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KR-20260067761-A - SATELLITE NAVIGATION SYSTEM BASED ON SECURED SATELLITE SIGNALS AND METHOD THEREOF

KR20260067761AKR 20260067761 AKR20260067761 AKR 20260067761AKR-20260067761-A

Abstract

The present invention relates to a satellite navigation system utilizing encrypted satellite signals. According to one aspect of the present invention, a method of operation of a satellite navigation system comprising at least one observation reference station and an integrated operating station may include: a step in which at least one observation reference station collects an encrypted satellite signal from at least one satellite; a step in which at least one observation reference station converts the satellite signal into an intermediate frequency signal; a step in which at least one observation reference station generates sample data for any time from the intermediate frequency signal; a step in which at least one observation reference station transmits the sample data to an integrated operating station; a step in which the integrated operating station extracts encrypted data from the sample data received from at least one observation reference station; and a step in which the integrated operating station decrypts the encrypted data to obtain navigation data and distance measurements.

Inventors

  • 소형민
  • 김동욱
  • 이장용

Assignees

  • 국방과학연구소

Dates

Publication Date
20260513
Application Date
20241106

Claims (17)

  1. A method of operation of a satellite navigation system comprising at least one observation reference station and an integrated operation station, The above-mentioned at least one observation reference station collects an encrypted satellite signal from at least one satellite; The above-mentioned at least one observation reference station converts the satellite signal into an intermediate frequency signal; The step of the above at least one observation reference station generating sample data for any time from the intermediate frequency signal; The step of the above at least one observation reference station transmitting the sample data to the integrated operation station; The above integrated operating station extracts encrypted data from the sample data received from the at least one observation reference station; and The above-mentioned integrated operation center decrypts the above-mentioned encrypted data to obtain navigation data and distance measurements; A method including
  2. In paragraph 1, The step of collecting the above-mentioned encrypted satellite signal is, Collecting multiple encrypted satellite signals having different frequencies that have each passed through the ionosphere, and The above distance measurement is, The distance measurement between the above at least one observation reference station and the above at least one satellite, method.
  3. In paragraph 1, The above satellite signal includes a public code and an encryption code transmitted via a carrier wave having mutually orthogonal phases, and The step of the above-mentioned at least one observation reference station generating sample data for any time from the intermediate frequency signal is A method for generating sample data by extracting only the encryption code and the navigation data components from a satellite signal converted into the above intermediate frequency signal.
  4. In paragraph 1, The above navigation data is, A method having at least one of the orbit error information and time error information of at least one of the above-mentioned satellite.
  5. In paragraph 1, The above satellite signal Is, It is expressed as, The above intermediate frequency signal Is, It is expressed as, Sample data for the above arbitrary time k Is, It is expressed as, The step of extracting the above encrypted data is, A method for acquiring the navigation data through a digital signal processing process for the sample data. (Here, is the signal magnitude, is encrypted data, is a navigation data code, is the carrier wave's center frequency and Doppler, represents the carrier phase).
  6. In paragraph 1, The above satellite signal Is, It is expressed as, The above intermediate frequency signal Is, It is expressed as, Sample data for the above arbitrary time K Is, It is expressed as, The step of extracting the above encrypted data is, A method for acquiring the navigation data through a digital signal processing process for the sample data. (Here, is the public signal C/A code, represents the encryption signal P(Y) code).
  7. The at least one observation reference station that collects an encrypted satellite signal from at least one satellite, converts the satellite signal into an intermediate frequency signal, generates sample data for any time from the intermediate frequency signal, and transmits the sample data to the integrated operation station; and An integrated operation station that extracts encrypted data from the sample data received from at least one observation reference station, and decrypts the encrypted data to obtain navigation data and distance measurements; A satellite navigation system including
  8. In Paragraph 7, The above-mentioned at least one observation reference station is, Collecting multiple encrypted satellite signals having different frequencies that have each passed through the ionosphere, and The above distance measurement is, The distance measurement between the above at least one observation reference station and the above at least one satellite, Satellite navigation system.
  9. In Paragraph 7, The above satellite signal includes a public code and an encryption code transmitted via a carrier wave having mutually orthogonal phases, and The above observation reference station is, A method for generating sample data by extracting only the encryption code and the navigation data components from a satellite signal converted into the above intermediate frequency signal.
  10. In Paragraph 7, The above distance measurement is, A satellite navigation system having at least one of the orbit information and time information of at least one of the above-mentioned satellite.
  11. In Paragraph 7, The above satellite signal Is, It is expressed as, The above intermediate frequency signal Is, It is expressed as, Sample data for the above arbitrary time k Is, It is expressed as, The step of extracting the above encrypted data is, A satellite navigation system that acquires the navigation data through a digital signal processing process for the sample data. (Here, is the signal magnitude, is encrypted data, is a navigation data code, is the carrier wave's center frequency and Doppler, represents the carrier phase).
  12. In Paragraph 7, The above satellite signal Is, It is expressed as, The above intermediate frequency signal Is, It is expressed as, Sample data for the above arbitrary time K Is, It is expressed as, The step of extracting the above encrypted data is, A satellite navigation system that acquires the navigation data through a digital signal processing process for the sample data. (Here, is the public signal C/A code, )
  13. As a method of operation for the integrated operations center, The step of at least one observation reference station collecting an encrypted satellite signal from at least one satellite, converting it into an intermediate frequency signal, and receiving sample data generated for an arbitrary time from said at least one observation reference station, A step of extracting encrypted data from the sample data received from at least one observation reference station; and A step of decrypting the above encrypted data to obtain navigation data and distance measurements; A method including
  14. As a method of operation for the integrated operations center, A step in which at least one observation reference station collects an encrypted satellite signal from at least one satellite, converts it into an intermediate frequency signal, and receives sample data generated for an arbitrary time from said at least one observation reference station. A step of extracting encrypted data from the sample data received from at least one observation reference station; and A step of decrypting the above encrypted data to obtain navigation data and distance measurements; A method including
  15. Memory containing instructions; and By executing the above command, A processor performing a method of operation of an integrated operation station, comprising: a step in which at least one observation reference station collects an encrypted satellite signal from at least one satellite, converts it into an intermediate frequency signal, and receives sample data generated for a random time from said at least one observation reference station; a step of extracting encrypted data from said sample data received from said at least one observation reference station; and a step of decrypting said encrypted data to obtain navigation data and distance measurements; Integrated Operations Bureau, including
  16. As a computer program stored on a computer-readable recording medium, The above computer program is, A computer program comprising instructions for a processor to perform a method of operation of an integrated operation station, the method comprising: a step of at least one observation reference station collecting an encrypted satellite signal from at least one satellite, converting it into an intermediate frequency signal, and receiving sample data generated for a random time from said at least one observation reference station; a step of extracting encrypted data from said sample data received from said at least one observation reference station; and a step of decrypting said encrypted data to obtain navigation data and distance measurements.
  17. As a computer-readable recording medium on which a computer program is recorded, The above computer program is, A computer-readable recording medium having a computer program recorded thereon, comprising instructions for a processor to perform a method comprising: a method of operation of an integrated operating station, wherein at least one observation reference station collects an encrypted satellite signal from at least one satellite, converts it into an intermediate frequency signal, and receives sample data generated for a random time from said at least one observation reference station; a step of extracting encrypted data from said sample data received from said at least one observation reference station; and a step of decrypting said encrypted data to obtain navigation data and distance measurements.

