JP2022535882A - Method, system and apparatus for transmitting and receiving differential correction data messages - Google Patents

Abstract

The present application relates to positioning technology and discloses a method, system and apparatus for transmitting and receiving differential correction data messages. The service side sends a first differential correction data message to the user terminal in a first information cycle, the number of bits occupied by the quality indicator data in the first differential correction data message is A (step 101), and the service side transmits a second differential correction data message to the user terminal in at least one consecutive information cycle after the first information cycle, and the number of bits occupied by the quality indicator data in the second differential correction data message is: B, A>B, A, B are positive integers (step 102), based on the conventional RTCM format, greatly reducing the amount of transmission of SSR information, greatly reducing the transmission cost and time save. [Selection drawing] Fig. 1

Description

The present application relates to positioning technology, and more particularly to technology for transmitting and receiving differential correction data messages.

At present, the encoding format of the internationally used high-precision correction data message transmitted from the satellite is various. Positioning and calibration can be achieved, but the amount of data is enormous, and the transmission time is long, so the amount of data transmitted at one time from SSR 1 to 3 is about several million bits (see web page 1 for the amount that can be referred to). ). The technical standard of compact SSR adopted in conventional QZSS is applied only in Japan, and most of the formats do not match the positioning demand in China, The amount of data to be transmitted in is one million bits (see web page 2 for available quantities). However, in the concrete PPP-RTK technology, there is no format that solves the compression problem of the information encoding format in the high-volume, high-concurrency and low-delay demand, thus increasing the channel redundancy and utilization rate. descend.

The purpose of the present application is to provide a method, system and apparatus for transmitting and receiving differential correction data messages based on the conventional RTCM format to greatly reduce the transmission amount of SSR information and greatly save transmission cost and time. and

The present application discloses a method of transmitting a differential correction data message, the method comprising:
the service side sending a first differential correction data message to the user terminal in a first information cycle;
said service side sending a second differential correction data message to said user terminal in at least one consecutive information cycle after said first information cycle;
wherein the number of bits occupied by the quality indicator data in the first differential correction data message is A, the number of bits occupied by the quality indicator data in the second differential correction data message is B, and A>B and A and B are positive integers.

In a preferred example, the message header of the differential correction data message includes an identification bit for indicating whether the number of bits occupied by the quality indicator data in the message is A bits or B bits.

In a preferred example, said first differential correction data message further comprises satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein said first differential correction data message the quality indicator data in corresponds to the first, second, third and fourth model multinomial coefficient data in the first differential correction data message;
The second differential correction data message further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein quality indicator data in the second differential correction data message correspond to the first, second, third and fourth model multinomial coefficient data in the second differential correction data message.

In a preferred example, the quality indicator data in said first differential correction data message is total quality indicator data and the quality indicator data in said second differential correction data message is incremental quality indicator data.

In one preferred example, the quality indicator data in said second differential correction data message is one increment of the current quality indicator data.

In a preferred example, before the service side sends a first differential correction data message to the user terminal in the first information cycle,
further comprising the service side receiving state space representation correction data transmitted by the satellite every information cycle;
The service side encodes a format for the state space representation correction data and calculates quality indicator data in the corresponding first differential correction data message or quality indicator data in the second differential correction data message. to generate.

The present application discloses a transmission system for differential correction data messages, the system comprising:
transmitting a first differential correction data message to the user terminal in a first information cycle, and transmitting a second differential correction data message in at least one consecutive information cycle after said first information cycle; a first transmission module used to transmit to a user terminal;
wherein the number of bits occupied by the quality indicator data in the first differential correction data message is A, the number of bits occupied by the quality indicator data in the second differential correction data message is B, and A> B, where A and B are positive integers.

In a preferred example, the message header of the differential correction data message includes an identification bit for indicating whether the number of bits occupied by the quality indicator data in the message is A bits or B bits.

In a preferred example, said first differential correction data message further comprises satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein said first differential correction data message the quality indicator data in corresponds to the first, second, third and fourth model multinomial coefficient data in the first differential correction data message;
The second differential correction data message further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein quality indicator data in the second differential correction data message correspond to the first, second, third and fourth model multinomial coefficient data in the second differential correction data message.

In a preferred example, the quality indicator data in said first differential correction data message is total quality indicator data and the quality indicator data in said second differential correction data message is incremental quality indicator data.

In one preferred example, the quality indicator data in said second differential correction data message is one increment of the current quality indicator data.

In a preferred example, further comprising a first receiving module and a calculating module,
the first receiving module is used to receive state-space representation correction data transmitted by the satellite every information cycle, the computing module encodes a format for the state-space representation correction data; It is used to calculate and generate quality indicator data in the corresponding first differential correction data message or quality indicator data in the second differential correction data message.

The present application further discloses a method of receiving a differential correction data message, the method comprising:
the user terminal receiving a differential correction data message from the service side;
the user terminal determining whether the received quality indicator data in the differential correction data message is A bits or B bits;
if the received quality indicator data is A-bit, updating the current quality indicator data to the A-bit quality indicator data;
if the received quality indicator data is B bits, updating the current quality indicator data based on the current quality indicator data and the B bits of quality indicator data;
Here, A>B, and A and B are positive integers.

