellite signal and only slightly shifted by the shift parameter. This enables interference-free synchronization by the tracking device, regardless of the type of coverage area, so that uninterrupted position detection of the tracking device is possible even in the transition area between the coverage area and the area with strong reception, where, for example, a weak satellite signal may still be received.is possible. Isolation of the original satellite signal is therefore not necessary. The positioning device therefore detects no difference between the actual satellite signal and the generated replica signal at the transition zone between the transmission range in the coverage area and the area with strong reception. This avoids synchronization-related errors when determining the position in the weak reception area, without impairing the functionality of the positioning device in areas with strong reception, as known from the prior art. The invention merely requires that the satellite signals be processed in real time and that the replica signals generated from them be transmitted to the transmitting antennas in real time. Since the difference in the displacement parameters Δt for replica signals from adjacent transmission areas is less than half the duration of the signal pattern,A seamless transition of the tracking device's positioning process between transmission ranges of different transmitting antennas can be achieved. By adhering to the inventive displacement parameter Δt, the tracking loop of the tracking device can be shifted step by step in the desired direction, whereby the position output by the tracking device also moves smoothly without sudden changes. When the tracking device moves from one transmission range to another, intermediate positions along a trajectory can therefore be specified.The trajectory runs between the specified target positions of the respective transmitting antennas of the adjacent transmission areas. The tracking device can therefore perform uninterrupted tracking even in the transition area between two transmission areas. The tracking device can also determine its position step by step based on the replica signals received in each transmission area. To generate the replica signals, a generator can be provided that has a processing unit for each transmitting antenna, to which a target position specification unit is assigned. In this way, the replica signals for each transmitting antenna can be generated centrally by the generator and then transmitted independently to the respective transmitting antennas. This leads to particularly resource-efficient signal generation.

[0012] In the method according to the invention, a satellite signal outside the coverage area is first received by a reference antenna. For this purpose, the reference antenna is located in a strong reception area, i.e., an area where satellite signals can be received from satellites. To determine the position of the tracking device, the reference antenna can receive satellite signals from at least four different satellites. For this purpose, the reference antenna is designed as an omnidirectional reference antenna.

[0013] The satellite signal, as is known from the prior art, comprises a carrier phase, a repeating, pseudo-random signal pattern, and a navigation message with satellite position data. The repeating signal pattern and the satellite position data are extracted from the received satellite signal, and the replica signal is generated from them. For this purpose, the satellite signal is acquired, demodulated from a carrier wave if necessary, and tracked. Tracking can be performed using the DLL (Delay Lock Loop) and / or PLL (Phase Lock Loop) and / or FLL (Frequency Lock Loop) methods known from the prior art.Tracking provides information about the propagation time of the satellite signal from the satellite to the reference antenna, as is well known from the state of the art. Using the well-known formula p = t * c (t = propagation time [s], c = speed of light [m / s], p = pseudorange [m]), the pseudorange between the satellite and the reference antenna and, subsequently, the position of the reference antenna can be determined. For unambiguous position determination according to the pseudorange method known from the state of the art, four pseudoranges between the reference antenna and four different satellites must be known.

[0014] However, since the positions of the transmission ranges of the transmitting antennas arranged in the coverage area differ from the position of the reference antenna, a separate replica signal is generated for each transmitting antenna, in which the tracked satellite signal is shifted by a displacement parameter Δt for each transmitting antenna. iThis displacement parameter Δt i corresponds to the difference between the transit time between a given target position in the transmission range of the respective transmitting antenna and the satellite and the propagation time between the reference antenna and this satellite t . The displacement parameter Δt according to the invention i is calculated by:

[0015] With surrendered is the pseudorange between target position and satellite i is the pseudorange between reference antenna and satellite i

[0016] According to the invention, the coverage area is divided into transmission areas of several transmitting antennas, with a target position X int which the tracking device should adopt as its own position when it is in the respective transmission range.

