Positioning system and positioning method using low earth orbit satellite
Disclosed are a positioning system and a positioning method using a low earth orbit satellite. The positioning system using a low earth orbit satellite according to the present invention comprises a generation unit for generating, when a communication period with a ground control station is reached, a first telemetry signal including a time value according to a reference time used by a low earth orbit satellite; a confirmation unit for confirming, on the basis of a navigation signal received from a navigation satellite, the GNSS time used as a reference by the navigation satellite; an adjustment unit for adjusting the time value in the first telemetry signal so as to be synchronized with the GNSS time; and a transmission unit for broadcast transmitting a second telemetry signal, after the adjustment, so that a positioning receiver on the ground can determine the position by using the second telemetry signal.
1 . A positioning system using a low earth orbit satellite, the positioning system comprises:
when a communication period with a ground control station arrives,
a generator configured to generate a first telemetry signal comprising a time value according to a reference time used by the low earth orbit satellite;
a verifier configured to verify a global navigation satellite system (GNSS) time that is used as a reference by a navigation satellite from a navigation signal received from the navigation satellite;
an adjuster configured to adjust the time value comprised in the first telemetry signal to be synchronized with the GNSS time; and
a transmitter configured to broadcast-transmit a second telemetry signal obtained through adjustment and cause a positioning receiver on the ground to perform positioning by using the second telemetry signal,
wherein the generator is further configured to,
during the communication period, encrypt collected data or status data transmitted from the low earth orbit satellite and create encrypted data, and
generate the first telemetry signal further comprising the encrypted data.
2 . The positioning system of claim 1 , wherein the transmitter is further configured to
transmit the first telemetry signal to the ground control station when broadcast-transmitting the second telemetry signal.
3 . The positioning system of claim 1 , wherein,
when a non-communication period arrives after the communication period,
the generator is further configured to generate the first telemetry signal further comprising dummy data instead of the encrypted data.
4 . The positioning system of claim 1 , further comprising:
an operator configured to operate unit movement trajectories of the low earth orbit satellite at a predetermined unit time interval according to a position value of the low earth orbit satellite, which is identified by the navigation signal, and
the adjuster is further configured to adjust the time value comprised in the first telemetry signal such that an average movement trajectory averaging the unit movement trajectories operated during the communication period is within a designated threshold.
5 . A positioning method using a low earth orbit satellite, the positioning method comprises:
when a communication period with a ground control station arrives,
generating a first telemetry signal comprising a time value according to a reference time used by the low earth orbit satellite;
verifying a global navigation satellite system (GNSS) time that is used as a reference by a navigation satellite from a navigation signal received from the navigation satellite;
adjusting the time value comprised in the first telemetry signal to be synchronized with the GNSS time; and
broadcast-transmitting a second telemetry signal obtained through adjustment and cause a positioning receiver on the ground to perform positioning by using the second telemetry signal,
wherein the generating the first telemetry signal comprises:
during the communication period, encrypting collected data or status data transmitted from the low earth orbit satellite and creating encrypted data; and
generating the first telemetry signal further comprising the encrypted data.
6 . The positioning method of claim 5 , further comprising:
transmitting the first telemetry signal to the ground control station when broadcast-transmitting the second telemetry signal.
7 . The positioning method of claim 5 , further comprising:
when a non-communication period arrives after the communication period, generating the first telemetry signal further comprising dummy data instead of the encrypted data.
8 . The positioning method of claim 5 , further comprising:
operating unit movement trajectories of the low earth orbit satellite at a predetermined unit time interval according to a position value of the low earth orbit satellite, which is identified by the navigation signal, and
the adjusting the time value to be synchronized with the GNSS time comprises: adjusting the time value comprised in the first telemetry signal such that an average movement trajectory averaging the unit movement trajectories operated during the communication period is within a designated threshold.
9 . A non-transitory computer-readable storage medium storing a program for performing the positioning method of claim 5 .