In a preferred example, in the step of the user terminal determining whether the received quality indicator data in the differential correction data message is A-bit or B-bit, the user terminal determines the message header of the differential correction data message: It is identified whether the quality index data is A bit or B bit based on the identification bit in .

In a preferred example, the A-bit quality indicator data is total quality indicator data, and the B-bit quality indicator data is incremental quality indicator data.

In a preferred example, the B-bit quality indicator data is one increment of the current quality indicator data.

The present application further discloses a system for receiving differential correction data messages, the system comprising:
a second receiving module used to receive differential correction data messages from the service side;
a determination module used to determine whether the received quality indicator data in the differential correction data message is A bits or B bits;
updating the current quality indicator data to the A-bit quality indicator data if the received quality indicator data is A bits, and if the received quality indicator data is B bits, the current quality indicator a processing module used to update the current quality indicator data based on the data and the B-bit quality indicator data;
Here, A>B, and A and B are positive integers.

In one preferred example, the determination module is used to identify whether the quality indicator data is A bit or B bit based on an identification bit in a message header of the differential correction data message.

In a preferred example, the A-bit quality indicator data is total quality indicator data, and the B-bit quality indicator data is incremental quality indicator data.

In a preferred example, the B-bit quality indicator data is one increment of the current quality indicator data.

The present application describes a memory used to store computer-executable instructions;
and a processor adapted, in executing the computer-executable instructions, to implement the steps in the transmission method as described above.

The present application further discloses a computer-readable storage medium for storing computer-executable instructions and implementing the steps in the transmission method as described above when the computer-executable instructions are executed by a processor.

The present application describes a memory used to store computer-executable instructions;
Further disclosed is an apparatus for receiving differential correction data messages comprising: a processor adapted to implement the steps in the receiving method as described above when executing the computer-executable instructions.

The present application further discloses a computer-readable storage medium for storing computer-executable instructions and implementing the steps in the receiving method as described above when the computer-executable instructions are executed by a processor.

In the embodiments of the present application, in the PPP-RTK positioning technology, the problem of compressing the total data volume by encoding the regional atmospheric correction number data format in a flexibly usable and organized manner is solved. solve.

In the embodiment of the present application, first, based on the conventional RTCM format, the organization and transmission method of the quality indicator data in the differential correction data message format are optimized, and the total quality indicator data and the incremental quality indicator data are combined to make the corresponding differential correction Send a data message. Here, by transmitting the incremental quality index data, the transmission volume of the differential correction data message can be greatly reduced, greatly saving the transmission cost and time and simplifying the data, so that the transmission distance of the synchronous satellite signal is increased. The increase in bit error rate due to long distances and high fading is reduced. In addition, since the total amount of quality index data is transmitted at one time at regular or irregular intervals, new user terminals acquire the initial amount (total amount of data). Ensure the user accuracy of the user terminal.

In addition, for the QZSS coding scheme, the technical indicators are redefined according to various different needs, and the calibration information is maintained with high precision to adapt to different geographical conditions or land areas and atmospheric conditions. For example, the corresponding organization optimization for the geographical situation of China. First, the method of organizing Classes and Values of QI can be optimized according to the region. However, the actual application situation does not require such a design throughout China. Due to the very large width of China from south to north, the atmospheric activity in the northern regions is not very intense, does not require very high resolution, and most of the data are relatively loose and can be quantized over a small range. Just do it. In addition, such a design should be adopted only in some areas of southern China, where atmospheric activity is intense. In addition, in the SSR correction number information, after securing a certain resolution, unless upper and lower limits are set based on the active state of the ionosphere above the current area, the positioning effect cannot be exhibited, and furthermore, it will have the opposite effect. There is also Since the active state of the ionosphere itself is strongly correlated with latitude, the closer the equator, the more active the ionosphere becomes, resulting in a wider correction range and lower resolution, resulting in an increased amount of data. In the embodiment of this application, by redefining the technical indicators (correction range, mesh range, etc.) based on the national conditions of China, the geographical situation or land area and atmospheric conditions of China while maintaining high-precision calibration information conform to

Many technical features are described in the specification of the present application, distributed in each technical solution, and listing all possible combinations of technical features of the present application (i.e. technical solution) makes the specification redundant. too much In order to avoid this problem, each technical feature disclosed in the above content of the present application, each technical feature disclosed in the following embodiments and examples, and each technical feature disclosed in the drawings Any of them can be freely combined with each other, and constitutes various new technical proposals unless such a combination of technical features is technically unfeasible (all of these technical proposals are be considered listed). For example, in one example, features A+B+C are disclosed, and in another example, features A+B+D+E are disclosed, and features C and D are equivalent technical means having the same effect, and there is no possibility of using them at the same time. , technically one of them can be selected and used. Technically, feature E can be combined with feature C. In this case, the technical solution A+B+C+D is technically infeasible and should not be regarded as already described, and the technical solution A+B+C+E has already been described. should be considered to be

FIG. 1 is a flow chart of a method for transmitting differential correction data messages according to a first embodiment of the present application. FIG. 2 is a schematic diagram of relevant bits of a message header according to one embodiment of the present application. FIG. 3 is a structural schematic diagram of a differential correction data message transmission system according to the second embodiment of the present application. FIG. 4 is a flowchart of a method for receiving differential correction data messages according to a third embodiment of the present application. FIG. 5 is a structural schematic diagram of a differential correction data message receiving system according to the fourth embodiment of the present application.