[0017] With

[0018] X intis the specifiable target position (known)

[0019] X i the satellite position is (known) b i are various pseudorange errors (satellite clock errors, ionospheric delay, troposphere delay, receiver clock deviation, etc.) regarding the satellite signal i

[0020] And with

[0021] X ref is the reference position of the reference antenna (determined)

[0022] Surrendered are errors regarding the processing and control time of the inventive method

[0023] If this displacement parameter Δt i known, the replica signal for a transmitting antenna can be derived from the satellite signal by shifting the repeating signal pattern of the satellite signal by the shift parameter Δt iThe shifted signal pattern is recombined with the satellite position data or the navigation message to form the replica signal, which is then modulated onto a carrier wave before being transmitted in this form to the respective transmitting antenna. Since both the reference antenna and the target position are constant within the transmission range of the transmitting antenna, any Doppler shift depends essentially on the movement of the respective satellite. Due to the comparatively short distance between the reference antenna and the target position, this Doppler shift between the satellite signal and the replica signal can remain constant.

[0024] To ensure that the satellite signal and the replica signal in the peripheral area of ​​the coverage area match to such an extent that they cannot be distinguished by the tracking device, it is proposed that for the transmission range of a transmitting antenna in the peripheral area of ​​the coverage area, the difference in the propagation time between the satellite and the tracking device in the transmission range and the propagation time between the satellite and the specified target position in the transmission range be less than half the duration of the signal pattern. In commercially available satellite navigation systems, for example, the signal pattern repeats every millisecond (GPS L1), so the required half duration of the signal pattern corresponds to 0.5 milliseconds. This means that the target position in a peripheral area of ​​the coverage area, in this example, cannot be further than 150 m from the edge of the coverage area.

[0025] In order to enable not only a seamless transition of the locating method of the locating device in the peripheral area of ​​the coverage area, but also a seamless transition between transmission ranges of different transmitting antennas, it is proposed that the difference in the displacement parameters for replica signals of adjacent transmission ranges be less than half the duration of the signal pattern.

[0026] Although the method according to the invention for generating replica signals can be used for only individual satellites, while other satellites in the coverage area are received without interference, usually only few or no satellite signals can be received in a coverage area, so that position determination can only be made possible with the help of replica signals.For this purpose, it is proposed that the satellite signals of several satellites are received by the reference antenna, wherein for each satellite the repeating signal pattern and the satellite position data are extracted from the satellite signal, the difference between the propagation time between a predetermined target position in the transmission range of the respective transmitting antenna and the satellite and the propagation time between the reference antenna and the satellite is determined as a shift parameter and the replica signal is generated from the satellite position data and the signal pattern shifted in time by the shift parameter, wherein a supply signal is formed from the replica signals for the transmission range of a transmitting antenna and transmitted to the transmitting antenna.A supply signal therefore comprises at least four replica signals, each shifted by a specific shift parameter so that, apart from minor deviations resulting from processing, they correspond to the satellite signals theoretically received at the destination location within the transmission range, assuming uninterrupted reception is possible at the destination location. To generate the supply signals, a generator can be provided that has a processing unit for each transmitting antenna, to which a target position specification unit is assigned. In this way, the supply signals for each transmitting antenna can be generated centrally by the generator and then transmitted independently of one another to the respective transmitting antennas. This leads to particularly resource-efficient signal generation.

[0027] If a locating device is located in an area with strong reception, positioning is carried out using the actual satellite signals. If the locating device enters the reception range of a transmitting antenna in the coverage area, the locating device receives the coverage signal comprising at least four replica signals via the transmitting antenna. Due to the method according to the invention, the replica signals match the satellite signals apart from minor deviations, so that the locating device does not perceive the replica signals as interference signals and therefore a seamless transition of the tracking process of the locating device takes place, particularly in the transition area between the area with strong reception and the coverage area. In the transmission range of the respective transmitting antenna, the locating device receives the replica signals processed with the displacement parameter and calculates the respective pseudoranges from these replica signals and determines them with at least four pseudoranges the specified target position. According to the invention, the replica signals or the supply signals are generated comprising at least four replica signals for all transmission ranges of the transmitting antennas.

