Resources Contact Us Home
Method and apparatus for determining the position of a vehicle

Image Number 6 for United States Patent #4897661.

There is provided a system in which a transponder is carried by each vehicle traveling on or above the earth's surface which transmits a signal which is responsive to an interrogation signal to a ground station through two or more satellites and in the ground station, the position of the vehicle is determined from the propagation time differences of the response signals received via the satellites. In this system, the information indicative of the time lag which is required for the transponder to receive the interrogation signal and to transmit the response signal responsive to the interrogation signal is included in the response signal and then such response signal is transmitted. Thus, the time lag which is peculiar to each transponder and corresponds to the time required from the reception of the interrogation signal to the transmission of the response signal can be corrected. With this system, the positioning accuracy of each vehicle can be improved.

  Recently Added Patents
Magnetic memory element, driving method for same, and nonvolatile storage device
Methods for enhancing tantalum filament life in hot wire chemical vapor deposition processes
Rain barrel
Optical switching device and communications system
System and method of supplying an electrical system with direct current
High-accuracy centered fractional fourier transform matrix for optical imaging and other applications
Image coding apparatus and image decoding apparatus
  Randomly Featured Patents
Headlamp automatic delay system
Method and apparatus for driving a brushless D.C. motor
Semiconductor device
Methods and systems for improving spatial and temporal resolution of computed images of moving objects
Ice container
Dynamic byte code examination to detect whether a GUI component handles mouse events
Semiconductor memory device
Method for enhancing paper strength
Adjustable safety and rapidly assembled connector
Skin care sponge