In the following description, numerous technical details are set forth to provide the reader with a better understanding of the present application. However, it should be understood by those skilled in the art that the technical solution protected by this application can be realized without various changes and modifications based on these technical details and the following embodiments. can.

Explanation of some concepts:
It is abbreviated as Global Navigation Satellite System, GNSS.
Beidou navigation satellite system (BDS navigation Satellite system), abbreviated as BDS.
It is abbreviated as State Space Representation, SSR.
It is abbreviated as Precise Point Positioning, PPP.
It is abbreviated as Real Time Kinematic, RTK.
Transmission Control Protocol/Internet Protocol, abbreviated as TCP/IP.
Networked Transport of RTCM via Internet, abbreviated NTRIP.
Radio Technical Commission for Maritime Services, abbreviated RTCM.
Quasi-Zenith Satellite System, abbreviated as QZSS.
Total Electron Content Unit, abbreviated as TECU.
Abbreviated as Quality Indicator, QI.

In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application are described in more detail below with reference to the drawings.

A first embodiment of the present application relates to a method for transmitting a differential correction data message, the flow of which is shown in Fig. 1 and includes the following steps.

First, perform step 101, in which the service side sends a first differential correction data message to the user terminal in a first information cycle, and the quality indicator data in the first differential correction data message ( The number of bits occupied by QI _A ) is A.

Preferably, before performing step 101, further comprising the following substeps A and B, firstly, the service side performs substep A of receiving the state space representation method correction data transmitted by the satellite every information cycle. do. Next, substep B of the service side encoding a format for the state space representation correction data and calculating and generating the corresponding first differential correction data message or the second differential correction data message. Run.

and then executing step 102, wherein the service side sends a second differential correction data message to the user terminal in at least one successive information cycle after the first information cycle, and the second differential The number of bits occupied by the quality indicator data (QI _B ) in the correction data message is B, where A>B and A, B are positive integers.

Generally, the first and second differential correction data messages are format data blocks. The data block preferably includes a start line describing a message, the data block preferably includes a header block (or message header/header) containing attributes, the data block It preferably includes a body portion (or body) comprising:

In one embodiment, the first and second differential correction data messages each include a header and a body portion.

Preferably, the body portion of the first differential correction data message includes A bits of quality indicator data and the body portion of the second differential correction data message includes B bits of quality indicator data. Preferably, the body portion of said first differential correction data message comprises satellite identification data, first, second, third and fourth model polynomial coefficient data ( _C00 , _C01 , _C10 , _C11 ) wherein the quality indicator data (QI _A ) in the first differential correction data message is the polynomial coefficients of the first, second, third and fourth models in the first differential correction data message Respond to data. Preferably, the body portion of said second differential correction data message comprises satellite identification data, first, second, third and fourth model polynomial coefficient data ( _C00 , _C01 , _C10 , _C11 ) wherein the quality indicator data (QI _B ) in the second differential correction data message is the polynomial coefficients of the first, second, third and fourth models in the second differential correction data message Respond to data.

Preferably, the headers of the first and second differential correction data messages include identification bits for indicating whether the number of bits occupied by the quality indicator data in the messages is A bits or B bits. . FIG. 2 is a schematic diagram of relevant bits of a message header (ie, header) according to one embodiment of the present application. Here, the 1-bit identification bit "STEC TYPE (the name is just an example and is not limited in actual application)" added to the header indicates that the "quality indicator data" is 6 bits or 1 bit. It is intended for the user (at the user terminal) to voluntarily know when using it. Specifically, "STEC TYPE" is set such that when this field is "1", it indicates that the "Quality Indicator Data ( _QIA )" in the SSR information associated with this message header is 1 bit. works. Similarly, when this field is '0', it indicates that the 'Quality Indicator Data (QI _A )' in the SSR information associated with this message header is 6 bits. 1 bit and 6 bits in FIG. 2 are just examples of the length of the quality indicator data, and can be adjusted according to the actual application, such as 2 bits and 6 bits, or 3 bits and 6 bits. and so on.

Preferably, the A-bit quality indicator data in the first differential correction data message is total quality indicator data, and the B-bit quality indicator data in the second differential correction data message is incremental quality indicator data. is.

The manner in which the service side sends the first or second differential correction data message may vary. Preferably, the service side transmits the first differential correction data message in a fixed cycle, for example one fixed cycle every N information cycles, i. Besides transmitting, it transmits increments in other information cycles. Preferably, the service side sends the first differential correction data message irregularly, for example sending the full amount in the first information cycle, sending the increments in the second and third information cycles, and sending the fourth , the increments in the 5th, 6th and 7th information cycles, the full amounts in the 8th information cycle, and the 9th, 10th, 11th and 12th information cycles. , and so on. For example, in the first information cycle the full amount is sent, in the second and third information cycles the increments are sent, in the fourth information cycle the full amount is sent, the fifth, sixth, seventh, eighth, and so on. The increments are sent in the ninth information cycle, the full amount is sent in the tenth information cycle, the increments are sent in the eleventh, twelfth, thirteenth, fourteenth, fifteenth information cycles, and so on. The A-bit (or full amount) of quality indicator data in the first differential correction data message is transmitted periodically or irregularly so that new user terminals obtain an initial amount. Therefore, the user's user accuracy is ensured, and a certain amount of information compression is ensured.