[0028] In order to enable higher resolution position determination in a coverage area with insufficient quality of one or more satellite signals, it is proposed that the coverage area be divided into at least two coverage area units, with at least two transmitting antennas being arranged in each coverage area unit. In the context of the invention, a coverage area unit is understood to be a contiguous room in which signal propagation can take place without interference to such an extent that the locating device can receive the signals from the at least two transmitting antennas at at least one position and process them without errors. A coverage area unit can therefore be regarded as a closed room in a building, to which another room as a further coverage area unit is adjacent. The two rooms as separate coverage area units can be separated from one another by a wall as an interfering object.In this way, multiple target positions can be specified in a coverage area unit, since each transmitting antenna can specify a specific target position. The transmitting antennas are arranged in the coverage area units so that they can receive the supply signals. Directional antennas are preferably used as transmitting antennas. The directional antennas preferably have a beamwidth of less than or equal to 65°, in particular less than or equal to 60°. The transmission range of a directional antenna preferably has a radius of less than or equal to 4 m, more preferably less than or equal to 2 m, in particular less than or equal to 1.5 m. In this way, the error of the locating device in adjacent transmission ranges can be limited to 3 m.

[0029] The invention also relates to a device for carrying out the method according to the invention, comprising a reference antenna for receiving a satellite signal, a receiving unit for extracting the repeating signal pattern and the satellite position data from the satellite signal, a generator for generating supply signals and a plurality of transmitting antennas for transmitting these supply signals in a respective transmission range of a service area, wherein the generator has a processing unit for each transmitting antenna, to which a target position specification unit is assigned.

[0030] The reference antenna is located in a strong reception area outside the coverage area and receives a satellite signal, or satellite signals from four different satellites, to determine the position. To avoid interference between a commercially available tracking device and the device, it is advantageous if the reference antenna has access to the same satellite signals, or at least a large proportion of the same satellite signals, as the tracking device when it is still located in the border area between the strong reception area and the coverage area. This means that the propagation time deviations of the satellite signals between the reference antenna and the first transmitting antenna in the coverage area, into whose reception range the tracking device enters, should be minimal.

[0031] The received GNSS satellite signals are forwarded from the reference antenna to a receiving unit. The receiving unit preferably comprises a preprocessing unit that converts and digitizes the high-frequency signal transmitted by the reference antenna into an intermediate-frequency signal.

[0032] The receiving unit acquires and tracks the digitized satellite signals. Furthermore, the position of the reference antenna can be determined using the state-of-the-art pseudorange method.

[0033] The generator according to the invention generates the replica signals by shifting the repeating signal pattern of the satellite signal i by the shift parameter Δt iand the shifted signal pattern is recombined with the satellite position data or the navigation message to form the replica signal. For this purpose, the generator has a separate processing unit for each transmitting antenna, with each processing unit being assigned the target position X intof the associated transmitting antenna. This results in the advantage that the replica signals for each transmitting antenna are generated centrally by the generator and then transferred independently to the respective transmitting antennas, resulting in particularly resource-efficient signal generation. The target position is assigned to the processing unit by a target position specification unit, which can include a memory in which the respective target position in the transmission range of the respective transmitting antenna can be stored, for example, when installing the transmitting antenna. In this way, a specific displacement parameter Δt is determined in each processing unit. i For each satellite signal i, the shift parameter Δt is calculated, by which the signal pattern must be shifted to generate the replica signal so that a tracking device calculates the desired pseudorange. idifferent processing units therefore arise due to the different target positions X int .

