摘要:
A GPS receiver includes a power supplying status detector for deriving a power-on or power-off signal by detecting a power supplying status of the GPS receiver, a clock for measuring time, a memory controller for controlling a nonvolatile memory upon receiving the power-off signal to store a time measured by the clock when the power is turned off or a time when the last ephemeris data is obtained and the last ephemeris data, and a position calculating circuitry for calculating the position of the user station upon receiving the power-on signal. A time duration is calculated from the time measured by the clock and the time stored in the nonvolatile memory. If it is determined that the measured time duration is shorter than a predetermined period of time, the positioning is performed based on the respective ephemeris data stored in the nonvolatile memory, whereas if it is determined that the measured time duration is no less than the predetermined period of time, the positioning is performed based on ephemeris data newly collected from the respective GPS satellites.
摘要:
A GPS receiver and related method for positioning on the Globe. The GPS receiver receives satellite signals in a sequential manner with a plurality of antennas, whereby any of the plurality of antennas which receives satellite signals from the maximum number of GPS satellites is selected by an antenna switching unit under the control of a control unit, a combination of GPS satellites having the smallest PDOP value or the signal strength in due order is selected by the control unit from among all of GPS satellites in contact with respective antennas when each of the antennas fails to receive satellite signals transmitted by the predetermined minimum number of GPS satellites. The related positioning method is for use with a motor vehicle-mounted GPS receiver having a plurality of receiving channels, wherein each receiving channel independently receives satellite signals from the GPS satellites in contact, a required number of GPS satellites which are currently considered to be the most suitable for positioning in view of PDOP value are selected from among all of GPS satellites in contact through each receiving channel, and thereby a GPS satellite other than the selected ones may be substituted for the obstructed GPS satellite for carrying out the positioning by making use of navigation data of the newly selected GPS satellite without any intermission.
摘要:
A communications system for identifying a responding station called by a communications system caller station over a call channel and a plurality of speech channels. The system transmits information from the caller station, such as the selected speech channel and the designated responding station through the call channel, and receives information from a responding station on the selected speech channel. The communication between the communications system and the responding station on the selected speech channel is enabled only when information from the responding station is identical to information of the designated responding station transmitted from the communications system.
摘要:
A navigation apparatus for a vehicle using a GPS (Global Positioning System) as sensing means in which information on the basis of sensed results, such as a present position, a running locus and the like are displayed in a predetermined form of display on a display section is disclosed. In cases where the GPS receiver cannot receive radio waves from artificial satellites, and sensing thus becomes disabled, a sensed final present position is displayed with an altered form of display.
摘要:
A navigation apparatus for a vehicle using a GPS (Global Positioning System) as sensing means in which information on the basis of sensing results, such as a present position, a running locus and the like are displayed in a predetermined form of display on a display section is disclosed. In cases where the GPS receiver cannot receive radio waves from artificial satellites, and sensing thus becomes disabled, a sensed final present position is displayed with an altered form of display.
摘要:
An antenna array system which comprises at least one balanced antenna having an electric neutral point and two output end terminals positioned closely to each other, at least one unbalanced antenna having one end thereof dc-coupled with the electric neutral point of the balance antenna and the other end thereof positioned closely to the end terminals of the balanced antenna, first means for picking up a first frequency wave signal such as FM wave signal from the balanced antenna, and second means for picking up a second frequency wave signal such as an AM wave signal from the unbalanced antenna.
摘要:
A communication apparatus comprises a first oscillator for generating a frequency fp.sub.1 at each channel step; a second oscillator for generating a modulated frequency fp.sub.2 ; a first mixer for creating a transmission frequency which is a sum fp.sub.1 +fp.sub.2 of the frequencies of the first and second oscillators and a difference fp.sub.1 -fp.sub.2 therebetween on high and low band transmissions respectively; a third oscillator for generating a frequency fp.sub.3 which is higher or lower than the frequency fp.sub.2 of the second oscillator by a given frequency .DELTA.f; and a second mixer for creating a sum fp.sub.1 +fp.sub.3 of the frequencies of the first and third oscillators means and a difference fp.sub.1 -fp.sub.3 therebetween on low and high band transmissions respectively.
摘要:
A complex antenna system including at least two loop antennas crossing each other and connected with each other at the electric neutral points thereof, and a rod antenna positioned at the central portion of the loop antennas. An FM and/or AM tuners combined with the complex antenna system utilizes selected one of the loop antennas for receiving an FM wave so as to avoid multi-path noises.
摘要:
An FM receiver provided with an array of antennas and suitable for use in a moving vehicle such as a motorcar, which is provided with means for automatically avoiding multipath noises. The means so operates as to connect one of the antennas in an instantaneously best sensing condition to an FM tuner.