Preferably, the B-bit quality indicator data in the second differential correction data message is an identifier indicating a change in the current quality indicator data. For example, the B bit is '1 bit', where '1 bit' is one identifier 1 or 0 indicating a change in the current quality indicator data, identifier 1 representing a decrease and identifier 0 representing an increase. In another embodiment, the B-bit quality indicator data in the second differential correction data message is one increment of the current quality indicator data.

A second embodiment of the present application relates to a differential correction data message transmission system, the structure of which is shown in FIG. 3, wherein the differential correction data message transmission system comprises a first transmission module. The first transmission module transmits a first differential correction data message to the user terminal in a first information cycle, and in at least one consecutive information cycle after the first information cycle, a first 2 differential correction data message to the user terminal, wherein the number of bits occupied by quality indicator data (QI _A ) in the first differential correction data message is A; The number of bits occupied by the quality indicator data (QI _B ) in the differential correction data message is B, and A>B, where A, B are positive integers.

Generally, the first and second differential correction data messages are format data blocks. The data block preferably includes a start line describing a message, the data block preferably includes a header block (or message header/header) containing attributes, the data block It preferably includes a body portion (or body) comprising:

In one embodiment, the first and second differential correction data messages each include a header and a body portion.

Preferably, the body portion of the first differential correction data message includes A bits of quality indicator data and the body portion of the second differential correction data message includes B bits of quality indicator data. Preferably, the body portion of said first differential correction data message comprises satellite identification data, first, second, third and fourth model polynomial coefficient data ( _C00 , _C01 , _C10 , _C11 ) wherein the quality indicator data (QI _A ) in the first differential correction data message is the polynomial coefficients of the first, second, third and fourth models in the first differential correction data message Respond to data. Preferably, the body portion of said second differential correction data message comprises satellite identification data, first, second, third and fourth model polynomial coefficient data ( _C00 , _C01 , _C10 , _C11 ) wherein the quality indicator data (QI _B ) in the second differential correction data message is the polynomial coefficients of the first, second, third and fourth models in the second differential correction data message Respond to data.

Preferably, the headers of the first and second differential correction data messages include identification bits for indicating whether the number of bits occupied by the quality indicator data in the messages is A bits or B bits. . FIG. 2 is a schematic diagram of relevant bits of a message header (ie, header) according to one embodiment of the present application. Here, the 1-bit identification bit "STEC TYPE (the name is just an example and is not limited in actual application)" added to the header indicates that the "quality indicator data" is 6 bits or 1 bit. It is intended for the user (at the user terminal) to voluntarily know when using it. Specifically, "STEC TYPE" is set such that when this field is "1", it indicates that the "Quality Indicator Data (QI _B )" in the SSR information associated with this message header is 1 bit. works. Similarly, when this field is '0', it indicates that the 'Quality Indicator Data (QI _A )' in the SSR information associated with this message header is 0 bits.

1 bit and 6 bits in FIG. 2 are just examples of the length of the quality indicator data, and can be adjusted according to the actual application, such as 2 bits and 6 bits, or 3 bits and 6 bits, etc. is. Preferably, the A-bit quality indicator data is total quality indicator data and the B-bit quality indicator data is incremental quality indicator data.

There are various manners in which the service side sends the first or second differential correction data message. Preferably, the service side transmits the first differential correction data message in a fixed cycle, e.g. N information cycles are one fixed cycle, i.e. the full amount is sent in the 1st, Nth information cycles. Send increments in other information cycles. Preferably, the service side sends the first differential correction data message irregularly, for example sending the full amount in the first information cycle, sending the increments in the second and third information cycles, and sending the fourth , the increments in the 5th, 6th and 7th information cycles, the full amounts in the 8th information cycle, and the 9th, 10th, 11th and 12th information cycles. , and so on. For example, in the first information cycle the full amount is sent, in the second and third information cycles the increments are sent, in the fourth information cycle the full amount is sent, the fifth, sixth, seventh, eighth, and so on. The increments are sent in the ninth information cycle, the full amount is sent in the tenth information cycle, the increments are sent in the eleventh, twelfth, thirteenth, fourteenth, fifteenth information cycles, and so on. The A-bit (or full amount) quality indicator data in the first differential correction data message is transmitted periodically or irregularly, thereby causing the new user terminal to acquire the initial amount. Therefore, the user's user accuracy is ensured, and a certain amount of information compression is ensured.

Preferably, the B-bit quality indicator data is an identifier indicating a change in the current quality indicator data. For example, the B bit is '1 bit', where '1 bit' is one identifier 1 or 0 indicating a change in the current quality indicator data, identifier 1 representing a decrease and identifier 0 representing an increase. In another embodiment, the B-bit quality indicator data is one increment of the current quality indicator data.

Preferably, the differential correction data message transmission system further comprises a first receiving module and a calculating module. the first receiving module is used to receive state-space representation correction data transmitted by the satellite every information cycle, the computing module encodes a format for the state-space representation correction data; It is used to calculate and generate quality indicator data in the corresponding first differential correction data message or quality indicator data in the second differential correction data message.

