NAVIGATION APPARATUS AND METHOD OF ACQUIRING EPHEMERIS DATA
First Claim
Patent Images
1. A navigation apparatus comprising:
- an acquisition unit for receiving a satellite signal from satellites and demodulates the satellite signal to acquire ephemeris data;
a storing unit for storing the ephemeris data;
a time measuring unit for measuring a valid time of the ephemeris data from timing of acquisition of the ephemeris data; and
a control unit for making the acquisition unit reacquire new ephemeris data before the valid time of the ephemeris data elapses in the time measuring unit.
1 Assignment
0 Petitions
Accused Products
Abstract
A navigation apparatus includes: an acquisition unit for receiving a satellite signal from satellites and demodulates the satellite signal to acquire ephemeris data; a storing unit for storing the ephemeris data; a time measuring unit for measuring a valid time of the ephemeris data from timing of acquisition of the ephemeris data; and a control unit for making the acquisition unit reacquire new ephemeris data before the valid time of the ephemeris data elapses in the time measuring unit.
-
Citations
8 Claims
-
1. A navigation apparatus comprising:
-
an acquisition unit for receiving a satellite signal from satellites and demodulates the satellite signal to acquire ephemeris data; a storing unit for storing the ephemeris data; a time measuring unit for measuring a valid time of the ephemeris data from timing of acquisition of the ephemeris data; and a control unit for making the acquisition unit reacquire new ephemeris data before the valid time of the ephemeris data elapses in the time measuring unit. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of acquiring ephemeris data, comprising:
-
an acquisition step of receiving a satellite signal from satellites and demodulating the satellite signal to acquire ephemeris data by using an acquisition unit; a storing step of storing the ephemeris data into a storing unit; a time measuring step of measuring a valid time of the ephemeris data by using a time measuring unit from timing of acquisition of the ephemeris data; and an ephemeris data reacquisition step of making a control unit reacquire new ephemeris data through the acquisition unit before the valid time of the ephemeris data elapses.
-
Specification