[0034] For precise positioning, at least four satellite signals i are required. This means that each processing unit can have at least four channel units. In each channel unit, a specific displacement parameter Δt i to generate the replica signal. The specific displacement parameters Δt i in the different channel units within a processing unit, due to the different satellite positions X i with constant position of the reference antenna X ref and constant target position X int . The position of the reference antenna X ref is the same for all processing units of the generator, while the target position X intis specifically specified for each processing unit. According to the invention, the generator calculates a specific displacement parameter for all transmitting antennas and all satellite signals and, by shifting the signal patterns, generates those replica signals that lead the locating device to locate the desired target position in the respective transmission range of a transmitting antenna. The inventive design of the generator allows the calculation of the required displacement parameters for all transmitting antennas and all satellite signals to be carried out in parallel.

[0035] After the replica signals have been generated, this signal, or a supply signal comprising the replica signals, is transmitted to each processing unit of the associated transmitting antenna. Transmission can be performed via a transmitting unit of the generator, which modulates the individual replica signals onto a carrier wave and combines them into a supply signal. The supply signal from the respective processing unit is transmitted to the transmitting antenna assigned to the processing unit, which in turn transmits the supply signal to the tracking device as soon as it enters the transmission range of the transmitting antenna.

[0036] If a tracking device is initially located in an area with strong reception, the position can be determined using satellite signals. When the tracking device enters the transmission range of a transmitting antenna, the coverage signal generated by the processing unit of the generator associated with this transmission range is forced upon the tracking device. Since the replica signals of the coverage signal essentially match the satellite signals except for minor deviations, the tracking device recognizes no difference between the coverage signals, especially in the transition area between the area with strong reception and the transmission range, and uses the coverage signal to determine the position without having to make any sudden changes during acquisition and tracking.

[0037] To ensure precise positioning in a large coverage area equipped with multiple transmitting antennas without mutual interference, it is proposed that the transmitting antennas be directional antennas. In particular, the transmitting antennas are arranged within the coverage area so that their transmission ranges do not overlap. The directional antennas are characterized by a narrow beamwidth, thus preventing overlap of the different transmission ranges. Preferably, the directional antennas have a beamwidth of less than or equal to 65°, in particular less than or equal to 60°.

[0038] Preferably, the transmission range of a directional antenna has a radius of less than or equal to 4 m, more preferably less than or equal to 2 m, in particular less than or equal to 1.5 m. In this way, the error of the locating device can be limited to 3 m for adjacent transmission ranges.

[0039] In order to avoid unwanted interference of the transmitting antennas with the satellite signals of the satellites in the border area between the coverage area and the area with strong reception, the supply signal sent by the transmitting antennas in the coverage area can have a higher signal strength than the satellite signals of the satellites.

[0040] In a particularly preferred embodiment, the device comprises a multi-channel transceiver comprising a receiving unit and a generator, which is connected to the reference antenna on the input side and to transmitting antennas on the output side. The receiving unit can comprise a preprocessing unit and a software-defined radio receiver (SDRR). The generator can comprise a software-defined radio transmitter (SDRT), which generates the replica signals and the resulting supply signals based on previously determined shift parameters.

[0041] To cover a larger coverage area, a device according to the invention can have several multi-channel transceivers connected to a common time and frequency base.

[0042] Brief description of the invention The drawing shows an example of the subject matter of the invention.

[0043] Fig. 1 is a schematic representation of the inventive supply of a service area with a satellite signal and

[0044] Fig. 2 is a schematic representation of the method according to the invention and the device according to the invention,

[0045] Fig. 3 is a schematic representation of the supply of another supply area with a satellite signal according to the invention.