The first embodiment is a method embodiment corresponding to this embodiment, the technical details in the first embodiment can be applied to this embodiment, and the technical details in this embodiment also apply to the first embodiment. can be applied to

A third embodiment of the present application relates to a method for receiving a differential correction data message, the flow of which is shown in Fig. 4, the method for receiving a differential correction data message includes the following steps.

At step 401, the user terminal receives a differential correction data message from the service side.

Preferably, said differential correction data message further comprises satellite identification data, first, second, third and fourth model polynomial coefficient data ( _C00 , _C01 , _C10 , _C11 ), wherein , the polynomial coefficient data of the first, second, third and fourth models correspond to one of the quality index data (QI _A or QI _B ).

Next, proceeding to step 402, the user terminal determines whether the received quality indicator data in the differential correction data message is A bits or B bits, where A>B, A, B is a positive integer.

Preferably, in said step 402, said user terminal identifies whether said quality indicator data is A bit or B bit based on an identification bit in a message header of said differential correction data message.

If the received quality indicator data is A bit, go to step 403 to update the current quality indicator data to the A bit quality indicator data. For example, the current quality indicator data can be directly replaced with the A-bit quality indicator data.

If the received quality indicator data is B bits, proceed to step 404 to update the current quality indicator data based on the current quality indicator data and the B bits of quality indicator data. For example, B-bit quality index data can be superimposed on the current quality index data as an increment.

Preferably, the A-bit quality indicator data is total quality indicator data and the B-bit quality indicator data is incremental quality indicator data.

There are various ways to set the B-bit quality indicator data. Preferably, the B-bit quality indicator data is an identifier indicating a change in the current quality indicator data, and the user terminal, based on a preset variable and a B-bit, for example 1 bit, received from the service side, Choose to increase or decrease the absolute value of the current (eg last received) quality indicator data (QI value) by a fixed amount according to a given communication protocol. Here, the 1 bit may be an identifier 1 or 0 indicating a change in the current quality indicator data, identifier 1 representing a decrease and identifier 0 representing an increase. Preferably, the B-bit quality indicator data is one increment of the current quality indicator data.

The method for receiving the differential correction data message according to the third embodiment of the present application may correspond to the method for transmitting the differential correction data message according to the first embodiment.

The fourth embodiment of the present application relates to a system for receiving differential correction data messages, the structure of which is shown in FIG. Prepare.

The receiving module according to this embodiment is used to receive differential correction data messages from the service side.

Preferably, said differential correction data message further comprises satellite identification data, first, second, third and fourth model polynomial coefficient data ( _C00 , _C01 , _C10 , _C11 ), wherein , the polynomial coefficient data of the first, second, third and fourth models correspond to one of the quality index data (QI _A or QI _B ).

The determining module according to the present embodiment is used to determine whether the received quality indicator data in the differential correction data message is A bits or B bits, where A>B, A, B is a positive integer.

Preferably, the decision module is used to identify whether the quality indicator data is A bit or B bit based on an identification bit in a message header of the differential correction data message.

Preferably, the A-bit quality indicator data (QI _A ) is total quality indicator data and the B-bit quality indicator data (QI _B ) is incremental quality indicator data.

Preferably, the B-bit quality indicator data is an identifier indicating a change in the current quality indicator data, or the B-bit quality indicator data is an increment of the current quality indicator data.

The processing module according to the present embodiment is used to update the current quality indicator data to A-bit quality indicator data when the received quality indicator data is A-bit, for example, update the current quality indicator data to can be directly substituted for the A-bit quality indicator data, and if the received quality indicator data is B-bit, the current quality indicator data based on the current quality indicator data and the B-bit quality indicator data; It is used to update the quality index data. For example, B-bit quality index data is superimposed on the current quality index data as an increment to obtain updated quality index data.

Preferably, the B-bit quality indicator data is an identifier indicating a change in the current quality indicator data, and the user terminal, based on a preset variable and a B-bit, for example 1 bit, received from the service side, Choose to increase or decrease the absolute value of the current (eg last received) quality indicator data (QI value) by a fixed amount according to a given communication protocol. Here, the 1 bit may be an identifier 1 or 0 indicating a change in the current quality indicator data, identifier 1 representing a decrease and identifier 0 representing an increase. Preferably, the B-bit quality indicator data is one increment of the current quality indicator data.

The third embodiment is a method embodiment corresponding to this embodiment, the technical details in the third embodiment can be applied to this embodiment, and the technical details in this embodiment also apply to the third embodiment. can be applied to

Some related technologies according to embodiments of the present application will be briefly described below.

The transmission and/or reception of differential correction data messages in this application is based on the RTCM standard message format, with reference to the format organization of the Japanese QZSS system (see webpages 3 and 4), and of conventional available GNSS systems. The correction data is organized and compressed according to the purpose.

GPS differential protocols and differential telegram algorithms are two important issues for differential systems. In the differential positioning application system, it is necessary to transmit a large amount of differential telegrams between the positioning terminal and the differential station, and the positioning terminal is often a target that can move at high speed. Conventionally, wireless communication (e.g., shortwave or very high frequency) is used to establish a data channel in this RTCM 10403.2 standard is established internationally to accommodate such communication modes and to achieve the basic requirements of high efficiency and error control. With the development of communication means, the network is widely used to establish a data link between the positioning terminal and the difference station, and the network communication data is transmitted according to the data packet, and the error is effectively eliminated in the data link layer. suppressed by Low cost, low error, high efficiency and high speed network communication bring new development opportunities to differential positioning applications. be the current main means.

