SATELLITE SIGNAL RECEPTION APPARATUS, SATELLITE SIGNAL PROCESSING METHOD AND PROGRAM

1 . A satellite signal reception device comprising:

a memory; and

a processor configured to execute:

Selecting a predetermined number of satellite signals on a basis of reception quality of satellite signals received by a GNSS antenna; and

performing positioning or time synchronization using the predetermined number of satellite signals selected by the selecting.

2 . The satellite signal reception device according to claim 1 , wherein the selecting normalizes reception quality measured from received satellite signals on a basis of GNSS types, frequency bands, or elevation angles of satellite signals, and selects the predetermined number of satellite signals using reception quality after normalization.

3 . The satellite signal reception device according to claim 2 , wherein the selecting performs the normalization by adding preset bias values on a basis of GNSS types, frequency bands, or elevation angles of satellite signals to reception quality measured from received satellite signals.

4 . The satellite signal reception device according to claim 3 , wherein the processor is further configured to execute:

obtaining fitting functions for an elevation angle and reception quality for frequency bands of each GNSS type on a basis of GNSS types, frequency bands, elevation angles, and reception quality of collected satellite signals, and sets the bias values using obtained fitting functions.

5 . The satellite signal reception device according to claim 1 , wherein the selecting normalizes reception quality of a satellite signal received from a specific satellite by adding a preset individual bias value to the specific satellite, and selects the predetermined number of satellite signals using reception quality after normalization.

6 . The satellite signal reception device according to claim 1 , wherein the selecting selects a satellite signal having best reception quality from all received satellite signals, and, using a value obtained by subtracting a predetermined value from a value of the best reception quality as a lower limit, selects all satellite signals having reception quality better than the lower limit.

7 . The satellite signal reception device according to claim 1 , wherein the selecting selects a satellite signal having best reception quality from all received satellite signals, and, using a value obtained by subtracting a predetermined value from a value of the best reception quality as a lower limit, selects all satellite signals having reception quality better than the lower limit and preset minimum reception quality.

8 . The satellite signal reception device according to claim 6 , wherein, when determining whether to select a certain satellite signal, the selecting uses a value that depends on an elevation angle of the satellite signal as the predetermined value.

9 . The satellite signal reception device according to claim 6 , wherein, in a case where a total number of satellite signals having the best reception quality and all satellite signals having reception quality better than the lower limit is less than the predetermined number, the selecting selects a satellite signal having reception quality lower than or equal to the lower limit on a basis of a priority order of GNSS types so that a total number of selected satellite signals reaches the predetermined number.

10 . The satellite signal reception device according to claim 6 , wherein, in a case where a total number of satellite signals having the best reception quality and all satellite signals having reception quality better than the lower limit is less than the predetermined number, the selecting selects a satellite signal having reception quality lower than or equal to the lower limit on a basis of a DOP value so that a total number of selected satellite signals reaches the predetermined number.

11 . A satellite signal processing method performed by a satellite signal reception device including a memory and a processor, the method comprising:

selecting a predetermined number of satellite signals on a basis of reception quality of satellite signals received by a GNSS antenna; and

performing positioning or time synchronization using the predetermined number of satellite signals selected by the signal selection step.

12 . A non-transitory computer-readable recording medium having computer-readable instructions stored thereon, which when executed, cause a computer to function as the satellite signal reception device according to claim 1 .