[0046] Ways to implement the invention

[0047] As can be seen from Fig. 1, in a method according to the invention for satellite-based position determination of a locating device 1 in a coverage area 2, a reference antenna 3 is used, which is arranged in a strong reception area 4 outside the coverage area 2. While satellite signals 5a, 5b, 5c, 5d from satellites 6a, 6b, 6c, 6d are accessible to the strong reception area, they are not accessible or only accessible to a limited extent to the coverage area 2. Transmitting antennas 7a, 7b, 7c, 7d are arranged in the coverage area 2, which transmit supply signals 9a, 9b, 9c, 9d, preferably comprising at least four replica signals 10a, 10b, 10c, 10d (Fig. 2), over their respective transmission ranges 8a, 8b, 8c, 8d. If a locating device 1 known from the prior art is located in an area 4 with strong reception, the position can be determined in a known manner using the satellite signals 5a, 5b, 5c, 5d of the satellites 6a, 6b, 6c, 6d.In coverage area 2, these satellite signals 5a, 5b, 5c, 5d are no longer accessible to the positioning device 1, or only accessible to a limited extent. Accordingly, when the positioning device 1 enters a transmission area 8a, 8b, 8c, 8d, it receives the coverage signal 9a. Since the coverage signal 9a essentially matches the satellite signals 5a, 5b, 5c, 5d, except for minor deviations, the positioning device 1 recognizes no difference between the coverage signal 9a, especially in the transition area between the area 4 with strong reception and the transmission area 9a, and uses the coverage signal 9a to determine the position without having to make a sudden change during acquisition and tracking.For a representative position determination of the locating device 1, the supply signals 9a, 9b, 9c, 9d must have a different information content than the satellite signals 5a, 5b, 5c, 5d at the position of the reference antenna 3, since otherwise the locating device 1 in the transmission areas 8a, 8b, 8c, 8d would determine the position of the reference antenna 3 as its own if only the satellite signals 5a, 5b, 5c, 5d are transmitted from the transmitting antennas 7a, 7b, 7c, 7d to the locating device 1. The supply signals 9a, 9b, 9c, 9d are therefore processed according to the invention in such a way that the locating device 1 determines a predeterminable target position 11a, 11b, 11c, 11d in the transmission ranges 8a, 8b, 8c, 8d from the respective supply signals 9a, 9b, 9c, 9d.

[0048] The processing according to the invention is explained in more detail with reference to Fig. 2, which shows an inventive device for satellite-based position determination in a coverage area 2. A device according to the invention has a reference antenna 3, which is arranged in a strong reception area 4 and thereby receives satellite signals 5a, 5b, 5c, 5d from at least four satellites 6a, 6b, 6c, 6d. The reference antenna 3 is an omnidirectional reference antenna 3. The received satellite signals 5a, 5b, 5c, 5d are transferred to a receiving unit 12. In the receiving unit 12, the detection and tracking of the satellite signals 5a, 5b, 5c, 5d and the position determination of the reference antenna 3 take place in a manner known from the prior art. Preferably, the receiving unit 12 comprises a preprocessing unit for converting and digitizing the satellite signals 5a, 5b, 5c, 5d.In the receiving unit 12, for each satellite signal 5a, 5b, 5c, 5d, its repeating signal pattern and satellite position data are extracted and the position of the reference antenna 3 is determined therefrom using the pseudorange method known from the prior art.

[0049] From the extracted signal patterns and the satellite position data, a generator 13 generates the replica signals 10a, 10b, 10c, 10d, in which the repeating signal pattern of the satellite signal 5a, 5b, 5c, 5d is shifted by a shift parameter Δt 5a ' 5b ' 5c ' 5d and the shifted signal pattern is recombined with the satellite position data or the navigation message to form the replica signal 10a, 10b, 10c, 10d. The shift parameter Δt 5a ' 5b ' 5c ' 5dTherefore, the replica signal 10a, 10b, 10c, 10d is modified such that a locating device 1 does not determine the position of the reference antenna 3, but rather a desired target position 11a, 11b, 11c, 11d. The generator 13 therefore has a separate processing unit 14a, 14b, 14c, 14d for each transmitting antenna 7a, 7b, 7c, 7d. Each processing unit 14a, 14b, 14c, 14d is assigned a target position specification unit 15a, 15b, 15c, which specifies the desired and known target position 11a, 11b, 11c, 11d in the transmission range 8a, 8b, 8c, 8d of the respective transmitting antenna 7a, 7b, 7c, 7d to the processing unit 14a, 14b, 14c, 14d. In this way, a specific displacement parameter Δt 5a ' 5b ' 5c ' 5d For each satellite signal 5a, 5b, 5c, 5dc, the amount by which the signal pattern must be shifted to generate the replica signal 10a, 10b, 10c, 10d is calculated so that a locating device 1 calculates the desired pseudorange.