The RTCM protocol specification includes application layer, presentation layer, transport layer, data link layer and physical layer. For encoding and decoding, the most important is the organization at the physical layer. In the physical layer organization, the amount of data has a direct and significant impact on the overall amount of information transmission per unit time. If there is no network connection, it is common to receive satellite signals to obtain correction data. It is important how efficiently and quickly transmission can be performed with limited satellite transmission speed/time.

In the PPP-RTK joint positioning technology, information is divided into three layers: SSR1, SSR2 and SSR3. Here, SSR1 includes correction classes of trajectory-4068.2, clock difference-4068.3, and code deviation-4068.4. SSR2 includes a phase deviation of -4068.5, a global ionospheric correction number (VTEC) correction number. SSR3 contains correction numbers of the Regional Atmospheric Correction Factors (Regional Ionospheric STEC-4068.8, Regional Ionospheric Residual RC-4068.9, Regional Atmospheric Layer Correction Tropo-4068.9). The name of the SSR information format and transmission interval information transmitted from the satellite base are as shown in Table 1 below.

The present application mainly optimizes the organization of field contents in the SSR information (including SSR1, SSR2 and SSR3) in differential correction data messages. One effective area (Network) corresponding to RTCM code and compact SSR code of QZSS is basically a range of 100km*100km, i.e., 1Network equals an area of 10000 square kilometers. The calculation of conventional encoding format data is as shown in Table 2 below.

As can be seen from Table 2 above, in conventional coding, for each visible satellite of each GNSS system (GPS, GLONASS, Galileo, Beidou, QZSS, etc.), there are four coefficients (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ) and one Quality Indicator (QI) corresponding to the four coefficients need to be transmitted. The conventional amount of data for this SSR information is 6 bits per transmission. Calculated from China's area of 9.6 million square kilometers, the number of networks is 960 (see the above 100km * 100km is the unit area of one region), and the message is transmitted once The amount of data is 6*960=5760 bits. These 6 bits are calculated by the following conversion formula (1).

As a result, a mapping table, which is an SSR QI conversion table such as Table 3 below, can be obtained.

According to the binary code, 3-bit data can represent 8 kinds of states from 000 to 111. Since Class and Value are each 3 bits, there are a total of 8*8=64 kinds of combinations, and a specific numerical value of SSR QI is obtained by conversion.

However, if each 4068 kinds of messages requires one QI value, the total amount of data increases greatly, putting pressure on the channel. Given that each satellite has a 6-bit QI value for each message, calculated with messages 4068.1-4068.10 as follows, the total QI value is:
6*80 (number of satellites in the four systems of GNSS)*10 (current message type)*960 (Network) = 4,608,000 bits.

The amount of data is very large compared to the content of a single message type. According to this calculation, the demand for satellite communication resources (rates typically between 1200 and 2400 bits per second) is very high. The peculiarity of 4068 information is that the data itself has a certain effectiveness, so the longer the interval, the worse the correction effect. Therefore, compressing this format significantly improves the overall satellite positioning results.

In order to better understand the technical solution of the present application, the following description will be made with reference to specific examples. The details listed in this example are for easy understanding and do not limit the scope of protection of this application.

Each embodiment of the present application applies to the northern regions of China. The organization of the northern region is as follows.

In the northern region, the range fluctuation of the SSR information in the differential correction data message is small (for example, from 2.5 TECU to 2.45 TECU every 30 seconds). and only increments (values of positive and negative fluctuations) are sent subsequently, not the full amount. Table 4 below is an example of newly organizing one piece of SSR information.

Compared to Table 2, Table 4 adds 6 bits or 1 bit which can be selected, and the user terminal can select based on preset variables and received bits (identifier 1 indicates decrement and identifier 0 indicates increment). , to increase or decrease the absolute value of the last received QI value by a fixed amount according to a given communication protocol. The 6-bit absolute value is batched in a certain cycle (e.g. every 10th information cycle is a certain transmission cycle, i.e. the 1st and 10th time the full amount is sent, but in the other information cycles send a 1-bit optimized format) to allow new user terminals to obtain an initial amount. Therefore, the user's user accuracy is ensured, and a certain amount of information compression is ensured. The amount of compressed data is
2*80 (number of satellites in the four systems of GNSS)*10 (type of current message)*960 (Network) = 1,356,000 bits.

This 1,356,000 bits is about one-third less than the previous amount of data, 4,608,000 bits. In the current situation where satellite flux is scarce and expensive, the resource saving advantage is obvious.