Description

Satellite navigation system based on encrypted satellite signals and method of operation thereof The present invention relates to a satellite navigation system utilizing encrypted satellite signals. A satellite navigation system or satellite navigation correction system is a system that enables a user to estimate their Position, Navigation, and Timing (PNT) information by receiving signals transmitted by navigation satellites based on the satellites' precise orbital and time information. A satellite navigation system consists of observation reference stations located at various locations on the ground, an integrated operations center that processes measurements from the observation reference stations and controls the satellites, and navigation satellites that transmit navigation and correction signals. Since satellite navigation or satellite navigation correction systems estimate the user's PNT information based on the accurate position and time information of the navigation satellite, multiple satellite navigation observation reference stations installed on the ground receive navigation satellite signals, and the integrated operation center aggregates them to calculate the precise orbit/time information of the navigation satellite. At this time, the satellite navigation observation reference stations receive the broadcast signal of the navigation satellite at a pre-precisely positioned location and obtain the distance measurement between the satellite and the observation reference station, which is raw data for estimating the satellite's orbit/time. Another key function for operating satellite navigation or phase navigation correction systems at the integrated operations center is to estimate ionospheric error, which is the primary error factor in satellite navigation. To this end, the observation reference station receives navigation satellite signals and obtains ionospheric delay values using measurements. The ionosphere is an error factor that degrades user navigation accuracy by delaying the propagation of navigation satellite signals. To enable users to overcome this error, the satellite navigation system and the phase navigation correction system broadcast an ionospheric error model to the users. In this process, the satellite navigation system and the phase navigation correction system utilize the ionospheric delay values measured at the observation reference station as raw data to generate the ionospheric error model. The ionosphere has the characteristics of a dispersion medium, meaning that the amount of delay varies depending on the frequency of the signal passing through it. Navigation satellites transmit navigation signals at two different frequencies, and on the ground, the actual ionospheric delay error along the propagation path is estimated from the difference in delay between these two frequency signals. As shown in Figure 2, the satellite navigation system and the phase navigation correction system operate multiple observation reference stations to obtain wide-area ionospheric delay measurements from multiple navigation satellites, and use these to generate an ionospheric model and broadcast it to users. As described above, observation reference stations play the role of acquiring raw data for operating satellite navigation systems and phase navigation correction systems. In this regard, to accurately estimate the orbits and times of navigation satellites, observation reference stations must be evenly distributed over as wide an area as possible. This is because geometrically accurate position estimation is possible only when distance measurements from navigation satellites are received from various directions. Furthermore, when estimating ionospheric error, ionospheric delay measurements must be acquired over as wide an area as possible to generate a wide-area ionospheric error model, thereby enabling the operation of services for users across a wide area. Satellite navigation systems and phase navigation correction systems are large-scale systems operated at the national level; to generate high-performance navigation and correction information and guarantee service coverage, satellite navigation observation reference stations are operated not only domestically but also overseas. For example, global systems such as the U.S. GPS operate satellite navigation observation reference stations worldwide, while regional satellite navigation systems such as Japan's QZSS and India's NAVIC also operate observation reference stations in neighboring countries as well as within their own borders. A typical satellite navigation observation base station consists of an observation base station antenna and an observation base station receiver. The observation base station receiver receives signals from multiple navigation satellites to acquire measurements and transmits them to the integrated operations center. The configuration of the observation reference station receiver varies depending on the signal