[0050] Since at least four satellite signals 5a, 5b, 5c, 5d must be specified for position determination using the pseudorange method, each processing unit 14a, 14b, 14c, 14d can generate at least four replica signals 10a, 10b, 10c, 10d, which can be combined to form a supply signal 9a, 9b, 9c, 9d. For this purpose, each processing unit 14a, 14b, 14c, 14d can have its own channel unit 16a, 16b, 16c, 16d for each replica signal 10a, 10b, 10c, 10d to be generated, i.e., at least four channel units 16a, 16b, 16c, 16d. In each channel unit 16a, 16b, 16c, 16d, a specific displacement parameter Δt 5a ' 5b ' 5c ' 5d to generate the replica signal 10a, 10b, 10c, 10d. While the specific displacement parameters Δt 5a ' 5b ' 5c ' 5ddifferent processing units 14a, 14b, 14c, 14d due to the different target positions 11 a, 11 b, 11 c, 11 d (X int ), the specific displacement parameters Δt 5a ' 5b ' 5c ' 5d different channel units 16a, 16b, 16c, 16d within a processing unit 14a,14b,14c,14d due to the different satellite positions ( X i ) with the position of the reference antenna 3 (X ref ) and constant target position 11 a, 11 b, 11 c, 11 d (X int )

[0051] The replica signals 10a, 10b, 10c, 10d are combined into supply signals 9a, 9b, 9c, 9d in each processing unit 14a, 14b, 14c, 14d. Each supply signal 9a, 9b, 9c, 9d is transmitted to the respective transmitting antenna 7a, 7b, 7c, 7d, which, as indicated in Fig. 1, transmits the supply signals 9a, 9b, 9c, 9d in the transmission range 8a, 8b, 8c, 8d. For reasons of clarity, only three transmitting antennas 7a, 7b, 7c are shown in Fig. 2 and four in Fig. 1. Naturally, more transmitting antennas 7a, 7b, 7c, 7d can also be provided.

[0052] The more transmitting antennas 7a, 7b, 7c, 7d are installed in coverage area 2, the more accurate the positioning can be. To ensure that many transmitting antennas 7a, 7b, 7c, 7d can be arranged side by side in a confined space without interference, directional antennas can be used, as they have a narrow transmission range 8a, 8b, 8c, 8d.

[0053] As can be seen from Fig. 1, the transmitting antennas 7a, 7b, 7c, 7d in the coverage area 2 are arranged such that their transmission ranges 8a, 8b, 8c, 8d do not overlap.

[0054] To enable interference-free transition for the locating device 1 from the area with strong reception to the coverage area 2, the coverage signal 9a, 9b, 9c, 9d transmitted by the transmitting antennas 7a, 7b, 7c, 7d can have a higher signal strength in the coverage area 2 than the satellite signals 5a, 5b, 5c, 5d of the satellites 6a, 6b, 6c, 6d. For resource-saving processing of the satellite signals 5a, 5b, 5c, 5d into several coverage signals 9a, 9b, 9c, 9d, at least one multi-channel transceiver 17 can be provided, which comprises a receiving unit 12 and a generator 13 and is connected on the input side to the reference antenna 3 and on the output side to the transmitting antennas 7a, 7b, 7c, 7d. Since multi-channel transceivers 17 usually only have a limited number of processing units 14a, 14b, 14c and thus also inputs and outputs.outputs, several multi-channel transceivers 17 can be provided to cover a larger supply area 2, which are connected to a common time and frequency base 18.