Web page 1, web page 2, web page 3, and web page 4 in this specification are specifically as follows.
Web page 1: http://www. rtcm. org/differential-global-navigation-satellite--dgnss--standards. html
Web page 2: http://qzss. go. jp/en/technical/download/pdf/ps-is-qzss/is-qzss-l6-001. pdf
Web page 3: http://qzss. go. jp/en/technical/download/pdf/ps-is-qzss/is-qzss-l6-001. pdf
Web page 4: http://qzss. go. jp/en/technical/ps-is-qzss/ps-is-qzss. html

As will be understood by those skilled in the art, the functions implemented by each module according to the embodiment of the differential correction data message receiving system or transmission system are related to the differential correction data message receiving system or transmission method. understood with reference to the description. The function of each module according to the embodiment of the above differential correction data message receiving system or transmitting system may be realized by a program (executable instructions) executed on a processor, and may be realized by a specific logic circuit. may When the differential correction data message receiving system or transmitting system according to the embodiments of the present application is implemented in the form of software functional modules and sold or used as an independent product, it is stored in a computer readable storage medium. good too. Based on this understanding, the essential parts of the technical solutions according to the embodiments of the present application or the parts contributing to the prior art can be embodied as software. The computer software is stored in a storage medium, and one computer (personal computer, server, network device, etc.) is used to execute all or part of the method described in each embodiment of the present application. including directives. The storage medium includes various media for storing program code such as USB memory, mobile hard disk, read only memory (ROM), magnetic disk or optical disk. As such, embodiments of the present application are not limited to any particular combination of hardware and software.

Accordingly, an embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions which, when executed by a processor, cause a first implementation of the present application. implement each method embodiment in the form or each method embodiment in the third embodiment of the present application. Computer-readable storage media, including permanent and non-permanent, removable and non-removable media, can provide information storage by any method or technology. Information may be computer readable instructions, data structures, program modules, or other data. Computer storage media include phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), and other types of random access memory used to store information accessible by computer devices. (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technology, disk read only memory (CD-ROM), digital versatile disk (DVD) or Including, but not limited to, other optical storage, magnetic cassette tape, tape disk storage or other magnetic storage device, or any other non-transmission medium. As defined herein, computer readable storage media does not include transitory media such as modulated data signals and carrier waves.

Embodiments of the present application also provide a memory used for storing computer-executable instructions, and when executing the computer-executable instructions in the memory, the steps in each method embodiment in the first embodiment above are performed. and a processor used to implement the differential correction data message. Here, the processor may be a central processing unit (abbreviated as "CPU"), other general-purpose processors, digital signal processors (abbreviated as "DSP"), dedicated integrated circuits (Application Specific Integrated Circuit, abbreviated as “ASIC”) or the like. The memory may be a read-only memory (abbreviated as "ROM"), a random access memory (abbreviated as "RAM"), a flash memory (Flash), a hard disk or a solid state drive. good too. The steps of the method according to each embodiment of the invention may be executed and completed by a hardware processor or by a combination of hardware and software modules in the processor.

Embodiments of the present application comprise a memory used for storing computer-executable instructions, and implementing the steps in each method embodiment in the third embodiment above when executing the computer-executable instructions in the memory. and a processor used to receive differential correction data messages. Here, the processor may be a central processing unit (abbreviated as "CPU"), other general-purpose processors, digital signal processors (abbreviated as "DSP"), dedicated integrated circuits (Application Specific Integrated Circuit, abbreviated as “ASIC”) or the like. The memory may be a read-only memory (abbreviated as "ROM"), a random access memory (abbreviated as "RAM"), a flash memory (Flash), a hard disk or a solid state drive. good too. The steps of the method according to each embodiment of the invention may be executed and completed by a hardware processor or by a combination of hardware and software modules in the processor.

It should be noted that in this application, related terms such as first and second are only used to distinguish one entity or action from another entity or action, and not necessarily between these entities or actions. does not necessarily require or imply that any practical relationship or order exists. Also, terms such as "comprising," "including," or other variations are intended to be of non-exclusive inclusion, whereby a process, method, article, or device comprising a set of elements includes only those elements. but may include other elements not expressly listed or may include elements specific to such processes, methods, articles or devices. Unless more limited, an element limited by phrases such as "including one" excludes that a process, method, article, or device containing the element also has other identical elements. is not. In this application, a reference to performing an action based on an element means performing the action based on at least that element, including performing the action based only on the element; Includes two situations: performing the action based on a factor and other factors. References to multiple, multiple times, multiple types, etc. include two, two times, two types, and two or more, two or more times, two or more types.

All documents referred to in this application are incorporated in their entirety into the disclosure of this application to serve as the basis for amendments where necessary. The above descriptions are only preferred embodiments of the present application and are not intended to limit the protection scope of the present application. Any amendment, equivalent replacement, change, etc. made within the spirit and principle of one or more embodiments of this specification shall fall within the protection scope of one or more embodiments of this specification. shall be included in

Claims (24)

