Gps receiver
First Claim
1. A GPS receiver, comprising:
- a receiving portion, receiving navigation messages transmitted from a plurality of GPS satellites respectively;
a navigation message analyzing portion, obtaining an ephemeris and an almanac from the received navigation message to restore;
an ephemeris storing portion, storing the obtained ephemeris;
an almanac storing portion, storing the restored almanac;
a clock portion, measuring a time to calculate a current time;
a satellite position calculating portion, calculating positions of the plurality of GPS satellites by using the current time calculated in the clock portion and the obtained ephemeris or the restored almanac; and
a position measuring portion, calculating a position measuring based on the navigation message transmitted from the GPS satellite as a communication object, wherein the navigation message analyzing portion includes a predicting portion which predicts a time information stored only in a final subframe, which serves as a reference to calculate positions of the plurality of GPS satellites, based on information indicating a lapsed week number on a basis of a predetermined week stored in each main frame of the received navigation message respectively, and a restoring portion which restores the almanac based on the predicted time information which serves as the reference to calculate the positions of the plurality of GPS satellites.
1 Assignment
0 Petitions
Accused Products
Abstract
It is an object of the present invention to provide a GPS receiver capable of deciding quickly a GPS satellite as a communication object while suppressing a consumption power. In order to attain the object, when a receiving portion 101 does not receive WNa in the navigation message transmitted from the GPS satellite but receives WN, the GPS receiver of the present invention predicts WNa based on the received WN, and then restores the almanac based on this. Then, the almanac is stored in an almanac storing portion 103, and a satellite position calculating portion 106 reads the almanac as the case may be, and calculates a position of the satellite based on the almanac. The receiving portion 101 is controlled based on the calculated position of the satellite such that the navigation messages from a plurality of satellites that exist in the sky can be received, and a position measuring portion 107 measures the current position based on the navigation messages from a plurality of GPS satellites, which are received by the receiving portion 101.
-
Citations
12 Claims
-
1. A GPS receiver, comprising:
-
a receiving portion, receiving navigation messages transmitted from a plurality of GPS satellites respectively;
a navigation message analyzing portion, obtaining an ephemeris and an almanac from the received navigation message to restore;
an ephemeris storing portion, storing the obtained ephemeris;
an almanac storing portion, storing the restored almanac;
a clock portion, measuring a time to calculate a current time;
a satellite position calculating portion, calculating positions of the plurality of GPS satellites by using the current time calculated in the clock portion and the obtained ephemeris or the restored almanac; and
a position measuring portion, calculating a position measuring based on the navigation message transmitted from the GPS satellite as a communication object, wherein the navigation message analyzing portion includes a predicting portion which predicts a time information stored only in a final subframe, which serves as a reference to calculate positions of the plurality of GPS satellites, based on information indicating a lapsed week number on a basis of a predetermined week stored in each main frame of the received navigation message respectively, and a restoring portion which restores the almanac based on the predicted time information which serves as the reference to calculate the positions of the plurality of GPS satellites. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
2. A GPS receiver, comprising:
-
a receiving portion, receiving navigation messages transmitted from a plurality of GPS satellites respectively;
a navigation message analyzing portion, obtaining an ephemeris and an almanac from the received navigation message to restore;
an ephemeris storing portion, storing the obtained ephemeris;
an almanac storing portion, storing the restored almanac;
a clock portion, measuring a time to calculate a current time;
a satellite position calculating portion, calculating positions of the plurality of GPS satellites by using the current time calculated in the clock portion and the obtained ephemeris or the restored almanac; and
a position measuring portion, calculating a position measuring based on the navigation message transmitted from the GPS satellite as a communication object, wherein the navigation message analyzing portion includes a predicting portion which predicts a time information stored only in a final subframe of the navigation message, which serves as a reference to calculate positions of the plurality of GPS satellites, based on the current time which is calculated in the clock portion, and a restoring portion which restores the almanac based on the predicted time information which serves as the reference to calculate the positions of the plurality of GPS satellites.
-
-
12. A GPS receiver, comprising:
-
a receiving portion, receiving navigation messages transmitted from a plurality of GPS satellites respectively;
a navigation message analyzing portion, obtaining an ephemeris and an almanac from the received navigation message to restore;
an ephemeris storing portion storing the obtained ephemeris;
an almanac storing portion, storing the restored almanac;
a clock portion, measuring a time to calculate a current time;
a satellite position calculating portion, calculating positions of the plurality of GPS satellites by using the current time calculated in the clock portion and the obtained ephemeris or the restored almanac; and
a position measuring portion, calculating a position measuring based on the navigation message transmitted from the GPS satellite as a communication object, wherein the almanac is formed on the basis of the obtained ephemeris.
-
Specification