[0055] Fig. 3 illustrates that the coverage area can be divided into at least two coverage area units 23a, 23b. At least two transmitting antennas 7a, 7b, 7c, 7d, 7e, 7f can be arranged in each coverage area unit 23a, 23b. The coverage area units 23a, 23b can be understood as interconnected rooms free from signal interference. A room of a building can therefore be regarded as a coverage area unit. Another room can be adjacent to the room as a further coverage area unit 23b. The two rooms can be separated from each other by a wall 24 as an interference object, thereby separating the coverage area units 23a, 23b. As a result of the preferred measures according to the invention, a higher resolution can be achieved in position determination, since several target positions 11a, 11b, 11c, 11d, 11e, 11f can be specified for each coverage area unit 23a, 23b.The transmitting antennas 11a, 11b, 11c, 11d, 11e, 11f are preferably arranged in the edge region of the coverage area units 23a, 23b so that they can receive the coverage signals 9a, 9b, 9c, 9d, 9e, 9f.

Claims

Patent claims 1. Method for satellite-based positioning of a tracking device (1) in a coverage area (2) with insufficient quality of a satellite signal (5a, 5b, 5c, 5d) from a satellite (6a, 6b, 6c, 6d), wherein the satellite signal (5a, 5b, 5c, 5d) is received outside the coverage area (2) by an omnidirectional reference antenna (3) and a repeating signal pattern and the satellite position data are extracted from the satellite signal (5a, 5b, 5c, 5d), after which a replica signal (10a, 10b, 10c, 10d) is generated for each of several transmitting antennas (7a, 7b, 7c, 7d) in the coverage area (2), wherein the difference between the travel time between a predetermined target position in the transmission range (8a, 8b, 8c, 8d) of the respective transmitting antenna (7a, 7b, 7c, 7d) and the satellite (6a, 6b, 6c, 6d) and the transit time between the reference antenna (3) and the satellite (6a, 6b, 6c, 6d) as the displacement parameter At and the replica signal (1 Oa, 10b, 10c,10d) is generated from the satellite position data and the signal pattern shifted in time by the displacement parameter At, wherein the satellite signal (5a, 5b, 5c, 5d) and the replica signal (10a, 10b, 10c, 10d) in the boundary area of ​​the coverage area (2) coincide to such an extent that they are not distinguished by the locating device (1) and wherein the difference of the displacement parameters At for replica signals (10a, 10b, 10c, 10d) of adjacent transmission areas (8a, 8b, 8c, 8d) is less than half the duration of the signal pattern.

2. Method according to claim 1, characterized in that for the transmission range (8a, 8b, 8c, 8d) of a transmitting antenna (7a, 7b, 7c, 7d) in the boundary area of ​​the coverage area (2) the difference between the transit time between the satellite (6a, 6b, 6c, 6d) and the locating device (1) in the transmission range (8a, 8b, 8c, 8d) and the transit time between the satellite (6a, 6b, 6c, 6d) and the predetermined target position (11a, 11b, 11c, 11d) in the transmission range (8a, 8b, 8c, 8d) is less than half the duration of the signal pattern.

3. Method according to claim 1 or 2, characterized in that the satellite signals (5a, 5b, 5c, 5d) of several satellites (6a, 6b, 6c, 6d) are received by the reference antenna (3), wherein for each satellite (6a, 6b, 6c, 6d) the repeating signal pattern and the satellite position data are extracted from the satellite signal (5a, 5b, 5c, 5d), the difference between the travel time between a predetermined target position (11a, 11b, 11c, 11d) in the transmission range (8a, 8b, 8c, 8d) of the respective transmitting antenna (7a, 7b, 7c, 7d) and the satellite (6a, 6b, 6c, 6d) and the propagation delay between the reference antenna (3) and the satellite (6a, 6b, 6c, 6d) is determined as the displacement parameter At, and the replica signal (10a, 10b, 10c, 10d) is generated from the satellite position data and the signal pattern shifted in time by the displacement parameter At, wherein a supply signal (9a, 9b, 9c, 9d) is formed from the replica signals (10a, 10b, 10c, 10d) for the transmission range (8a, 8b, 8c, 8d) of a transmitting antenna (7a, 7b, 7c, 7d) and is sent to the transmitting antenna (7a, 7b, 7c, 7d) is transferred.