the service side sending a first differential correction data message to the user terminal in a first information cycle;
said service side sending a second differential correction data message to said user terminal in at least one consecutive information cycle after said first information cycle;
wherein the number of bits occupied by the quality indicator data in the first differential correction data message is A, the number of bits occupied by the quality indicator data in the second differential correction data message is B, and A>B and A, B are positive integers;
A method for transmitting a differential correction data message, characterized by: The message header of the differential correction data message includes an identification bit for indicating whether the number of bits occupied by the quality indicator data in the message is A bits or B bits.
A method of transmitting a differential correction data message according to claim 1, characterized in that: The first differential correction data message further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein quality indicator data in the first differential correction data message corresponds to the first, second, third and fourth model multinomial coefficient data in the first differential correction data message;
The second differential correction data message further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein quality indicator data in the second differential correction data message corresponds to the first, second, third and fourth model multinomial coefficient data in the second differential correction data message;
A method of transmitting a differential correction data message according to claim 1, characterized in that: the quality indicator data in the first differential correction data message is total quality indicator data and the quality indicator data in the second differential correction data message is incremental quality indicator data;
A method of transmitting a differential correction data message according to claim 1, characterized in that: the quality indicator data in the second differential correction data message is one increment of the current quality indicator data;
A method of transmitting a differential correction data message according to claim 1, characterized in that: Before the service side sends a first differential correction data message to the user terminal in the first information cycle,
further comprising the service side receiving state space representation correction data transmitted by the satellite every information cycle;
The service side encodes a format for the state space representation correction data and calculates quality indicator data in the corresponding first differential correction data message or quality indicator data in the second differential correction data message. to generate
A method of transmitting a differential correction data message according to any one of claims 1 to 5, characterized in that: transmitting a first differential correction data message to the user terminal in a first information cycle, and transmitting a second differential correction data message in at least one consecutive information cycle after said first information cycle; a first transmission module used to transmit to a user terminal;
wherein the number of bits occupied by the quality indicator data in the first differential correction data message is A, the number of bits occupied by the quality indicator data in the second differential correction data message is B, and A> B, where A and B are positive integers;
A differential correction data message transmission system, characterized by: The message header of the differential correction data message includes an identification bit for indicating whether the number of bits occupied by the quality indicator data in the message is A bits or B bits.
8. A transmission system for differential correction data messages according to claim 7, characterized in that: The first differential correction data message further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein quality indicator data in the first differential correction data message corresponds to the first, second, third and fourth model multinomial coefficient data in the first differential correction data message;
The second differential correction data message further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein quality indicator data in the second differential correction data message corresponds to the first, second, third and fourth model multinomial coefficient data in the second differential correction data message;
8. A transmission system for differential correction data messages according to claim 7, characterized in that: the quality indicator data in the first differential correction data message is total quality indicator data and the quality indicator data in the second differential correction data message is incremental quality indicator data;
8. A transmission system for differential correction data messages according to claim 7, characterized in that: the quality indicator data in the second differential correction data message is one increment of the current quality indicator data;
8. A transmission system for differential correction data messages according to claim 7, characterized in that: further comprising a first receiving module and a computing module;
the first receiving module is used to receive state-space representation correction data transmitted by the satellite every information cycle, the computing module encodes a format for the state-space representation correction data; used to calculate and generate quality indicator data in the corresponding first differential correction data message or quality indicator data in the second differential correction data message;
A system for transmitting differential correction data messages according to any one of claims 7 to 11, characterized in that: the user terminal receiving a differential correction data message from the service side;
the user terminal determining whether the received quality indicator data in the differential correction data message is A bits or B bits;
if the received quality indicator data is A-bit, updating the current quality indicator data to the A-bit quality indicator data;
if the received quality indicator data is B bits, updating the current quality indicator data based on the current quality indicator data and the B bits of quality indicator data;
where A>B, and A and B are positive integers;
A method for receiving a differential correction data message, characterized by: In the step of the user terminal determining whether the received quality indicator data in the differential correction data message is an A bit or a B bit, the user terminal determines an identification bit in a message header of the differential correction data message. identifying whether the quality indicator data is A-bit or B-bit based on
14. A method for receiving a differential correction data message according to claim 13, characterized by: The A-bit quality indicator data is total quality indicator data, and the B-bit quality indicator data is incremental quality indicator data.
14. A method for receiving a differential correction data message according to claim 13, characterized by: the B-bit quality indicator data is one increment of the current quality indicator data;
16. A method for receiving a differential correction data message according to any one of claims 13-15. a second receiving module used to receive differential correction data messages from the service side;
a determination module used to determine whether the received quality indicator data in the differential correction data message is A bits or B bits;
updating the current quality indicator data to the A-bit quality indicator data if the received quality indicator data is A bits, and if the received quality indicator data is B bits, the current quality indicator a processing module used to update the current quality indicator data based on the data and the B-bit quality indicator data;
where A>B, and A and B are positive integers;
A system for receiving differential correction data messages, characterized by: wherein the determination module is used to identify whether the quality indicator data is A-bit or B-bit based on an identification bit in a message header of the differential correction data message;
18. The system for receiving differential correction data messages of claim 17, wherein: The A-bit quality indicator data is total quality indicator data, and the B-bit quality indicator data is incremental quality indicator data.
18. The system for receiving differential correction data messages of claim 17, wherein: the B-bit quality indicator data is one increment of the current quality indicator data;
20. A system for receiving differential correction data messages according to any one of claims 17-19. a memory used to store computer-executable instructions;
a processor which, when executing the computer-executable instructions, is used to implement the steps in the method of any one of claims 1 to 6;
An apparatus for transmitting differential correction data messages, characterized by: A computer-readable storage medium storing computer-executable instructions, comprising:
implementing the steps in the method of any one of claims 1 to 6 when said computer-executable instructions are executed by a processor;
A computer-readable storage medium characterized by: a memory used to store computer-executable instructions;
a processor used to implement the steps in the method of any one of claims 13 to 16 when executing said computer-executable instructions;
An apparatus for receiving differential correction data messages, characterized by: A computer-readable storage medium storing computer-executable instructions, comprising:
implementing the steps in the method of any one of claims 13 to 16 when said computer-executable instructions are executed by a processor;
A computer-readable storage medium characterized by:

Images