4. Method according to one of claims 1 to 3, characterized in that the supply area (2) is divided into at least two supply area units (23a, 23b), wherein at least two transmitting antennas (7a, 7b, 7c, 7d) are arranged in each supply area unit (23a, 23b).

5. Device for carrying out a method according to one of claims 1 to 4, comprising an omnidirectional reference antenna (3) for receiving a satellite signal (5a, 5b, 5c, 5d), a receiving unit (12) for extracting the repeating signal pattern and the satellite position data from the satellite signal (5a, 5b, 5c, 5d), a generator (13) for generating supply signals (9a, 9b, 9c, 9d), and several transmitting antennas (7a, 7b, 7c, 7d) for transmitting these supply signals (9a, 9b, 9c, 9d) in a respective transmission range (8a, 8b, 8c, 8d) of a coverage area (2), characterized in that the generator (13) provides a processing unit for each transmitting antenna (7a, 7b, 7c, 7d). (14a,14b,14c14d) has a target position specification unit (15a, 15b, 15c) assigned to it.

6. Device according to claim 5, characterized in that the supply signals (9a, 9b, 9c) comprise replica signals (10a, 10b, 10c, 10d), wherein the processing units (14a, 14b, 14c) comprise a channel unit (16a, 16b, 16c, 16d) for each replica signal (10a, 10b, 10c, 10d) for the parallel generation of the replica signals (10a, 10b, 10c, 10d).

7. Device according to claim 5 or 6, characterized in that the transmitting antennas (7a, 7b, 7c, 7d) are directional antennas.

8. Device according to one of claims 5 to 7, characterized in that the transmitting antennas (7a, 7b, 7c, 7d) are arranged in the supply area (2) such that their transmission ranges (8a, 8b, 8c, 8d) do not overlap.

9. Device according to one of claims 5 to 8, characterized in that the supply signals (9a, 9b, 9c, 9d) transmitted by the transmitting antennas (7a, 7b, 7c, 7d) in the supply area (2) have a higher signal strength than the satellite signals (5a, 5b, 5c, 5d) of the satellites (6a, 6b, 6c, 6d).

10. Device according to one of claims 5 to 9 characterized by at least one multi-channel transceiver comprising a receiving unit (12) and a generator (13) and connected on the input side to the reference antenna (3) and on the output side to transmitting antennas (7a, 7b, 7c, 7d).

11. Device according to one of claims 5 to 10, characterized in that the generator (13) for generating the supply signals (9a, 9b, 9c, 9d) is configured to generate a replica signal (10a, 10b, 10c, 10d) for each of the transmitting antennas (7a, 7b, 7c, 7d) in the supply area (2), wherein the difference between the travel time between a predetermined target position in the transmission area (8a, 8b, 8c, 8d) of the respective transmitting antenna (7a, 7b, 7c, 7d) and the satellite (6a, 6b, 6c, 6d) and the travel time between the reference antenna (3) and the satellite (6a, 6b, 6c, 6d) is determined as the displacement parameter At and the replica signal (10a, 10b, 10c, 10d) is derived from the satellite position data and the time difference. The shift parameter At generates a shifted signal pattern. wherein the satellite signal (5a, 5b, 5c, 5d) and the replica signal (1 Oa,1 Ob,1 Oc,1 Od) in the boundary area of ​​the coverage area (2) are so similar that they cannot be distinguished by the locating device (1 ) and wherein the difference of the displacement parameters At for replica signals (10a,10b,10c,10d) of adjacent transmission areas (8a, 8b, 8c, 8d) is less than half the duration of the signal pattern.

12. Device according to one of claims 5 to 11, characterized in that the supply area (2) is divided into at least two supply area units (23a, 23b), wherein at least two transmitting antennas (7a, 7b, 7c, 7d) are arranged in each supply area unit (23a, 23b).

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